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diff --git a/builtins/enable.def b/builtins/enable.def
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+This file is enable.def, from which is created enable.c.
+It implements the builtin "enable" in Bash.
+
+Copyright (C) 1987-2016 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/>.
+
+$PRODUCES enable.c
+
+$BUILTIN enable
+$FUNCTION enable_builtin
+$SHORT_DOC enable [-a] [-dnps] [-f filename] [name ...]
+Enable and disable shell builtins.
+
+Enables and disables builtin shell commands. Disabling allows you to
+execute a disk command which has the same name as a shell builtin
+without using a full pathname.
+
+Options:
+ -a print a list of builtins showing whether or not each is enabled
+ -n disable each NAME or display a list of disabled builtins
+ -p print the list of builtins in a reusable format
+ -s print only the names of Posix `special' builtins
+
+Options controlling dynamic loading:
+ -f Load builtin NAME from shared object FILENAME
+ -d Remove a builtin loaded with -f
+
+Without options, each NAME is enabled.
+
+To use the `test' found in $PATH instead of the shell builtin
+version, type `enable -n test'.
+
+Exit Status:
+Returns success unless NAME is not a shell builtin or an error occurs.
+$END
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+# ifdef _MINIX
+# include <sys/types.h>
+# endif
+# include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "../bashansi.h"
+#include "../bashintl.h"
+
+#include "../shell.h"
+#include "../builtins.h"
+#include "../flags.h"
+#include "common.h"
+#include "bashgetopt.h"
+#include "findcmd.h"
+
+#if defined (PROGRAMMABLE_COMPLETION)
+# include "../pcomplete.h"
+#endif
+
+#define ENABLED 1
+#define DISABLED 2
+#define SPECIAL 4
+
+#define AFLAG 0x01
+#define DFLAG 0x02
+#define FFLAG 0x04
+#define NFLAG 0x08
+#define PFLAG 0x10
+#define SFLAG 0x20
+
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+static int dyn_load_builtin __P((WORD_LIST *, int, char *));
+#endif
+
+#if defined (HAVE_DLCLOSE)
+static int dyn_unload_builtin __P((char *));
+static void delete_builtin __P((struct builtin *));
+static int local_dlclose __P((void *));
+#endif
+
+#define STRUCT_SUFFIX "_struct"
+/* for now */
+#define LOAD_SUFFIX "_builtin_load"
+#define UNLOAD_SUFFIX "_builtin_unload"
+
+static void list_some_builtins __P((int));
+static int enable_shell_command __P((char *, int));
+
+/* Enable/disable shell commands present in LIST. If list is not specified,
+ then print out a list of shell commands showing which are enabled and
+ which are disabled. */
+int
+enable_builtin (list)
+ WORD_LIST *list;
+{
+ int result, flags;
+ int opt, filter;
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+ char *filename;
+#endif
+
+ result = EXECUTION_SUCCESS;
+ flags = 0;
+
+ reset_internal_getopt ();
+ while ((opt = internal_getopt (list, "adnpsf:")) != -1)
+ {
+ switch (opt)
+ {
+ case 'a':
+ flags |= AFLAG;
+ break;
+ case 'n':
+ flags |= NFLAG;
+ break;
+ case 'p':
+ flags |= PFLAG;
+ break;
+ case 's':
+ flags |= SFLAG;
+ break;
+ case 'f':
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+ flags |= FFLAG;
+ filename = list_optarg;
+ break;
+#else
+ builtin_error (_("dynamic loading not available"));
+ return (EX_USAGE);
+#endif
+#if defined (HAVE_DLCLOSE)
+ case 'd':
+ flags |= DFLAG;
+ break;
+#else
+ builtin_error (_("dynamic loading not available"));
+ return (EX_USAGE);
+#endif /* HAVE_DLCLOSE */
+ CASE_HELPOPT;
+ default:
+ builtin_usage ();
+ return (EX_USAGE);
+ }
+ }
+
+ list = loptend;
+
+#if defined (RESTRICTED_SHELL)
+ /* Restricted shells cannot load new builtins. */
+ if (restricted && (flags & (FFLAG|DFLAG)))
+ {
+ sh_restricted ((char *)NULL);
+ return (EXECUTION_FAILURE);
+ }
+#endif
+
+ if (list == 0 || (flags & PFLAG))
+ {
+ filter = (flags & AFLAG) ? (ENABLED | DISABLED)
+ : (flags & NFLAG) ? DISABLED : ENABLED;
+
+ if (flags & SFLAG)
+ filter |= SPECIAL;
+
+ list_some_builtins (filter);
+ }
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+ else if (flags & FFLAG)
+ {
+ filter = (flags & NFLAG) ? DISABLED : ENABLED;
+ if (flags & SFLAG)
+ filter |= SPECIAL;
+
+ result = dyn_load_builtin (list, filter, filename);
+#if defined (PROGRAMMABLE_COMPLETION)
+ set_itemlist_dirty (&it_builtins);
+#endif
+ }
+#endif
+#if defined (HAVE_DLCLOSE)
+ else if (flags & DFLAG)
+ {
+ while (list)
+ {
+ opt = dyn_unload_builtin (list->word->word);
+ if (opt == EXECUTION_FAILURE)
+ result = EXECUTION_FAILURE;
+ list = list->next;
+ }
+#if defined (PROGRAMMABLE_COMPLETION)
+ set_itemlist_dirty (&it_builtins);
+#endif
+ }
+#endif
+ else
+ {
+ while (list)
+ {
+ opt = enable_shell_command (list->word->word, flags & NFLAG);
+
+ if (opt == EXECUTION_FAILURE)
+ {
+ sh_notbuiltin (list->word->word);
+ result = EXECUTION_FAILURE;
+ }
+ list = list->next;
+ }
+ }
+ return (result);
+}
+
+/* List some builtins.
+ FILTER is a mask with two slots: ENABLED and DISABLED. */
+static void
+list_some_builtins (filter)
+ int filter;
+{
+ register int i;
+
+ for (i = 0; i < num_shell_builtins; i++)
+ {
+ if (shell_builtins[i].function == 0 || (shell_builtins[i].flags & BUILTIN_DELETED))
+ continue;
+
+ if ((filter & SPECIAL) &&
+ (shell_builtins[i].flags & SPECIAL_BUILTIN) == 0)
+ continue;
+
+ if ((filter & ENABLED) && (shell_builtins[i].flags & BUILTIN_ENABLED))
+ printf ("enable %s\n", shell_builtins[i].name);
+ else if ((filter & DISABLED) &&
+ ((shell_builtins[i].flags & BUILTIN_ENABLED) == 0))
+ printf ("enable -n %s\n", shell_builtins[i].name);
+ }
+}
+
+/* Enable the shell command NAME. If DISABLE_P is non-zero, then
+ disable NAME instead. */
+static int
+enable_shell_command (name, disable_p)
+ char *name;
+ int disable_p;
+{
+ struct builtin *b;
+
+ b = builtin_address_internal (name, 1);
+ if (b == 0)
+ return (EXECUTION_FAILURE);
+
+ if (disable_p)
+ b->flags &= ~BUILTIN_ENABLED;
+#if defined (RESTRICTED_SHELL)
+ else if (restricted && ((b->flags & BUILTIN_ENABLED) == 0))
+ {
+ sh_restricted ((char *)NULL);
+ return (EXECUTION_FAILURE);
+ }
+#endif
+ else
+ b->flags |= BUILTIN_ENABLED;
+
+#if defined (PROGRAMMABLE_COMPLETION)
+ set_itemlist_dirty (&it_enabled);
+ set_itemlist_dirty (&it_disabled);
+#endif
+
+ return (EXECUTION_SUCCESS);
+}
+
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+
+#if defined (HAVE_DLFCN_H)
+# include <dlfcn.h>
+#endif
+
+static int
+dyn_load_builtin (list, flags, filename)
+ WORD_LIST *list;
+ int flags;
+ char *filename;
+{
+ WORD_LIST *l;
+ void *handle;
+
+ int total, size, new, replaced, r;
+ char *struct_name, *name, *funcname;
+ sh_load_func_t *loadfunc;
+ struct builtin **new_builtins, *b, *new_shell_builtins, *old_builtin;
+ char *loadables_path, *load_path;
+
+ if (list == 0)
+ return (EXECUTION_FAILURE);
+
+#ifndef RTLD_LAZY
+#define RTLD_LAZY 1
+#endif
+
+ handle = 0;
+ if (absolute_program (filename) == 0)
+ {
+ loadables_path = get_string_value ("BASH_LOADABLES_PATH");
+ if (loadables_path)
+ {
+ load_path = find_in_path (filename, loadables_path, FS_NODIRS|FS_EXEC_PREFERRED);
+ if (load_path)
+ {
+#if defined (_AIX)
+ handle = dlopen (load_path, RTLD_NOW|RTLD_GLOBAL);
+#else
+ handle = dlopen (load_path, RTLD_LAZY);
+#endif /* !_AIX */
+ free (load_path);
+ }
+ }
+ }
+
+ /* Fall back to current directory for now */
+ if (handle == 0)
+#if defined (_AIX)
+ handle = dlopen (filename, RTLD_NOW|RTLD_GLOBAL);
+#else
+ handle = dlopen (filename, RTLD_LAZY);
+#endif /* !_AIX */
+
+ if (handle == 0)
+ {
+ name = printable_filename (filename, 0);
+ builtin_error (_("cannot open shared object %s: %s"), name, dlerror ());
+ if (name != filename)
+ free (name);
+ return (EXECUTION_FAILURE);
+ }
+
+ for (new = 0, l = list; l; l = l->next, new++)
+ ;
+ new_builtins = (struct builtin **)xmalloc (new * sizeof (struct builtin *));
+
+ /* For each new builtin in the shared object, find it and its describing
+ structure. If this is overwriting an existing builtin, do so, otherwise
+ save the loaded struct for creating the new list of builtins. */
+ for (replaced = new = 0; list; list = list->next)
+ {
+ name = list->word->word;
+
+ size = strlen (name);
+ struct_name = (char *)xmalloc (size + 8);
+ strcpy (struct_name, name);
+ strcpy (struct_name + size, STRUCT_SUFFIX);
+
+ b = (struct builtin *)dlsym (handle, struct_name);
+ if (b == 0)
+ {
+ name = printable_filename (filename, 0);
+ builtin_error (_("cannot find %s in shared object %s: %s"),
+ struct_name, name, dlerror ());
+ if (name != filename)
+ free (name);
+ free (struct_name);
+ continue;
+ }
+
+ funcname = xrealloc (struct_name, size + sizeof (LOAD_SUFFIX) + 1);
+ strcpy (funcname, name);
+ strcpy (funcname + size, LOAD_SUFFIX);
+
+ loadfunc = (sh_load_func_t *)dlsym (handle, funcname);
+ if (loadfunc)
+ {
+ r = (*loadfunc) (name);
+ if (r == 0)
+ {
+ builtin_error (_("load function for %s returns failure (%d): not loaded"), name, r);
+ free (funcname);
+ continue;
+ }
+ }
+ free (funcname);
+
+ b->flags &= ~STATIC_BUILTIN;
+ if (flags & SPECIAL)
+ b->flags |= SPECIAL_BUILTIN;
+ b->handle = handle;
+
+ if (old_builtin = builtin_address_internal (name, 1))
+ {
+ replaced++;
+ FASTCOPY ((char *)b, (char *)old_builtin, sizeof (struct builtin));
+ }
+ else
+ new_builtins[new++] = b;
+ }
+
+ if (replaced == 0 && new == 0)
+ {
+ free (new_builtins);
+ dlclose (handle);
+ return (EXECUTION_FAILURE);
+ }
+
+ if (new)
+ {
+ total = num_shell_builtins + new;
+ size = (total + 1) * sizeof (struct builtin);
+
+ new_shell_builtins = (struct builtin *)xmalloc (size);
+ FASTCOPY ((char *)shell_builtins, (char *)new_shell_builtins,
+ num_shell_builtins * sizeof (struct builtin));
+ for (replaced = 0; replaced < new; replaced++)
+ FASTCOPY ((char *)new_builtins[replaced],
+ (char *)&new_shell_builtins[num_shell_builtins + replaced],
+ sizeof (struct builtin));
+
+ new_shell_builtins[total].name = (char *)0;
+ new_shell_builtins[total].function = (sh_builtin_func_t *)0;
+ new_shell_builtins[total].flags = 0;
+
+ if (shell_builtins != static_shell_builtins)
+ free (shell_builtins);
+
+ shell_builtins = new_shell_builtins;
+ num_shell_builtins = total;
+ initialize_shell_builtins ();
+ }
+
+ free (new_builtins);
+ return (EXECUTION_SUCCESS);
+}
+#endif
+
+#if defined (HAVE_DLCLOSE)
+static void
+delete_builtin (b)
+ struct builtin *b;
+{
+ int ind, size;
+ struct builtin *new_shell_builtins;
+
+ /* XXX - funky pointer arithmetic - XXX */
+#ifdef __STDC__
+ ind = b - shell_builtins;
+#else
+ ind = ((int)b - (int)shell_builtins) / sizeof (struct builtin);
+#endif
+ size = num_shell_builtins * sizeof (struct builtin);
+ new_shell_builtins = (struct builtin *)xmalloc (size);
+
+ /* Copy shell_builtins[0]...shell_builtins[ind - 1] to new_shell_builtins */
+ if (ind)
+ FASTCOPY ((char *)shell_builtins, (char *)new_shell_builtins,
+ ind * sizeof (struct builtin));
+ /* Copy shell_builtins[ind+1]...shell_builtins[num_shell_builtins to
+ new_shell_builtins, starting at ind. */
+ FASTCOPY ((char *)(&shell_builtins[ind+1]),
+ (char *)(&new_shell_builtins[ind]),
+ (num_shell_builtins - ind) * sizeof (struct builtin));
+
+ if (shell_builtins != static_shell_builtins)
+ free (shell_builtins);
+
+ /* The result is still sorted. */
+ num_shell_builtins--;
+ shell_builtins = new_shell_builtins;
+}
+
+/* Tenon's MachTen has a dlclose that doesn't return a value, so we
+ finesse it with a local wrapper. */
+static int
+local_dlclose (handle)
+ void *handle;
+{
+#if !defined (__MACHTEN__)
+ return (dlclose (handle));
+#else /* __MACHTEN__ */
+ dlclose (handle);
+ return ((dlerror () != NULL) ? -1 : 0);
+#endif /* __MACHTEN__ */
+}
+
+static int
+dyn_unload_builtin (name)
+ char *name;
+{
+ struct builtin *b;
+ void *handle;
+ char *funcname;
+ sh_unload_func_t *unloadfunc;
+ int ref, i, size;
+
+ b = builtin_address_internal (name, 1);
+ if (b == 0)
+ {
+ sh_notbuiltin (name);
+ return (EXECUTION_FAILURE);
+ }
+ if (b->flags & STATIC_BUILTIN)
+ {
+ builtin_error (_("%s: not dynamically loaded"), name);
+ return (EXECUTION_FAILURE);
+ }
+
+ handle = (void *)b->handle;
+ for (ref = i = 0; i < num_shell_builtins; i++)
+ {
+ if (shell_builtins[i].handle == b->handle)
+ ref++;
+ }
+
+ /* Call any unload function */
+ size = strlen (name);
+ funcname = xmalloc (size + sizeof (UNLOAD_SUFFIX) + 1);
+ strcpy (funcname, name);
+ strcpy (funcname + size, UNLOAD_SUFFIX);
+
+ unloadfunc = (sh_unload_func_t *)dlsym (handle, funcname);
+ if (unloadfunc)
+ (*unloadfunc) (name); /* void function */
+ free (funcname);
+
+ /* Don't remove the shared object unless the reference count of builtins
+ using it drops to zero. */
+ if (ref == 1 && local_dlclose (handle) != 0)
+ {
+ builtin_error (_("%s: cannot delete: %s"), name, dlerror ());
+ return (EXECUTION_FAILURE);
+ }
+
+ /* Now remove this entry from the builtin table and reinitialize. */
+ delete_builtin (b);
+
+ return (EXECUTION_SUCCESS);
+}
+#endif
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