Adding upstream version 5.1.upstream/5.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

47 files changed, 8309 insertions, 0 deletions

diff --git a/examples/loadables/Makefile.in b/examples/loadables/Makefile.in
new file mode 100644
index 0000000..be46121
--- /dev/null
+++ b/examples/loadables/Makefile.in
@@ -0,0 +1,324 @@
+#
+# Simple makefile for the sample loadable builtins
+#
+# Copyright (C) 1996-2019 Free Software Foundation, Inc.
+
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+PACKAGE = @PACKAGE_NAME@
+VERSION = @PACKAGE_VERSION@
+
+# Include some boilerplate Gnu makefile definitions.
+prefix = @prefix@
+
+exec_prefix = @exec_prefix@
+bindir = @bindir@
+libdir = @libdir@
+infodir = @infodir@
+includedir = @includedir@
+
+datarootdir = @datarootdir@
+
+loadablesdir = @loadablesdir@
+headersdir = @headersdir@
+
+topdir = @top_srcdir@
+BUILD_DIR = @BUILD_DIR@
+srcdir = @srcdir@
+VPATH = @srcdir@
+
+# Support an alternate destination root directory for package building
+DESTDIR =
+
+INSTALL = @INSTALL@
+INSTALL_PROGRAM = @INSTALL_PROGRAM@
+INSTALL_SCRIPT = @INSTALL_SCRIPT@
+INSTALL_DATA = @INSTALL_DATA@
+INSTALLMODE= -m 0755
+
+@SET_MAKE@
+CC = @CC@
+RM = rm -f
+
+SHELL = @MAKE_SHELL@
+
+host_os = @host_os@
+host_cpu = @host_cpu@
+host_vendor = @host_vendor@
+
+CFLAGS = @CFLAGS@
+LOCAL_CFLAGS = @LOCAL_CFLAGS@
+DEFS = @DEFS@
+LOCAL_DEFS = @LOCAL_DEFS@
+
+CPPFLAGS = @CPPFLAGS@
+
+BASHINCDIR = ${topdir}/include
+
+SUPPORT_SRC = $(topdir)/support/
+
+LIBBUILD = ${BUILD_DIR}/lib
+
+INTL_LIBSRC = ${topdir}/lib/intl
+INTL_BUILDDIR = ${LIBBUILD}/intl
+INTL_INC = @INTL_INC@
+LIBINTL_H = @LIBINTL_H@
+
+CCFLAGS = $(DEFS) $(LOCAL_DEFS) $(LOCAL_CFLAGS) $(CPPFLAGS) $(CFLAGS)
+
+#
+# These values are generated for configure by ${topdir}/support/shobj-conf.
+# If your system is not supported by that script, but includes facilities for
+# dynamic loading of shared objects, please update the script and send the
+# changes to bash-maintainers@gnu.org.
+#
+SHOBJ_CC = @SHOBJ_CC@
+SHOBJ_CFLAGS = @SHOBJ_CFLAGS@
+SHOBJ_LD = @SHOBJ_LD@
+SHOBJ_LDFLAGS = @SHOBJ_LDFLAGS@ @LDFLAGS@
+SHOBJ_XLDFLAGS = @SHOBJ_XLDFLAGS@
+SHOBJ_LIBS = @SHOBJ_LIBS@
+SHOBJ_STATUS = @SHOBJ_STATUS@
+
+INC = -I. -I.. -I$(topdir) -I$(topdir)/lib -I$(topdir)/builtins -I${srcdir} \
+      -I$(BASHINCDIR) -I$(BUILD_DIR) -I$(LIBBUILD) \
+      -I$(BUILD_DIR)/builtins $(INTL_INC)
+
+.c.o:
+	$(SHOBJ_CC) $(SHOBJ_CFLAGS) $(CCFLAGS) $(INC) -c -o $@ $<
+
+
+ALLPROG = print truefalse sleep finfo logname basename dirname fdflags \
+	  tty pathchk tee head mkdir rmdir mkfifo mktemp printenv id whoami \
+	  uname sync push ln unlink realpath strftime mypid setpgid seq rm \
+	  accept csv cut
+OTHERPROG = necho hello cat pushd stat asort
+
+all:	$(SHOBJ_STATUS)
+
+supported:	$(ALLPROG)
+others:		$(OTHERPROG)
+
+unsupported:
+	@echo "Your system (${host_os}) is not supported by the"
+	@echo "${topdir}/support/shobj-conf script."
+	@echo "If your operating system provides facilities for dynamic"
+	@echo "loading of shared objects using the dlopen(3) interface,"
+	@echo "please update the script and re-run configure."
+	@echo "Please send the changes you made to bash-maintainers@gnu.org"
+	@echo "for inclusion in future bash releases."
+
+everything: supported others
+
+print:	print.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ print.o $(SHOBJ_LIBS)
+
+necho:	necho.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ necho.o $(SHOBJ_LIBS)
+
+hello:	hello.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ hello.o $(SHOBJ_LIBS)
+
+truefalse: truefalse.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ truefalse.o $(SHOBJ_LIBS)
+
+accept:	accept.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ accept.o $(SHOBJ_LIBS)
+
+sleep:	sleep.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ sleep.o $(SHOBJ_LIBS)
+
+finfo:	finfo.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ finfo.o $(SHOBJ_LIBS)
+
+cat:	cat.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ cat.o $(SHOBJ_LIBS)
+
+rm:	rm.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ rm.o $(SHOBJ_LIBS)
+
+fdflags:	fdflags.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ fdflags.o $(SHOBJ_LIBS)
+
+seq:	seq.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ seq.o $(SHOBJ_LIBS)
+
+logname:	logname.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ logname.o $(SHOBJ_LIBS)
+
+basename:	basename.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ basename.o $(SHOBJ_LIBS)
+
+dirname:	dirname.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ dirname.o $(SHOBJ_LIBS)
+
+tty:	tty.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ tty.o $(SHOBJ_LIBS)
+
+pathchk:	pathchk.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ pathchk.o $(SHOBJ_LIBS)
+
+tee:	tee.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ tee.o $(SHOBJ_LIBS)
+
+mkdir:	mkdir.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ mkdir.o $(SHOBJ_LIBS)
+
+rmdir:	rmdir.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ rmdir.o $(SHOBJ_LIBS)
+
+mkfifo:	mkfifo.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ mkfifo.o $(SHOBJ_LIBS)
+
+mktemp:	mktemp.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ mktemp.o $(SHOBJ_LIBS)
+
+head:	head.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ head.o $(SHOBJ_LIBS)
+
+printenv:	printenv.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ printenv.o $(SHOBJ_LIBS)
+
+id:	id.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ id.o $(SHOBJ_LIBS)
+
+whoami:	whoami.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ whoami.o $(SHOBJ_LIBS)
+
+uname:	uname.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ uname.o $(SHOBJ_LIBS)
+
+sync:	sync.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ sync.o $(SHOBJ_LIBS)
+
+push:	push.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ push.o $(SHOBJ_LIBS)
+
+ln:	ln.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ ln.o $(SHOBJ_LIBS)
+
+unlink:	unlink.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ unlink.o $(SHOBJ_LIBS)
+
+realpath:	realpath.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ realpath.o $(SHOBJ_LIBS)
+
+csv:	csv.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ csv.o $(SHOBJ_LIBS)
+
+cut:	cut.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ cut.o $(SHOBJ_LIBS)
+
+strftime:	strftime.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ strftime.o $(SHOBJ_LIBS)
+
+mypid:	mypid.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ mypid.o $(SHOBJ_LIBS)
+
+setpgid:	setpgid.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ setpgid.o $(SHOBJ_LIBS)
+
+stat:	stat.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ stat.o $(SHOBJ_LIBS)
+
+asort:	asort.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ asort.o $(SHOBJ_LIBS)
+
+# pushd is a special case.  We use the same source that the builtin version
+# uses, with special compilation options.
+#
+pushd.c:	${topdir}/builtins/pushd.def
+	$(RM) $@
+	${BUILD_DIR}/builtins/mkbuiltins -D ${topdir}/builtins ${topdir}/builtins/pushd.def
+
+pushd.o:	pushd.c
+	$(RM) $@
+	$(SHOBJ_CC) -DHAVE_CONFIG_H -DPUSHD_AND_POPD -DLOADABLE_BUILTIN $(SHOBJ_CFLAGS) $(CFLAGS) $(CPPFLAGS) $(INC) -c -o $@ $<
+
+pushd:	pushd.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ pushd.o $(SHOBJ_LIBS)
+
+clean:
+	$(RM) $(ALLPROG) $(OTHERPROG) *.o
+	-( cd perl && ${MAKE} ${MFLAGS} $@ )
+
+mostlyclean:	clean
+	-( cd perl && ${MAKE} ${MFLAGS} $@ )
+
+distclean maintainer-clean: clean
+	$(RM) Makefile Makefile.inc pushd.c
+	-( cd perl && ${MAKE} ${MFLAGS} $@ )
+
+installdirs:
+	@${SHELL} $(SUPPORT_SRC)mkinstalldirs $(DESTDIR)$(loadablesdir)
+
+install-dev:	installdirs
+	@$(INSTALL_DATA) Makefile.inc $(DESTDIR)$(loadablesdir)/Makefile.inc
+	@$(INSTALL_DATA) $(srcdir)/loadables.h $(DESTDIR)$(loadablesdir)/loadables.h
+	@( cd $(BUILD_DIR) && ${MAKE} ${MFLAGS} DESTDIR="$(DESTDIR)" install-headers)
+
+install-supported:	all installdirs install-dev
+	@echo installing example loadable builtins in $(DESTDIR)${loadablesdir}
+	@for prog in ${ALLPROG}; do \
+		echo $$prog ; \
+		$(INSTALL_PROGRAM) $(INSTALLMODE) $$prog $(DESTDIR)$(loadablesdir)/$$prog ;\
+	done
+
+uninstall-dev:
+	-$(RM) $(DESTDIR)$(loadablesdir)/Makefile.inc $(DESTDIR)$(loadablesdir)/loadables.h
+	-( cd $(BUILD_DIR) && ${MAKE} ${MFLAGS} DESTDIR="$(DESTDIR)" uninstall-headers)
+
+uninstall-supported:	uninstall-dev
+	-( cd $(DESTDIR)${loadablesdir} && $(RM) ${ALLPROG} )
+
+install-unsupported:
+uninstall-unsupported:
+
+install:	install-$(SHOBJ_STATUS)
+uninstall:	uninstall-$(SHOBJ_STATUS)
+
+print.o: print.c
+truefalse.o: truefalse.c
+accept.o: accept.c
+sleep.o: sleep.c
+finfo.o: finfo.c
+logname.o: logname.c
+basename.o: basename.c
+dirname.o: dirname.c
+tty.o: tty.c
+pathchk.o: pathchk.c
+tee.o: tee.c
+head.o: head.c
+rmdir.o: rmdir.c
+necho.o: necho.c
+hello.o: hello.c
+cat.o: cat.c
+csv.o: csv.c
+cut.o: cut.c
+printenv.o: printenv.c
+id.o: id.c
+whoami.o: whoami.c
+uname.o: uname.c
+sync.o: sync.c
+push.o: push.c
+mkdir.o: mkdir.c
+mktemp.o: mktemp.c
+realpath.o: realpath.c
+strftime.o: strftime.c
+setpgid.o: setpgid.c
+stat.o: stat.c
+fdflags.o: fdflags.c
+seq.o: seq.c
+asort.o: asort.c
diff --git a/examples/loadables/Makefile.inc.in b/examples/loadables/Makefile.inc.in
new file mode 100644
index 0000000..8b419a7
--- /dev/null
+++ b/examples/loadables/Makefile.inc.in
@@ -0,0 +1,108 @@
+#
+# Sample makefile for bash loadable builtin development
+#
+# Copyright (C) 2015 Free Software Foundation, Inc.     
+
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+PACKAGE = @PACKAGE_NAME@
+VERSION = @PACKAGE_VERSION@
+
+PACKAGE_NAME = @PACKAGE_NAME@
+PACKAGE_VERSION = @PACKAGE_VERSION@
+
+# Include some boilerplate Gnu makefile definitions.
+prefix = @prefix@
+
+exec_prefix = @exec_prefix@
+bindir = @bindir@
+libdir = @libdir@
+infodir = @infodir@
+includedir = @includedir@
+
+datarootdir = @datarootdir@
+
+loadablesdir = @loadablesdir@
+headersdir = @headersdir@
+
+topdir = @top_srcdir@
+BUILD_DIR = @BUILD_DIR@
+srcdir = @srcdir@
+VPATH = @srcdir@
+
+# Support an alternate destination root directory for package building
+DESTDIR =
+
+INSTALL = @INSTALL@
+INSTALL_PROGRAM = @INSTALL_PROGRAM@
+INSTALL_SCRIPT = @INSTALL_SCRIPT@
+INSTALL_DATA = @INSTALL_DATA@
+INSTALLMODE= -m 0755
+
+@SET_MAKE@
+CC = @CC@
+RM = rm -f
+
+SHELL = @MAKE_SHELL@
+
+host_os = @host_os@
+host_cpu = @host_cpu@
+host_vendor = @host_vendor@
+
+CFLAGS = @CFLAGS@
+LOCAL_CFLAGS = @LOCAL_CFLAGS@
+DEFS = @DEFS@
+LOCAL_DEFS = @LOCAL_DEFS@
+
+CPPFLAGS = @CPPFLAGS@
+
+BASHINCDIR = ${topdir}/include
+
+SUPPORT_SRC = $(topdir)/support/
+
+LIBBUILD = ${BUILD_DIR}/lib
+
+INTL_LIBSRC = ${topdir}/lib/intl
+INTL_BUILDDIR = ${LIBBUILD}/intl
+INTL_INC = @INTL_INC@
+LIBINTL_H = @LIBINTL_H@
+
+CCFLAGS = $(DEFS) $(LOCAL_DEFS) $(LOCAL_CFLAGS) $(CFLAGS)
+
+#
+# These values are generated for configure by ${topdir}/support/shobj-conf.
+# If your system is not supported by that script, but includes facilities for
+# dynamic loading of shared objects, please update the script and send the
+# changes to bash-maintainers@gnu.org.
+#
+SHOBJ_CC = @SHOBJ_CC@
+SHOBJ_CFLAGS = @SHOBJ_CFLAGS@
+SHOBJ_LD = @SHOBJ_LD@
+SHOBJ_LDFLAGS = @SHOBJ_LDFLAGS@ @LDFLAGS@
+SHOBJ_XLDFLAGS = @SHOBJ_XLDFLAGS@
+SHOBJ_LIBS = @SHOBJ_LIBS@
+SHOBJ_STATUS = @SHOBJ_STATUS@
+
+INC = -I$(headersdir) -I$(headersdir)/include -I$(headersdir)/builtins
+
+.c.o:
+	$(SHOBJ_CC) $(SHOBJ_CFLAGS) $(CCFLAGS) $(INC) -c -o $@ $<
+
+all:	example
+
+example:	example.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ example.o $(SHOBJ_LIBS)
+
+example.o: example.c
diff --git a/examples/loadables/README b/examples/loadables/README
new file mode 100644
index 0000000..6820c96
--- /dev/null
+++ b/examples/loadables/README
@@ -0,0 +1,76 @@
+Some examples of ready-to-dynamic-load builtins.  Most of the
+examples given are reimplementations of standard commands whose
+execution time is dominated by process startup time.  The
+exceptions are sleep, which allows you to sleep for fractions
+of a second, finfo, which provides access to the rest of the
+elements of the `stat' structure that `test' doesn't let you
+see, and pushd/popd/dirs, which allows you to compile them out
+of the shell.
+
+All of the new builtins in ksh93 that bash didn't already have
+are included here, as is the ksh `print' builtin.
+
+The configure script in the top-level source directory uses the
+support/shobj-conf script to set the right values in the Makefile,
+so you should not need to change the Makefile.  If your system
+is not supported by support/shobj-conf, and it has the necessary
+facilities for building shared objects and support for the
+dlopen/dlsyn/dlclose/dlerror family of functions, please make
+the necessary changes to support/shobj-conf and send the changes
+to bash-maintainers@gnu.org.
+
+Loadable builtins are loaded into a running shell with
+
+	enable -f filename builtin-name
+
+enable uses a simple reference-counting scheme to avoid unloading a
+shared object that implements more than one loadable builtin before
+all loadable builtins implemented in the object are removed.
+
+Many of the details needed by builtin writers are found in hello.c,
+the canonical example.  There is no real `builtin writers' programming
+guide'.  The file template.c provides a template to use for creating
+new loadable builtins.
+
+The file "Makefile.inc" is created using the same values that configure
+writes into Makefile.in, and is installed in the same directory as the
+rest of the example builtins. It's intended to be a start at something
+that can be modified or included to help you build your own loadables
+without having to search for the right CFLAGS and LDFLAGS.
+
+basename.c	Return non-directory portion of pathname.
+cat.c		cat(1) replacement with no options - the way cat was intended.
+dirname.c	Return directory portion of pathname.
+fdflags.c	Change the flag associated with one of bash's open file descriptors.
+finfo.c		Print file info.
+head.c		Copy first part of files.
+hello.c		Obligatory "Hello World" / sample loadable.
+id.c		POSIX.2 user identity.
+ln.c		Make links.
+loadables.h	File loadable builtins can include for shell definitions.
+logname.c	Print login name of current user.
+Makefile.in	Simple makefile for the sample loadable builtins.
+Makefile.inc.in	Sample makefile to use for loadable builtin development.
+mkdir.c		Make directories.
+mypid.c		Add $MYPID variable, demonstrate use of unload hook functio.n
+necho.c		echo without options or argument interpretation.
+pathchk.c	Check pathnames for validity and portability.
+print.c		Loadable ksh-93 style print builtin.
+printenv.c	Minimal builtin clone of BSD printenv(1).
+push.c		Anyone remember TOPS-20?
+realpath.c	Canonicalize pathnames, resolving symlinks.
+rm.c		Remove files and directories.
+rmdir.c		Remove directory.
+seq.c		Print a sequence of decimal or floating point numbers.
+setpgid.c	Set a process's pgrp; example of how to wrap a system call.
+sleep.c		sleep for fractions of a second.
+stat.c		populate an associative array with information about a file
+strftime.c	Loadable builtin interface to strftime(3).
+sync.c		Sync the disks by forcing pending filesystem writes to complete.
+tee.c		Duplicate standard input.
+template.c	Example template for loadable builtin.
+truefalse.c	True and false builtins.
+tty.c		Return terminal name.
+uname.c		Print system information.
+unlink.c	Remove a directory entry.
+whoami.c	Print out username of current user.
diff --git a/examples/loadables/accept.c b/examples/loadables/accept.c
new file mode 100644
index 0000000..54cf38c
--- /dev/null
+++ b/examples/loadables/accept.c
@@ -0,0 +1,234 @@
+/* accept - listen for and accept a remote network connection on a given port */
+
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "bashtypes.h"
+#include <errno.h>
+#include <time.h>
+#include "typemax.h"
+
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include "loadables.h"
+
+static int accept_bind_variable (char *, int);
+
+int
+accept_builtin (list)
+     WORD_LIST *list;
+{
+  WORD_LIST *l;
+  SHELL_VAR *v;
+  intmax_t iport;
+  int opt;
+  char *tmoutarg, *fdvar, *rhostvar, *rhost;
+  unsigned short uport;
+  int servsock, clisock;
+  struct sockaddr_in server, client;
+  socklen_t clientlen;
+  struct timeval timeval;
+  struct linger linger = { 0, 0 };
+
+  rhostvar = tmoutarg = fdvar = rhost = (char *)NULL;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "r:t:v:")) != -1)
+    {
+      switch (opt)
+	{
+	case 'r':
+	  rhostvar = list_optarg;
+	  break;
+	case 't':
+	  tmoutarg = list_optarg;
+	  break;
+	case 'v':
+	  fdvar = list_optarg;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  
+  list = loptend;
+
+  /* Validate input and variables */
+  if (tmoutarg)
+    {
+      long ival, uval;
+      opt = uconvert (tmoutarg, &ival, &uval, (char **)0);
+      if (opt == 0 || ival < 0 || uval < 0)
+	{
+	  builtin_error ("%s: invalid timeout specification", tmoutarg);
+	  return (EXECUTION_FAILURE);
+	}
+      timeval.tv_sec = ival;
+      timeval.tv_usec = uval;
+      /* XXX - should we warn if ival == uval == 0 ? */
+    }
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (legal_number (list->word->word, &iport) == 0 || iport < 0 || iport > TYPE_MAXIMUM (unsigned short))
+    {
+      builtin_error ("%s: invalid port number", list->word->word);
+      return (EXECUTION_FAILURE);
+    }
+  uport = (unsigned short)iport;
+
+  if (fdvar == 0)
+    fdvar = "ACCEPT_FD";
+
+  unbind_variable (fdvar);
+  if (rhostvar)
+    unbind_variable (rhostvar);
+    
+  if ((servsock = socket (AF_INET, SOCK_STREAM, IPPROTO_IP)) < 0)
+    {
+      builtin_error ("cannot create socket: %s", strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+
+  memset ((char *)&server, 0, sizeof (server));
+  server.sin_family = AF_INET;
+  server.sin_port = htons(uport);
+  server.sin_addr.s_addr = htonl(INADDR_ANY);
+
+  if (bind (servsock, (struct sockaddr *)&server, sizeof (server)) < 0)
+    {
+      builtin_error ("socket bind failure: %s", strerror (errno));
+      close (servsock);
+      return (EXECUTION_FAILURE);
+    }
+
+  opt = 1;
+  setsockopt (servsock, SOL_SOCKET, SO_REUSEADDR, (void *)&opt, sizeof (opt));
+  setsockopt (servsock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof (linger));
+
+  if (listen (servsock, 1) < 0)
+    {
+      builtin_error ("listen failure: %s", strerror (errno));
+      close (servsock);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (tmoutarg)
+    {
+      fd_set iofds;
+
+      FD_ZERO(&iofds);
+      FD_SET(servsock, &iofds);
+
+      opt = select (servsock+1, &iofds, 0, 0, &timeval);
+      if (opt < 0)
+        builtin_error ("select failure: %s", strerror (errno));
+      if (opt <= 0)
+        {
+          close (servsock);
+          return (EXECUTION_FAILURE);
+        }
+    }
+
+  clientlen = sizeof (client);
+  if ((clisock = accept (servsock, (struct sockaddr *)&client, &clientlen)) < 0)
+    {
+      builtin_error ("client accept failure: %s", strerror (errno));
+      close (servsock);
+      return (EXECUTION_FAILURE);
+    }
+
+  close (servsock);
+
+  accept_bind_variable (fdvar, clisock);  
+  if (rhostvar)
+    {
+      rhost = inet_ntoa (client.sin_addr);
+      v = builtin_bind_variable (rhostvar, rhost, 0);
+      if (v == 0 || readonly_p (v) || noassign_p (v))
+	builtin_error ("%s: cannot set variable", rhostvar);
+    }
+
+  return (EXECUTION_SUCCESS);
+}
+
+static int
+accept_bind_variable (varname, intval)
+     char *varname;
+     int intval;
+{
+  SHELL_VAR *v;
+  char ibuf[INT_STRLEN_BOUND (int) + 1], *p;
+
+  p = fmtulong (intval, 10, ibuf, sizeof (ibuf), 0);
+  v = builtin_bind_variable (varname, p, 0);
+  if (v == 0 || readonly_p (v) || noassign_p (v))
+    builtin_error ("%s: cannot set variable", varname);
+  return (v != 0);
+}
+
+char *accept_doc[] = {
+	"Accept a network connection on a specified port.",
+	""
+	"This builtin allows a bash script to act as a TCP/IP server.",
+	"",
+	"Options, if supplied, have the following meanings:",
+	"    -t timeout    wait TIMEOUT seconds for a connection. TIMEOUT may",
+	"                  be a decimal number including a fractional portion",
+	"    -v varname    store the numeric file descriptor of the connected",
+	"                  socket into VARNAME. The default VARNAME is ACCEPT_FD",
+	"    -r rhost      store the IP address of the remote host into the shell",
+	"                  variable RHOST, in dotted-decimal notation",
+	"",
+	"If successful, the shell variable ACCEPT_FD, or the variable named by the",
+	"-v option, will be set to the fd of the connected socket, suitable for",
+	"use as 'read -u$ACCEPT_FD'. RHOST, if supplied, will hold the IP address",
+	"of the remote client. The return status is 0.",
+	"",
+	"On failure, the return status is 1 and ACCEPT_FD (or VARNAME) and RHOST,",
+	"if supplied, will be unset.",
+	"",
+	"The server socket fd will be closed before accept returns.",
+	(char *) NULL
+};
+
+struct builtin accept_struct = {
+	"accept",		/* builtin name */
+	accept_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	accept_doc,		/* array of long documentation strings. */
+	"accept [-t timeout] [-v varname] [-r addrvar ] port",		/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/asort.c b/examples/loadables/asort.c
new file mode 100644
index 0000000..e847ef8
--- /dev/null
+++ b/examples/loadables/asort.c
@@ -0,0 +1,279 @@
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include "bashtypes.h"
+#include "shell.h"
+#include "builtins.h"
+#include "common.h"
+#include "xmalloc.h"
+#include "bashgetopt.h"
+
+typedef struct sort_element {
+    ARRAY_ELEMENT *v;   // used when sorting array in-place
+    char *key;          // used when sorting assoc array
+    char *value;        // points to value of array element or assoc entry
+    double num;         // used for numeric sort
+} sort_element;
+
+static int reverse_flag;
+static int numeric_flag;
+
+static int
+compare(const void *p1, const void *p2) {
+    const sort_element e1 = *(sort_element *) p1;
+    const sort_element e2 = *(sort_element *) p2;
+
+    if (numeric_flag) {
+        if (reverse_flag)
+            return (e2.num > e1.num) ? 1 : (e2.num < e1.num) ? -1 : 0;
+        else
+            return (e1.num > e2.num) ? 1 : (e1.num < e2.num) ? -1 : 0;
+    }
+    else {
+        if (reverse_flag)
+            return strcoll(e2.value, e1.value);
+        else
+            return strcoll(e1.value, e2.value);
+    }
+}
+
+static int
+sort_index(SHELL_VAR *dest, SHELL_VAR *source) {
+    HASH_TABLE *hash;
+    BUCKET_CONTENTS *bucket;
+    sort_element *sa;
+    ARRAY *array, *dest_array;
+    ARRAY_ELEMENT *ae;
+    size_t i, j, n;
+    char ibuf[INT_STRLEN_BOUND (intmax_t) + 1]; // used by fmtulong
+    char *key;
+
+    dest_array = array_cell(dest);
+
+    if (assoc_p(source)) {
+        hash = assoc_cell(source);
+        n = hash->nentries;
+        sa = xmalloc(n * sizeof(sort_element));
+        i = 0;
+        for ( j = 0; j < hash->nbuckets; ++j ) {
+            bucket = hash->bucket_array[j];
+            while ( bucket ) {
+                sa[i].v = NULL;
+                sa[i].key = bucket->key;
+                if ( numeric_flag )
+                    sa[i].num = strtod(bucket->data, NULL);
+                else
+                    sa[i].value = bucket->data;
+                i++;
+                bucket = bucket->next;
+            }
+        }
+    }
+    else {
+        array = array_cell(source);
+        n = array_num_elements(array);
+        sa = xmalloc(n * sizeof(sort_element));
+        i = 0;
+
+        for (ae = element_forw(array->head); ae != array->head; ae = element_forw(ae)) {
+            sa[i].v = ae;
+            if (numeric_flag)
+                sa[i].num = strtod(element_value(ae), NULL);
+            else
+                sa[i].value = element_value(ae);
+            i++;
+        }
+    }
+
+    // sanity check
+    if ( i != n ) {
+        builtin_error("%s: corrupt array", source->name);
+        return EXECUTION_FAILURE;
+    }
+
+    qsort(sa, n, sizeof(sort_element), compare);
+
+    array_flush(dest_array);
+
+    for ( i = 0; i < n; ++i ) {
+        if ( assoc_p(source) )
+            key = sa[i].key;
+        else
+            key = fmtulong((long unsigned)sa[i].v->ind, 10, ibuf, sizeof(ibuf), 0);
+
+        array_insert(dest_array, i, key);
+    }
+
+    return EXECUTION_SUCCESS;
+}
+
+static int
+sort_inplace(SHELL_VAR *var) {
+    size_t i, n;
+    ARRAY *a;
+    ARRAY_ELEMENT *ae;
+    sort_element *sa = 0;
+
+    a = array_cell(var);
+    n = array_num_elements(a);
+
+    if ( n == 0 )
+        return EXECUTION_SUCCESS;
+
+    sa = xmalloc(n * sizeof(sort_element));
+
+    i = 0;
+    for (ae = element_forw(a->head); ae != a->head; ae = element_forw(ae)) {
+        sa[i].v = ae;
+        if (numeric_flag)
+            sa[i].num = strtod(element_value(ae), NULL);
+        else
+            sa[i].value = element_value(ae);
+        i++;
+    }
+
+    // sanity check
+    if ( i != n ) {
+        builtin_error("%s: corrupt array", var->name);
+        return EXECUTION_FAILURE;
+    }
+
+    qsort(sa, n, sizeof(sort_element), compare);
+
+    // for in-place sort, simply "rewire" the array elements
+    sa[0].v->prev = sa[n-1].v->next = a->head;
+    a->head->next = sa[0].v;
+    a->head->prev = sa[n-1].v;
+    a->max_index = n - 1;
+    for (i = 0; i < n; i++) {
+        sa[i].v->ind = i;
+        if (i > 0)
+            sa[i].v->prev = sa[i-1].v;
+        if (i < n - 1)
+            sa[i].v->next = sa[i+1].v;
+    }
+    xfree(sa);
+    return EXECUTION_SUCCESS;
+}
+
+int
+asort_builtin(WORD_LIST *list) {
+    SHELL_VAR *var, *var2;
+    char *word;
+    int opt, ret;
+    int index_flag = 0;
+
+    numeric_flag = 0;
+    reverse_flag = 0;
+
+    reset_internal_getopt();
+    while ((opt = internal_getopt(list, "inr")) != -1) {
+        switch (opt) {
+            case 'i': index_flag = 1; break;
+            case 'n': numeric_flag = 1; break;
+            case 'r': reverse_flag = 1; break;
+            CASE_HELPOPT;
+            default:
+                builtin_usage();
+                return (EX_USAGE);
+        }
+    }
+    list = loptend;
+
+    if (list == 0) {
+        builtin_usage();
+        return EX_USAGE;
+    }
+
+    if (legal_identifier (list->word->word) == 0) {
+        sh_invalidid (list->word->word);
+        return EXECUTION_FAILURE;
+    }
+
+    if ( index_flag ) {
+        if ( list->next == 0 || list->next->next ) {
+            builtin_usage();
+            return EX_USAGE;
+        }
+        if (legal_identifier (list->next->word->word) == 0) {
+            sh_invalidid (list->next->word->word);
+            return EXECUTION_FAILURE;
+        }
+        var = find_or_make_array_variable(list->word->word, 1);
+        if (var == 0)
+            return EXECUTION_FAILURE;
+        var2 = find_variable(list->next->word->word);
+        if ( !var2 || ( !array_p(var2) && !assoc_p(var2) ) ) {
+            builtin_error("%s: Not an array", list->next->word->word);
+            return EXECUTION_FAILURE;
+        }
+        return sort_index(var, var2);
+    }
+
+    while (list) {
+        word = list->word->word;
+        var = find_variable(word);
+        list = list->next;
+
+        if (var == 0 || array_p(var) == 0) {
+            builtin_error("%s: Not an array", word);
+            continue;
+        }
+        if (readonly_p(var) || noassign_p(var)) {
+            if (readonly_p(var))
+                err_readonly(word);
+            continue;
+        }
+
+        if ( (ret = sort_inplace(var)) != EXECUTION_SUCCESS )
+            return ret;
+    }
+    return EXECUTION_SUCCESS;
+
+}
+
+char *asort_doc[] = {
+    "Sort arrays in-place.",
+    "",
+    "Options:",
+    "  -n  compare according to string numerical value",
+    "  -r  reverse the result of comparisons",
+    "  -i  sort using indices/keys",
+    "",
+    "If -i is supplied, SOURCE is not sorted in-place, but the indices (or keys",
+    "if associative) of SOURCE, after sorting it by its values, are placed as",
+    "values in the indexed array DEST",
+    "",
+    "Associative arrays may not be sorted in-place.",
+    "",
+    "Exit status:",
+    "Return value is zero unless an error happened (like invalid variable name",
+    "or readonly array).",
+    (char *)NULL
+};
+
+struct builtin asort_struct = {
+    "asort",
+    asort_builtin,
+    BUILTIN_ENABLED,
+    asort_doc,
+    "asort [-nr] array ...  or  asort [-nr] -i dest source",
+    0
+};
diff --git a/examples/loadables/basename.c b/examples/loadables/basename.c
new file mode 100644
index 0000000..29dd1a6
--- /dev/null
+++ b/examples/loadables/basename.c
@@ -0,0 +1,131 @@
+/* basename - return nondirectory portion of pathname */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+int
+basename_builtin (list)
+     WORD_LIST *list;
+{
+  int slen, sufflen, off;
+  char *string, *suffix, *fn;
+
+  if (no_options (list))
+    return (EX_USAGE);
+  list = loptend;
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }    
+
+  string = list->word->word;
+  suffix = (char *)NULL;
+  if (list->next)
+    {
+      list = list->next;
+      suffix = list->word->word;
+    }
+
+  if (list->next)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  slen = strlen (string);
+
+  /* Strip trailing slashes */
+  while (slen > 0 && string[slen - 1] == '/')
+    slen--;
+
+  /* (2) If string consists entirely of slash characters, string shall be
+	 set to a single slash character.  In this case, skip steps (3)
+	 through (5). */
+  if (slen == 0)
+    {
+      fputs ("/\n", stdout);
+      return (EXECUTION_SUCCESS);
+    }
+
+  /* (3) If there are any trailing slash characters in string, they
+	 shall be removed. */
+  string[slen] = '\0';
+
+  /* (4) If there are any slash characters remaining in string, the prefix
+	 of string up to an including the last slash character in string
+	 shall be removed. */
+  while (--slen >= 0)
+    if (string[slen] == '/')
+      break;
+
+  fn = string + slen + 1;
+
+  /* (5) If the suffix operand is present, is not identical to the
+	 characters remaining in string, and is identical to a suffix
+	 of the characters remaining in string, the suffix suffix
+	 shall be removed from string.  Otherwise, string shall not be
+	 modified by this step. */
+  if (suffix)
+    {
+      sufflen = strlen (suffix);
+      slen = strlen (fn);
+      if (sufflen < slen)
+        {
+          off = slen - sufflen;
+          if (strcmp (fn + off, suffix) == 0)
+            fn[off] = '\0';
+        }
+    }
+  printf ("%s\n", fn);
+  return (EXECUTION_SUCCESS);
+}
+
+char *basename_doc[] = {
+	"Return non-directory portion of pathname.",
+	"",
+	"The STRING is converted to a filename corresponding to the last",
+	"pathname component in STRING.  If the suffix string SUFFIX is",
+	"supplied, it is removed.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin basename_struct = {
+	"basename",		/* builtin name */
+	basename_builtin,	/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	basename_doc,		/* array of long documentation strings. */
+	"basename string [suffix]",	/* usage synopsis */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/cat.c b/examples/loadables/cat.c
new file mode 100644
index 0000000..be99c4c
--- /dev/null
+++ b/examples/loadables/cat.c
@@ -0,0 +1,122 @@
+/*
+ * cat replacement
+ *
+ * no options - the way cat was intended
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <fcntl.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+
+#ifndef errno
+extern int errno;
+#endif
+
+extern char *strerror ();
+extern char **make_builtin_argv ();
+
+static int
+fcopy(fd)
+int	fd;
+{
+	char	buf[1024], *s;
+	int	n, w, e;
+
+	while (n = read(fd, buf, sizeof (buf))) {
+		w = write(1, buf, n);
+		if (w != n) {
+			e = errno;
+			write(2, "cat: write error: ", 18);
+			s = strerror(e);
+			write(2, s, strlen(s));
+			write(2, "\n", 1);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+int
+cat_main (argc, argv)
+int	argc;
+char	**argv;
+{
+	int	i, fd, r;
+	char	*s;
+
+	if (argc == 1)
+		return (fcopy(0));
+
+	for (i = r = 1; i < argc; i++) {
+		if (argv[i][0] == '-' && argv[i][1] == '\0')
+			fd = 0;
+		else {
+			fd = open(argv[i], O_RDONLY, 0666);
+			if (fd < 0) {
+				s = strerror(errno);
+				write(2, "cat: cannot open ", 17);
+				write(2, argv[i], strlen(argv[i]));
+				write(2, ": ", 2);
+				write(2, s, strlen(s));
+				write(2, "\n", 1);
+				continue;
+			}
+		}
+		r = fcopy(fd);
+		if (fd != 0)
+			close(fd);
+	}
+	return (r);
+}
+
+int
+cat_builtin(list)
+WORD_LIST *list;
+{
+	char	**v;
+	int	c, r;
+
+	v = make_builtin_argv(list, &c);
+	r = cat_main(c, v);
+	free(v);
+
+	return r;
+}
+
+char *cat_doc[] = {
+	"Display files.",
+	"",
+	"Read each FILE and display it on the standard output.   If any",
+	"FILE is `-' or if no FILE argument is given, the standard input",
+	"is read.",
+	(char *)0
+};
+
+struct builtin cat_struct = {
+	"cat",
+	cat_builtin,
+	BUILTIN_ENABLED,
+	cat_doc,
+	"cat [-] [file ...]",
+	0
+};
diff --git a/examples/loadables/csv.c b/examples/loadables/csv.c
new file mode 100644
index 0000000..11228f1
--- /dev/null
+++ b/examples/loadables/csv.c
@@ -0,0 +1,206 @@
+/* csv - process a line of csv data and populate an indexed array with the
+	 fields */
+
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* See Makefile for compilation details. */
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+#include "bashansi.h"
+#include <stdio.h>
+
+#include "loadables.h"
+
+#define CSV_ARRAY_DEFAULT	"CSV"
+
+#define NQUOTE	0
+#define DQUOTE	1
+
+/* Split LINE into comma-separated fields, storing each field into a separate
+   element of array variable CSV, starting at index 0. The format of LINE is
+   as described in RFC 4180. */
+static int
+csvsplit (csv, line)
+     SHELL_VAR *csv;
+     char *line;
+{
+  arrayind_t ind;
+  char *field, *prev, *buf, *xbuf;
+  int delim, qstate;
+  int b, rval;
+
+  xbuf = 0;
+  ind = 0;
+  field = prev = line;
+
+  do
+    {
+      if (*prev == '"')
+	{
+	  if (xbuf == 0)
+	    xbuf = xmalloc (strlen (prev) + 1);
+	  buf = xbuf;
+	  b = 0;
+	  qstate = DQUOTE;
+	  for (field = ++prev; *field; field++)
+	    {
+	      if (qstate == DQUOTE && *field == '"' && field[1] == '"')
+		buf[b++] = *field++;	/* skip double quote */
+	      else if (qstate == DQUOTE && *field == '"')
+	        qstate = NQUOTE;
+	      else if (qstate == NQUOTE && *field == ',')
+		break;
+	      else
+		/* This copies any text between a closing double quote and the
+		   delimiter. If you want to change that, make sure to do the
+		   copy only if qstate == DQUOTE. */
+		buf[b++] = *field;
+	    }
+	  buf[b] = '\0';
+	}
+      else
+	{
+	  buf = prev;
+	  field = prev + strcspn (prev, ",");
+	}
+
+      delim = *field;
+      *field = '\0';
+
+      bind_array_element (csv, ind, buf, 0);
+      ind++;
+
+      *field = delim;
+
+      if (delim == ',')
+	prev = field + 1;
+    }
+  while (delim == ',');
+
+  if (xbuf)
+    free (xbuf);
+
+  return (rval = ind);				/* number of fields */
+}
+
+int
+csv_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, rval;
+  char *array_name, *csvstring;
+  SHELL_VAR *v;
+
+  array_name = 0;
+  rval = EXECUTION_SUCCESS;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "a:")) != -1)
+    {
+      switch (opt)
+	{
+	case 'a':
+	  array_name = list_optarg;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (array_name == 0)
+    array_name = CSV_ARRAY_DEFAULT;
+
+  if (legal_identifier (array_name) == 0)
+    {
+      sh_invalidid (array_name);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (list == 0)
+    {
+      builtin_error ("csv string argument required");
+      return (EX_USAGE);
+    }
+
+  v = find_or_make_array_variable (array_name, 1);
+  if (v == 0 || readonly_p (v) || noassign_p (v))
+    {
+      if (v && readonly_p (v))
+	err_readonly (array_name);
+      return (EXECUTION_FAILURE);
+    }
+  else if (array_p (v) == 0)
+    {
+      builtin_error ("%s: not an indexed array", array_name);
+      return (EXECUTION_FAILURE);
+    }
+  if (invisible_p (v))
+    VUNSETATTR (v, att_invisible);
+  array_flush (array_cell (v));
+
+  csvstring = list->word->word;
+
+  if (csvstring == 0 || *csvstring == 0)
+    return (EXECUTION_SUCCESS);
+
+  opt = csvsplit (v, csvstring);
+  /* Maybe do something with OPT here, it's the number of fields */
+
+  return (rval);
+}
+
+/* Called when builtin is enabled and loaded from the shared object.  If this
+   function returns 0, the load fails. */
+int
+csv_builtin_load (name)
+     char *name;
+{
+  return (1);
+}
+
+/* Called when builtin is disabled. */
+void
+csv_builtin_unload (name)
+     char *name;
+{
+}
+
+char *csv_doc[] = {
+	"Read comma-separated fields from a string.",
+	"",
+	"Parse STRING, a line of comma-separated values, into individual fields,",
+	"and store them into the indexed array ARRAYNAME starting at index 0.",
+	"If ARRAYNAME is not supplied, \"CSV\" is the default array name.",
+	(char *)NULL
+};
+
+struct builtin csv_struct = {
+	"csv",			/* builtin name */
+	csv_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	csv_doc,		/* array of long documentation strings. */
+	"csv [-a ARRAY] string",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/cut.c b/examples/loadables/cut.c
new file mode 100644
index 0000000..ad9a833
--- /dev/null
+++ b/examples/loadables/cut.c
@@ -0,0 +1,625 @@
+/* cut,lcut - extract specified fields from a line and assign them to an array
+	      or print them to the standard output */
+
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* See Makefile for compilation details. */
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+#include "bashansi.h"
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "loadables.h"
+#include "shmbutil.h"
+
+#define CUT_ARRAY_DEFAULT	"CUTFIELDS"
+
+#define NOPOS	-2		/* sentinel for unset startpos/endpos */
+
+#define BOL	0		
+#define EOL	INT_MAX
+#define NORANGE	-1		/* just a position, no range */
+
+#define BFLAG	(1 << 0)
+#define CFLAG	(1 << 1)
+#define DFLAG	(1 << 2)
+#define FFLAG	(1 << 3)
+#define SFLAG	(1 << 4)
+
+struct cutpos
+{
+  int startpos, endpos;		/* zero-based, correction done in getlist() */
+};
+
+struct cutop
+{
+  int flags;
+  int delim;
+  int npos;
+  struct cutpos *poslist;
+};
+
+static int
+poscmp (a, b)
+     void *a, *b;
+{
+  struct cutpos *p1, *p2;
+
+  p1 = (struct cutpos *)a;
+  p2 = (struct cutpos *)b;
+  return (p1->startpos - p2->startpos);
+}
+
+static int
+getlist (arg, opp)
+     char *arg;
+     struct cutpos **opp;
+{
+  char *ntok, *ltok, *larg;
+  int s, e;
+  intmax_t num;
+  struct cutpos *poslist;
+  int npos, nsize;
+
+  poslist = 0;
+  nsize = npos = 0;
+  s = e = 0;
+  larg = arg;
+  while (ltok = strsep (&larg, ","))
+    {
+      if (*ltok == 0)
+        continue;
+
+      ntok = strsep (&ltok, "-");
+      if (*ntok == 0)
+        s = BOL;
+      else
+	{
+	  if (legal_number (ntok, &num) == 0 || (int)num != num || num <= 0)
+	    {
+	      builtin_error ("%s: invalid list value", ntok);
+	      *opp = poslist;
+	      return -1;
+	    }
+	  s = num;
+	  s--;		/* fields are 1-based */
+	}
+      if (ltok == 0)
+	e = NORANGE;
+      else if (*ltok == 0)
+	e = EOL;
+      else
+	{
+	  if (legal_number (ltok, &num) == 0 || (int)num != num || num <= 0)
+	    {
+	      builtin_error ("%s: invalid list value", ltok);
+	      *opp = poslist;
+	      return -1;
+	    }
+	  e = num;
+	  e--;
+	  if (e == s)
+	    e = NORANGE;
+	}
+
+      if (npos == nsize)
+	{
+	  nsize += 4;
+	  poslist = (struct cutpos *)xrealloc (poslist, nsize * sizeof (struct cutpos));
+	}
+      poslist[npos].startpos = s;
+      poslist[npos].endpos = e; 
+      npos++;
+    }
+  if (npos == 0)
+    {
+      builtin_error ("missing list of positions");
+      *opp = poslist;
+      return -1;
+    }
+
+  qsort (poslist, npos, sizeof(poslist[0]), poscmp);
+  *opp = poslist;
+
+  return npos;
+}
+
+static int
+cutbytes (v, line, ops)
+     SHELL_VAR *v;
+     char *line;
+     struct cutop *ops;
+{
+  arrayind_t ind;
+  char *buf, *bmap;
+  size_t llen;
+  int i, b, n, s, e;
+
+  llen = strlen (line);
+  buf = xmalloc (llen + 1);
+  bmap = xmalloc (llen + 1);
+  memset (bmap, 0, llen);
+
+  for (n = 0; n < ops->npos; n++)
+    {
+      s = ops->poslist[n].startpos;		/* no translation needed yet */
+      e = ops->poslist[n].endpos;
+      if (e == NORANGE)
+        e = s;
+      else if (e == EOL || e >= llen)
+	e = llen - 1;
+      /* even if a column is specified multiple times, it will only be printed
+         once */
+      for (i = s; i <= e; i++)
+	bmap[i] = 1;
+    }
+
+  b = 0;
+  for (i = 0; i < llen; i++)
+    if (bmap[i])
+      buf[b++] = line[i];
+  buf[b] = 0; 
+
+  if (v)
+    {
+      ind = 0;
+      bind_array_element (v, ind, buf, 0);
+      ind++;
+    }
+  else
+    printf ("%s\n", buf);
+
+  free (buf);
+  free (bmap);
+
+  return ind;
+}
+
+static int
+cutchars (v, line, ops)
+     SHELL_VAR *v;
+     char *line;
+     struct cutop *ops;
+{
+  arrayind_t ind;
+  char *buf, *bmap;
+  wchar_t *wbuf, *wb2;
+  size_t llen, wlen;
+  int i, b, n, s, e;
+
+  if (MB_CUR_MAX == 1)
+    return (cutbytes (v, line, ops));
+  if (locale_utf8locale && utf8_mbsmbchar (line) == 0)
+    return (cutbytes (v, line, ops));
+
+  llen = strlen (line);
+  wbuf = (wchar_t *)xmalloc ((llen + 1) * sizeof (wchar_t));
+
+  wlen = mbstowcs (wbuf, line, llen);
+  if (MB_INVALIDCH (wlen))
+    {
+      free (wbuf);
+      return (cutbytes (v, line, ops));
+    }
+
+  bmap = xmalloc (llen + 1);
+  memset (bmap, 0, llen);
+  
+  for (n = 0; n < ops->npos; n++)
+    {
+      s = ops->poslist[n].startpos;		/* no translation needed yet */
+      e = ops->poslist[n].endpos;
+      if (e == NORANGE)
+        e = s;
+      else if (e == EOL || e >= wlen)
+	e = wlen - 1;
+      /* even if a column is specified multiple times, it will only be printed
+         once */
+      for (i = s; i <= e; i++)
+	bmap[i] = 1;
+    }
+
+  wb2 = (wchar_t *)xmalloc ((wlen + 1) * sizeof (wchar_t));
+  b = 0;
+  for (i = 0; i < wlen; i++)
+    if (bmap[i])
+      wb2[b++] = wbuf[i];
+  wb2[b] = 0;
+
+  free (wbuf);
+
+  buf = bmap;
+  n = wcstombs (buf, wb2, llen);
+
+  if (v)
+    {
+      ind = 0;
+      bind_array_element (v, ind, buf, 0);
+      ind++;
+    }
+  else
+    printf ("%s\n", buf);
+
+  free (buf);
+  free (wb2);
+
+  return ind;
+}
+
+/* The basic strategy is to cut the line into fields using strsep, populate
+   an array of fields from 0..nf, then select those fields using the same
+   bitmap approach as cut{bytes,chars} and assign them to the array variable
+   V or print them on stdout. This function obeys SFLAG. */
+static int
+cutfields (v, line, ops)
+     SHELL_VAR *v;
+     char *line;
+     struct cutop *ops;
+{
+  arrayind_t ind;
+  char *buf, *bmap, *field, **fields, delim[2];
+  size_t llen, fsize;
+  int i, b, n, s, e, nf;
+
+  ind = 0;
+
+  delim[0] = ops->delim;
+  delim[1] = '\0';
+
+  fields = 0;
+  nf = 0;
+  fsize = 0;
+
+  field = buf = line;
+  do
+    {
+      field = strsep (&buf, delim);	/* destructive */
+      if (nf == fsize)
+	{
+	  fsize += 8;
+	  fields = xrealloc (fields, fsize * sizeof (char *));
+	}
+      fields[nf] = field;
+      if (field)
+	nf++;
+    }
+  while (field);
+
+  if (nf == 1)
+    {
+      free (fields);
+      if (ops->flags & SFLAG)
+	return ind;
+      if (v)
+	{
+	  bind_array_element (v, ind, line, 0);
+	  ind++;
+	}
+      else
+	printf ("%s\n", line);
+      return ind;
+    }
+
+  bmap = xmalloc (nf + 1);
+  memset (bmap, 0, nf);
+
+  for (n = 0; n < ops->npos; n++)
+    {
+      s = ops->poslist[n].startpos;		/* no translation needed yet */
+      e = ops->poslist[n].endpos;
+      if (e == NORANGE)
+        e = s;
+      else if (e == EOL || e >= nf)
+	e = nf - 1;
+      /* even if a column is specified multiple times, it will only be printed
+         once */
+      for (i = s; i <= e; i++)
+	bmap[i] = 1;
+    }
+
+  for (i = 1, b = 0; b < nf; b++)
+    {
+      if (bmap[b] == 0)
+	continue;
+      if (v)
+	{
+	  bind_array_element (v, ind, fields[b], 0);
+	  ind++;
+	}
+      else
+	{
+	  if (i == 0)
+	    putchar (ops->delim);
+	  printf ("%s", fields[b]);
+	}
+      i = 0;
+    }
+  if (v == 0)
+    putchar ('\n');
+
+  return nf;
+}
+
+static int
+cutline (v, line, ops)
+     SHELL_VAR *v;
+     char *line;
+     struct cutop *ops;
+{
+  int rval;
+
+  if (ops->flags & BFLAG)
+    rval = cutbytes (v, line, ops);
+  else if (ops->flags & CFLAG)
+    rval = cutchars (v, line, ops);
+  else
+    rval = cutfields (v, line, ops);
+
+  return (rval >= 0 ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
+}
+
+static int
+cutfile (v, list, ops)
+     SHELL_VAR *v;
+     WORD_LIST *list;
+     struct cutop *ops;
+{
+  int fd, unbuffered_read;
+  char *line, *b;
+  size_t llen;
+  WORD_LIST *l;
+  ssize_t n;
+
+  line = 0;
+  llen = 0;
+
+  l = list;
+  do
+    {
+      /* for each file */
+      if (l == 0 || (l->word->word[0] == '-' && l->word->word[1] == '\0'))
+	fd = 0;
+      else
+	fd = open (l->word->word, O_RDONLY);
+      if (fd < 0)
+	{
+	  file_error (l->word->word);
+	  return (EXECUTION_FAILURE);
+	}
+
+#ifndef __CYGWIN__
+      unbuffered_read = (lseek (fd, 0L, SEEK_CUR) < 0) && (errno == ESPIPE);
+#else
+      unbuffered_read = 1;
+#endif
+
+      while ((n = zgetline (fd, &line, &llen, '\n', unbuffered_read)) != -1)
+	  cutline (v, line, ops);		/* can modify line */
+      if (fd > 0)
+	close (fd);
+
+      if (l)
+	l = l->next;
+    }
+  while (l);
+
+  free (line);
+  return EXECUTION_SUCCESS;
+}
+
+#define OPTSET(x)	     ((cutflags & (x)) ? 1 : 0)
+
+static int
+cut_internal (which, list)
+     int which;				/* not used yet */
+     WORD_LIST *list;
+{
+  int opt, rval, cutflags, delim, npos;
+  char *array_name, *cutstring, *list_arg;
+  SHELL_VAR *v;
+  struct cutop op;
+  struct cutpos *poslist;
+
+  v = 0;
+  rval = EXECUTION_SUCCESS;
+
+  cutflags = 0;
+  array_name = 0;
+  list_arg = 0;
+  delim = '\t';
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "a:b:c:d:f:sn")) != -1)
+    {
+      switch (opt)
+	{
+	case 'a':
+	  array_name = list_optarg;
+	  break;
+	case 'b':
+	  cutflags |= BFLAG;
+	  list_arg = list_optarg;
+	  break;
+	case 'c':
+	  cutflags |= CFLAG;
+	  list_arg = list_optarg;
+	  break;
+	case 'd':
+	  cutflags |= DFLAG;
+	  delim = list_optarg[0];
+	  if (delim == 0 || list_optarg[1])
+	    {
+	      builtin_error ("delimiter must be a single non-null character");
+	      return (EX_USAGE);
+	    }
+	  break;
+	case 'f':
+	  cutflags |= FFLAG;
+	  list_arg = list_optarg;
+	  break;
+	case 'n':
+	  break;
+	case 's':
+	  cutflags |= SFLAG;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (array_name && (legal_identifier (array_name) == 0))
+    {
+      sh_invalidid (array_name);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (list == 0 && which == 0)
+    {
+      builtin_error ("string argument required");
+      return (EX_USAGE);
+    }
+
+  /* options are mutually exclusive and one is required */
+  if ((OPTSET (BFLAG) + OPTSET (CFLAG) + OPTSET (FFLAG)) != 1)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if ((npos = getlist (list_arg, &poslist)) < 0)
+    {
+      free (poslist);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (array_name)
+    {      
+      v = find_or_make_array_variable (array_name, 1);
+      if (v == 0 || readonly_p (v) || noassign_p (v))
+	{
+	  if (v && readonly_p (v))
+	    err_readonly (array_name);
+	  return (EXECUTION_FAILURE);
+	}
+      else if (array_p (v) == 0)
+	{
+	  builtin_error ("%s: not an indexed array", array_name);
+	  return (EXECUTION_FAILURE);
+	}
+      if (invisible_p (v))
+	VUNSETATTR (v, att_invisible);
+      array_flush (array_cell (v));
+    }
+
+  op.flags = cutflags;
+  op.delim = delim;
+  op.npos = npos;
+  op.poslist = poslist;
+
+  /* we implement cut as a builtin with a cutfile() function that opens each
+     filename in LIST as a filename (or `-' for stdin) and runs cutline on
+     every line in the file. */
+  if (which == 0)
+    {
+      cutstring = list->word->word;
+      if (cutstring == 0 || *cutstring == 0)
+	{
+	  free (poslist);
+	  return (EXECUTION_SUCCESS);
+	}
+      rval = cutline (v, cutstring, &op);
+    }
+  else
+    rval = cutfile (v, list, &op);
+
+  return (rval);
+}
+
+int
+lcut_builtin (list)
+     WORD_LIST *list;
+{
+  return (cut_internal (0, list));
+}
+
+int
+cut_builtin (list)
+     WORD_LIST *list;
+{
+  return (cut_internal (1, list));
+}
+
+char *lcut_doc[] = {
+	"Extract selected fields from a string.",
+	"",
+        "Select portions of LINE (as specified by LIST) and assign them to",
+        "elements of the indexed array ARRAY starting at index 0, or write",
+        "them to the standard output if -a is not specified.",
+        "",
+	"Items specified by LIST are either column positions or fields delimited",
+	"by a special character, and are described more completely in cut(1).",
+	"",
+	"Columns correspond to bytes (-b), characters (-c), or fields (-f). The",
+	"field delimiter is specified by -d (default TAB). Column numbering",
+	"starts at 1.",
+	(char *)NULL
+};
+
+struct builtin lcut_struct = {
+	"lcut",			/* builtin name */
+	lcut_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	lcut_doc,		/* array of long documentation strings. */
+	"lcut [-a ARRAY] [-b LIST] [-c LIST] [-f LIST] [-d CHAR] [-sn] line",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
+
+char *cut_doc[] = {
+	"Extract selected fields from each line of a file.",
+	"",
+        "Select portions of each line (as specified by LIST) from each FILE",
+        "and write them to the standard output. cut reads from the standard",
+        "input if no FILE arguments are specified or if a FILE argument is a",
+        "single hyphen.",
+        "",
+	"Items specified by LIST are either column positions or fields delimited",
+	"by a special character, and are described more completely in cut(1).",
+	"",
+	"Columns correspond to bytes (-b), characters (-c), or fields (-f). The",
+	"field delimiter is specified by -d (default TAB). Column numbering",
+	"starts at 1.",
+	(char *)NULL
+};
+
+struct builtin cut_struct = {
+	"cut",			/* builtin name */
+	cut_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	cut_doc,		/* array of long documentation strings. */
+	"cut [-a ARRAY] [-b LIST] [-c LIST] [-f LIST] [-d CHAR] [-sn] [file ...]",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/dirname.c b/examples/loadables/dirname.c
new file mode 100644
index 0000000..d802ca7
--- /dev/null
+++ b/examples/loadables/dirname.c
@@ -0,0 +1,119 @@
+/* dirname - return directory portion of pathname */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+int
+dirname_builtin (list)
+     WORD_LIST *list;
+{
+  int slen;
+  char *string;
+
+  if (no_options (list))
+    return (EX_USAGE);
+  list = loptend;
+
+  if (list == 0 || list->next)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  string = list->word->word;
+  slen = strlen (string);
+
+  /* Strip trailing slashes */
+  while (slen > 0 && string[slen - 1] == '/')
+    slen--;
+
+  /* (2) If string consists entirely of slash characters, string shall be
+	 set to a single slash character.  In this case, skip steps (3)
+	 through (8). */
+  if (slen == 0)
+    {
+      fputs ("/\n", stdout);
+      return (EXECUTION_SUCCESS);
+    }
+
+  /* (3) If there are any trailing slash characters in string, they
+	 shall be removed. */
+  string[slen] = '\0';
+
+  /* (4) If there are no slash characters remaining in string, string
+	 shall be set to a single period character.  In this case, skip
+	 steps (5) through (8).
+
+     (5) If there are any trailing nonslash characters in string,
+	 they shall be removed. */
+
+  while (--slen >= 0)
+    if (string[slen] == '/')
+      break;
+
+  if (slen < 0)
+    {
+      fputs (".\n", stdout);
+      return (EXECUTION_SUCCESS);
+    }
+
+  /* (7) If there are any trailing slash characters in string, they
+	 shall be removed. */
+  while (--slen >= 0)
+    if (string[slen] != '/')
+      break;
+  string[++slen] = '\0';
+
+  /* (8) If the remaining string is empty, string shall be set to a single
+	 slash character. */
+  printf ("%s\n", (slen == 0) ? "/" : string);
+  return (EXECUTION_SUCCESS);
+}
+
+char *dirname_doc[] = {
+	"Display directory portion of pathname.",
+	"",
+	"The STRING is converted to the name of the directory containing",	
+	"the filename corresponding to the last pathname component in STRING.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin dirname_struct = {
+	"dirname",		/* builtin name */
+	dirname_builtin,	/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	dirname_doc,		/* array of long documentation strings. */
+	"dirname string",	/* usage synopsis */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/fdflags.c b/examples/loadables/fdflags.c
new file mode 100644
index 0000000..fbe5230
--- /dev/null
+++ b/examples/loadables/fdflags.c
@@ -0,0 +1,374 @@
+/* Loadable builtin to get and set file descriptor flags. */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 2017,2018,2019 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+#include <fcntl.h>
+#include <errno.h>
+#include "bashansi.h"
+#include <stdio.h>
+
+#include "loadables.h"
+
+#ifndef FD_CLOEXEC
+#  define FD_CLOEXEC 1
+#endif
+
+static const struct
+{
+  const char *name;
+  int value;
+} file_flags[] =
+{
+#ifdef O_APPEND
+  { "append",	O_APPEND 	},
+#else
+#  define O_APPEND 0
+#endif
+#ifdef O_ASYNC
+  { "async",	O_ASYNC		},
+#else
+#  define O_ASYNC 0
+#endif
+#ifdef O_SYNC
+  { "sync",	O_SYNC		},
+#else
+#  define O_SYNC 0
+#endif
+#ifdef O_NONBLOCK
+  { "nonblock",	O_NONBLOCK	},
+#else
+#  define O_NONBLOCK 0
+#endif
+#ifdef O_FSYNC
+  { "fsync",	O_FSYNC		},
+#else
+#  define O_FSYNC 0
+#endif
+#ifdef O_DSYNC
+  { "dsync",	O_DSYNC		},
+#else
+#  define O_DSYNC 0
+#endif
+#ifdef O_RSYNC
+  { "rsync",	O_RSYNC		},
+#else
+#  define O_RSYNC 0
+#endif
+#ifdef O_ALT_IO
+  { "altio",	O_ALT_IO	},
+#else
+#  define O_ALT_IO 0
+#endif
+#ifdef O_DIRECT
+  { "direct",	O_DIRECT	},
+#else
+#  define O_DIRECT 0
+#endif
+#ifdef O_NOATIME
+  { "noatime",	O_NOATIME	},
+#else
+#  define O_NOATIME 0
+#endif
+#ifdef O_NOSIGPIPE
+  { "nosigpipe",	O_NOSIGPIPE	},
+#else
+#  define O_NOSIGPIPE 0
+#endif
+
+#ifndef O_CLOEXEC
+#  define ALLFLAGS (O_APPEND|O_ASYNC|O_SYNC|O_NONBLOCK|O_FSYNC|O_DSYNC|\
+	O_RSYNC|O_ALT_IO|O_DIRECT|O_NOATIME|O_NOSIGPIPE)
+
+/* An unsed bit in the file status flags word we can use to pass around the
+   state of close-on-exec. */
+# define O_CLOEXEC      ((~ALLFLAGS) ^ ((~ALLFLAGS) & ((~ALLFLAGS) - 1)))
+#endif
+
+#ifdef O_CLOEXEC
+  { "cloexec",	O_CLOEXEC	},
+#endif
+};
+
+#define N_FLAGS		(sizeof (file_flags) / sizeof (file_flags[0]))
+
+#ifndef errno
+extern int errno;
+#endif
+
+/* FIX THIS */
+static int
+getallflags ()
+{
+  int i, allflags;
+  
+  for (i = allflags = 0; i < N_FLAGS; i++)
+    allflags |= file_flags[i].value;
+  return allflags;
+}
+
+static int
+getflags(int fd, int p)
+{
+  int c, f;
+  int allflags;
+
+  if ((c = fcntl(fd, F_GETFD)) == -1)
+    {
+      if (p)
+	builtin_error("can't get status for fd %d: %s", fd, strerror(errno));
+      return -1;
+    }
+    
+  if ((f = fcntl(fd, F_GETFL)) == -1)
+    {
+      if (p)
+	builtin_error("Can't get flags for fd %d: %s", fd, strerror(errno));
+      return -1;
+    }
+
+  if (c)
+    f |= O_CLOEXEC;
+
+  return f & getallflags();
+}
+
+static void
+printone(int fd, int p, int verbose)
+{
+  int f;
+  size_t i;
+
+  if ((f = getflags(fd, p)) == -1)
+    return;
+
+  printf ("%d:", fd);
+
+  for (i = 0; i < N_FLAGS; i++)
+    {
+      if (f & file_flags[i].value)
+	{
+	  printf ("%s%s", verbose ? "+" : "", file_flags[i].name);
+	  f &= ~file_flags[i].value;
+	}
+      else if (verbose)
+	printf ( "-%s", file_flags[i].name);
+      else
+	continue;
+
+      if (f || (verbose && i != N_FLAGS - 1))
+	putchar (',');
+    }
+  printf ("\n");
+}
+
+static int
+parseflags(char *s, int *p, int *n)
+{
+  int f, *v;
+  size_t i;
+
+  f = 0;
+  *p = *n = 0;
+
+  for (s = strtok(s, ","); s; s = strtok(NULL, ","))
+    {
+      switch (*s)
+        {
+	case '+':
+	  v = p;
+	  s++;
+	  break;
+	case '-':
+	  v = n;
+	  s++;
+	  break;
+	default:
+	  v = &f;
+	  break;
+	}
+			
+      for (i = 0; i < N_FLAGS; i++)
+	if (strcmp(s, file_flags[i].name) == 0)
+	  {
+	    *v |= file_flags[i].value;
+	    break;
+	  }
+      if (i == N_FLAGS)
+	builtin_error("invalid flag `%s'", s);
+    }
+
+  return f;
+}
+
+static void
+setone(int fd, char *v, int verbose)
+{
+  int f, n, pos, neg, cloexec;
+
+  f = getflags(fd, 1);
+  if (f == -1)
+    return;
+
+  parseflags(v, &pos, &neg);
+
+  cloexec = -1;
+
+  if ((pos & O_CLOEXEC) && (f & O_CLOEXEC) == 0)
+    cloexec = FD_CLOEXEC;
+  if ((neg & O_CLOEXEC) && (f & O_CLOEXEC))
+    cloexec = 0;
+
+  if (cloexec != -1 && fcntl(fd, F_SETFD, cloexec) == -1)
+    builtin_error("can't set status for fd %d: %s", fd, strerror(errno));
+
+  pos &= ~O_CLOEXEC;
+  neg &= ~O_CLOEXEC;
+  f &= ~O_CLOEXEC;
+
+  n = f;
+  n |= pos;
+  n &= ~neg;
+
+  if (n != f && fcntl(fd, F_SETFL, n) == -1)
+    builtin_error("can't set flags for fd %d: %s", fd, strerror(errno));
+}
+
+static int
+getmaxfd ()
+{
+  int maxfd, ignore;
+
+#ifdef F_MAXFD
+  maxfd = fcntl (0, F_MAXFD);
+  if (maxfd > 0)
+    return maxfd;
+#endif
+
+  maxfd = getdtablesize ();
+  if (maxfd <= 0)
+    maxfd = HIGH_FD_MAX;
+  for (maxfd--; maxfd > 0; maxfd--)
+    if (fcntl (maxfd, F_GETFD, &ignore) != -1)
+      break;
+
+  return maxfd;
+}
+
+int
+fdflags_builtin (WORD_LIST *list)
+{
+  int opt, maxfd, i, num, verbose, setflag;
+  char *setspec;
+  WORD_LIST *l;
+  intmax_t inum;
+
+  setflag = verbose = 0;
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "s:v")) != -1)
+    {
+      switch (opt)
+	{
+	case 's':
+	  setflag = 1;
+	  setspec = list_optarg;
+	  break;
+	case 'v':
+	  verbose = 1;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+	
+    }
+  list = loptend;
+
+  /* Maybe we could provide some default here, but we don't yet. */
+  if (list == 0 && setflag)
+    return (EXECUTION_SUCCESS);
+
+  if (list == 0)
+    {
+      maxfd = getmaxfd ();
+      if (maxfd < 0)
+	{
+	  builtin_error ("can't get max fd: %s", strerror (errno));
+	  return (EXECUTION_FAILURE);
+	}
+      for (i = 0; i < maxfd; i++)
+	printone (i, 0, verbose);
+      return (EXECUTION_SUCCESS);
+    }
+
+  opt = EXECUTION_SUCCESS;
+  for (l = list; l; l = l->next)
+    {
+      if (legal_number (l->word->word, &inum) == 0 || inum < 0)
+	{
+	  builtin_error ("%s: invalid file descriptor", l->word->word);
+	  opt = EXECUTION_FAILURE;
+	  continue;
+	}
+      num = inum;		/* truncate to int */
+      if (setflag)
+	setone (num, setspec, verbose);
+      else
+	printone (num, 1, verbose);
+    }
+
+  return (opt);
+}
+
+char *fdflags_doc[] =
+{
+  "Display and modify file descriptor flags.",
+  "",
+  "Display or, if the -s option is supplied, set flags for each file",
+  "descriptor supplied as an argument.  If the -v option is supplied,",
+  "the display is verbose, including each settable option name in the",
+  "form of a string such as that accepted by the -s option.",
+  "",
+  "The -s option accepts a string with a list of flag names, each preceded",
+  "by a `+' (set) or `-' (unset).  Those changes are applied to each file",
+  "descriptor supplied as an argument.",
+  "",
+  "If no file descriptor arguments are supplied, the displayed information",
+  "consists of the status of flags for each of the shell's open files.",
+  (char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures.  The flags must include BUILTIN_ENABLED so the
+   builtin can be used. */
+struct builtin fdflags_struct = {
+	"fdflags",		/* builtin name */
+	fdflags_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	fdflags_doc,		/* array of long documentation strings. */
+	"fdflags [-v] [-s flags_string] [fd ...]",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/finfo.c b/examples/loadables/finfo.c
new file mode 100644
index 0000000..8c278c3
--- /dev/null
+++ b/examples/loadables/finfo.c
@@ -0,0 +1,629 @@
+/*
+ * finfo - print file info
+ *
+ * Chet Ramey
+ * chet@po.cwru.edu
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <sys/types.h>
+#ifdef MAJOR_IN_MKDEV
+#  include <sys/mkdev.h>
+#endif
+#ifdef MAJOR_IN_SYSMACROS
+#  include <sys/sysmacros.h>
+#endif
+#include "posixstat.h"
+#include <stdio.h>
+#include <pwd.h>
+#include <grp.h>
+#include <errno.h>
+#include "posixtime.h"
+
+#include "bashansi.h"
+#include "shell.h"
+#include "builtins.h"
+#include "common.h"
+#include "getopt.h"
+
+#ifndef errno
+extern int	errno;
+#endif
+
+extern char	**make_builtin_argv ();
+
+static void	perms();
+static int	printst();
+static int	printsome();
+static void	printmode();
+static int	printfinfo();
+static int	finfo_main();
+
+extern int	sh_optind;
+extern char	*sh_optarg;
+extern char	*this_command_name;
+
+static char	*prog;
+static int	pmask;
+
+#define OPT_UID		0x00001
+#define OPT_GID		0x00002
+#define OPT_DEV		0x00004
+#define OPT_INO		0x00008
+#define OPT_PERM	0x00010
+#define OPT_LNKNAM	0x00020
+#define OPT_FID		0x00040
+#define OPT_NLINK	0x00080
+#define OPT_RDEV	0x00100
+#define OPT_SIZE	0x00200
+#define OPT_ATIME	0x00400
+#define OPT_MTIME	0x00800
+#define OPT_CTIME	0x01000
+#define OPT_BLKSIZE	0x02000
+#define OPT_BLKS	0x04000
+#define OPT_FTYPE	0x08000
+#define OPT_PMASK	0x10000
+#define OPT_OPERM	0x20000
+
+#define OPT_ASCII	0x1000000
+
+#define OPTIONS		"acdgiflmnopsuACGMP:U"
+
+static int
+octal(s)
+char	*s;
+{
+	int	r;
+
+	r = *s - '0';
+	while (*++s >= '0' && *s <= '7')
+		r = (r * 8) + (*s - '0');
+	return r;
+}
+
+static int
+finfo_main(argc, argv)
+int	argc;
+char	**argv;
+{
+	register int	i;
+	int	mode, flags, opt;
+
+	sh_optind = 0;	/* XXX */
+	prog = base_pathname(argv[0]);
+	if (argc == 1) {
+		builtin_usage();
+		return(1);
+	}
+	flags = 0;
+	while ((opt = sh_getopt(argc, argv, OPTIONS)) != EOF) {
+		switch(opt) {
+		case 'a': flags |= OPT_ATIME; break;
+		case 'A': flags |= OPT_ATIME|OPT_ASCII; break;
+		case 'c': flags |= OPT_CTIME; break;
+		case 'C': flags |= OPT_CTIME|OPT_ASCII; break;
+		case 'd': flags |= OPT_DEV; break;
+		case 'i': flags |= OPT_INO; break;
+		case 'f': flags |= OPT_FID; break;
+		case 'g': flags |= OPT_GID; break;
+		case 'G': flags |= OPT_GID|OPT_ASCII; break;
+		case 'l': flags |= OPT_LNKNAM; break;
+		case 'm': flags |= OPT_MTIME; break;
+		case 'M': flags |= OPT_MTIME|OPT_ASCII; break;
+		case 'n': flags |= OPT_NLINK; break;
+		case 'o': flags |= OPT_OPERM; break;
+		case 'p': flags |= OPT_PERM; break;
+		case 'P': flags |= OPT_PMASK; pmask = octal(sh_optarg); break;
+		case 's': flags |= OPT_SIZE; break;
+		case 'u': flags |= OPT_UID; break;
+		case 'U': flags |= OPT_UID|OPT_ASCII; break;
+		default: builtin_usage (); return(1);
+		}
+	}
+
+	argc -= sh_optind;
+	argv += sh_optind;
+
+	if (argc == 0) {
+		builtin_usage();
+		return(1);
+	}
+
+	for (i = 0; i < argc; i++)
+		opt = flags ? printsome (argv[i], flags) : printfinfo(argv[i]);
+
+	return(opt);
+}
+
+static struct stat *
+getstat(f)
+char	*f;
+{
+	static struct stat st;
+	int	fd, r;
+	intmax_t lfd;
+
+	if (strncmp(f, "/dev/fd/", 8) == 0) {
+		if ((legal_number(f + 8, &lfd) == 0) || (int)lfd != lfd) {
+			builtin_error("%s: invalid fd", f + 8);
+			return ((struct stat *)0);
+		}
+		fd = lfd;
+		r = fstat(fd, &st);
+	} else
+#ifdef HAVE_LSTAT
+		r = lstat(f, &st);
+#else
+		r = stat(f, &st);
+#endif
+	if (r < 0) {
+		builtin_error("%s: cannot stat: %s", f, strerror(errno));
+		return ((struct stat *)0);
+	}
+	return (&st);
+}
+
+static int
+printfinfo(f)
+char	*f;
+{
+	struct stat *st;
+
+	st = getstat(f);
+	return (st ? printst(st) : 1);
+}
+
+static int
+getperm(m)
+int	m;
+{
+	return (m & (S_IRWXU|S_IRWXG|S_IRWXO|S_ISUID|S_ISGID));
+}
+
+static void
+perms(m)
+int	m;
+{
+	char ubits[4], gbits[4], obits[4];	/* u=rwx,g=rwx,o=rwx */
+	int i;
+
+	i = 0;
+	if (m & S_IRUSR)
+		ubits[i++] = 'r';
+	if (m & S_IWUSR)
+		ubits[i++] = 'w';
+	if (m & S_IXUSR)
+		ubits[i++] = 'x';
+	ubits[i] = '\0';
+
+	i = 0;
+	if (m & S_IRGRP)
+		gbits[i++] = 'r';
+	if (m & S_IWGRP)
+		gbits[i++] = 'w';
+	if (m & S_IXGRP)
+		gbits[i++] = 'x';
+	gbits[i] = '\0';
+
+	i = 0;
+	if (m & S_IROTH)
+		obits[i++] = 'r';
+	if (m & S_IWOTH)
+		obits[i++] = 'w';
+	if (m & S_IXOTH)
+		obits[i++] = 'x';
+	obits[i] = '\0';
+
+	if (m & S_ISUID)
+		ubits[2] = (m & S_IXUSR) ? 's' : 'S';
+	if (m & S_ISGID)
+		gbits[2] = (m & S_IXGRP) ? 's' : 'S';
+	if (m & S_ISVTX)
+		obits[2] = (m & S_IXOTH) ? 't' : 'T';
+
+	printf ("u=%s,g=%s,o=%s", ubits, gbits, obits);
+}
+
+static void
+printmode(mode)
+int	mode;
+{
+	if (S_ISBLK(mode))
+		printf("S_IFBLK ");
+	if (S_ISCHR(mode))
+		printf("S_IFCHR ");
+	if (S_ISDIR(mode))
+		printf("S_IFDIR ");
+	if (S_ISREG(mode))
+		printf("S_IFREG ");
+	if (S_ISFIFO(mode))
+		printf("S_IFIFO ");
+	if (S_ISLNK(mode))
+		printf("S_IFLNK ");
+	if (S_ISSOCK(mode))
+		printf("S_IFSOCK ");
+#ifdef S_ISWHT
+	if (S_ISWHT(mode))
+		printf("S_ISWHT ");
+#endif
+	perms(getperm(mode));
+	printf("\n");
+}
+
+static int
+printst(st)
+struct stat *st;
+{
+	struct passwd	*pw;
+	struct group	*gr;
+	char	*owner;
+	int	ma, mi, d;
+
+	ma = major (st->st_rdev);
+	mi = minor (st->st_rdev);
+#if defined (makedev)
+	d = makedev (ma, mi);
+#else
+	d = st->st_rdev & 0xFF;
+#endif
+	printf("Device (major/minor): %d (%d/%d)\n", d, ma, mi);
+
+	printf("Inode: %d\n", (int) st->st_ino);
+	printf("Mode: (%o) ", (int) st->st_mode);
+	printmode((int) st->st_mode);
+	printf("Link count: %d\n", (int) st->st_nlink);
+	pw = getpwuid(st->st_uid);
+	owner = pw ? pw->pw_name : "unknown";
+	printf("Uid of owner: %d (%s)\n", (int) st->st_uid, owner);
+	gr = getgrgid(st->st_gid);
+	owner = gr ? gr->gr_name : "unknown";
+	printf("Gid of owner: %d (%s)\n", (int) st->st_gid, owner);
+	printf("Device type: %d\n", (int) st->st_rdev);
+	printf("File size: %ld\n", (long) st->st_size);
+	printf("File last access time: %s", ctime (&st->st_atime));
+	printf("File last modify time: %s", ctime (&st->st_mtime));
+	printf("File last status change time: %s", ctime (&st->st_ctime));
+	fflush(stdout);
+	return(0);
+}
+
+static int
+printsome(f, flags)
+char	*f;
+int	flags;
+{
+	struct stat *st;
+	struct passwd *pw;
+	struct group *gr;
+	int	p;
+	char	*b;
+
+	st = getstat(f);
+	if (st == NULL)
+		return (1);
+
+	/* Print requested info */
+	if (flags & OPT_ATIME) {
+		if (flags & OPT_ASCII)
+			printf("%s", ctime(&st->st_atime));
+		else
+			printf("%ld\n", st->st_atime);
+	} else if (flags & OPT_MTIME) {
+		if (flags & OPT_ASCII)
+			printf("%s", ctime(&st->st_mtime));
+		else
+			printf("%ld\n", st->st_mtime);
+	} else if (flags & OPT_CTIME) {
+		if (flags & OPT_ASCII)
+			printf("%s", ctime(&st->st_ctime));
+		else
+			printf("%ld\n", st->st_ctime);
+	} else if (flags & OPT_DEV)
+		printf("%lu\n", (unsigned long)st->st_dev);
+	else if (flags & OPT_INO)
+		printf("%lu\n", (unsigned long)st->st_ino);
+	else if (flags & OPT_FID)
+		printf("%lu:%lu\n", (unsigned long)st->st_dev, (unsigned long)st->st_ino);
+	else if (flags & OPT_NLINK)
+		printf("%lu\n", (unsigned long)st->st_nlink);
+	else if (flags & OPT_LNKNAM) {
+#ifdef S_ISLNK
+		b = xmalloc(4096);
+		p = readlink(f, b, 4096);
+		if (p >= 0 && p < 4096)
+			b[p] = '\0';
+		else {
+			p = errno;
+			strcpy(b, prog);
+			strcat(b, ": ");
+			strcat(b, strerror(p));
+		}
+		printf("%s\n", b);
+		free(b);
+#else
+		printf("%s\n", f);
+#endif
+	} else if (flags & OPT_PERM) {
+		perms(st->st_mode);
+		printf("\n");
+	} else if (flags & OPT_OPERM)
+		printf("%o\n", getperm(st->st_mode));
+	else if (flags & OPT_PMASK)
+		printf("%o\n", getperm(st->st_mode) & pmask);
+	else if (flags & OPT_UID) {
+		pw = getpwuid(st->st_uid);
+		if (flags & OPT_ASCII)
+			printf("%s\n", pw ? pw->pw_name : "unknown");
+		else
+			printf("%d\n", st->st_uid);
+	} else if (flags & OPT_GID) {
+		gr = getgrgid(st->st_gid);
+		if (flags & OPT_ASCII)
+			printf("%s\n", gr ? gr->gr_name : "unknown");
+		else
+			printf("%d\n", st->st_gid);
+	} else if (flags & OPT_SIZE)
+		printf("%ld\n", (long) st->st_size);
+
+	return (0);
+}
+
+#ifndef NOBUILTIN
+int
+finfo_builtin(list)
+     WORD_LIST *list;
+{
+  int c, r;
+  char **v;
+  WORD_LIST *l;
+
+  v = make_builtin_argv (list, &c);
+  r = finfo_main (c, v);
+  free (v);
+
+  return r;
+}
+
+static char *finfo_doc[] = {
+  "Display information about file attributes.",
+  "",
+  "Display information about each FILE.  Only single operators should",
+  "be supplied.  If no options are supplied, a summary of the info",
+  "available about each FILE is printed.  If FILE is of the form",
+  "/dev/fd/XX, file descriptor XX is described.  Operators, if supplied,",
+  "have the following meanings:",
+  "",
+  "	-a	last file access time",
+  "	-A	last file access time in ctime format",
+  "	-c	last file status change time",
+  "	-C	last file status change time in ctime format",
+  "	-m	last file modification time",
+  "	-M	last file modification time in ctime format",
+  "	-d	device",
+  "	-i	inode",
+  "	-f	composite file identifier (device:inode)",
+  "	-g	gid of owner",
+  "	-G	group name of owner",
+  "	-l	name of file pointed to by symlink",
+  "	-n	link count",
+  "	-o	permissions in octal",
+  "	-p	permissions in ascii",
+  "	-P mask permissions ANDed with MASK (like with umask)",
+  "	-s	file size in bytes",
+  "	-u	uid of owner",
+  "	-U	user name of owner",
+  (char *)0
+};
+
+struct builtin finfo_struct = {
+	"finfo",
+	finfo_builtin,
+	BUILTIN_ENABLED,
+	finfo_doc,
+	"finfo [-acdgiflmnopsuACGMPU] file [file...]",
+	0
+};
+#endif
+
+#ifdef NOBUILTIN
+#if defined (PREFER_STDARG)
+#  include <stdarg.h>
+#else
+#  if defined (PREFER_VARARGS)
+#    include <varargs.h>
+#  endif
+#endif
+
+char *this_command_name;
+
+main(argc, argv)
+int	argc;
+char	**argv;
+{
+	this_command_name = argv[0];
+	exit(finfo_main(argc, argv));
+}
+
+void
+builtin_usage()
+{
+	fprintf(stderr, "%s: usage: %s [-%s] [file ...]\n", prog, prog, OPTIONS);
+}
+
+#ifndef HAVE_STRERROR
+char *
+strerror(e)
+int	e;
+{
+	static char	ebuf[40];
+	extern int	sys_nerr;
+	extern char	*sys_errlist[];
+
+	if (e < 0 || e > sys_nerr) {
+		sprintf(ebuf,"Unknown error code %d", e);
+		return (&ebuf[0]);
+	}
+	return (sys_errlist[e]);
+}
+#endif
+
+char *
+xmalloc(s)
+size_t	s;
+{
+	char	*ret;
+	extern char *malloc();
+
+	ret = malloc(s);
+	if (ret)
+		return (ret);
+	fprintf(stderr, "%s: cannot malloc %d bytes\n", prog, s);
+	exit(1);
+}
+
+char *
+base_pathname(p)
+char	*p;
+{
+	char	*t;
+
+	if (t = strrchr(p, '/'))
+		return(++t);
+	return(p);
+}
+
+int
+legal_number (string, result)
+     char *string;
+     long *result;
+{
+  int sign;
+  long value;
+
+  sign = 1;
+  value = 0;
+
+  if (result)
+    *result = 0;
+
+  /* Skip leading whitespace characters. */
+  while (whitespace (*string))
+    string++;
+
+  if (!*string)
+    return (0);
+
+  /* We allow leading `-' or `+'. */
+  if (*string == '-' || *string == '+')
+    {
+      if (!digit (string[1]))
+        return (0);
+
+      if (*string == '-')
+        sign = -1;
+
+      string++;
+    }
+
+  while (digit (*string))
+    {
+      if (result)
+        value = (value * 10) + digit_value (*string);
+      string++;
+    }
+
+  /* Skip trailing whitespace, if any. */
+  while (whitespace (*string))
+    string++;
+
+  /* Error if not at end of string. */
+  if (*string)
+    return (0);
+
+  if (result)
+    *result = value * sign;
+
+  return (1);
+}
+
+int sh_optind;
+char *sh_optarg;
+int sh_opterr;
+
+extern int optind;
+extern char *optarg;
+
+int
+sh_getopt(c, v, o)
+int	c;
+char	**v, *o;
+{
+	int	r;
+
+	r = getopt(c, v, o);
+	sh_optind = optind;
+	sh_optarg = optarg;
+	return r;
+}
+
+#if defined (USE_VARARGS)
+void
+#if defined (PREFER_STDARG)
+builtin_error (const char *format, ...)
+#else
+builtin_error (format, va_alist)
+     const char *format;
+     va_dcl
+#endif
+{
+  va_list args;
+
+  if (this_command_name && *this_command_name)
+    fprintf (stderr, "%s: ", this_command_name);
+
+#if defined (PREFER_STDARG)
+  va_start (args, format);
+#else
+  va_start (args);
+#endif
+
+  vfprintf (stderr, format, args);
+  va_end (args);
+  fprintf (stderr, "\n");
+}
+#else
+void
+builtin_error (format, arg1, arg2, arg3, arg4, arg5)
+     char *format, *arg1, *arg2, *arg3, *arg4, *arg5;
+{
+  if (this_command_name && *this_command_name)
+    fprintf (stderr, "%s: ", this_command_name);
+
+  fprintf (stderr, format, arg1, arg2, arg3, arg4, arg5);
+  fprintf (stderr, "\n");
+  fflush (stderr);
+}
+#endif /* !USE_VARARGS */
+
+#endif
diff --git a/examples/loadables/head.c b/examples/loadables/head.c
new file mode 100644
index 0000000..1edca6c
--- /dev/null
+++ b/examples/loadables/head.c
@@ -0,0 +1,167 @@
+/* head - copy first part of files. */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include "bashtypes.h"
+#include "posixstat.h"
+#include "filecntl.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "bashansi.h"
+
+#include <stdio.h>
+#include <errno.h>
+#include "chartypes.h"
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+static void
+munge_list (list)
+     WORD_LIST *list;
+{
+  WORD_LIST *l, *nl;
+  WORD_DESC *wd;
+  char *arg;
+
+  for (l = list; l; l = l->next)
+    {
+      arg = l->word->word;
+      if (arg[0] != '-' || arg[1] == '-' || (DIGIT(arg[1]) == 0))
+        return;
+      /* We have -[0-9]* */
+      wd = make_bare_word (arg+1);
+      nl = make_word_list (wd, l->next);
+      l->word->word[1] = 'n';
+      l->word->word[2] = '\0';
+      l->next = nl;
+      l = nl;	/* skip over new argument */
+    }
+}
+
+static int
+file_head (fp, cnt)
+     FILE *fp;
+     int cnt;
+{
+  int ch;
+
+  while (cnt--)
+    {
+      while ((ch = getc (fp)) != EOF)
+	{
+	  if (putchar (ch) == EOF)
+	    {
+	      builtin_error ("write error: %s", strerror (errno));
+	      return EXECUTION_FAILURE;
+	    }
+	  if (ch == '\n')
+	    break;
+	}
+    }
+  return (EXECUTION_SUCCESS);
+}
+
+int
+head_builtin (list)
+     WORD_LIST *list;
+{
+  int nline, opt, rval;
+  WORD_LIST *l;
+  FILE *fp;
+
+  char *t;
+
+  munge_list (list);	/* change -num into -n num */
+
+  reset_internal_getopt ();
+  nline = 10;
+  while ((opt = internal_getopt (list, "n:")) != -1)
+    {
+      switch (opt)
+	{
+	case 'n':
+	  nline = atoi (list_optarg);
+	  if (nline <= 0)
+	    {
+	      builtin_error ("bad line count: %s", list_optarg);
+	      return (EX_USAGE);
+	    }
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (list == 0)
+    return (file_head (stdin, nline));
+
+  for (rval = EXECUTION_SUCCESS, opt = 1, l = list; l; l = l->next)
+    {
+      fp = fopen (l->word->word, "r");
+      if (fp == NULL)
+	{
+	  builtin_error ("%s: %s", l->word->word, strerror (errno));
+	  continue;
+	}
+      if (list->next)	/* more than one file */
+	{
+	  printf ("%s==> %s <==\n", opt ? "" : "\n", l->word->word);
+	  opt = 0;
+	}
+      rval = file_head (fp, nline);
+      fclose (fp);
+    }
+   
+  return (rval);
+}
+
+char *head_doc[] = {
+	"Display lines from beginning of file.",
+	"",
+	"Copy the first N lines from the input files to the standard output.",
+	"N is supplied as an argument to the `-n' option.  If N is not given,",
+	"the first ten lines are copied.",
+	(char *)NULL
+};
+
+struct builtin head_struct = {
+	"head",			/* builtin name */
+	head_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	head_doc,		/* array of long documentation strings. */
+	"head [-n num] [file ...]", /* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/hello.c b/examples/loadables/hello.c
new file mode 100644
index 0000000..b09362b
--- /dev/null
+++ b/examples/loadables/hello.c
@@ -0,0 +1,96 @@
+/* Sample builtin to be dynamically loaded with enable -f and create a new
+   builtin. */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+
+#include "loadables.h"
+
+/* A builtin `xxx' is normally implemented with an `xxx_builtin' function.
+   If you're converting a command that uses the normal Unix argc/argv
+   calling convention, use argv = make_builtin_argv (list, &argc) and call
+   the original `main' something like `xxx_main'.  Look at cat.c for an
+   example.
+
+   Builtins should use internal_getopt to parse options.  It is the same as
+   getopt(3), but it takes a WORD_LIST *.  Look at print.c for an example
+   of its use.
+
+   If the builtin takes no options, call no_options(list) before doing
+   anything else.  If it returns a non-zero value, your builtin should
+   immediately return EX_USAGE.  Look at logname.c for an example.
+
+   A builtin command returns EXECUTION_SUCCESS for success and
+   EXECUTION_FAILURE to indicate failure. */
+int
+hello_builtin (list)
+     WORD_LIST *list;
+{
+  printf("hello world\n");
+  fflush (stdout);
+  return (EXECUTION_SUCCESS);
+}
+
+int
+hello_builtin_load (s)
+     char *s;
+{
+  printf ("hello builtin loaded\n");
+  fflush (stdout);
+  return (1);
+}
+
+void
+hello_builtin_unload (s)
+     char *s;
+{
+  printf ("hello builtin unloaded\n");
+  fflush (stdout);
+}
+
+/* An array of strings forming the `long' documentation for a builtin xxx,
+   which is printed by `help xxx'.  It must end with a NULL.  By convention,
+   the first line is a short description. */
+char *hello_doc[] = {
+	"Sample builtin.",
+	"",
+	"this is the long doc for the sample hello builtin",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures.  The flags must include BUILTIN_ENABLED so the
+   builtin can be used. */
+struct builtin hello_struct = {
+	"hello",		/* builtin name */
+	hello_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	hello_doc,		/* array of long documentation strings. */
+	"hello",		/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/id.c b/examples/loadables/id.c
new file mode 100644
index 0000000..f857b54
--- /dev/null
+++ b/examples/loadables/id.c
@@ -0,0 +1,329 @@
+/*
+ * id - POSIX.2 user identity
+ *
+ * (INCOMPLETE -- supplementary groups for other users not yet done)
+ *
+ * usage: id [-Ggu] [-nr] [user]
+ *
+ * The default output format looks something like:
+ *	uid=xxx(chet) gid=xx groups=aa(aname), bb(bname), cc(cname)
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <stdio.h>
+#include "bashtypes.h"
+#include <pwd.h>
+#include <grp.h>
+#include "bashansi.h"
+
+#ifdef HAVE_LIMITS_H
+#  include <limits.h>
+#else
+#  include <sys/param.h>
+#endif
+
+#if !defined (HAVE_GETPW_DECLS)
+extern struct passwd *getpwuid ();
+#endif
+extern struct group *getgrgid ();
+
+#include "shell.h"
+#include "builtins.h"
+#include "stdc.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+#define ID_ALLGROUPS	0x001		/* -G */
+#define ID_GIDONLY	0x002		/* -g */
+#define ID_USENAME	0x004		/* -n */
+#define ID_USEREAL	0x008		/* -r */
+#define ID_USERONLY	0x010		/* -u */
+
+#define ID_FLAGSET(s)	((id_flags & (s)) != 0)
+
+static int id_flags;
+
+static uid_t ruid, euid;
+static gid_t rgid, egid;
+
+static char *id_user;
+
+static int inituser ();
+
+static int id_pruser ();
+static int id_prgrp ();
+static int id_prgroups ();
+static int id_prall ();
+
+int
+id_builtin (list)
+     WORD_LIST *list;
+{
+  int opt;
+  char *user;
+
+  id_flags = 0;
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "Ggnru")) != -1)
+    {
+      switch (opt)
+	{
+	case 'G': id_flags |= ID_ALLGROUPS; break;
+	case 'g': id_flags |= ID_GIDONLY; break;
+	case 'n': id_flags |= ID_USENAME; break;
+	case 'r': id_flags |= ID_USEREAL; break;
+	case 'u': id_flags |= ID_USERONLY; break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  user = list ? list->word->word : (char *)NULL;
+
+  /* Check for some invalid option combinations */
+  opt = ID_FLAGSET (ID_ALLGROUPS) + ID_FLAGSET (ID_GIDONLY) + ID_FLAGSET (ID_USERONLY);
+  if (opt > 1 || (opt == 0 && ((id_flags & (ID_USEREAL|ID_USENAME)) != 0)))
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (list && list->next)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (inituser (user) < 0)
+    return (EXECUTION_FAILURE);
+
+  opt = 0;
+  if (id_flags & ID_USERONLY)
+    opt += id_pruser ((id_flags & ID_USEREAL) ? ruid : euid);
+  else if (id_flags & ID_GIDONLY)
+    opt += id_prgrp ((id_flags & ID_USEREAL) ? rgid : egid);
+  else if (id_flags & ID_ALLGROUPS)
+    opt += id_prgroups (user);
+  else
+    opt += id_prall (user);
+  putchar ('\n');
+  fflush (stdout);
+
+  return (opt == 0 ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
+}
+
+static int
+inituser (uname)
+     char *uname;
+{
+  struct passwd *pwd;
+
+  if (uname)
+    {
+      pwd = getpwnam (uname);
+      if (pwd == 0)
+	{
+	  builtin_error ("%s: no such user", uname);
+	  return -1;
+	}
+      ruid = euid = pwd->pw_uid;
+      rgid = egid = pwd->pw_gid;
+    }
+  else
+    {
+      ruid = current_user.uid;
+      euid = current_user.euid;
+      rgid = current_user.gid;
+      egid = current_user.egid;
+    }
+  return 0;
+}
+
+/* Print the name or value of user ID UID. */
+static int
+id_pruser (uid)
+     int uid;
+{
+  struct passwd *pwd = NULL;
+  int r;
+
+  r = 0;
+  if (id_flags & ID_USENAME)
+    {
+      pwd = getpwuid (uid);
+      if (pwd == NULL)
+        r = 1;
+    }
+  if (pwd)
+    printf ("%s", pwd->pw_name);
+  else
+    printf ("%u", (unsigned) uid);
+      
+  return r;
+}
+
+/* Print the name or value of group ID GID. */
+
+static int
+id_prgrp (gid)
+     int gid;
+{
+  struct group *grp = NULL;
+  int r;
+
+  r = 0;
+  if (id_flags & ID_USENAME)
+    {
+      grp = getgrgid (gid);
+      if (grp == NULL)
+	r = 1;
+    }
+
+  if (grp)
+    printf ("%s", grp->gr_name);
+  else
+    printf ("%u", (unsigned) gid);
+
+  return r;
+}
+
+static int
+id_prgroups (uname)
+     char *uname;
+{
+  int *glist, ng, i, r;
+
+  r = 0;
+  id_prgrp (rgid);
+  if (egid != rgid)
+    {
+      putchar (' ');
+      id_prgrp (egid);
+    }
+
+  if (uname)
+    {
+      builtin_error ("supplementary groups for other users not yet implemented");
+      glist = (int *)NULL;
+      ng = 0;
+      r = 1;
+    }
+  else
+    glist = get_group_array (&ng);
+
+  for (i = 0; i < ng; i++)
+    if (glist[i] != rgid && glist[i] != egid)
+      {
+	putchar (' ');
+	id_prgrp (glist[i]);
+      }
+  
+  return r;
+}
+
+static int
+id_prall (uname)
+     char *uname;
+{
+  int r, i, ng, *glist;
+  struct passwd *pwd;
+  struct group *grp;
+
+  r = 0;
+  printf ("uid=%u", (unsigned) ruid);
+  pwd = getpwuid (ruid);
+  if (pwd == NULL)
+    r = 1;
+  else
+    printf ("(%s)", pwd->pw_name);
+
+  printf (" gid=%u", (unsigned) rgid);
+  grp = getgrgid (rgid);
+  if (grp == NULL)
+    r = 1;
+  else
+    printf ("(%s)", grp->gr_name);
+
+  if (euid != ruid)
+    { 
+      printf (" euid=%u", (unsigned) euid);
+      pwd = getpwuid (euid);
+      if (pwd == NULL)
+	r = 1;
+      else 
+	printf ("(%s)", pwd->pw_name);
+    }
+
+  if (egid != rgid) 
+    {
+      printf (" egid=%u", (unsigned) egid);
+      grp = getgrgid (egid);
+      if (grp == NULL)
+	r = 1;
+      else
+	printf ("(%s)", grp->gr_name);
+    }
+
+  if (uname)
+    {
+      builtin_error ("supplementary groups for other users not yet implemented");
+      glist = (int *)NULL;
+      ng = 0;
+      r = 1;
+    }
+  else
+    glist = get_group_array (&ng);
+
+  if (ng > 0)
+    printf (" groups=");
+  for (i = 0; i < ng; i++)
+    {
+      if (i > 0)
+	printf (", ");
+      printf ("%u", (unsigned) glist[i]);
+      grp = getgrgid (glist[i]);
+      if (grp == NULL)
+	r = 1;
+      else
+	printf ("(%s)", grp->gr_name);
+    }
+
+  return r;
+}
+
+char *id_doc[] = {
+	"Display information about user."
+	"",
+	"Return information about user identity",
+	(char *)NULL
+};
+
+struct builtin id_struct = {
+	"id",
+	id_builtin,
+	BUILTIN_ENABLED,
+	id_doc,
+	"id [user]\n\tid -G [-n] [user]\n\tid -g [-nr] [user]\n\tid -u [-nr] [user]",
+	0
+};
diff --git a/examples/loadables/ln.c b/examples/loadables/ln.c
new file mode 100644
index 0000000..874e9db
--- /dev/null
+++ b/examples/loadables/ln.c
@@ -0,0 +1,236 @@
+/* ln - make links */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include "bashtypes.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "posixstat.h"
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+typedef int unix_link_syscall_t PARAMS((const char *, const char *));
+
+#define LN_SYMLINK 0x01
+#define LN_UNLINK  0x02
+#define LN_NOFOLLOW 0x04
+
+static unix_link_syscall_t *linkfn;
+static int dolink ();
+
+int
+ln_builtin (list)
+     WORD_LIST *list;
+{
+  int rval, opt, flags;
+  WORD_LIST *l;
+  char *sdir;
+  struct stat sb;
+
+  flags = 0;
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "fs")) != -1)
+    {
+      switch (opt)
+	{
+	case 'f':
+	  flags |= LN_UNLINK;
+	  break;
+	case 's':
+	  flags |= LN_SYMLINK;
+	  break;
+	case 'h':
+	case 'n':
+	  flags |= LN_NOFOLLOW;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+    
+  linkfn = (flags & LN_SYMLINK) ? symlink : link;  
+
+  if (list->next == 0)			/* ln target, equivalent to ln target . */
+    return (dolink (list->word->word, ".", flags));
+
+  if (list->next->next == 0)		/* ln target source */
+    return (dolink (list->word->word, list->next->word->word, flags));
+
+  /* ln target1 target2 ... directory */
+
+  /* find last argument: target directory, and make sure it's an existing
+     directory. */
+  for (l = list; l->next; l = l->next)  
+    ;
+  sdir = l->word->word;
+
+  if (stat(sdir, &sb) < 0)
+    {
+      builtin_error ("%s", sdir);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (S_ISDIR (sb.st_mode) == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  for (rval = EXECUTION_SUCCESS; list != l; list = list->next)
+    rval += dolink (list->word->word, sdir, flags);
+  
+  return rval;
+}
+
+static char *
+mkdirpath (dir, file)
+     char *dir, *file;
+{
+  int dlen, flen;
+  char *ret;
+
+  dlen = strlen (dir);
+  flen = strlen (file);
+
+  ret = xmalloc (2 + dlen + flen);
+
+  strcpy (ret, dir);
+  if (ret[dlen - 1] != '/')
+    ret[dlen++] = '/';
+  strcpy (ret + dlen, file);
+  return ret;
+}
+
+#if defined (HAVE_LSTAT)
+#  define LSTAT lstat
+#  define LSTAT_OR_STAT_IF(c, f, b)	((c) ? lstat((f), (b)) : stat((f), (b)))
+#else
+#  define LSTAT stat
+#  define LSTAT_OR_STAT_IF(c, f, b)	(stat((f), (b)))
+#endif
+
+static int
+dolink (src, dst, flags)
+     char *src, *dst;
+     int flags;
+{
+  struct stat ssb, dsb;
+  int exists;
+  char *dst_path, *p;
+
+  /* If we're not doing symlinks, the source must exist and not be a 
+     directory. */
+  if ((flags & LN_SYMLINK) == 0)
+    {
+      if (stat (src, &ssb) != 0)
+	{
+	  builtin_error ("%s: %s", src, strerror (errno));
+	  return (EXECUTION_FAILURE);
+	}
+      if (S_ISDIR (ssb.st_mode))
+	{
+	  errno = EISDIR;
+	  builtin_error ("%s: %s", src, strerror (errno));
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  /* If the destination is a directory, create the final filename by appending
+     the basename of the source to the destination. */
+  dst_path = 0;
+  if ((LSTAT_OR_STAT_IF((flags & LN_NOFOLLOW), dst, &dsb) == 0) && S_ISDIR (dsb.st_mode))
+    {
+      if ((p = strrchr (src, '/')) == 0)
+	p = src;
+      else
+	p++;
+
+      dst_path = mkdirpath (dst, p);
+      dst = dst_path;
+    }
+
+  exists = LSTAT (dst, &dsb) == 0;
+
+  /* If -f was specified, and the destination exists, unlink it. */
+  if ((flags & LN_UNLINK) && exists && unlink (dst) != 0)
+    {
+      builtin_error ("%s: cannot unlink: %s", dst, strerror (errno));
+      FREE (dst_path);
+      return (EXECUTION_FAILURE);
+    }
+
+  /* Perform the link. */
+  if ((*linkfn) (src, dst) != 0)
+    {
+      builtin_error ("cannot link %s to %s: %s", dst, src, strerror (errno));
+      FREE (dst_path);
+      return (EXECUTION_FAILURE);
+    }
+
+  FREE (dst_path);
+  return (EXECUTION_SUCCESS);
+}
+
+char *ln_doc[] = {
+	"Link files.",
+	"",
+	"Create a new directory entry with the same modes as the original",
+	"file.  The -f option means to unlink any existing file, permitting",
+	"the link to occur.  The -s option means to create a symbolic link.",
+	"By default, ln makes hard links.  Specifying -n or its synonym -h",
+	"causes ln to not resolve symlinks in the target file or directory.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin ln_struct = {
+	"ln",		/* builtin name */
+	ln_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	ln_doc,		/* array of long documentation strings. */
+	"ln [-fhns] file1 [file2] OR ln [-fhns] file ... directory",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/loadables.h b/examples/loadables/loadables.h
new file mode 100644
index 0000000..c730357
--- /dev/null
+++ b/examples/loadables/loadables.h
@@ -0,0 +1,34 @@
+/* loadables.h -- Include files needed by all loadable builtins */
+
+/* Copyright (C) 2015 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#ifndef __LOADABLES_H_
+#define __LOADABLES_H_
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#endif
diff --git a/examples/loadables/logname.c b/examples/loadables/logname.c
new file mode 100644
index 0000000..27e6591
--- /dev/null
+++ b/examples/loadables/logname.c
@@ -0,0 +1,74 @@
+/* logname - print login name of current user */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+int
+logname_builtin (list)
+     WORD_LIST *list;
+{
+  char *np;
+
+  if (no_options (list))
+    return (EX_USAGE);
+
+  np = getlogin ();
+  if (np == 0)
+    {
+      builtin_error ("cannot find username: %s", strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+  printf ("%s\n", np);
+  return (EXECUTION_SUCCESS);
+}
+
+char *logname_doc[] = {
+	"Display user login name.",
+	"",
+	"Write the current user's login name to the standard output",
+	"and exit.  logname ignores the LOGNAME and USER variables.",
+	"logname ignores any non-option arguments.",
+	(char *)NULL
+};
+	
+struct builtin logname_struct = {
+	"logname",
+	logname_builtin,
+	BUILTIN_ENABLED,
+	logname_doc,
+	"logname",
+	0
+};
+	
diff --git a/examples/loadables/mkdir.c b/examples/loadables/mkdir.c
new file mode 100644
index 0000000..d5d3955
--- /dev/null
+++ b/examples/loadables/mkdir.c
@@ -0,0 +1,245 @@
+/* mkdir - make directories */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#include "bashtypes.h"
+#include "posixstat.h"
+#include <errno.h>
+#include <stdio.h>
+#include "bashansi.h"
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#define ISOCTAL(c)	((c) >= '0' && (c) <= '7')
+
+extern int parse_symbolic_mode ();
+
+static int make_path ();
+
+static int original_umask;
+
+int
+mkdir_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, pflag, mflag, omode, rval, nmode, parent_mode;
+  char *mode;
+  WORD_LIST *l;
+
+  reset_internal_getopt ();
+  pflag = mflag = 0;
+  mode = (char *)NULL;
+  while ((opt = internal_getopt(list, "m:p")) != -1)
+    switch (opt)
+      {
+	case 'p':
+	  pflag = 1;
+	  break;
+	case 'm':
+	  mflag = 1;
+	  mode = list_optarg;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage();
+	  return (EX_USAGE);
+      }
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (mode == NULL)
+    omode = S_IRWXU | S_IRWXG | S_IRWXO;	/* a=rwx */
+  else if (ISOCTAL (*mode))	/* octal number */
+    {
+      omode = read_octal (mode);
+      if (omode < 0)
+	{
+	  builtin_error ("invalid file mode: %s", mode);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+  else 				/* symbolic mode */
+    {
+      /* initial bits are a=rwx; the mode argument modifies them */
+      omode = parse_symbolic_mode (mode, S_IRWXU | S_IRWXG | S_IRWXO);
+      if (omode < 0)
+	{
+	  builtin_error ("invalid file mode: %s", mode);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  /* Make the new mode */
+  original_umask = umask (0);
+  umask (original_umask);
+
+  nmode = (S_IRWXU | S_IRWXG | S_IRWXO) & ~original_umask;
+  parent_mode = nmode | (S_IWUSR|S_IXUSR);	/* u+wx */
+
+  /* Adjust new mode based on mode argument */
+  nmode &= omode;
+
+  for (rval = EXECUTION_SUCCESS, l = list; l; l = l->next)
+    {
+      if (pflag && make_path (l->word->word, mflag, nmode, parent_mode))
+	{
+	  rval = EXECUTION_FAILURE;
+	  continue;
+	}
+      else if (pflag == 0 && mkdir (l->word->word, nmode) < 0)
+        {
+          builtin_error ("cannot create directory `%s': %s", l->word->word, strerror (errno));
+          rval = EXECUTION_FAILURE;
+        }
+    }
+  return rval;
+}
+
+/* Make all the directories leading up to PATH, then create PATH.  Note that
+   this changes the process's umask; make sure that all paths leading to a
+   return reset it to ORIGINAL_UMASK */
+static int
+make_path (path, user_mode, nmode, parent_mode)
+     char *path;
+     int user_mode;
+     int nmode, parent_mode;
+{
+  int oumask;
+  struct stat sb;
+  char *p, *npath;
+
+  if (stat (path, &sb) == 0)
+    {
+      if (S_ISDIR (sb.st_mode) == 0)
+	{
+	  builtin_error ("`%s': file exists but is not a directory", path);
+	  return 1;
+	}
+	
+      if (user_mode && chmod (path, nmode))
+        {
+          builtin_error ("%s: %s", path, strerror (errno));
+          return 1;
+        }
+
+      return 0;
+    }
+
+  oumask = umask (0);
+  npath = savestring (path);	/* So we can write to it. */
+    
+  /* Check whether or not we need to do anything with intermediate dirs. */
+
+  /* Skip leading slashes. */
+  p = npath;
+  while (*p == '/')
+    p++;
+
+  while (p = strchr (p, '/'))
+    {
+      *p = '\0';
+      if (stat (npath, &sb) != 0)
+	{
+	  if (mkdir (npath, 0))
+	    {
+	      builtin_error ("cannot create directory `%s': %s", npath, strerror (errno));
+	      umask (original_umask);
+	      free (npath);
+	      return 1;
+	    }
+	  if (chmod (npath, parent_mode) != 0)
+	    {
+	      builtin_error ("cannot chmod directory `%s': %s", npath, strerror (errno));
+	      umask (original_umask);
+	      free (npath);
+	      return 1;
+	    }
+	}
+      else if (S_ISDIR (sb.st_mode) == 0)
+        {
+          builtin_error ("`%s': file exists but is not a directory", npath);
+          umask (original_umask);
+          free (npath);
+          return 1;
+        }
+
+      *p++ = '/';	/* restore slash */
+      while (*p == '/')
+	p++;
+    }
+
+  /* Create the final directory component. */
+  if (stat (npath, &sb) && mkdir (npath, nmode))
+    {
+      builtin_error ("cannot create directory `%s': %s", npath, strerror (errno));
+      umask (original_umask);
+      free (npath);
+      return 1;
+    }
+
+  umask (original_umask);
+  free (npath);
+  return 0;
+}
+
+char *mkdir_doc[] = {
+	"Create directories.",
+	"",
+	"Make directories.  Create the directories named as arguments, in",
+	"the order specified, using mode rwxrwxrwx as modified by the current",
+	"umask (see `help umask').  The -m option causes the file permission",
+	"bits of the final directory to be MODE.  The MODE argument may be",
+	"an octal number or a symbolic mode like that used by chmod(1).  If",
+	"a symbolic mode is used, the operations are interpreted relative to",
+	"an initial mode of \"a=rwx\".  The -p option causes any required",
+	"intermediate directories in PATH to be created.  The directories",
+	"are created with permssion bits of rwxrwxrwx as modified by the current",
+	"umask, plus write and search permissions for the owner.  mkdir",
+	"returns 0 if the directories are created successfully, and non-zero",
+	"if an error occurs.",
+	(char *)NULL
+};
+
+struct builtin mkdir_struct = {
+	"mkdir",
+	mkdir_builtin,
+	BUILTIN_ENABLED,
+	mkdir_doc,
+	"mkdir [-p] [-m mode] directory [directory ...]",
+	0
+};
diff --git a/examples/loadables/mkfifo.c b/examples/loadables/mkfifo.c
new file mode 100644
index 0000000..2bc4e98
--- /dev/null
+++ b/examples/loadables/mkfifo.c
@@ -0,0 +1,146 @@
+/* mkfifo - make FIFOs */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#include "bashtypes.h"
+#include "posixstat.h"
+#include <errno.h>
+#include <stdio.h>
+#include "bashansi.h"
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#define ISOCTAL(c)	((c) >= '0' && (c) <= '7')
+
+extern int parse_symbolic_mode ();
+
+static int original_umask;
+
+int
+mkfifo_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, mflag, omode, rval, nmode, basemode;
+  char *mode;
+  WORD_LIST *l;
+
+  mflag = 0;
+  mode = (char *)NULL;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt(list, "m:")) != -1)
+    switch (opt)
+      {
+	case 'm':
+	  mflag = 1;
+	  mode = list_optarg;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage();
+	  return (EX_USAGE);
+      }
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  basemode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+  if (mode == NULL)
+    omode = basemode;
+  else if (ISOCTAL (*mode))	/* octal number */
+    {
+      omode = read_octal (mode);
+      if (omode < 0)
+	{
+	  builtin_error ("invalid file mode: %s", mode);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+  else 				/* symbolic mode */
+    {
+      /* initial bits are a=rwx; the mode argument modifies them */
+      omode = parse_symbolic_mode (mode, basemode);
+      if (omode < 0)
+	{
+	  builtin_error ("invalid file mode: %s", mode);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  /* Make the new mode */
+  original_umask = umask (0);
+  umask (original_umask);
+
+  nmode = basemode & ~original_umask;
+  /* Adjust new mode based on mode argument */
+  nmode &= omode;
+
+  for (rval = EXECUTION_SUCCESS, l = list; l; l = l->next)
+    {
+      if (mkfifo (l->word->word, nmode) < 0)
+        {
+          builtin_error ("cannot create FIFO `%s': %s", l->word->word, strerror (errno));
+          rval = EXECUTION_FAILURE;
+        }
+    }
+  return rval;
+}
+
+
+char *mkfifo_doc[] = {
+	"Create FIFOs (named pipes).",
+	"",
+	"Make FIFOs.  Create the FIFOs named as arguments, in",
+	"the order specified, using mode a=rw as modified by the current",
+	"umask (see `help umask').  The -m option causes the file permission",
+	"bits of the final FIFO to be MODE.  The MODE argument may be",
+	"an octal number or a symbolic mode like that used by chmod(1).  If",
+	"a symbolic mode is used, the operations are interpreted relative to",
+	"an initial mode of \"a=rw\".  mkfifo returns 0 if the FIFOs are",
+	"umask, plus write and search permissions for the owner.  mkdir",
+	"created successfully, and non-zero if an error occurs.",
+	(char *)NULL
+};
+
+struct builtin mkfifo_struct = {
+	"mkfifo",
+	mkfifo_builtin,
+	BUILTIN_ENABLED,
+	mkfifo_doc,
+	"mkfifo [-m mode] fifo_name [fifo_name ...]",
+	0
+};
diff --git a/examples/loadables/mktemp.c b/examples/loadables/mktemp.c
new file mode 100644
index 0000000..1f7c9ad
--- /dev/null
+++ b/examples/loadables/mktemp.c
@@ -0,0 +1,212 @@
+/* mktemp - create temporary file or directory */
+
+/*
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "bashansi.h"
+
+#include "loadables.h"
+
+#define DEFAULT_PREFIX	"shtmp"
+
+int
+mktemp_builtin (list)
+     WORD_LIST *list;
+{
+  WORD_LIST *l;
+  int rval, opt, fd, mflags, base_mflags;
+  int dflag, qflag, tflag, uflag, onetime;
+  char *prefix, *varname, *filename, *template;
+  SHELL_VAR *v;
+
+  dflag = qflag = uflag = tflag = onetime = 0;
+  prefix = varname = 0;
+  rval = EXECUTION_SUCCESS;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "dqut:v:")) != -1)
+    {
+      switch (opt)
+	{
+	case 'd':
+	  dflag = 1;
+	  break;
+	case 'q':
+	  qflag = 1;
+	  break;
+	case 't':
+	  tflag = 1;
+	  prefix = list_optarg;
+	  break;
+	case 'u':
+	  uflag = 1;
+	  break;
+	case 'v':
+	  varname = list_optarg;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (varname)			/* check for validity, not readonly */
+    {
+      if (legal_identifier (varname) == 0)
+	{
+	  if (qflag == 0)
+	    sh_invalidid (varname);
+	  return (EXECUTION_FAILURE);
+	}
+      v = find_variable (varname);
+      if (v && readonly_p (v))
+	{
+	  if (qflag == 0)
+	    sh_readonly (varname);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  onetime = (list == 0);	/* once through the loop, $TMPDIR/prefix.XXXXXX */
+
+  if (prefix == 0)
+    prefix = DEFAULT_PREFIX;
+  base_mflags = MT_USETMPDIR|MT_USERANDOM;	/* USERANDOM not strictly needed */
+
+  while (list || onetime)
+    {
+      mflags = base_mflags;
+      onetime = 0;
+#if defined (USE_MKTEMP) && defined (USE_MKSTEMP)
+      if (list)
+	{
+	  template = list->word->word;
+	  mflags |= MT_TEMPLATE;
+	}
+#else
+      /* This is sub-optimal. */
+      if (list)
+	{
+	  /* Treat the basename as a prefix */
+	  template = strrchr (list->word->word, '/');
+	  if (template)
+	    template++;
+	  else
+	    template = list->word->word;
+	}
+#endif
+      else
+	template = prefix;
+
+      if (dflag)
+	{
+	  filename = sh_mktmpdir (template, mflags);
+	  if (filename == 0)
+	    {
+	      if (qflag == 0)
+		builtin_error ("%s: cannot create directory", template);
+	      rval = EXECUTION_FAILURE;
+	    }
+	  else
+	    {
+	      if (uflag)
+		rmdir (filename);
+	      printf ("%s\n", filename);
+	    }
+	}
+      else		/* filename */
+	{
+	  fd = sh_mktmpfd (template, mflags, &filename);
+	  if (fd < 0)
+	    {
+	      if (qflag == 0)
+		builtin_error ("%s: cannot create file", template);
+	      rval = EXECUTION_FAILURE;
+	    }
+	  else
+	    {
+	      close (fd);
+	      if (uflag)
+		unlink (filename);
+	      printf ("%s\n", filename);
+	    }
+	}
+
+      /* Assign variable if requested */
+      if (filename && varname)
+	{
+	  v = builtin_bind_variable (varname, filename, 0);
+	  if (v == 0 || readonly_p (v) || noassign_p (v))
+	    {
+	      builtin_error ("%s: cannot set variable", varname);
+	      rval = EXECUTION_FAILURE;
+	    }
+	}
+
+      FREE (filename);
+
+      if (list)
+        list = list->next;
+    }
+
+  return (rval);
+}
+
+char *mktemp_doc[] = {
+	"Make unique temporary file name",
+	"",
+	"Take each supplied filename template and overwrite a portion of it",
+	"to create a filename, which is unique and may be used by the calling",
+	"script. TEMPLATE is a string ending in some number of 'X's. If",
+	"TEMPLATE is not supplied, shtmp.XXXXXX is used and $TMPDIR is used as",
+	"the name of the containing directory. Files are created u+rw; directories",
+	"are created u+rwx.",
+	"",
+	"Options, if supplied, have the following meanings:",
+	"",
+	"    -d    Create a directory instead of a file",
+	"    -q    Do not print error messages about file creation failure",
+	"    -t PREFIX Use PREFIX as the directory in which to create files",
+	"    -u    Do not create anything; simply print a name",
+	"    -v VAR    Store the generated name into shell variable VAR",
+	"",
+	"Any PREFIX supplied with -t is ignored if TEMPLATE is supplied.",
+	"",
+	"The return status is true if the file or directory was created successfully;",
+	"false if an error occurs or VAR is invalid or readonly.",
+
+	(char *)NULL
+};
+
+struct builtin mktemp_struct = {
+	"mktemp",		/* builtin name */
+	mktemp_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	mktemp_doc,		/* array of long documentation strings. */
+	"mktemp [-d] [-q] [-t prefix] [-u] [-v varname] [template] ...",
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/mypid.c b/examples/loadables/mypid.c
new file mode 100644
index 0000000..fc1b267
--- /dev/null
+++ b/examples/loadables/mypid.c
@@ -0,0 +1,89 @@
+/* This module should be dynamically loaded with enable -f
+ * which would create a new builtin named mypid. You'll need
+ * the source code for GNU bash to recompile this module.
+ *
+ * Then, from within bash, enable -f ./mypid enable_mypid, where ./mypid
+ * is the binary obtained from running make. Hereafter, `${MYPID}'
+ * is a shell builtin variable.
+ *
+ * This defines an unload hook function that is called when the builtin is
+ * deleted with enable -d that will unbind the MYPID variable so future
+ * references to it do not attempt to access memory that is no longer part
+ * of this process's address space.
+ */
+#include <config.h>
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#include "builtins.h"
+#include "shell.h"
+
+#define INIT_DYNAMIC_VAR(var, val, gfunc, afunc) \
+  do \
+    { SHELL_VAR *v = bind_variable (var, (val), 0); \
+      if (v) \
+	{ \
+	  v->dynamic_value = gfunc; \
+	  v->assign_func = afunc; \
+	} \
+    } \
+  while (0)
+
+static SHELL_VAR *
+assign_mypid (
+     SHELL_VAR *self,
+     char *value,
+     arrayind_t unused,
+     char *key )
+{
+  return (self);
+}
+
+static SHELL_VAR *
+get_mypid (SHELL_VAR *var)
+{
+  int rv;
+  char *p;
+
+  rv = getpid();
+  p = itos (rv);
+
+  FREE (value_cell (var));
+
+  VSETATTR (var, att_integer);
+  var_setvalue (var, p);
+  return (var);
+}
+
+int
+enable_mypid_builtin(WORD_LIST *list)
+{
+  INIT_DYNAMIC_VAR ("MYPID", (char *)NULL, get_mypid, assign_mypid);
+
+  return 0;
+}
+
+void
+enable_mypid_builtin_unload (char *s)
+{
+  unbind_variable ("MYPID");
+}
+
+char const *enable_mypid_doc[] = {
+  "Enable $MYPID.",
+  "",
+  "Enables use of the ${MYPID} dynamic variable.  ",
+  "It will yield the current pid of a subshell.",
+  (char *)0
+};
+
+struct builtin enable_mypid_struct = {
+  "enable_mypid",
+  enable_mypid_builtin,
+  BUILTIN_ENABLED,
+  (char**)(void*)enable_mypid_doc,
+  "enable_mypid N",
+  0
+};
diff --git a/examples/loadables/necho.c b/examples/loadables/necho.c
new file mode 100644
index 0000000..dd2092b
--- /dev/null
+++ b/examples/loadables/necho.c
@@ -0,0 +1,54 @@
+/* necho - echo without options or argument interpretation */
+
+/* Sample builtin to be dynamically loaded with enable -f and replace an
+   existing builtin. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdio.h>
+#include "builtins.h"
+#include "shell.h"
+
+int
+necho_builtin (list)
+WORD_LIST *list;
+{
+	print_word_list (list, " ");
+	printf("\n");
+	fflush (stdout);
+	return (EXECUTION_SUCCESS);
+}
+
+char *necho_doc[] = {
+	"Display arguments.",
+	"",
+	"Print the arguments to the standard output separated",
+	"by space characters and terminated with a newline.",
+	(char *)NULL
+};
+	
+struct builtin necho_struct = {
+	"echo",
+	necho_builtin,
+	BUILTIN_ENABLED,
+	necho_doc,
+	"echo [args]",
+	0
+};
+	
diff --git a/examples/loadables/pathchk.c b/examples/loadables/pathchk.c
new file mode 100644
index 0000000..c1151db
--- /dev/null
+++ b/examples/loadables/pathchk.c
@@ -0,0 +1,381 @@
+/* pathchk - check pathnames for validity and portability */
+
+/* Usage: pathchk [-p] path ...
+
+   For each PATH, print a message if any of these conditions are false:
+   * all existing leading directories in PATH have search (execute) permission
+   * strlen (PATH) <= PATH_MAX
+   * strlen (each_directory_in_PATH) <= NAME_MAX
+
+   Exit status:
+   0			All PATH names passed all of the tests.
+   1			An error occurred.
+
+   Options:
+   -p			Instead of performing length checks on the
+			underlying filesystem, test the length of the
+			pathname and its components against the POSIX.1
+			minimum limits for portability, _POSIX_NAME_MAX
+			and _POSIX_PATH_MAX in 2.9.2.  Also check that
+			the pathname contains no character not in the
+			portable filename character set. */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#include <sys/types.h>
+#include "posixstat.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#if defined (HAVE_LIMITS_H)
+#  include <limits.h>
+#endif
+
+#include "bashansi.h"
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "stdc.h"
+#include "bashgetopt.h"
+#include "maxpath.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#if !defined (_POSIX_PATH_MAX)
+#  define _POSIX_PATH_MAX 255
+#endif
+#if !defined (_POSIX_NAME_MAX)
+#  define _POSIX_NAME_MAX 14
+#endif
+
+/* How do we get PATH_MAX? */
+#if defined (_POSIX_VERSION) && !defined (PATH_MAX)
+#  define PATH_MAX_FOR(p) pathconf ((p), _PC_PATH_MAX)
+#endif
+
+/* How do we get NAME_MAX? */
+#if defined (_POSIX_VERSION) && !defined (NAME_MAX)
+#  define NAME_MAX_FOR(p) pathconf ((p), _PC_NAME_MAX)
+#endif
+
+#if !defined (PATH_MAX_FOR)
+#  define PATH_MAX_FOR(p)	PATH_MAX
+#endif
+
+#if !defined (NAME_MAX_FOR)
+#  define NAME_MAX_FOR(p)	NAME_MAX
+#endif
+
+extern char *strerror ();
+
+static int validate_path ();
+
+int
+pathchk_builtin (list)
+     WORD_LIST *list;
+{
+  int retval, pflag, opt;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "p")) != -1)
+    {
+      switch (opt)
+	{
+	case 'p':
+	  pflag = 1;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  for (retval = 0; list; list = list->next)
+    retval |= validate_path (list->word->word, pflag);
+
+  return (retval ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
+}
+
+char *pathchk_doc[] = {
+	"Check pathnames for validity.",
+	"",
+	"Check each pathname argument for validity (i.e., it may be used to",
+	"create or access a file without causing syntax errors) and portability",
+	"(i.e., no filename truncation will result).  If the `-p' option is",
+	"supplied, more extensive portability checks are performed.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin pathchk_struct = {
+	"pathchk",		/* builtin name */
+	pathchk_builtin,	/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	pathchk_doc,		/* array of long documentation strings. */
+	"pathchk [-p] pathname ...",	/* usage synopsis */
+	0			/* reserved for internal use */
+};
+
+/* The remainder of this file is stolen shamelessly from `pathchk.c' in
+   the sh-utils-1.12 distribution, by 
+
+   David MacKenzie <djm@gnu.ai.mit.edu>
+   and Jim Meyering <meyering@cs.utexas.edu> */
+
+/* Each element is nonzero if the corresponding ASCII character is
+   in the POSIX portable character set, and zero if it is not.
+   In addition, the entry for `/' is nonzero to simplify checking. */
+static char const portable_chars[256] =
+{
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0-15 */
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 16-31 */
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, /* 32-47 */
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 48-63 */
+  0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 64-79 */
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 80-95 */
+  0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 96-111 */
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, /* 112-127 */
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+/* If PATH contains only portable characters, return 1, else 0.  */
+
+static int
+portable_chars_only (path)
+     const char *path;
+{
+  const char *p;
+
+  for (p = path; *p; ++p)
+    if (portable_chars[(const unsigned char) *p] == 0)
+      {
+	builtin_error ("path `%s' contains nonportable character `%c'", path, *p);
+	return 0;
+      }
+  return 1;
+}
+
+/* On some systems, stat can return EINTR.  */
+
+#ifndef EINTR
+# define SAFE_STAT(name, buf) stat (name, buf)
+#else
+# define SAFE_STAT(name, buf) safe_stat (name, buf)
+static inline int
+safe_stat (name, buf)
+     const char *name;
+     struct stat *buf;
+{
+  int ret;
+
+  do
+    ret = stat (name, buf);
+  while (ret < 0 && errno == EINTR);
+
+  return ret;
+}
+#endif
+
+/* Return 1 if PATH is a usable leading directory, 0 if not,
+   2 if it doesn't exist.  */
+
+static int
+dir_ok (path)
+     const char *path;
+{
+  struct stat stats;
+
+  if (SAFE_STAT (path, &stats))
+    return 2;
+
+  if (!S_ISDIR (stats.st_mode))
+    {
+      builtin_error ("`%s' is not a directory", path);
+      return 0;
+    }
+
+  /* Use access to test for search permission because
+     testing permission bits of st_mode can lose with new
+     access control mechanisms.  Of course, access loses if you're
+     running setuid. */
+  if (access (path, X_OK) != 0)
+    {
+      if (errno == EACCES)
+	builtin_error ("directory `%s' is not searchable", path);
+      else
+	builtin_error ("%s: %s", path, strerror (errno));
+      return 0;
+    }
+
+  return 1;
+}
+
+static char *
+xstrdup (s)
+     char *s;
+{
+  return (savestring (s));
+}
+
+/* Make sure that
+   strlen (PATH) <= PATH_MAX
+   && strlen (each-existing-directory-in-PATH) <= NAME_MAX
+
+   If PORTABILITY is nonzero, compare against _POSIX_PATH_MAX and
+   _POSIX_NAME_MAX instead, and make sure that PATH contains no
+   characters not in the POSIX portable filename character set, which
+   consists of A-Z, a-z, 0-9, ., _, -.
+
+   Make sure that all leading directories along PATH that exist have
+   `x' permission.
+
+   Return 0 if all of these tests are successful, 1 if any fail. */
+
+static int
+validate_path (path, portability)
+     char *path;
+     int portability;
+{
+  int path_max;
+  int last_elem;		/* Nonzero if checking last element of path. */
+  int exists;			/* 2 if the path element exists.  */
+  char *slash;
+  char *parent;			/* Last existing leading directory so far.  */
+
+  if (portability && !portable_chars_only (path))
+    return 1;
+
+  if (*path == '\0')
+    return 0;
+
+#ifdef lint
+  /* Suppress `used before initialized' warning.  */
+  exists = 0;
+#endif
+
+  /* Figure out the parent of the first element in PATH.  */
+  parent = xstrdup (*path == '/' ? "/" : ".");
+
+  slash = path;
+  last_elem = 0;
+  while (1)
+    {
+      int name_max;
+      int length;		/* Length of partial path being checked. */
+      char *start;		/* Start of path element being checked. */
+
+      /* Find the end of this element of the path.
+	 Then chop off the rest of the path after this element. */
+      while (*slash == '/')
+	slash++;
+      start = slash;
+      slash = strchr (slash, '/');
+      if (slash != NULL)
+	*slash = '\0';
+      else
+	{
+	  last_elem = 1;
+	  slash = strchr (start, '\0');
+	}
+
+      if (!last_elem)
+	{
+	  exists = dir_ok (path);
+	  if (exists == 0)
+	    {
+	      free (parent);
+	      return 1;
+	    }
+	}
+
+      length = slash - start;
+      /* Since we know that `parent' is a directory, it's ok to call
+	 pathconf with it as the argument.  (If `parent' isn't a directory
+	 or doesn't exist, the behavior of pathconf is undefined.)
+	 But if `parent' is a directory and is on a remote file system,
+	 it's likely that pathconf can't give us a reasonable value
+	 and will return -1.  (NFS and tempfs are not POSIX . . .)
+	 In that case, we have no choice but to assume the pessimal
+	 POSIX minimums.  */
+      name_max = portability ? _POSIX_NAME_MAX : NAME_MAX_FOR (parent);
+      if (name_max < 0)
+	name_max = _POSIX_NAME_MAX;
+      if (length > name_max)
+	{
+	  builtin_error ("name `%s' has length %d; exceeds limit of %d",
+		 start, length, name_max);
+	  free (parent);
+	  return 1;
+	}
+
+      if (last_elem)
+	break;
+
+      if (exists == 1)
+	{
+	  free (parent);
+	  parent = xstrdup (path);
+	}
+
+      *slash++ = '/';
+    }
+
+  /* `parent' is now the last existing leading directory in the whole path,
+     so it's ok to call pathconf with it as the argument.  */
+  path_max = portability ? _POSIX_PATH_MAX : PATH_MAX_FOR (parent);
+  if (path_max < 0)
+    path_max = _POSIX_PATH_MAX;
+  free (parent);
+  if (strlen (path) > path_max)
+    {
+      builtin_error ("path `%s' has length %lu; exceeds limit of %d",
+	     path, (unsigned long)strlen (path), path_max);
+      return 1;
+    }
+
+  return 0;
+}
diff --git a/examples/loadables/perl/Makefile.in b/examples/loadables/perl/Makefile.in
new file mode 100644
index 0000000..59f39b6
--- /dev/null
+++ b/examples/loadables/perl/Makefile.in
@@ -0,0 +1,99 @@
+#
+# Makefile for builtin perl interpreter
+#
+#
+#   Copyright (C) 1998 Free Software Foundation, Inc.     
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# Include some boilerplate Gnu makefile definitions.
+prefix = @prefix@
+exec_prefix = @exec_prefix@
+
+bindir = @bindir@
+libdir = @libdir@
+infodir = @infodir@
+includedir = @includedir@
+
+datarootdir = @datarootdir@
+
+topdir = @top_srcdir@
+BUILD_DIR = @BUILD_DIR@
+srcdir = @srcdir@
+VPATH = @srcdir@
+
+@SET_MAKE@
+CC = @CC@
+RM = rm -f
+
+SHELL = @MAKE_SHELL@
+
+PERL5 = perl5
+
+CFLAGS = @CFLAGS@
+
+#
+# These values are generated for configure by ${topdir}/support/shobj-conf.
+# If your system is not supported by that script, but includes facilities for
+# dynamic loading of shared objects, please update the script and send the
+# changes to bash-maintainers@gnu.org.
+#
+SHOBJ_CC = @SHOBJ_CC@
+SHOBJ_CFLAGS = @SHOBJ_CFLAGS@
+SHOBJ_LD = @SHOBJ_LD@
+SHOBJ_LDFLAGS = @SHOBJ_LDFLAGS@
+SHOBJ_XLDFLAGS = @SHOBJ_XLDFLAGS@
+SHOBJ_LIBS = @SHOBJ_LIBS@
+SHOBJ_STATUS = @SHOBJ_STATUS@
+
+# Values used for compiling the perl files
+PERL_LDOPTS = `${PERL5} -MExtUtils::Embed -e ldopts`
+PERL_CFLAGS = ${CCFLAGS} `${PERL5} -MExtUtils::Embed -e ccopts`
+
+SRC = bperl.c iperl.c perlxsi.c
+OBJ = bperl.o iperl.o perlxsi.o
+
+BUILTIN = bperl5
+
+INC = -I. -I.. -I$(topdir) -I$(topdir)/lib -I$(topdir)/builtins \
+      -I$(topdir)/include -I$(BUILD_DIR) -I$(BUILD_DIR)/lib \
+      -I$(BUILD_DIR)/builtins
+
+
+${BUILTIN}:	${OBJ}
+	${RM} $@
+	${SHOBJ_LD} ${SHOBJ_LDFLAGS} ${SHOBJ_XLDFLAGS} -o $@ ${OBJ} ${PERL_LDOPTS} ${SHOBJ_LIBS}
+
+bperl.o:	bperl.c
+	${RM} $@
+	$(SHOBJ_CC) $(SHOBJ_CFLAGS) $(CFLAGS) $(INC) -c -o $@ ${srcdir}/bperl.c
+
+iperl.o:	iperl.c
+	${RM} $@
+	$(SHOBJ_CC) ${SHOBJ_CFLAGS} $(PERL_CFLAGS) -c -o $@ ${srcdir}/iperl.c
+
+perlxsi.c:
+	${PERL5} -MExtUtils::Embed -e xsinit -- -o $@
+
+perlxsi.o:	perlxsi.c
+	${RM} $@
+	${SHOBJ_CC} ${SHOBJ_CFLAGS} $(PERL_CFLAGS) -c -o $@ perlxsi.c
+
+clean mostlyclean:
+	${RM} ${OBJ}
+	${RM} ${BUILTIN}
+
+distclean maintainer-clean: clean
+	${RM} perlxsi.c
diff --git a/examples/loadables/perl/README b/examples/loadables/perl/README
new file mode 100644
index 0000000..a70a99b
--- /dev/null
+++ b/examples/loadables/perl/README
@@ -0,0 +1,6 @@
+This illustrates how to build a perl interpreter into bash.  It's not
+especially useful; more a proof of concept (it provides none of the
+bash internals to the perl interpreter, for example).
+
+This *may* require adding "-rpath /path/to/perl/CORE" and -lperl options
+when compiling bash itself.
diff --git a/examples/loadables/perl/bperl.c b/examples/loadables/perl/bperl.c
new file mode 100644
index 0000000..77e3f7c
--- /dev/null
+++ b/examples/loadables/perl/bperl.c
@@ -0,0 +1,46 @@
+/*
+ * perl builtin
+ */
+#include <config.h>
+
+#include <fcntl.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+
+#ifndef errno
+extern int errno;
+#endif
+
+extern char **make_builtin_argv ();
+extern char **export_env;
+
+extern int perl_main();
+
+bperl_builtin(list)
+WORD_LIST *list;
+{
+	char	**v;
+	int	c, r;
+
+	v = make_builtin_argv(list, &c);
+	r = perl_main(c, v, export_env);
+	free(v);
+
+	return r;
+}
+
+char *bperl_doc[] = {
+	"An interface to a perl5 interpreter.",
+	(char *)0
+};
+
+struct builtin bperl_struct = {
+	"bperl",
+	bperl_builtin,
+	BUILTIN_ENABLED,
+	bperl_doc,
+	"bperl [perl options] [file ...]",
+	0
+};
diff --git a/examples/loadables/perl/iperl.c b/examples/loadables/perl/iperl.c
new file mode 100644
index 0000000..92a6038
--- /dev/null
+++ b/examples/loadables/perl/iperl.c
@@ -0,0 +1,24 @@
+#include <EXTERN.h>               /* from the Perl distribution     */
+#include <perl.h>                 /* from the Perl distribution     */
+
+extern void xs_init _((void));
+
+static PerlInterpreter *iperl;  /***    The Perl interpreter    ***/
+
+int
+perl_main(int argc, char **argv, char **env)
+{
+	int	r;
+
+	iperl = perl_alloc();
+	perl_construct(iperl);
+	perl_parse(iperl, xs_init, argc, argv, (char **)NULL);
+	r = perl_run(iperl);
+
+PerlIO_flush(PerlIO_stdout());
+PerlIO_flush(PerlIO_stderr());
+
+	perl_destruct(iperl);
+	perl_free(iperl);
+	return (r);
+}
diff --git a/examples/loadables/print.c b/examples/loadables/print.c
new file mode 100644
index 0000000..0120dbf
--- /dev/null
+++ b/examples/loadables/print.c
@@ -0,0 +1,192 @@
+/*
+ * print -- loadable ksh-93 style print builtin
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "bashtypes.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+
+#include "bashansi.h"
+#include "shell.h"
+#include "builtins.h"
+#include "stdc.h"
+#include "bashgetopt.h"
+#include "builtext.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+int print_builtin ();
+static int printargs ();
+
+static FILE *ofp;
+
+extern char *this_command_name;
+
+static char *print_doc[] = {
+  "Display arguments.",
+  "",
+  "Output the arguments.  The -f option means to use the argument as a",
+  "format string as would be supplied to printf(1).  The rest of the",
+  "options are as in ksh.",
+  (char *)NULL
+};
+
+struct builtin print_struct = {
+	"print",
+	print_builtin,
+	BUILTIN_ENABLED,
+	print_doc,
+	"print [-Rnprs] [-u unit] [-f format] [arguments]",
+	(char *)0
+};
+
+#ifndef ISOPTION
+#define ISOPTION(s, c)	(s[0] == '-' && s[2] == '\0' && s[1] == c)
+#endif
+
+int
+print_builtin (list)
+     WORD_LIST *list;
+{
+  int c, r, nflag, raw, ofd, sflag;
+  intmax_t lfd;
+  char **v, *pfmt, *arg;
+  WORD_LIST *l;
+
+  nflag = raw = sflag = 0;
+  ofd = 1;
+  pfmt = 0;
+
+  reset_internal_getopt ();
+  while ((c = internal_getopt (list, "Rnprsu:f:")) != -1)
+    {
+      switch (c)
+	{
+	case 'R':
+	  raw = 2;
+	  loptend = lcurrent;
+	  if (loptend && ISOPTION (loptend->word->word, 'n'))
+	    {
+	      loptend = loptend->next;
+	      nflag = 1;
+	    }
+	  goto opt_end;
+	case 'r':
+	  raw = 1;
+	  break;
+	case 'n':
+	  nflag = 1;
+	  break;
+	case 's':
+	  sflag = 1;
+	  break;
+	case 'p':
+	  break;	/* NOP */
+	case 'u':
+	  if (all_digits (list_optarg) && legal_number (list_optarg, &lfd) && lfd == (int)lfd)
+	    ofd = lfd;
+	  else
+	    {
+	      for (l = list; l->next && l->next != lcurrent; l = l->next);
+	      lcurrent = loptend = l;
+	      goto opt_end;
+	    }
+	  break;
+	case 'f':
+	  pfmt = list_optarg;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+
+opt_end:
+  list = loptend;
+
+  ofp = (ofd == 1) ? stdout : fdopen (dup (ofd), "w");
+
+  if (pfmt)
+    {
+      WORD_DESC *w;
+      WORD_LIST *nlist;
+
+      w = make_word (pfmt);
+      nlist = make_word_list (w, list);
+      r = printf_builtin (nlist);
+      nlist->next = (WORD_LIST *)NULL;
+      dispose_words (nlist);
+      return (r);
+    }
+
+  if (raw)
+    {
+      for (l = list; l; l = l->next)
+	{
+	  fprintf (ofp, "%s", l->word->word);
+	  if (l->next)
+	    fprintf (ofp, " ");
+	}
+      if (nflag == 0)
+	fprintf (ofp, "\n");
+      fflush (ofp);
+      return (0);	
+    }
+        
+  r = printargs (list, ofp);
+  if (r && nflag == 0)
+    fprintf (ofp, "\n");
+  if (ofd != 1)
+    fclose (ofp);
+  return 0;
+}
+
+static int
+printargs (list, ofp)
+     WORD_LIST *list;
+     FILE *ofp;
+{
+  WORD_LIST *l;
+  char *ostr;
+  int sawc;
+
+  for (sawc = 0, l = list; l; l = l->next)
+    {
+      ostr = ansicstr (l->word->word, strlen (l->word->word), 0, &sawc, (int *)0);
+      fprintf (ofp, "%s", ostr);
+      free (ostr);
+      if (sawc)
+        return (0);
+      if (l->next)
+        fprintf (ofp, " ");
+    }
+  return (1);
+}
diff --git a/examples/loadables/printenv.c b/examples/loadables/printenv.c
new file mode 100644
index 0000000..8c7f720
--- /dev/null
+++ b/examples/loadables/printenv.c
@@ -0,0 +1,94 @@
+/*
+ * printenv -- minimal builtin clone of BSD printenv(1).
+ *
+ * usage: printenv [varname]
+ *
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <stdio.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+extern char **export_env;
+
+int
+printenv_builtin (list) 
+     WORD_LIST *list;
+{
+  register char **envp;
+  int opt;
+  SHELL_VAR *var;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "")) != -1)
+    {
+      switch (opt)
+	{
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  /* printenv */
+  if (list == 0)
+    {
+      maybe_make_export_env ();		/* this allows minimal code */
+      for (envp = export_env; *envp; envp++)
+	printf ("%s\n", *envp);
+      return (EXECUTION_SUCCESS);
+    }
+
+  /* printenv varname */
+  var = find_variable (list->word->word);
+  if (var == 0 || (exported_p (var) == 0))
+    return (EXECUTION_FAILURE);
+
+  if (function_p (var))
+    print_var_function (var);
+  else
+    print_var_value (var, 0);
+
+  printf("\n");
+  return (EXECUTION_SUCCESS);
+}
+
+char *printenv_doc[] = {
+	"Display environment.",
+	"",
+	"Print names and values of environment variables",
+	(char *)NULL
+};
+
+struct builtin printenv_struct = {
+	"printenv",
+	printenv_builtin,
+	BUILTIN_ENABLED,
+	printenv_doc,
+	"printenv [varname]",
+	0
+};
diff --git a/examples/loadables/push.c b/examples/loadables/push.c
new file mode 100644
index 0000000..b27455b
--- /dev/null
+++ b/examples/loadables/push.c
@@ -0,0 +1,117 @@
+/*
+ * push - anyone remember TOPS-20?
+ *
+ */
+
+/*
+   Copyright (C) 1999-2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "jobs.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#ifndef errno
+extern int errno;
+#endif
+
+extern pid_t dollar_dollar_pid;
+extern int last_command_exit_value;
+
+int
+push_builtin (list)
+     WORD_LIST *list;
+{
+  pid_t pid;
+  int xstatus, opt;
+
+  xstatus = EXECUTION_SUCCESS;
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "")) != -1)
+    {
+      switch (opt)
+	{
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;  
+
+  pid = make_child (savestring ("push"), 0);
+  if (pid == -1)
+    {
+      builtin_error ("cannot fork: %s", strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+  else if (pid == 0)
+    {
+      /* Shell variable adjustments: $SHLVL, $$, $PPID, $! */
+      adjust_shell_level (1);
+      dollar_dollar_pid = getpid ();
+      set_ppid ();
+
+      /* Clean up job control stuff. */
+      stop_making_children ();
+      cleanup_the_pipeline ();
+      delete_all_jobs (0);
+
+      last_asynchronous_pid = NO_PID;
+
+      /* Make sure the job control code has the right values for
+	 the shell's process group and tty process group, and that
+	 the signals are set correctly for job control. */
+      initialize_job_control (0);
+      initialize_job_signals ();
+
+      /* And read commands until exit. */
+      reader_loop ();
+      exit_shell (last_command_exit_value);
+    }
+  else
+    {
+      stop_pipeline (0, (COMMAND *)NULL);
+      xstatus = wait_for (pid, 0);
+      return (xstatus);
+    }   
+}
+
+char *push_doc[] = {
+	"Create child shell.",
+	"",
+	"Create a child that is an exact duplicate of the running shell",
+	"and wait for it to exit.  The $SHLVL, $!, $$, and $PPID variables",
+	"are adjusted in the child.  The return value is the exit status",
+	"of the child.",
+	(char *)NULL
+};
+
+struct builtin push_struct = {
+	"push",
+	push_builtin,
+	BUILTIN_ENABLED,
+	push_doc,
+	"push",
+	0
+};
diff --git a/examples/loadables/realpath.c b/examples/loadables/realpath.c
new file mode 100644
index 0000000..0974ac4
--- /dev/null
+++ b/examples/loadables/realpath.c
@@ -0,0 +1,145 @@
+/*
+ * realpath -- canonicalize pathnames, resolving symlinks
+ *
+ * usage: realpath [-csv] pathname [pathname...]
+ *
+ * options:	-c	check whether or not each resolved path exists
+ *		-s	no output, exit status determines whether path is valid
+ *		-v	produce verbose output
+ *
+ *
+ * exit status:	0	if all pathnames resolved
+ *		1	if any of the pathname arguments could not be resolved
+ *
+ *
+ * Bash loadable builtin version
+ *
+ * Chet Ramey
+ * chet@po.cwru.edu
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
+#include "bashansi.h"
+#include <maxpath.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#ifndef errno
+extern int	errno;
+#endif
+
+extern char	*sh_realpath();
+
+int
+realpath_builtin(list)
+WORD_LIST	*list;
+{
+	int	opt, cflag, vflag, sflag, es;
+	char	*r, realbuf[PATH_MAX], *p;
+	struct stat sb;
+
+	if (list == 0) {
+		builtin_usage();
+		return (EX_USAGE);
+	}
+
+	vflag = cflag = sflag = 0;
+	reset_internal_getopt();
+	while ((opt = internal_getopt (list, "csv")) != -1) {
+		switch (opt) {
+		case 'c':
+			cflag = 1;
+			break;
+		case 's':
+			sflag = 1;
+			break;
+		case 'v':
+			vflag = 1;
+			break;
+		CASE_HELPOPT;
+		default:
+			builtin_usage();
+			return (EX_USAGE);
+		}
+	}
+
+	list = loptend;
+
+	if (list == 0) {
+		builtin_usage();
+		return (EX_USAGE);
+	}
+
+	for (es = EXECUTION_SUCCESS; list; list = list->next) {
+		p = list->word->word;
+		r = sh_realpath(p, realbuf);
+		if (r == 0) {
+			es = EXECUTION_FAILURE;
+			if (sflag == 0)
+				builtin_error("%s: cannot resolve: %s", p, strerror(errno));
+			continue;
+		}
+		if (cflag && (stat(realbuf, &sb) < 0)) {
+			es = EXECUTION_FAILURE;
+			if (sflag == 0)
+				builtin_error("%s: %s", p, strerror(errno));
+			continue;
+		}
+		if (sflag == 0) {
+			if (vflag)
+				printf ("%s -> ", p);
+			printf("%s\n", realbuf);
+		}
+	}
+	return es;
+}
+
+char *realpath_doc[] = {
+	"Display pathname in canonical form.",
+	"",
+	"Display the canonicalized version of each PATHNAME argument, resolving",
+	"symbolic links.  The -c option checks whether or not each resolved name",
+	"exists.  The -s option produces no output; the exit status determines the",
+	"validity of each PATHNAME.  The -v option produces verbose output.  The",
+	"exit status is 0 if each PATHNAME was resolved; non-zero otherwise.",
+	(char *)NULL
+};
+
+struct builtin realpath_struct = {
+	"realpath",		/* builtin name */
+	realpath_builtin,	/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	realpath_doc,		/* array of long documentation strings */
+	"realpath [-csv] pathname [pathname...]",	/* usage synopsis */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/rm.c b/examples/loadables/rm.c
new file mode 100644
index 0000000..0af5493
--- /dev/null
+++ b/examples/loadables/rm.c
@@ -0,0 +1,181 @@
+/* rm - remove files and directories with -r */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 2016 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include <stdio.h>
+#include <errno.h>
+#include <dirent.h>
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+static int rm_file(const char *fname);
+
+static int force, recursive;
+
+static int
+_remove_directory(const char *dirname)
+{
+  DIR *dir;
+  struct dirent *dp;
+  size_t dirlen;
+  int err;
+
+  dirlen = strlen (dirname);
+  err = 0;
+
+  if ((dir = opendir(dirname)))
+    {
+      while ((dp = readdir(dir)))
+	{	
+#ifdef __GNUC__
+	  char fname[dirlen + 1 + strlen (dp->d_name) + 1];
+#else
+	  char *fname;
+	  int fnsize;
+#endif
+	  
+          if (*dp->d_name == '.' && (dp->d_name[1] == 0 || (dp->d_name[1] == '.' && dp->d_name[2] == 0)))
+            continue;
+
+#ifdef __GNUC__
+	  snprintf(fname, sizeof (fname), "%s/%s", dirname, dp->d_name);
+#else
+	  fnsize = dirlen + 1 + strlen (dp->d_name) + 1;
+          fname = xmalloc (fnsize);
+	  snprintf(fname, fnsize, "%s/%s", dirname, dp->d_name);
+#endif
+
+           if (rm_file (fname) && force == 0)
+             err = 1;
+#ifndef __GNUC__
+           free (fname);
+#endif
+        }
+
+      closedir(dir);
+		
+      if (err == 0 && rmdir (dirname) && force == 0)
+        err = 1;
+    }
+  else if (force == 0)
+    err = 1;
+
+  if (err)
+    builtin_error ("%s: %s", dirname, strerror (errno));
+
+  return err;
+}
+
+static int
+rm_file(const char *fname)
+{
+  if (unlink (fname) == 0)
+    return 0;
+
+  /* If FNAME is a directory glibc returns EISDIR but correct POSIX value
+     would be EPERM.  If we get that error and FNAME is a directory and -r
+     was supplied, recursively remove the directory and its contents */
+  if ((errno == EISDIR || errno == EPERM) && recursive && file_isdir (fname))
+    return _remove_directory(fname);
+  else if (force)
+    return 0;
+
+  builtin_error ("%s: %s", fname, strerror (errno));
+  return 1;
+}
+
+int
+rm_builtin (list)
+     WORD_LIST *list;
+{
+  const char *name;
+  WORD_LIST *l;
+  int rval, opt;
+
+  recursive = force = 0;
+  rval = EXECUTION_SUCCESS;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "Rrfi")) != -1)
+    {
+      switch (opt)
+	{
+	case 'R':
+	case 'r':
+	  recursive = 1;
+	  break;
+	case 'f':
+	  force = 1;
+	  break;
+	case 'i':
+	  return (EX_DISKFALLBACK);
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (list == 0)
+    {
+      if (force == 0)
+	{
+          builtin_usage ();
+          return (EXECUTION_FAILURE);
+	}
+      return (EXECUTION_SUCCESS);      
+    }
+
+  for (l = list; l; l = l->next)
+    {
+      if (rm_file(l->word->word) && force == 0)
+	rval = EXECUTION_FAILURE;
+    }
+
+  return rval;
+}
+
+char *rm_doc[] = {
+	"Remove files.",
+	"",
+	"rm removes the files specified as arguments.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin rm_struct = {
+	"rm",			/* builtin name */
+	rm_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	rm_doc,			/* array of long documentation strings. */
+	"rm [-rf] file ...",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/rmdir.c b/examples/loadables/rmdir.c
new file mode 100644
index 0000000..001c2bd
--- /dev/null
+++ b/examples/loadables/rmdir.c
@@ -0,0 +1,72 @@
+/* rmdir - remove directory */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include <stdio.h>
+#include <errno.h>
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+int
+rmdir_builtin (list)
+     WORD_LIST *list;
+{
+  int rval;
+  WORD_LIST *l;
+
+  if (no_options (list))
+    return (EX_USAGE);
+
+  for (rval = EXECUTION_SUCCESS, l = list; l; l = l->next)
+    if (rmdir (l->word->word) < 0)
+      {
+	builtin_error ("%s: %s", l->word->word, strerror (errno));
+	rval = EXECUTION_FAILURE;
+      }
+
+  return rval;
+}
+
+char *rmdir_doc[] = {
+	"Remove directory.",
+	"",
+	"rmdir removes the directory entry specified by each argument,",
+	"provided the directory is empty.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin rmdir_struct = {
+	"rmdir",		/* builtin name */
+	rmdir_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	rmdir_doc,		/* array of long documentation strings. */
+	"rmdir directory ...",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/seq.c b/examples/loadables/seq.c
new file mode 100644
index 0000000..e562407
--- /dev/null
+++ b/examples/loadables/seq.c
@@ -0,0 +1,490 @@
+/* seq - print sequence of numbers to standard output.
+   Copyright (C) 2018-2020 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written as bash builtin by Chet Ramey. Portions from seq.c by Ulrich Drepper. */
+
+#include <config.h>
+
+#include <sys/types.h>
+
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "bashansi.h"
+#include "loadables.h"
+#include "bashintl.h"
+
+#ifndef errno
+extern int errno;
+#endif
+
+#if defined (HAVE_LONG_DOUBLE) && HAVE_DECL_STRTOLD && !defined(STRTOLD_BROKEN)
+typedef long double floatmax_t;
+#  define FLOATMAX_CONV "L"
+#  define strtofltmax   strtold
+#  define FLOATMAX_FMT "%Lg"
+#  define FLOATMAX_WFMT "%0.Lf"
+#  define USE_LONG_DOUBLE
+#else
+typedef double floatmax_t;
+#  define FLOATMAX_CONV ""
+#  define strtofltmax   strtod
+#  define FLOATMAX_FMT "%g"
+#  define FLOATMAX_WFMT "%0.f"
+#endif
+static floatmax_t getfloatmax PARAMS((const char *));
+static char *genformat PARAMS((floatmax_t, floatmax_t, floatmax_t));
+
+#define MAX(a, b) (((a) < (b))? (b) : (a))
+
+static int conversion_error = 0;
+
+/* If true print all number with equal width.  */
+static int equal_width;
+
+/* The string used to separate two numbers.  */
+static char const *separator;
+
+/* The string output after all numbers have been output. */
+static char const terminator[] = "\n";
+
+static char decimal_point;
+
+/* Pretty much the same as the version in builtins/printf.def */
+static floatmax_t
+getfloatmax (arg)
+     const char *arg;
+{
+  floatmax_t ret;
+  char *ep;
+
+  errno = 0;
+  ret = strtofltmax (arg, &ep);
+
+  if (*ep)
+    {
+      sh_invalidnum ((char *)arg);
+      conversion_error = 1;
+    }
+  else if (errno == ERANGE)
+    {
+      builtin_error ("warning: %s: %s", arg, strerror(ERANGE));
+      conversion_error = 1;
+    }
+
+  if (ret == -0.0)
+    ret = 0.0;
+
+  return (ret);
+}
+
+/* If FORMAT is a valid printf format for a double argument, return
+   its long double equivalent, allocated from dynamic storage. This
+   was written by Ulrich Drepper, taken from coreutils:seq.c */
+static char *
+long_double_format (char const *fmt)
+{
+  size_t i;
+  size_t length_modifier_offset;
+  int has_L;
+
+  for (i = 0; ! (fmt[i] == '%' && fmt[i + 1] != '%'); i += (fmt[i] == '%') + 1)
+    {
+      if (!fmt[i])
+	{
+	  builtin_error ("format %s has no %% directive", fmt);
+	  return 0;
+	}
+    }
+
+  i++;
+  i += strspn (fmt + i, "-+#0 '");	/* zero or more flags */
+  i += strspn (fmt + i, "0123456789");	/* optional minimum field width */
+  if (fmt[i] == '.')			/* optional precision */
+    {
+      i++;
+      i += strspn (fmt + i, "0123456789");
+    }
+
+  length_modifier_offset = i;		/* optional length modifier */
+  /* we could ignore an 'l' length modifier here */
+  has_L = (fmt[i] == 'L');
+  i += has_L;
+  switch (fmt[i])
+    {
+    case '\0':
+      builtin_error ("format %s ends in %%", fmt);
+      return 0;
+    case 'A':
+    case 'a':
+    case 'e':
+    case 'E':
+    case 'f':
+    case 'F':
+    case 'g':
+    case 'G':
+      break;
+    default:
+      builtin_error ("format %s has unknown `%%%c' directive", fmt, fmt[i]);
+      return 0;
+    }
+  for (i++; ; i += (fmt[i] == '%') + 1)
+    if (fmt[i] == '%' && fmt[i + 1] != '%')
+      {
+        builtin_error ("format %s has too many %% directives", fmt);
+        return 0;
+      }
+    else if (fmt[i] == 0)
+      {
+        size_t format_size = i + 1;
+        char *ldfmt = xmalloc (format_size + 1);
+        memcpy (ldfmt, fmt, length_modifier_offset);
+#ifdef USE_LONG_DOUBLE
+        ldfmt[length_modifier_offset] = 'L';
+        strcpy (ldfmt + length_modifier_offset + 1,
+                fmt + length_modifier_offset + has_L);
+#else
+        strcpy (ldfmt + length_modifier_offset, fmt + length_modifier_offset);
+#endif
+        return ldfmt;
+      }
+}
+
+/* Return the number of digits following the decimal point in NUMBUF */
+static int
+getprec (numbuf)
+     const char *numbuf;
+{
+  int p;
+  char *dp;
+
+  if (dp = strchr (numbuf, decimal_point))
+    dp++;		/* skip over decimal point */
+  for (p = 0; dp && *dp && ISDIGIT (*dp); dp++)
+    p++;
+  return p;
+}
+
+/* Return the default format given FIRST, INCR, and LAST.  */
+static char *
+genformat (first, incr, last)
+       floatmax_t first, incr, last;
+{
+  static char buf[6 + 2 * INT_STRLEN_BOUND (int)];
+  int wfirst, wlast, width;
+  int iprec, fprec, lprec, prec;
+
+  if (equal_width == 0)
+    return (FLOATMAX_FMT);
+
+  /* OK, we have to figure out the largest number of decimal places. This is
+     a little more expensive than using the original strings. */
+  snprintf (buf, sizeof (buf), FLOATMAX_FMT, incr);
+  iprec = getprec (buf);
+
+  wfirst = snprintf (buf, sizeof (buf), FLOATMAX_FMT, first);
+  fprec = getprec (buf);
+    
+  prec = MAX (fprec, iprec);
+
+  wlast = snprintf (buf, sizeof (buf), FLOATMAX_FMT, last);
+  lprec = getprec (buf);
+
+  /* increase first width by any increased precision in increment */
+  wfirst += (prec - fprec);
+
+  /* adjust last width to use precision from first/incr */
+  wlast += (prec - lprec);
+
+  if (lprec && prec == 0)
+    wlast--;		/* no decimal point */
+  if (lprec == 0 && prec)
+    wlast++;		/* include decimal point */
+  if (fprec == 0 && prec)
+    wfirst++;		/* include decimal point */
+
+  width = MAX (wfirst, wlast);
+  if (width)
+    sprintf (buf, "%%0%d.%d%sf", width, prec, FLOATMAX_CONV);
+  else
+    sprintf (buf, "%%.%d%sf", prec, FLOATMAX_CONV);
+
+  return buf;
+}
+
+int
+print_fltseq (fmt, first, last, incr)
+     const char *fmt;
+     floatmax_t first, last, incr;
+{
+  int n;
+  floatmax_t next;
+  const char *s;
+
+  n = 0;		/* iteration counter */
+  s = "";
+  for (next = first; incr >= 0 ? (next <= last) : (next >= last); next = first + n * incr)
+    {
+      QUIT;
+      if (*s && fputs (s, stdout) == EOF)
+	return (sh_chkwrite (EXECUTION_FAILURE));
+      if (printf (fmt, next) < 0)
+	return (sh_chkwrite (EXECUTION_FAILURE));
+      s = separator;
+      n++;
+    }
+
+  if (n > 0 && fputs (terminator, stdout) == EOF)
+    return (sh_chkwrite (EXECUTION_FAILURE));
+  return (sh_chkwrite (EXECUTION_SUCCESS));
+}
+
+/* must be <= INT_STRLEN_BOUND(intmax_t) */
+int
+width_needed (num)
+     intmax_t num;
+{
+  int ret;
+
+  ret = num < 0;		/* sign */
+  if (ret)
+    num = -num;
+  do
+    ret++;
+  while (num /= 10);
+  return ret;
+}
+
+int
+print_intseq (ifirst, ilast, iincr)
+     intmax_t ifirst, ilast, iincr;
+{
+  char intwfmt[6 + INT_STRLEN_BOUND(int) + sizeof (PRIdMAX)];
+  const char *s;
+  intmax_t i, next;
+
+  /* compute integer format string */
+  if (equal_width)	/* -w supplied */
+    {
+      int wfirst, wlast, width;
+
+      wfirst = width_needed (ifirst);
+      wlast = width_needed (ilast);
+      width = MAX(wfirst, wlast);
+
+      /* The leading %s is for the separator */
+      snprintf (intwfmt, sizeof (intwfmt), "%%s%%0%u" PRIdMAX, width);
+    }
+
+  /* We could use braces.c:mkseq here but that allocates lots of memory */
+  s = "";
+  for (i = ifirst; (ifirst <= ilast) ? (i <= ilast) : (i >= ilast); i = next)
+    {
+      QUIT;
+      /* The leading %s is for the separator */
+      if (printf (equal_width ?  intwfmt : "%s%" PRIdMAX, s, i) < 0)
+	return (sh_chkwrite (EXECUTION_FAILURE));
+      s = separator;
+      next = i + iincr;
+    }
+
+  if (fputs (terminator, stdout) == EOF)
+    return (sh_chkwrite (EXECUTION_FAILURE));
+  return (sh_chkwrite (EXECUTION_SUCCESS));
+}
+
+int
+seq_builtin (list)
+     WORD_LIST *list;
+{
+  floatmax_t first, last, incr;
+  intmax_t ifirst, ilast, iincr;
+  WORD_LIST *l;
+  int opt, nargs, intseq, freefmt;
+  char *first_str, *incr_str, *last_str;
+  char const *fmtstr;		/* The printf(3) format used for output.  */
+
+  equal_width = 0;
+  separator = "\n";
+  fmtstr = NULL;
+
+  first = 1.0;
+  last = 0.0;
+  incr = 0.0;		/* set later */
+  ifirst = ilast = iincr = 0;
+  first_str = incr_str = last_str = 0;
+
+  intseq = freefmt = 0;
+  opt = 0;
+
+  reset_internal_getopt ();
+  while (opt != -1)
+    {
+      l = lcurrent ? lcurrent : list;
+      if (l && l->word && l->word->word && l->word->word[0] == '-' &&
+	   (l->word->word[1] == '.' || DIGIT (l->word->word[1])))
+	{
+	  loptend = l;
+	  break;	/* negative number */
+	}
+      if ((opt = internal_getopt (list, "f:s:w")) == -1)
+        break;
+
+      switch (opt)
+	{
+	case 'f':
+	  fmtstr = list_optarg;
+	  break;
+	case 's':
+	  separator = list_optarg;
+	  break;
+	case 'w':
+	  equal_width = 1;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EXECUTION_FAILURE);
+    }
+
+  for (nargs = 1, l = list; l->next; l = l->next)
+    nargs++;
+  if (nargs > 3)
+    {
+      builtin_usage ();
+      return (EXECUTION_FAILURE);
+    }
+
+  /* LAST */
+  conversion_error = 0;
+  last = getfloatmax (last_str = l->word->word);
+  if (conversion_error)
+    return (EXECUTION_FAILURE);
+
+  /* FIRST LAST */
+  if (nargs > 1)
+    {
+      conversion_error = 0;
+      first = getfloatmax (first_str = list->word->word);
+      if (conversion_error)
+	return (EXECUTION_FAILURE);
+    }
+
+  /* FIRST INCR LAST */
+  if (nargs > 2)
+    {
+      conversion_error = 0;
+      incr = getfloatmax (incr_str = list->next->word->word);
+      if (conversion_error)
+	return (EXECUTION_FAILURE);
+      if (incr == 0.0)
+	{
+	  builtin_error ("zero %screment", (first < last) ?  "in" : "de");
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  /* Sanitize arguments */
+  if (incr == 0.0)
+    incr = (first <= last) ?  1.0 : -1.0;
+  if ((incr < 0.0 && first < last) || (incr > 0 && first > last))
+    {
+      builtin_error ("incorrect %screment", (first < last) ?  "in" : "de");
+      return (EXECUTION_FAILURE);
+    }
+
+  /* validate format here */
+  if (fmtstr)
+    {
+      fmtstr = long_double_format (fmtstr);
+      freefmt = 1;
+      if (fmtstr == 0)
+	return (EXECUTION_FAILURE);
+    }
+      
+  if (fmtstr != NULL && equal_width)
+    {
+      builtin_warning ("-w ignored when the format string is specified");
+      equal_width = 0;
+    }
+
+  /* Placeholder for later additional conditions */
+  if (last_str && all_digits (last_str) &&
+      (first_str == 0 || all_digits (first_str)) &&
+      (incr_str == 0 || all_digits (incr_str)) &&
+      fmtstr == NULL)
+    intseq = 1;
+
+  if (intseq)
+    {
+      ifirst = (intmax_t)first; /* truncation */
+      ilast = (intmax_t)last;
+      iincr = (intmax_t)incr;
+
+      return (print_intseq (ifirst, ilast, iincr));
+    }
+
+  decimal_point = locale_decpoint ();
+  if (fmtstr == NULL)
+    fmtstr = genformat (first, incr, last);
+
+  print_fltseq (fmtstr, first, last, incr);
+
+  if (freefmt)
+    free ((void *)fmtstr);
+  return sh_chkwrite (EXECUTION_SUCCESS);
+}
+
+/* Taken largely from GNU seq. */
+char *seq_doc[] = {
+	"Print numbers from FIRST to LAST, in steps of INCREMENT.",
+	"",
+	"-f FORMAT    use printf style floating-point FORMAT",
+	"-s STRING    use STRING to separate numbers (default: \\n)",
+	"-w           equalize width by padding with leading zeroes",
+	"",
+	"If FIRST or INCREMENT is omitted, it defaults to 1.  However, an",
+	"omitted INCREMENT defaults to -1 when LAST is smaller than FIRST.",
+	"The sequence of numbers ends when the sum of the current number and",
+	"INCREMENT would become greater than LAST.",
+	"FIRST, INCREMENT, and LAST are interpreted as floating point values.",
+	"",
+	"FORMAT must be suitable for printing one argument of type 'double';",
+	"it defaults to %.PRECf if FIRST, INCREMENT, and LAST are all fixed point",
+	"decimal numbers with maximum precision PREC, and to %g otherwise.",
+	(char *)NULL
+};	
+
+struct builtin seq_struct = {
+	"seq",
+	seq_builtin,
+	BUILTIN_ENABLED,
+	seq_doc,
+	"seq [-f format] [-s separator] [-w] [FIRST [INCR]] LAST",
+	0
+};
diff --git a/examples/loadables/setpgid.c b/examples/loadables/setpgid.c
new file mode 100644
index 0000000..e56fd51
--- /dev/null
+++ b/examples/loadables/setpgid.c
@@ -0,0 +1,121 @@
+/* setpgid.c: bash loadable wrapper for setpgid system call
+
+   An example of how to wrap a system call with a loadable builtin.
+
+   Originally contributed by Jason Vas Dias <jason.vas.dias@gmail.com>
+   
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+#include <errno.h>
+#include <string.h>
+
+#include "bashtypes.h"
+#include "posixtime.h"
+
+#include <stdio.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+
+#include "bashgetopt.h"
+
+#if !defined (_POSIX_VERSION)
+#  define setpgid(pid, pgrp)      setpgrp (pid, pgrp)
+#endif
+
+int
+setpgid_builtin (list)
+      WORD_LIST *list;
+{
+  register WORD_LIST *wl;
+  intmax_t pid_arg, pgid_arg;
+  pid_t pid, pgid;
+  char *pidstr, *pgidstr;
+
+  wl = list;
+  pid = pgid = 0;
+
+  if (wl == 0 || wl->next == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  pidstr = wl->word ? wl->word->word : 0;
+  pgidstr = wl->next->word ? wl->next->word->word : 0;
+
+  if (pidstr == 0 || pgidstr == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+      
+  if (legal_number (pidstr, &pid_arg) == 0)
+    {
+      builtin_error ("%s: pid argument must be numeric", pidstr);
+      return (EXECUTION_FAILURE);
+    }
+  if (pid_arg < 0)
+    {
+      builtin_error("%s: negative pid  values not allowed", pidstr);
+      return (EXECUTION_FAILURE);
+    }
+  pid = pid_arg;
+
+  if (legal_number (pgidstr, &pgid_arg) == 0)
+    {
+      builtin_error ("%s: pgrp argument must be numeric", pgidstr);
+      return (EXECUTION_FAILURE);
+    }
+  if (pgid_arg < 0)
+    {
+      builtin_error ("%s: negative pgrp values not allowed", pgidstr);
+      return (EXECUTION_FAILURE);
+    }
+  pgid = pgid_arg;
+
+  errno = 0;
+  if (setpgid(pid, pgid) < 0)
+    {
+      builtin_error("setpgid failed: %s", strerror (errno));
+      return (EXECUTION_FAILURE);     
+    }
+  return (EXECUTION_SUCCESS);     
+}
+
+const char *setpgid_doc[] = {
+	"invoke the setpgid(2) system call",
+	"",
+	"Arguments:",
+	"   pid : numeric process identifier, >= 0",
+	"   pgrpid: numeric process group identifier, >=0",
+	"See the setpgid(2) manual page.",
+	(const char *)NULL
+};
+
+struct builtin setpgid_struct = {
+	"setpgid",
+	setpgid_builtin,
+	BUILTIN_ENABLED,
+	(char **)setpgid_doc,
+	"setpgid pid pgrpid",
+	0
+};
diff --git a/examples/loadables/sleep.c b/examples/loadables/sleep.c
new file mode 100644
index 0000000..fc2203d
--- /dev/null
+++ b/examples/loadables/sleep.c
@@ -0,0 +1,101 @@
+/*
+ * sleep -- sleep for fractions of a second
+ *
+ * usage: sleep seconds[.fraction]
+ */
+
+/*
+   Copyright (C) 1999-2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include "bashtypes.h"
+
+#if defined (TIME_WITH_SYS_TIME)
+#  include <sys/time.h>
+#  include <time.h>
+#else
+#  if defined (HAVE_SYS_TIME_H)
+#    include <sys/time.h>
+#  else
+#    include <time.h>
+#  endif
+#endif
+
+#if defined (HAVE_UNISTD_H)
+#include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "chartypes.h"
+
+#include "shell.h"
+#include "builtins.h"
+#include "common.h"
+
+int
+sleep_builtin (list)
+WORD_LIST	*list;
+{
+	long	sec, usec;
+	char	*ep;
+	int	r, mul;
+	time_t	t;
+
+	if (list == 0) {
+		builtin_usage();
+		return(EX_USAGE);
+	}
+
+	/* Skip over `--' */
+	if (list->word && ISOPTION (list->word->word, '-'))
+		list = list->next;
+
+	if (*list->word->word == '-' || list->next) {
+		builtin_usage ();
+		return (EX_USAGE);
+	}
+
+    	r = uconvert(list->word->word, &sec, &usec, &ep);
+	/* Maybe postprocess conversion failures here based on EP */
+    		
+    	if (r) {
+		fsleep(sec, usec);
+		QUIT;
+		return(EXECUTION_SUCCESS);
+    	}
+
+	builtin_error("%s: bad sleep interval", list->word->word);
+	return (EXECUTION_FAILURE);
+}
+
+static char *sleep_doc[] = {
+	"Suspend execution for specified period.",
+	""
+	"sleep suspends execution for a minimum of SECONDS[.FRACTION] seconds.",
+	(char *)NULL
+};
+
+struct builtin sleep_struct = {
+	"sleep",
+	sleep_builtin,
+	BUILTIN_ENABLED,
+	sleep_doc,
+	"sleep seconds[.fraction]",
+	0
+};
diff --git a/examples/loadables/stat.c b/examples/loadables/stat.c
new file mode 100644
index 0000000..52b9580
--- /dev/null
+++ b/examples/loadables/stat.c
@@ -0,0 +1,430 @@
+/* stat - load up an associative array with stat information about a file */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 2016 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+
+#include <sys/types.h>
+#include "posixstat.h"
+#include <stdio.h>
+#include <pwd.h>
+#include <grp.h>
+#include <errno.h>
+#include "posixtime.h"
+
+#include "bashansi.h"
+#include "shell.h"
+#include "builtins.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+#ifndef errno
+extern int	errno;
+#endif
+
+#define ST_NAME		0
+#define ST_DEV		1
+#define ST_INO		2
+#define ST_MODE		3
+#define ST_NLINK	4
+#define ST_UID		5
+#define ST_GID		6
+#define ST_RDEV		7
+#define ST_SIZE		8
+#define ST_ATIME	9
+#define ST_MTIME	10
+#define ST_CTIME	11
+#define ST_BLKSIZE	12
+#define ST_BLOCKS	13
+#define ST_CHASELINK	14
+#define ST_PERMS	15
+
+#define ST_END		16
+
+static char *arraysubs[] =
+  {
+    "name", "device", "inode", "type", "nlink", "uid", "gid", "rdev",
+    "size", "atime", "mtime", "ctime", "blksize", "blocks", "link", "perms",
+    0
+  };
+
+static int
+getstat (fname, flags, sp)
+     const char *fname;
+     int flags;
+     struct stat *sp;
+{
+  intmax_t lfd;
+  int fd, r;
+
+  if (strncmp (fname, "/dev/fd/", 8) == 0)
+    {
+      if ((legal_number(fname + 8, &lfd) == 0) || (int)lfd != lfd)
+	{
+	  errno = EINVAL;
+	  return -1;
+	}
+      fd = lfd;
+      r = fstat(fd, sp);
+    }
+#ifdef HAVE_LSTAT
+  else if (flags & 1)
+    r = lstat(fname, sp);
+#endif
+  else
+    r = stat(fname, sp);
+
+  return r;
+}
+
+static char *
+statlink (fname, sp)
+     char *fname;
+     struct stat *sp;
+{
+#if defined (HAVE_READLINK)
+  char linkbuf[PATH_MAX];
+  int n;
+
+  if (fname && S_ISLNK (sp->st_mode) && (n = readlink (fname, linkbuf, PATH_MAX)) > 0)
+    {
+      linkbuf[n] = '\0';
+      return (savestring (linkbuf));
+    }
+  else
+#endif
+    return (savestring (fname));
+}
+
+static char *
+octalperms (m)
+     int m;
+{
+  int operms;
+  char *ret;
+
+  operms = 0;
+
+  if (m & S_IRUSR)
+    operms |= 0400;
+  if (m & S_IWUSR)
+    operms |= 0200;
+  if (m & S_IXUSR)
+    operms |= 0100;
+
+  if (m & S_IRGRP)
+    operms |= 0040;
+  if (m & S_IWGRP)
+    operms |= 0020;
+  if (m & S_IXGRP)
+    operms |= 0010;
+
+  if (m & S_IROTH)
+    operms |= 0004;
+  if (m & S_IWOTH)
+    operms |= 0002;
+  if (m & S_IXOTH)
+    operms |= 0001;
+
+  if (m & S_ISUID)
+    operms |= 04000;
+  if (m & S_ISGID)
+    operms |= 02000;
+  if (m & S_ISVTX)
+    operms |= 01000;
+
+  ret = (char *)xmalloc (16);
+  snprintf (ret, 16, "%04o", operms);
+  return ret;
+}
+
+static char *
+statperms (m)
+     int m;
+{
+  char ubits[4], gbits[4], obits[4];	/* u=rwx,g=rwx,o=rwx */
+  int i;
+  char *ret;
+
+  i = 0;
+  if (m & S_IRUSR)
+    ubits[i++] = 'r';
+  if (m & S_IWUSR)
+    ubits[i++] = 'w';
+  if (m & S_IXUSR)
+    ubits[i++] = 'x';
+  ubits[i] = '\0';
+
+  i = 0;
+  if (m & S_IRGRP)
+    gbits[i++] = 'r';
+  if (m & S_IWGRP)
+    gbits[i++] = 'w';
+  if (m & S_IXGRP)
+    gbits[i++] = 'x';
+  gbits[i] = '\0';
+
+  i = 0;
+  if (m & S_IROTH)
+    obits[i++] = 'r';
+  if (m & S_IWOTH)
+    obits[i++] = 'w';
+  if (m & S_IXOTH)
+    obits[i++] = 'x';
+  obits[i] = '\0';
+
+  if (m & S_ISUID)
+    ubits[2] = (m & S_IXUSR) ? 's' : 'S';
+  if (m & S_ISGID)
+    gbits[2] = (m & S_IXGRP) ? 's' : 'S';
+  if (m & S_ISVTX)
+    obits[2] = (m & S_IXOTH) ? 't' : 'T';
+
+  ret = (char *)xmalloc (32);
+  snprintf (ret, 32, "u=%s,g=%s,o=%s", ubits, gbits, obits);
+  return ret;
+}
+
+static char *
+statmode(mode)
+     int mode;
+{
+  char *modestr, *m;
+
+  modestr = m = (char *)xmalloc (8);
+  if (S_ISBLK (mode))
+    *m++ = 'b';
+  if (S_ISCHR (mode))
+    *m++ = 'c';
+  if (S_ISDIR (mode))
+    *m++ = 'd';
+  if (S_ISREG(mode))
+    *m++ = '-';
+  if (S_ISFIFO(mode))
+    *m++ = 'p';
+  if (S_ISLNK(mode))
+    *m++ = 'l';
+  if (S_ISSOCK(mode))
+    *m++ = 's';
+
+#ifdef S_ISDOOR
+  if (S_ISDOOR (mode))
+    *m++ = 'D';
+#endif
+#ifdef S_ISWHT
+  if (S_ISWHT(mode))
+    *m++ = 'W';
+#endif
+#ifdef S_ISNWK
+  if (S_ISNWK(mode))
+    *m++ = 'n';
+#endif
+#ifdef S_ISMPC
+  if (S_ISMPC (mode))
+    *m++ = 'm';
+#endif
+
+  *m = '\0';
+  return (modestr);
+}
+
+static char *
+stattime (t)
+     time_t t;
+{
+  char *tbuf, *ret;
+  size_t tlen;
+
+  tbuf = ctime (&t);
+  tlen = strlen (tbuf);
+  ret = savestring (tbuf);
+  ret[tlen-1] = '\0';
+  return ret;
+}
+
+static char *
+statval (which, fname, flags, sp)
+     int which;
+     char *fname;
+     int flags;
+     struct stat *sp;
+{
+  int temp;
+
+  switch (which)
+    {
+    case ST_NAME:
+      return savestring (fname);
+    case ST_DEV:
+      return itos (sp->st_dev);
+    case ST_INO:
+      return itos (sp->st_ino);
+    case ST_MODE:
+      return (statmode (sp->st_mode));
+    case ST_NLINK:
+      return itos (sp->st_nlink);
+    case ST_UID:
+      return itos (sp->st_uid);
+    case ST_GID:
+      return itos (sp->st_gid);
+    case ST_RDEV:
+      return itos (sp->st_rdev);
+    case ST_SIZE:
+      return itos (sp->st_size);
+    case ST_ATIME:
+      return ((flags & 2) ? stattime (sp->st_atime) : itos (sp->st_atime));
+    case ST_MTIME:
+      return ((flags & 2) ? stattime (sp->st_mtime) : itos (sp->st_mtime));
+    case ST_CTIME:
+      return ((flags & 2) ? stattime (sp->st_ctime) : itos (sp->st_ctime));
+    case ST_BLKSIZE:
+      return itos (sp->st_blksize);
+    case ST_BLOCKS:
+      return itos (sp->st_blocks);
+    case ST_CHASELINK:
+      return (statlink (fname, sp));
+    case ST_PERMS:
+      temp = sp->st_mode & (S_IRWXU|S_IRWXG|S_IRWXO|S_ISUID|S_ISGID);
+      return (flags & 2) ? statperms (temp) : octalperms (temp);
+    default:
+      return savestring ("42");
+    }
+}
+
+static int
+loadstat (vname, var, fname, flags, sp)
+     char *vname;
+     SHELL_VAR *var;
+     char *fname;
+     int flags;
+     struct stat *sp;
+{
+  int i;
+  char *key, *value;
+  SHELL_VAR *v;
+
+  for (i = 0; arraysubs[i]; i++)
+    {
+      key = savestring (arraysubs[i]);
+      value = statval (i, fname, flags, sp);
+      v = bind_assoc_variable (var, vname, key, value, ASS_FORCE);
+    }
+  return 0;
+}
+
+int
+stat_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, flags;
+  char *aname, *fname;
+  struct stat st;
+  SHELL_VAR *v;
+
+  aname = "STAT";
+  flags = 0;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "A:Ll")) != -1)
+    {
+      switch (opt)
+	{
+	case 'A':
+	  aname = list_optarg;
+	  break;
+	case 'L':
+	  flags |= 1;		/* operate on links rather than resolving them */
+	  break;
+	case 'l':
+	  flags |= 2;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+
+  list = loptend;
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  fname = list->word->word;
+
+  if (getstat (fname, flags, &st) < 0)
+    {
+      builtin_error ("%s: cannot stat: %s", fname, strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+
+  unbind_variable (aname);
+  v = make_new_assoc_variable (aname);
+  if (v == 0)
+    {
+      builtin_error ("%s: cannot create variable", aname);
+      return (EXECUTION_FAILURE);
+    }
+  if (loadstat (aname, v, fname, flags, &st) < 0)
+    {
+      builtin_error ("%s: cannot assign file status information", aname);
+      unbind_variable (aname);
+      return (EXECUTION_FAILURE);
+    }
+
+  return (EXECUTION_SUCCESS);
+}
+
+/* An array of strings forming the `long' documentation for a builtin xxx,
+   which is printed by `help xxx'.  It must end with a NULL.  By convention,
+   the first line is a short description. */
+char *stat_doc[] = {
+	"Load an associative array with file status information.",
+	"",
+	"Take a filename and load the status information returned by a",
+	"stat(2) call on that file into the associative array specified",
+	"by the -A option.  The default array name is STAT.  If the -L",
+	"option is supplied, stat does not resolve symbolic links and",
+	"reports information about the link itself.  The -l option results",
+	"in longer-form listings for some of the fields. The exit status is 0",
+	"unless the stat fails or assigning the array is unsuccessful.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures.  The flags must include BUILTIN_ENABLED so the
+   builtin can be used. */
+struct builtin stat_struct = {
+	"stat",			/* builtin name */
+	stat_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	stat_doc,		/* array of long documentation strings. */
+	"stat [-lL] [-A aname] file",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/strftime.c b/examples/loadables/strftime.c
new file mode 100644
index 0000000..f4e194e
--- /dev/null
+++ b/examples/loadables/strftime.c
@@ -0,0 +1,128 @@
+/* strftime - loadable builtin interface to strftime(3) */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "bashtypes.h"
+#include "posixtime.h"
+
+#include <stdio.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+int
+strftime_builtin (list)
+     WORD_LIST *list;
+{
+  char *format, *tbuf;
+  size_t tbsize, tsize;
+  time_t secs;
+  struct tm *t;
+  int n;
+  intmax_t i;
+
+  if (no_options (list))
+    return (EX_USAGE);
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  format = list->word->word;
+  if (format == 0 || *format == 0)
+    {
+      printf ("\n");
+      return (EXECUTION_SUCCESS);
+    }
+
+  list = list->next;
+
+  if (list && list->word->word)
+    {
+      n = legal_number (list->word->word, &i);
+      if (n == 0 || i < 0 || i != (time_t)i)
+	{
+	  sh_invalidnum (list->word->word);
+	  return (EXECUTION_FAILURE);
+	}
+      else
+        secs = i;
+    }
+  else
+    secs = NOW;
+
+  t = localtime (&secs);
+
+  tbsize = strlen (format) * 4;
+  tbuf = 0;
+
+  /* Now try to figure out how big the buffer should really be.  strftime(3)
+     will return the number of bytes placed in the buffer unless it's greater
+     than MAXSIZE, in which case it returns 0. */
+  for (n = 1; n <= 8; n++)
+    {
+      tbuf = xrealloc (tbuf, tbsize * n);
+      tsize = strftime (tbuf, tbsize * n, format, t);
+      if (tsize)
+        break;
+    }
+
+  if (tsize)
+    printf ("%s\n", tbuf);
+  free (tbuf);
+
+  return (EXECUTION_SUCCESS);
+}
+
+/* An array of strings forming the `long' documentation for a builtin xxx,
+   which is printed by `help xxx'.  It must end with a NULL. */
+char *strftime_doc[] = {
+	"Display formatted time.",
+	"",
+	"Converts date and time format to a string and displays it on the",
+	"standard output.  If the optional second argument is supplied, it",
+	"is used as the number of seconds since the epoch to use in the",
+	"conversion, otherwise the current time is used.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures.  The flags must include BUILTIN_ENABLED so the
+   builtin can be used. */
+struct builtin strftime_struct = {
+	"strftime",		/* builtin name */
+	strftime_builtin,	/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	strftime_doc,		/* array of long documentation strings. */
+	"strftime format [seconds]",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/sync.c b/examples/loadables/sync.c
new file mode 100644
index 0000000..4fbeee1
--- /dev/null
+++ b/examples/loadables/sync.c
@@ -0,0 +1,53 @@
+/* sync - sync the disks by forcing pending filesystem writes to complete */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+
+int
+sync_builtin (list)
+     WORD_LIST *list;
+{
+  sync();
+  return (EXECUTION_SUCCESS);
+}
+
+char *sync_doc[] = {
+	"Sync disks.",
+	""
+	"Force completion of pending disk writes",
+	(char *)NULL
+};
+
+struct builtin sync_struct = {
+	"sync",			/* builtin name */
+	sync_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	sync_doc,		/* array of long documentation strings. */
+	"sync",			/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/tee.c b/examples/loadables/tee.c
new file mode 100644
index 0000000..283f23f
--- /dev/null
+++ b/examples/loadables/tee.c
@@ -0,0 +1,180 @@
+/* tee - duplicate standard input */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include "bashtypes.h"
+#include "posixstat.h"
+#include "filecntl.h"
+
+#include <signal.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "bashansi.h"
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+typedef struct flist {
+  struct flist *next;
+  int fd;
+  char *fname;
+} FLIST;
+
+static FLIST *tee_flist;
+
+#define TEE_BUFSIZE	8192
+
+extern int interrupt_immediately;
+
+extern char *strerror ();
+
+int
+tee_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, append, nointr, rval, fd, fflags;
+  int n, nr, nw;
+  FLIST *fl;
+  char *buf, *bp;
+
+  char *t;
+
+  reset_internal_getopt ();
+  append = nointr = 0;
+  tee_flist = (FLIST *)NULL;
+  while ((opt = internal_getopt (list, "ai")) != -1)
+    {
+      switch (opt)
+	{
+	case 'a':
+	  append = 1;
+	  break;
+	case 'i':
+	  nointr = 1;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (nointr == 0)
+    interrupt_immediately++;
+
+  buf = xmalloc (TEE_BUFSIZE);
+
+  /* Initialize output file list. */
+  fl = tee_flist = (FLIST *)xmalloc (sizeof(FLIST));
+  tee_flist->fd = 1;
+  tee_flist->fname = "stdout";
+  tee_flist->next = (FLIST *)NULL;
+
+  /* Add file arguments to list of output files. */
+  fflags = append ? O_WRONLY|O_CREAT|O_APPEND : O_WRONLY|O_CREAT|O_TRUNC;
+  for (rval = EXECUTION_SUCCESS; list; list = list->next)
+    {
+      fd = open (list->word->word, fflags, 0666);
+      if (fd < 0)
+        {
+          builtin_error ("%s: cannot open: %s", list->word->word, strerror (errno));
+          rval = EXECUTION_FAILURE;
+        }
+      else
+        {
+          fl->next = (FLIST *)xmalloc (sizeof(FLIST));
+          fl->next->fd = fd;
+          fl->next->fname = list->word->word;
+          fl = fl->next;
+          fl->next = (FLIST *)NULL;
+        }
+    }
+
+  while ((nr = read(0, buf, TEE_BUFSIZE)) > 0)
+    for (fl = tee_flist; fl; fl = fl->next)
+      {
+	n = nr;
+	bp = buf;
+	do
+	  {
+	    if ((nw = write (fl->fd, bp, n)) == -1)
+	      {
+		builtin_error ("%s: write error: %s", fl->fname, strerror (errno));
+		rval = EXECUTION_FAILURE;
+		break;
+	      }
+            bp += nw;
+	  }
+	while (n -= nw);
+      }
+  if (nr < 0)
+    builtin_error ("read error: %s", strerror (errno));
+
+  /* Deallocate resources -- this is a builtin command. */
+  tee_flist = tee_flist->next;		/* skip bogus close of stdout */
+  while (tee_flist)
+    {
+      fl = tee_flist;
+      if (close (fl->fd) < 0)
+	{
+	  builtin_error ("%s: close_error: %s", fl->fname, strerror (errno));
+	  rval = EXECUTION_FAILURE;
+	}
+      tee_flist = tee_flist->next;
+      free (fl);
+    }
+  
+  return (rval);
+}
+
+char *tee_doc[] = {
+	"Duplicate standard output.",
+	"",
+	"Copy standard input to standard output, making a copy in each",
+	"filename argument.  If the `-a' option is given, the specified",
+	"files are appended to, otherwise they are overwritten.  If the",
+	"`-i' option is supplied, tee ignores interrupts.",
+	(char *)NULL
+};
+
+struct builtin tee_struct = {
+	"tee",			/* builtin name */
+	tee_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	tee_doc,		/* array of long documentation strings. */
+	"tee [-ai] [file ...]",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/template.c b/examples/loadables/template.c
new file mode 100644
index 0000000..094b80c
--- /dev/null
+++ b/examples/loadables/template.c
@@ -0,0 +1,75 @@
+/* template - example template for loadable builtin */
+
+/* See Makefile for compilation details. */
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+#include "bashansi.h"
+#include <stdio.h>
+#include <errno.h>
+
+#include "loadables.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+extern char *strerror ();
+
+int
+template_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, rval;
+
+  rval = EXECUTION_SUCCESS;
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "")) != -1)
+    {
+      switch (opt)
+	{
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  return (rval);
+}
+
+/* Called when `template' is enabled and loaded from the shared object.  If this
+   function returns 0, the load fails. */
+int
+template_builtin_load (name)
+     char *name;
+{
+  return (1);
+}
+
+/* Called when `template' is disabled. */
+void
+template_builtin_unload (name)
+     char *name;
+{
+}
+
+char *template_doc[] = {
+	"Short description.",
+	""
+	"Longer description of builtin and usage.",
+	(char *)NULL
+};
+
+struct builtin template_struct = {
+	"template",			/* builtin name */
+	template_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,		/* initial flags for builtin */
+	template_doc,			/* array of long documentation strings. */
+	"template",			/* usage synopsis; becomes short_doc */
+	0				/* reserved for internal use */
+};
diff --git a/examples/loadables/truefalse.c b/examples/loadables/truefalse.c
new file mode 100644
index 0000000..e011fa1
--- /dev/null
+++ b/examples/loadables/truefalse.c
@@ -0,0 +1,72 @@
+/* true and false builtins */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#include "bashtypes.h"
+#include "shell.h"
+#include "builtins.h"
+#include "common.h"
+
+int
+true_builtin (list)
+     WORD_LIST *list;
+{
+  return EXECUTION_SUCCESS;
+}
+
+int
+false_builtin (list)
+     WORD_LIST *list;
+{
+  return EXECUTION_FAILURE;
+}
+
+static char *true_doc[] = {
+	"Exit successfully.",
+	"",
+	"Return a successful result.",
+	(char *)NULL
+};
+
+static char *false_doc[] = {
+	"Exit unsuccessfully.",
+	"",
+	"Return an unsuccessful result.",
+	(char *)NULL
+};
+
+struct builtin true_struct = {
+	"true",
+	true_builtin,
+	BUILTIN_ENABLED,
+	true_doc,
+	"true",
+	0
+};
+
+struct builtin false_struct = {
+	"false",
+	false_builtin,
+	BUILTIN_ENABLED,
+	false_doc,
+	"false",
+	0
+};
diff --git a/examples/loadables/tty.c b/examples/loadables/tty.c
new file mode 100644
index 0000000..febf518
--- /dev/null
+++ b/examples/loadables/tty.c
@@ -0,0 +1,82 @@
+/* tty - return terminal name */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include <stdio.h>
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+extern char *ttyname ();
+
+int
+tty_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, sflag;
+  char *t;
+
+  reset_internal_getopt ();
+  sflag = 0;
+  while ((opt = internal_getopt (list, "s")) != -1)
+    {
+      switch (opt)
+	{
+	case 's':
+	  sflag = 1;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  t = ttyname (0);
+  if (sflag == 0)
+    puts (t ? t : "not a tty");
+  return (t ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
+}
+
+char *tty_doc[] = {
+	"Display terminal name.",
+	"",
+	"tty writes the name of the terminal that is opened for standard",
+	"input to standard output.  If the `-s' option is supplied, nothing",
+	"is written; the exit status determines whether or not the standard",
+	"input is connected to a tty.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin tty_struct = {
+	"tty",			/* builtin name */
+	tty_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	tty_doc,		/* array of long documentation strings. */
+	"tty [-s]",		/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/uname.c b/examples/loadables/uname.c
new file mode 100644
index 0000000..106a1c8
--- /dev/null
+++ b/examples/loadables/uname.c
@@ -0,0 +1,162 @@
+/*
+ * uname - print system information
+ *
+ * usage: uname [-amnrsv]
+ *
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <stdio.h>
+
+#include "bashtypes.h"
+
+#if defined (HAVE_UNAME)
+#  include <sys/utsname.h>
+#else
+struct utsname {
+	char	sysname[32];
+	char	nodename[32];
+	char	release[32];
+	char	version[32];
+	char	machine[32];
+};
+#endif
+
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#define FLAG_SYSNAME	0x01	/* -s */
+#define FLAG_NODENAME	0x02	/* -n */
+#define FLAG_RELEASE	0x04	/* -r */
+#define FLAG_VERSION	0x08	/* -v */
+#define FLAG_MACHINE	0x10	/* -m, -p */
+
+#define FLAG_ALL	0x1f
+
+#ifndef errno
+extern int errno;
+#endif
+
+static void uprint();
+
+static int uname_flags;
+
+int
+uname_builtin (list)
+     WORD_LIST *list;
+{
+  int opt, r;
+  struct utsname uninfo;
+
+  uname_flags = 0;
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "amnprsv")) != -1)
+    {
+      switch (opt)
+	{
+	case 'a':
+	  uname_flags |= FLAG_ALL;
+	  break;
+	case 'm':
+	case 'p':
+	  uname_flags |= FLAG_MACHINE;
+	  break;
+	case 'n':
+	  uname_flags |= FLAG_NODENAME;
+	  break;
+	case 'r':
+	  uname_flags |= FLAG_RELEASE;
+	  break;
+	case 's':
+	  uname_flags |= FLAG_SYSNAME;
+	  break;
+	case 'v':
+	  uname_flags |= FLAG_VERSION;
+	  break;
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (list)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (uname_flags == 0)
+    uname_flags = FLAG_SYSNAME;
+
+  /* Only ancient systems will not have uname(2). */
+#ifdef HAVE_UNAME
+  if (uname (&uninfo) < 0)
+    {
+      builtin_error ("cannot get system name: %s", strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+#else
+  builtin_error ("cannot get system information: uname(2) not available");
+  return (EXECUTION_FAILURE);
+#endif
+
+  uprint (FLAG_SYSNAME, uninfo.sysname);
+  uprint (FLAG_NODENAME, uninfo.nodename);
+  uprint (FLAG_RELEASE, uninfo.release);
+  uprint (FLAG_VERSION, uninfo.version);
+  uprint (FLAG_MACHINE, uninfo.machine);
+
+  return (EXECUTION_SUCCESS);
+}
+
+static void
+uprint (flag, info)
+     int flag;
+     char *info;
+{
+  if (uname_flags & flag)
+    {
+      uname_flags &= ~flag;
+      printf ("%s%c", info, uname_flags ? ' ' : '\n');
+    }
+}
+
+char *uname_doc[] = {
+	"Display system information.",
+	"",
+	"Display information about the system hardware and OS.",
+	(char *)NULL
+};
+
+struct builtin uname_struct = {
+	"uname",
+	uname_builtin,
+	BUILTIN_ENABLED,
+	uname_doc,
+	"uname [-amnrsv]",
+	0
+};
diff --git a/examples/loadables/unlink.c b/examples/loadables/unlink.c
new file mode 100644
index 0000000..ff2a78a
--- /dev/null
+++ b/examples/loadables/unlink.c
@@ -0,0 +1,74 @@
+/* unlink - remove a directory entry */
+
+/* Should only be used to remove directories by a superuser prepared to let
+   fsck clean up the file system. */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "common.h"
+
+#ifndef errno
+extern int errno;
+#endif
+
+int
+unlink_builtin (list)
+     WORD_LIST *list;
+{
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (unlink (list->word->word) != 0)
+    {
+      builtin_error ("%s: cannot unlink: %s", list->word->word, strerror (errno));
+      return (EXECUTION_FAILURE);
+    }
+
+  return (EXECUTION_SUCCESS);
+}
+
+char *unlink_doc[] = {
+	"Remove a directory entry.",
+	"",
+	"Forcibly remove a directory entry, even if it's a directory.",
+	(char *)NULL
+};
+
+struct builtin unlink_struct = {
+	"unlink",		/* builtin name */
+	unlink_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	unlink_doc,		/* array of long documentation strings. */
+	"unlink name",		/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};
diff --git a/examples/loadables/whoami.c b/examples/loadables/whoami.c
new file mode 100644
index 0000000..3e7e36e
--- /dev/null
+++ b/examples/loadables/whoami.c
@@ -0,0 +1,75 @@
+/*
+ * whoami - print out username of current user
+ */
+
+/*
+   Copyright (C) 1999-2009 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash.
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <stdio.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+int
+whoami_builtin (list)
+     WORD_LIST *list;
+{
+  int opt;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "")) != -1)
+    {
+      switch (opt)
+	{
+	CASE_HELPOPT;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+  if (list)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  if (current_user.user_name == 0)
+    get_current_user_info ();
+  printf ("%s\n", current_user.user_name);
+  return (EXECUTION_SUCCESS);
+}
+
+char *whoami_doc[] = {
+	"Print user name",
+	"",
+	"Display name of current user.",
+	(char *)NULL
+};
+
+struct builtin whoami_struct = {
+	"whoami",
+	whoami_builtin,
+	BUILTIN_ENABLED,
+	whoami_doc,
+	"whoami",
+	0
+};