1 files changed, 336 insertions, 0 deletions
diff --git a/examples/loadables/fdflags.c b/examples/loadables/fdflags.c
new file mode 100644
index 0000000..f309466
--- /dev/null
+++ b/examples/loadables/fdflags.c
@@ -0,0 +1,336 @@
+/* Loadable builtin to get and set file descriptor flags. */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 2017 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"
+
+static const struct
+{
+  const char *name;
+  int value;
+} file_flags[] =
+{
+#ifdef O_APPEND
+  { "append",	O_APPEND 	},
+#endif
+#ifdef O_ASYNC
+  { "async",	O_ASYNC		},
+#endif
+#ifdef O_SYNC
+  { "sync",	O_SYNC		},
+#endif
+#ifdef O_NONBLOCK
+  { "nonblock",	O_NONBLOCK	},
+#endif
+#ifdef O_FSYNC
+  { "fsync",	O_FSYNC		},
+#endif
+#ifdef O_DSYNC
+  { "dsync",	O_DSYNC		},
+#endif
+#ifdef O_RSYNC
+  { "rsync",	O_RSYNC		},
+#endif
+#ifdef O_ALT_IO
+  { "altio",	O_ALT_IO	},
+#endif
+#ifdef O_DIRECT
+  { "direct",	O_DIRECT	},
+#endif
+#ifdef O_NOATIME
+  { "noatime",	O_NOATIME	},
+#endif
+#ifdef O_NOSIGPIPE
+  { "nosigpipe",	O_NOSIGPIPE	},
+#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 */
+};