Adding upstream version 5.2.15.upstream/5.2.15upstream

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

1 files changed, 1528 insertions, 0 deletions

diff --git a/redir.c b/redir.c
new file mode 100644
index 0000000..8369adc
--- /dev/null
+++ b/redir.c
@@ -0,0 +1,1528 @@
+/* redir.c -- Functions to perform input and output redirection. */
+
+/* Copyright (C) 1997-2021 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/>.
+*/
+
+#include "config.h"
+
+#if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX)
+  #pragma alloca
+#endif /* _AIX && RISC6000 && !__GNUC__ */
+
+#include <stdio.h>
+#include "bashtypes.h"
+#if !defined (_MINIX) && defined (HAVE_SYS_FILE_H)
+#  include <sys/file.h>
+#endif
+#include "filecntl.h"
+#include "posixstat.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <errno.h>
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#include "bashansi.h"
+#include "bashintl.h"
+#include "memalloc.h"
+
+#define NEED_FPURGE_DECL
+
+#include "shell.h"
+#include "flags.h"
+#include "execute_cmd.h"
+#include "redir.h"
+#include "trap.h"
+
+#if defined (BUFFERED_INPUT)
+#  include "input.h"
+#endif
+
+#include "builtins/pipesize.h"
+
+/* FreeBSD 13 can reliably handle atomic writes at this capacity without
+   hanging. */
+#if __FreeBSD__ && !defined (HEREDOC_PIPESIZE)
+#  define HEREDOC_PIPESIZE 4096
+#endif
+
+/* Normally set by a build process command that computes pipe capacity */
+#ifndef PIPESIZE
+#  ifdef PIPE_BUF
+#    define PIPESIZE PIPE_BUF
+#  else
+#    define PIPESIZE 4096
+#  endif
+#endif
+
+#ifndef HEREDOC_PIPESIZE
+#  define HEREDOC_PIPESIZE PIPESIZE
+#endif
+
+#if defined (HEREDOC_PIPEMAX)
+#  if HEREDOC_PIPESIZE > HEREDOC_PIPEMAX
+#    define HEREDOC_PIPESIZE HEREDOC_PIPEMAX
+#  endif
+#endif
+
+#define SHELL_FD_BASE	10
+
+int expanding_redir;
+int varassign_redir_autoclose = 0;
+
+extern REDIRECT *redirection_undo_list;
+extern REDIRECT *exec_redirection_undo_list;
+
+/* Static functions defined and used in this file. */
+static void add_exec_redirect PARAMS((REDIRECT *));
+static int add_undo_redirect PARAMS((int, enum r_instruction, int));
+static int add_undo_close_redirect PARAMS((int));
+static int expandable_redirection_filename PARAMS((REDIRECT *));
+static int stdin_redirection PARAMS((enum r_instruction, int));
+static int undoablefd PARAMS((int));
+static int do_redirection_internal PARAMS((REDIRECT *, int, char **));
+
+static char *heredoc_expand PARAMS((WORD_DESC *, enum r_instruction, size_t *));
+static int heredoc_write PARAMS((int, char *, size_t));
+static int here_document_to_fd PARAMS((WORD_DESC *, enum r_instruction));
+
+static int redir_special_open PARAMS((int, char *, int, int, enum r_instruction));
+static int noclobber_open PARAMS((char *, int, int, enum r_instruction));
+static int redir_open PARAMS((char *, int, int, enum r_instruction));
+
+static int redir_varassign PARAMS((REDIRECT *, int));
+static int redir_varvalue PARAMS((REDIRECT *));
+
+/* Spare redirector used when translating [N]>&WORD[-] or [N]<&WORD[-] to
+   a new redirection and when creating the redirection undo list. */
+static REDIRECTEE rd;
+
+/* Set to errno when a here document cannot be created for some reason.
+   Used to print a reasonable error message. */
+static int heredoc_errno;
+
+#define REDIRECTION_ERROR(r, e, fd) \
+do { \
+  if ((r) < 0) \
+    { \
+      if (fd >= 0) \
+	close (fd); \
+      set_exit_status (EXECUTION_FAILURE);\
+      return ((e) == 0 ? EINVAL : (e));\
+    } \
+} while (0)
+
+void
+redirection_error (temp, error, fn)
+     REDIRECT *temp;
+     int error;
+     char *fn;		/* already-expanded filename */
+{
+  char *filename, *allocname;
+  int oflags;
+
+  allocname = 0;
+  if ((temp->rflags & REDIR_VARASSIGN) && error < 0)
+    filename = allocname = savestring (temp->redirector.filename->word);
+  else if ((temp->rflags & REDIR_VARASSIGN) == 0 && temp->redirector.dest < 0)
+    /* This can happen when read_token_word encounters overflow, like in
+       exec 4294967297>x */
+    filename = _("file descriptor out of range");
+#ifdef EBADF
+  /* This error can never involve NOCLOBBER */
+  else if (error != NOCLOBBER_REDIRECT && temp->redirector.dest >= 0 && error == EBADF)
+    {
+      /* If we're dealing with two file descriptors, we have to guess about
+         which one is invalid; in the cases of r_{duplicating,move}_input and
+         r_{duplicating,move}_output we're here because dup2() failed. */
+      switch (temp->instruction)
+        {
+        case r_duplicating_input:
+        case r_duplicating_output:
+        case r_move_input:
+        case r_move_output:
+	  filename = allocname = itos (temp->redirectee.dest);
+	  break;
+	case r_duplicating_input_word:
+	  if (temp->redirector.dest == 0)	/* Guess */
+	    filename = temp->redirectee.filename->word;	/* XXX */
+	  else
+	    filename = allocname = itos (temp->redirector.dest);
+	  break;
+	case r_duplicating_output_word:
+	  if (temp->redirector.dest == 1)	/* Guess */
+	    filename = temp->redirectee.filename->word;	/* XXX */
+	  else
+	    filename = allocname = itos (temp->redirector.dest);
+	  break;
+	default:
+	  filename = allocname = itos (temp->redirector.dest);
+	  break;
+        }
+    }
+#endif
+  else if (fn)
+    filename = fn;
+  else if (expandable_redirection_filename (temp))
+    {
+      oflags = temp->redirectee.filename->flags;
+      if (posixly_correct && interactive_shell == 0)
+	temp->redirectee.filename->flags |= W_NOGLOB;
+      temp->redirectee.filename->flags |= W_NOCOMSUB;
+      filename = allocname = redirection_expand (temp->redirectee.filename);
+      temp->redirectee.filename->flags = oflags;
+      if (filename == 0)
+	filename = temp->redirectee.filename->word;
+    }
+  else if (temp->redirectee.dest < 0)
+    filename = _("file descriptor out of range");
+  else
+    filename = allocname = itos (temp->redirectee.dest);
+
+  switch (error)
+    {
+    case AMBIGUOUS_REDIRECT:
+      internal_error (_("%s: ambiguous redirect"), filename);
+      break;
+
+    case NOCLOBBER_REDIRECT:
+      internal_error (_("%s: cannot overwrite existing file"), filename);
+      break;
+
+#if defined (RESTRICTED_SHELL)
+    case RESTRICTED_REDIRECT:
+      internal_error (_("%s: restricted: cannot redirect output"), filename);
+      break;
+#endif /* RESTRICTED_SHELL */
+
+    case HEREDOC_REDIRECT:
+      internal_error (_("cannot create temp file for here-document: %s"), strerror (heredoc_errno));
+      break;
+
+    case BADVAR_REDIRECT:
+      internal_error (_("%s: cannot assign fd to variable"), filename);
+      break;
+
+    default:
+      internal_error ("%s: %s", filename, strerror (error));
+      break;
+    }
+
+  FREE (allocname);
+}
+
+/* Perform the redirections on LIST.  If flags & RX_ACTIVE, then actually
+   make input and output file descriptors, otherwise just do whatever is
+   necessary for side effecting.  flags & RX_UNDOABLE says to remember
+   how to undo the redirections later, if non-zero.  If flags & RX_CLEXEC
+   is non-zero, file descriptors opened in do_redirection () have their
+   close-on-exec flag set. */
+int
+do_redirections (list, flags)
+     REDIRECT *list;
+     int flags;
+{
+  int error;
+  REDIRECT *temp;
+  char *fn;
+
+  if (flags & RX_UNDOABLE)
+    {
+      if (redirection_undo_list)
+	{
+	  dispose_redirects (redirection_undo_list);
+	  redirection_undo_list = (REDIRECT *)NULL;
+	}
+      if (exec_redirection_undo_list)
+	dispose_exec_redirects ();
+    }
+
+  for (temp = list; temp; temp = temp->next)
+    {
+      fn = 0;
+      error = do_redirection_internal (temp, flags, &fn);
+      if (error)
+	{
+	  redirection_error (temp, error, fn);
+	  FREE (fn);
+	  return (error);
+	}
+      FREE (fn);
+    }
+  return (0);
+}
+
+/* Return non-zero if the redirection pointed to by REDIRECT has a
+   redirectee.filename that can be expanded. */
+static int
+expandable_redirection_filename (redirect)
+     REDIRECT *redirect;
+{
+  switch (redirect->instruction)
+    {
+    case r_output_direction:
+    case r_appending_to:
+    case r_input_direction:
+    case r_inputa_direction:
+    case r_err_and_out:
+    case r_append_err_and_out:
+    case r_input_output:
+    case r_output_force:
+    case r_duplicating_input_word:
+    case r_duplicating_output_word:
+    case r_move_input_word:
+    case r_move_output_word:
+      return 1;
+
+    default:
+      return 0;
+    }
+}
+
+/* Expand the word in WORD returning a string.  If WORD expands to
+   multiple words (or no words), then return NULL. */
+char *
+redirection_expand (word)
+     WORD_DESC *word;
+{
+  char *result;
+  WORD_LIST *tlist1, *tlist2;
+  WORD_DESC *w;
+  int old;
+
+  w = copy_word (word);
+  if (posixly_correct)
+    w->flags |= W_NOSPLIT;
+
+  tlist1 = make_word_list (w, (WORD_LIST *)NULL);
+  expanding_redir = 1;
+  /* Now that we've changed the variable search order to ignore the temp
+     environment, see if we need to change the cached IFS values. */
+  sv_ifs ("IFS");
+  tlist2 = expand_words_no_vars (tlist1);
+  expanding_redir = 0;
+  /* Now we need to change the variable search order back to include the temp
+     environment.  We force the temp environment search by forcing
+     executing_builtin to 1.  This is what makes `read' get the right values
+     for the IFS-related cached variables, for example. */
+  old = executing_builtin;
+  executing_builtin = 1;
+  sv_ifs ("IFS");
+  executing_builtin = old;
+  dispose_words (tlist1);
+
+  if (tlist2 == 0 || tlist2->next)
+    {
+      /* We expanded to no words, or to more than a single word.
+	 Dispose of the word list and return NULL. */
+      if (tlist2)
+	dispose_words (tlist2);
+      return ((char *)NULL);
+    }
+  result = string_list (tlist2);  /* XXX savestring (tlist2->word->word)? */
+  dispose_words (tlist2);
+  return (result);
+}
+
+/* Expand a here-document or here-string (determined by RI) contained in
+   REDIRECTEE and return the expanded document. If LENP is non-zero, put
+   the length of the returned string into *LENP.
+
+   This captures everything about expanding here-documents and here-strings:
+   the returned document should be written directly to whatever file
+   descriptor is specified. In particular, it adds a newline to the end of
+   a here-string to preserve previous semantics. */
+static char *
+heredoc_expand (redirectee, ri, lenp)
+     WORD_DESC *redirectee;
+     enum r_instruction ri;
+     size_t *lenp;
+{
+  char *document;
+  size_t dlen;
+  int old;
+
+  if (redirectee->word == 0 || redirectee->word[0] == '\0')
+    {
+      if (lenp)
+        *lenp = 0;
+      return (redirectee->word);
+    }
+
+  /* Quoted here documents are not expanded */
+  if (ri != r_reading_string && (redirectee->flags & W_QUOTED))
+    {
+      if (lenp)
+        *lenp = STRLEN (redirectee->word);
+      return (redirectee->word);
+    }
+  
+  expanding_redir = 1;
+  /* Now that we've changed the variable search order to ignore the temp
+     environment, see if we need to change the cached IFS values. */
+  sv_ifs ("IFS");
+  document = (ri == r_reading_string) ? expand_assignment_string_to_string (redirectee->word, 0)
+  				      : expand_string_to_string (redirectee->word, Q_HERE_DOCUMENT);
+  expanding_redir = 0;
+  /* Now we need to change the variable search order back to include the temp
+     environment.  We force the temp environment search by forcing
+     executing_builtin to 1.  This is what makes `read' get the right values
+     for the IFS-related cached variables, for example. */
+  old = executing_builtin;
+  executing_builtin = 1;
+  sv_ifs ("IFS");
+  executing_builtin = old;
+
+  dlen = STRLEN (document);
+  /* XXX - Add trailing newline to here-string */
+  if (ri == r_reading_string)
+    {
+      document = xrealloc (document, dlen + 2);
+      document[dlen++] = '\n';
+      document[dlen] = '\0';
+    }
+  if (lenp)
+    *lenp = dlen;    
+
+  return document;
+}
+
+/* Write HEREDOC (of length HDLEN) to FD, returning 0 on success and ERRNO on
+   error. Don't handle interrupts. */
+static int
+heredoc_write (fd, heredoc, herelen)
+     int fd;
+     char *heredoc;
+     size_t herelen;
+{
+  ssize_t nw;
+  int e;
+
+  errno = 0;
+  nw = write (fd, heredoc, herelen);
+  e = errno;
+  if (nw != herelen)
+    {
+      if (e == 0)
+	e = ENOSPC;
+      return e;
+    }
+  return 0;
+}
+
+/* Create a temporary file or pipe holding the text of the here document
+   pointed to by REDIRECTEE, and return a file descriptor open for reading
+   to it. Return -1 on any error, and make sure errno is set appropriately. */
+static int
+here_document_to_fd (redirectee, ri)
+     WORD_DESC *redirectee;
+     enum r_instruction ri;
+{
+  char *filename;
+  int r, fd, fd2, herepipe[2];
+  char *document;
+  size_t document_len;
+#if HEREDOC_PARANOID
+  struct stat st1, st2;
+#endif
+
+  /* Expand the here-document/here-string first and then decide what to do. */
+  document = heredoc_expand (redirectee, ri, &document_len);
+
+  /* If we have a zero-length document, don't mess with a temp file */
+  if (document_len == 0)
+    {
+      fd = open ("/dev/null", O_RDONLY);
+      r = errno;
+      if (document != redirectee->word)
+	FREE (document);
+      errno = r;
+      return fd;
+    }
+
+  if (shell_compatibility_level <= 50)
+    goto use_tempfile;
+
+#if HEREDOC_PIPESIZE
+  /* Try to use a pipe internal to this process if the document is shorter
+     than the system's pipe capacity (computed at build time). We want to
+     write the entire document without write blocking. */
+  if (document_len <= HEREDOC_PIPESIZE)
+    {
+      if (pipe (herepipe) < 0)
+	{
+	  /* XXX - goto use_tempfile; ? */
+	  r = errno;
+	  if (document != redirectee->word)
+	    free (document);
+	  errno = r;
+	  return (-1);
+	}
+
+#if defined (F_GETPIPE_SZ)
+      if (fcntl (herepipe[1], F_GETPIPE_SZ, 0) < document_len)
+	goto use_tempfile;
+#endif
+
+      r = heredoc_write (herepipe[1], document, document_len);
+      if (document != redirectee->word)
+	free (document);
+      close (herepipe[1]);
+      if (r)			/* write error */
+	{
+	  close (herepipe[0]);
+	  errno = r;
+	  return (-1);
+	}
+      return (herepipe[0]);
+    }
+#endif
+
+use_tempfile:
+
+  fd = sh_mktmpfd ("sh-thd", MT_USERANDOM|MT_USETMPDIR, &filename);
+
+  /* If we failed for some reason other than the file existing, abort */
+  if (fd < 0)
+    {
+      r = errno;
+      FREE (filename);
+      if (document != redirectee->word)
+	FREE (document);
+      errno = r;
+      return (fd);
+    }
+
+  fchmod (fd, S_IRUSR | S_IWUSR);
+  SET_CLOSE_ON_EXEC (fd);
+
+  errno = r = 0;		/* XXX */
+  r = heredoc_write (fd, document, document_len);
+  if (document != redirectee->word)
+    FREE (document);
+
+  if (r)
+    {
+      close (fd);
+      unlink (filename);
+      free (filename);
+      errno = r;
+      return (-1);
+    }
+
+  /* In an attempt to avoid races, we close the first fd only after opening
+     the second. */
+  /* Make the document really temporary.  Also make it the input. */
+  fd2 = open (filename, O_RDONLY|O_BINARY, 0600);
+
+  if (fd2 < 0)
+    {
+      r = errno;
+      unlink (filename);
+      free (filename);
+      close (fd);
+      errno = r;
+      return -1;
+    }
+
+#if HEREDOC_PARANOID
+  /* We can use same_file here to check whether or not fd and fd2 refer to
+     the same file, but we don't do that unless HEREDOC_PARANOID is defined. */
+  if (fstat (fd, &st1) < 0 || S_ISREG (st1.st_mode) == 0 ||
+      fstat (fd2, &st2) < 0 || S_ISREG (st2.st_mode) == 0 ||
+      same_file (filename, filename, &st1, &st2) == 0)
+    {
+      unlink (filename);
+      free (filename);
+      close (fd);
+      close (fd2);
+      errno = EEXIST;
+      return -1;
+    }
+#endif
+
+  close (fd);
+  if (unlink (filename) < 0)
+    {
+      r = errno;
+      close (fd2);
+      free (filename);
+      errno = r;
+      return (-1);
+    }
+
+  free (filename);
+
+  fchmod (fd2, S_IRUSR);
+  return (fd2);
+}
+
+#define RF_DEVFD	1
+#define RF_DEVSTDERR	2
+#define RF_DEVSTDIN	3
+#define RF_DEVSTDOUT	4
+#define RF_DEVTCP	5
+#define RF_DEVUDP	6
+
+/* A list of pattern/value pairs for filenames that the redirection
+   code handles specially. */
+static STRING_INT_ALIST _redir_special_filenames[] = {
+#if !defined (HAVE_DEV_FD)
+  { "/dev/fd/[0-9]*", RF_DEVFD },
+#endif
+#if !defined (HAVE_DEV_STDIN)
+  { "/dev/stderr", RF_DEVSTDERR },
+  { "/dev/stdin", RF_DEVSTDIN },
+  { "/dev/stdout", RF_DEVSTDOUT },
+#endif
+#if defined (NETWORK_REDIRECTIONS)
+  { "/dev/tcp/*/*", RF_DEVTCP },
+  { "/dev/udp/*/*", RF_DEVUDP },
+#endif
+  { (char *)NULL, -1 }
+};
+
+static int
+redir_special_open (spec, filename, flags, mode, ri)
+     int spec;
+     char *filename;
+     int flags, mode;
+     enum r_instruction ri;
+{
+  int fd;
+#if !defined (HAVE_DEV_FD)
+  intmax_t lfd;
+#endif
+
+  fd = -1;
+  switch (spec)
+    {
+#if !defined (HAVE_DEV_FD)
+    case RF_DEVFD:
+      if (all_digits (filename+8) && legal_number (filename+8, &lfd) && lfd == (int)lfd)
+	{
+	  fd = lfd;
+	  fd = fcntl (fd, F_DUPFD, SHELL_FD_BASE);
+	}
+      else
+	fd = AMBIGUOUS_REDIRECT;
+      break;
+#endif
+
+#if !defined (HAVE_DEV_STDIN)
+    case RF_DEVSTDIN:
+      fd = fcntl (0, F_DUPFD, SHELL_FD_BASE);
+      break;
+    case RF_DEVSTDOUT:
+      fd = fcntl (1, F_DUPFD, SHELL_FD_BASE);
+      break;
+    case RF_DEVSTDERR:
+      fd = fcntl (2, F_DUPFD, SHELL_FD_BASE);
+      break;
+#endif
+
+#if defined (NETWORK_REDIRECTIONS)
+    case RF_DEVTCP:
+    case RF_DEVUDP:
+#if defined (RESTRICTED_SHELL)
+      if (restricted)
+	return (RESTRICTED_REDIRECT);
+#endif
+#if defined (HAVE_NETWORK)
+      fd = netopen (filename);
+#else
+      internal_warning (_("/dev/(tcp|udp)/host/port not supported without networking"));
+      fd = open (filename, flags, mode);
+#endif
+      break;
+#endif /* NETWORK_REDIRECTIONS */
+    }
+
+  return fd;
+}
+      
+/* Open FILENAME with FLAGS in noclobber mode, hopefully avoiding most
+   race conditions and avoiding the problem where the file is replaced
+   between the stat(2) and open(2). */
+static int
+noclobber_open (filename, flags, mode, ri)
+     char *filename;
+     int flags, mode;
+     enum r_instruction ri;
+{
+  int r, fd;
+  struct stat finfo, finfo2;
+
+  /* If the file exists and is a regular file, return an error
+     immediately. */
+  r = stat (filename, &finfo);
+  if (r == 0 && (S_ISREG (finfo.st_mode)))
+    return (NOCLOBBER_REDIRECT);
+
+  /* If the file was not present (r != 0), make sure we open it
+     exclusively so that if it is created before we open it, our open
+     will fail.  Make sure that we do not truncate an existing file.
+     Note that we don't turn on O_EXCL unless the stat failed -- if
+     the file was not a regular file, we leave O_EXCL off. */
+  flags &= ~O_TRUNC;
+  if (r != 0)
+    {
+      fd = open (filename, flags|O_EXCL, mode);
+      return ((fd < 0 && errno == EEXIST) ? NOCLOBBER_REDIRECT : fd);
+    }
+  fd = open (filename, flags, mode);
+
+  /* If the open failed, return the file descriptor right away. */
+  if (fd < 0)
+    return (errno == EEXIST ? NOCLOBBER_REDIRECT : fd);
+
+  /* OK, the open succeeded, but the file may have been changed from a
+     non-regular file to a regular file between the stat and the open.
+     We are assuming that the O_EXCL open handles the case where FILENAME
+     did not exist and is symlinked to an existing file between the stat
+     and open. */
+
+  /* If we can open it and fstat the file descriptor, and neither check
+     revealed that it was a regular file, and the file has not been replaced,
+     return the file descriptor. */
+  if ((fstat (fd, &finfo2) == 0) && (S_ISREG (finfo2.st_mode) == 0) &&
+      r == 0 && (S_ISREG (finfo.st_mode) == 0) &&
+      same_file (filename, filename, &finfo, &finfo2))
+    return fd;
+
+  /* The file has been replaced.  badness. */
+  close (fd);  
+  errno = EEXIST;
+  return (NOCLOBBER_REDIRECT);
+}
+
+static int
+redir_open (filename, flags, mode, ri)
+     char *filename;
+     int flags, mode;
+     enum r_instruction ri;
+{
+  int fd, r, e;
+
+  r = find_string_in_alist (filename, _redir_special_filenames, 1);
+  if (r >= 0)
+    return (redir_special_open (r, filename, flags, mode, ri));
+
+  /* If we are in noclobber mode, you are not allowed to overwrite
+     existing files.  Check before opening. */
+  if (noclobber && CLOBBERING_REDIRECT (ri))
+    {
+      fd = noclobber_open (filename, flags, mode, ri);
+      if (fd == NOCLOBBER_REDIRECT)
+	return (NOCLOBBER_REDIRECT);
+    }
+  else
+    {
+      do
+	{
+	  fd = open (filename, flags, mode);
+	  e = errno;
+	  if (fd < 0 && e == EINTR)
+	    {
+	      QUIT;
+	      run_pending_traps ();
+	    }
+	  errno = e;
+	}
+      while (fd < 0 && errno == EINTR);
+
+#if defined (AFS)
+      if ((fd < 0) && (errno == EACCES))
+	{
+	  fd = open (filename, flags & ~O_CREAT, mode);
+	  errno = EACCES;	/* restore errno */
+	}
+#endif /* AFS */
+    }
+
+  return fd;
+}
+
+static int
+undoablefd (fd)
+     int fd;
+{
+  int clexec;
+
+  clexec = fcntl (fd, F_GETFD, 0);
+  if (clexec == -1 || (fd >= SHELL_FD_BASE && clexec == 1))
+    return 0;
+  return 1;
+}
+
+/* Do the specific redirection requested.  Returns errno or one of the
+   special redirection errors (*_REDIRECT) in case of error, 0 on success.
+   If flags & RX_ACTIVE is zero, then just do whatever is necessary to
+   produce the appropriate side effects.   flags & RX_UNDOABLE, if non-zero,
+   says to remember how to undo each redirection.  If flags & RX_CLEXEC is
+   non-zero, then we set all file descriptors > 2 that we open to be
+   close-on-exec. FNP, if non-null is a pointer to a location where the
+   expanded filename is stored. The caller will free it. */
+static int
+do_redirection_internal (redirect, flags, fnp)
+     REDIRECT *redirect;
+     int flags;
+     char **fnp;
+{
+  WORD_DESC *redirectee;
+  int redir_fd, fd, redirector, r, oflags;
+  intmax_t lfd;
+  char *redirectee_word;
+  enum r_instruction ri;
+  REDIRECT *new_redirect;
+  REDIRECTEE sd;
+
+  redirectee = redirect->redirectee.filename;
+  redir_fd = redirect->redirectee.dest;
+  redirector = redirect->redirector.dest;
+  ri = redirect->instruction;
+
+  if (redirect->flags & RX_INTERNAL)
+    flags |= RX_INTERNAL;
+
+  if (TRANSLATE_REDIRECT (ri))
+    {
+      /* We have [N]>&WORD[-] or [N]<&WORD[-] (or {V}>&WORD[-] or {V}<&WORD-).
+         and WORD, then translate the redirection into a new one and 
+	 continue. */
+      redirectee_word = redirection_expand (redirectee);
+
+      /* XXX - what to do with [N]<&$w- where w is unset or null?  ksh93
+	       turns it into [N]<&- or [N]>&- and closes N. */
+      if ((ri == r_move_input_word || ri == r_move_output_word) && redirectee_word == 0)
+	{
+	  sd = redirect->redirector;
+	  rd.dest = 0;
+	  new_redirect = make_redirection (sd, r_close_this, rd, 0);
+	}
+      else if (redirectee_word == 0)
+	return (AMBIGUOUS_REDIRECT);
+      else if (redirectee_word[0] == '-' && redirectee_word[1] == '\0')
+	{
+	  sd = redirect->redirector;
+	  rd.dest = 0;
+	  new_redirect = make_redirection (sd, r_close_this, rd, 0);
+	}
+      else if (all_digits (redirectee_word))
+	{
+	  sd = redirect->redirector;
+	  if (legal_number (redirectee_word, &lfd) && (int)lfd == lfd)
+	    rd.dest = lfd;
+	  else
+	    rd.dest = -1;	/* XXX */
+	  switch (ri)
+	    {
+	    case r_duplicating_input_word:
+	      new_redirect = make_redirection (sd, r_duplicating_input, rd, 0);
+	      break;
+	    case r_duplicating_output_word:
+	      new_redirect = make_redirection (sd, r_duplicating_output, rd, 0);
+	      break;
+	    case r_move_input_word:
+	      new_redirect = make_redirection (sd, r_move_input, rd, 0);
+	      break;
+	    case r_move_output_word:
+	      new_redirect = make_redirection (sd, r_move_output, rd, 0);
+	      break;
+	    default:
+	      break;	/* shut up gcc */
+	    }
+	}
+      else if (ri == r_duplicating_output_word && (redirect->rflags & REDIR_VARASSIGN) == 0 && redirector == 1)
+	{
+	  sd = redirect->redirector;
+	  rd.filename = make_bare_word (redirectee_word);
+	  new_redirect = make_redirection (sd, r_err_and_out, rd, 0);
+	}
+      else
+	{
+	  free (redirectee_word);
+	  return (AMBIGUOUS_REDIRECT);
+	}
+
+      free (redirectee_word);
+
+      /* Set up the variables needed by the rest of the function from the
+	 new redirection. */
+      if (new_redirect->instruction == r_err_and_out)
+	{
+	  char *alloca_hack;
+
+	  /* Copy the word without allocating any memory that must be
+	     explicitly freed. */
+	  redirectee = (WORD_DESC *)alloca (sizeof (WORD_DESC));
+	  xbcopy ((char *)new_redirect->redirectee.filename,
+		 (char *)redirectee, sizeof (WORD_DESC));
+
+	  alloca_hack = (char *)
+	    alloca (1 + strlen (new_redirect->redirectee.filename->word));
+	  redirectee->word = alloca_hack;
+	  strcpy (redirectee->word, new_redirect->redirectee.filename->word);
+	}
+      else
+	/* It's guaranteed to be an integer, and shouldn't be freed. */
+	redirectee = new_redirect->redirectee.filename;
+
+      redir_fd = new_redirect->redirectee.dest;
+      redirector = new_redirect->redirector.dest;
+      ri = new_redirect->instruction;
+
+      /* Overwrite the flags element of the old redirect with the new value. */
+      redirect->flags = new_redirect->flags;
+      dispose_redirects (new_redirect);
+    }
+
+  switch (ri)
+    {
+    case r_output_direction:
+    case r_appending_to:
+    case r_input_direction:
+    case r_inputa_direction:
+    case r_err_and_out:		/* command &>filename */
+    case r_append_err_and_out:	/* command &>> filename */
+    case r_input_output:
+    case r_output_force:
+      if (posixly_correct && interactive_shell == 0)
+	{
+	  oflags = redirectee->flags;
+	  redirectee->flags |= W_NOGLOB;
+	}
+      redirectee_word = redirection_expand (redirectee);
+      if (posixly_correct && interactive_shell == 0)
+	redirectee->flags = oflags;
+
+      if (redirectee_word == 0)
+	return (AMBIGUOUS_REDIRECT);
+
+#if defined (RESTRICTED_SHELL)
+      if (restricted && (WRITE_REDIRECT (ri)))
+	{
+	  free (redirectee_word);
+	  return (RESTRICTED_REDIRECT);
+	}
+#endif /* RESTRICTED_SHELL */
+
+      fd = redir_open (redirectee_word, redirect->flags, 0666, ri);
+      if (fnp)
+	*fnp = redirectee_word;
+      else
+	free (redirectee_word);
+
+      if (fd == NOCLOBBER_REDIRECT || fd == RESTRICTED_REDIRECT)
+	return (fd);
+
+      if (fd < 0)
+	return (errno);
+
+      if (flags & RX_ACTIVE)
+	{
+	  if (redirect->rflags & REDIR_VARASSIGN)
+	    {
+	      redirector = fcntl (fd, F_DUPFD, SHELL_FD_BASE);		/* XXX try this for now */
+	      r = errno;
+	      if (redirector < 0)
+		sys_error (_("redirection error: cannot duplicate fd"));
+	      REDIRECTION_ERROR (redirector, r, fd);
+	    }
+
+	  if ((flags & RX_UNDOABLE) && ((redirect->rflags & REDIR_VARASSIGN) == 0 || varassign_redir_autoclose))
+	    {
+	      /* Only setup to undo it if the thing to undo is active. We want
+		 to autoclose if we are doing a varassign redirection and the
+		 varredir_close shell option is set, and we can't test
+		 redirector in this case since we just assigned it above. */		 
+	      if (fd != redirector && (redirect->rflags & REDIR_VARASSIGN) && varassign_redir_autoclose)
+		r = add_undo_close_redirect (redirector);	      
+	      else if ((fd != redirector) && (fcntl (redirector, F_GETFD, 0) != -1))
+		r = add_undo_redirect (redirector, ri, -1);
+	      else
+		r = add_undo_close_redirect (redirector);
+	      REDIRECTION_ERROR (r, errno, fd);
+	    }
+
+#if defined (BUFFERED_INPUT)
+	  /* inhibit call to sync_buffered_stream() for async processes */
+	  if (redirector != 0 || (subshell_environment & SUBSHELL_ASYNC) == 0)
+	    check_bash_input (redirector);
+#endif
+
+	  /* Make sure there is no pending output before we change the state
+	     of the underlying file descriptor, since the builtins use stdio
+	     for output. */
+	  if (redirector == 1 && fileno (stdout) == redirector)
+	    {
+	      fflush (stdout);
+	      fpurge (stdout);
+	    }
+	  else if (redirector == 2 && fileno (stderr) == redirector)
+	    {
+	      fflush (stderr);
+	      fpurge (stderr);
+	    }
+
+	  if (redirect->rflags & REDIR_VARASSIGN)
+	    {
+	      if ((r = redir_varassign (redirect, redirector)) < 0)
+		{
+		  close (redirector);
+		  close (fd);
+		  return (r);	/* XXX */
+		}
+	    }
+	  else if ((fd != redirector) && (dup2 (fd, redirector) < 0))
+	    {
+	      close (fd);	/* dup2 failed? must be fd limit issue */
+	      return (errno);
+	    }
+
+#if defined (BUFFERED_INPUT)
+	  /* Do not change the buffered stream for an implicit redirection
+	     of /dev/null to fd 0 for asynchronous commands without job
+	     control (r_inputa_direction). */
+	  if (ri == r_input_direction || ri == r_input_output)
+	    duplicate_buffered_stream (fd, redirector);
+#endif /* BUFFERED_INPUT */
+
+	  /*
+	   * If we're remembering, then this is the result of a while, for
+	   * or until loop with a loop redirection, or a function/builtin
+	   * executing in the parent shell with a redirection.  In the
+	   * function/builtin case, we want to set all file descriptors > 2
+	   * to be close-on-exec to duplicate the effect of the old
+	   * for i = 3 to NOFILE close(i) loop.  In the case of the loops,
+	   * both sh and ksh leave the file descriptors open across execs.
+	   * The Posix standard mentions only the exec builtin.
+	   */
+	  if ((flags & RX_CLEXEC) && (redirector > 2))
+	    SET_CLOSE_ON_EXEC (redirector);
+	}
+
+      if (fd != redirector)
+	{
+#if defined (BUFFERED_INPUT)
+	  if (INPUT_REDIRECT (ri))
+	    close_buffered_fd (fd);
+	  else
+#endif /* !BUFFERED_INPUT */
+	    close (fd);		/* Don't close what we just opened! */
+	}
+
+      /* If we are hacking both stdout and stderr, do the stderr
+	 redirection here.  XXX - handle {var} here? */
+      if (ri == r_err_and_out || ri == r_append_err_and_out)
+	{
+	  if (flags & RX_ACTIVE)
+	    {
+	      if (flags & RX_UNDOABLE)
+		add_undo_redirect (2, ri, -1);
+	      if (dup2 (1, 2) < 0)
+		return (errno);
+	    }
+	}
+      break;
+
+    case r_reading_until:
+    case r_deblank_reading_until:
+    case r_reading_string:
+      /* REDIRECTEE is a pointer to a WORD_DESC containing the text of
+	 the new input.  Place it in a temporary file. */
+      if (redirectee)
+	{
+	  fd = here_document_to_fd (redirectee, ri);
+
+	  if (fd < 0)
+	    {
+	      heredoc_errno = errno;
+	      return (HEREDOC_REDIRECT);
+	    }
+
+	  if (redirect->rflags & REDIR_VARASSIGN)
+	    {
+	      redirector = fcntl (fd, F_DUPFD, SHELL_FD_BASE);		/* XXX try this for now */
+	      r = errno;
+	      if (redirector < 0)
+		sys_error (_("redirection error: cannot duplicate fd"));
+	      REDIRECTION_ERROR (redirector, r, fd);
+	    }
+
+	  if (flags & RX_ACTIVE)
+	    {
+	      if ((flags & RX_UNDOABLE) && ((redirect->rflags & REDIR_VARASSIGN) == 0 || varassign_redir_autoclose))
+	        {
+		  /* Only setup to undo it if the thing to undo is active.
+		     Close if the right option is set and we are doing a
+		     varassign redirection. */
+		  if (fd != redirector && (redirect->rflags & REDIR_VARASSIGN) && varassign_redir_autoclose)
+		    r = add_undo_close_redirect (redirector);	      
+		  else if ((fd != redirector) && (fcntl (redirector, F_GETFD, 0) != -1))
+		    r = add_undo_redirect (redirector, ri, -1);
+		  else
+		    r = add_undo_close_redirect (redirector);
+		  REDIRECTION_ERROR (r, errno, fd);
+	        }
+
+#if defined (BUFFERED_INPUT)
+	      check_bash_input (redirector);
+#endif
+	      if (redirect->rflags & REDIR_VARASSIGN)
+		{
+		  if ((r = redir_varassign (redirect, redirector)) < 0)
+		    {
+		      close (redirector);
+		      close (fd);
+		      return (r);	/* XXX */
+		    }
+		}
+	      else if (fd != redirector && dup2 (fd, redirector) < 0)
+		{
+		  r = errno;
+		  close (fd);
+		  return (r);
+		}
+
+#if defined (BUFFERED_INPUT)
+	      duplicate_buffered_stream (fd, redirector);
+#endif
+
+	      if ((flags & RX_CLEXEC) && (redirector > 2))
+		SET_CLOSE_ON_EXEC (redirector);
+	    }
+
+	  if (fd != redirector)
+#if defined (BUFFERED_INPUT)
+	    close_buffered_fd (fd);
+#else
+	    close (fd);
+#endif
+	}
+      break;
+
+    case r_duplicating_input:
+    case r_duplicating_output:
+    case r_move_input:
+    case r_move_output:
+      if ((flags & RX_ACTIVE) && (redirect->rflags & REDIR_VARASSIGN))
+        {
+	  redirector = fcntl (redir_fd, F_DUPFD, SHELL_FD_BASE);		/* XXX try this for now */
+	  r = errno;
+	  if (redirector < 0)
+	    sys_error (_("redirection error: cannot duplicate fd"));
+	  REDIRECTION_ERROR (redirector, r, -1);
+        }
+
+      if ((flags & RX_ACTIVE) && (redir_fd != redirector))
+	{
+	  if ((flags & RX_UNDOABLE) && ((redirect->rflags & REDIR_VARASSIGN) == 0 || varassign_redir_autoclose))
+	    {
+	      /* Only setup to undo it if the thing to undo is active.
+		 Close if the right option is set and we are doing a
+		 varassign redirection. */
+	      if ((redirect->rflags & REDIR_VARASSIGN) && varassign_redir_autoclose)
+		r = add_undo_close_redirect (redirector);	      
+	      else if (fcntl (redirector, F_GETFD, 0) != -1)
+		r = add_undo_redirect (redirector, ri, redir_fd);
+	      else
+		r = add_undo_close_redirect (redirector);
+	      REDIRECTION_ERROR (r, errno, -1);
+	    }
+	  if ((flags & RX_UNDOABLE) && (ri == r_move_input || ri == r_move_output))
+	    {
+	      /* r_move_input and r_move_output add an additional close()
+		 that needs to be undone */
+	      if (fcntl (redirector, F_GETFD, 0) != -1)
+		{
+		  r = add_undo_redirect (redir_fd, r_close_this, -1);
+		  REDIRECTION_ERROR (r, errno, -1);
+		}
+	    }
+#if defined (BUFFERED_INPUT)
+	  /* inhibit call to sync_buffered_stream() for async processes */
+	  if (redirector != 0 || (subshell_environment & SUBSHELL_ASYNC) == 0)
+	    check_bash_input (redirector);
+#endif
+	  if (redirect->rflags & REDIR_VARASSIGN)
+	    {
+	      if ((r = redir_varassign (redirect, redirector)) < 0)
+		{
+		  close (redirector);
+		  return (r);	/* XXX */
+		}
+	    }
+	  /* This is correct.  2>&1 means dup2 (1, 2); */
+	  else if (dup2 (redir_fd, redirector) < 0)
+	    return (errno);
+
+#if defined (BUFFERED_INPUT)
+	  if (ri == r_duplicating_input || ri == r_move_input)
+	    duplicate_buffered_stream (redir_fd, redirector);
+#endif /* BUFFERED_INPUT */
+
+	  /* First duplicate the close-on-exec state of redirectee.  dup2
+	     leaves the flag unset on the new descriptor, which means it
+	     stays open.  Only set the close-on-exec bit for file descriptors
+	     greater than 2 in any case, since 0-2 should always be open
+	     unless closed by something like `exec 2<&-'.  It should always
+	     be safe to set fds > 2 to close-on-exec if they're being used to
+	     save file descriptors < 2, since we don't need to preserve the
+	     state of the close-on-exec flag for those fds -- they should
+	     always be open. */
+	  /* if ((already_set || set_unconditionally) && (ok_to_set))
+		set_it () */
+#if 0
+	  if (((fcntl (redir_fd, F_GETFD, 0) == 1) || redir_fd < 2 || (flags & RX_CLEXEC)) &&
+	       (redirector > 2))
+#else
+	  if (((fcntl (redir_fd, F_GETFD, 0) == 1) || (redir_fd < 2 && (flags & RX_INTERNAL)) || (flags & RX_CLEXEC)) &&
+	       (redirector > 2))
+#endif
+	    SET_CLOSE_ON_EXEC (redirector);
+
+	  /* When undoing saving of non-standard file descriptors (>=3) using
+	     file descriptors >= SHELL_FD_BASE, we set the saving fd to be
+	     close-on-exec and use a flag to decide how to set close-on-exec
+	     when the fd is restored. */
+	  if ((redirect->flags & RX_INTERNAL) && (redirect->flags & RX_SAVCLEXEC) && redirector >= 3 && (redir_fd >= SHELL_FD_BASE || (redirect->flags & RX_SAVEFD)))
+	    SET_OPEN_ON_EXEC (redirector);
+	    
+	  /* dup-and-close redirection */
+	  if (ri == r_move_input || ri == r_move_output)
+	    {
+	      xtrace_fdchk (redir_fd);
+
+	      close (redir_fd);
+#if defined (COPROCESS_SUPPORT)
+	      coproc_fdchk (redir_fd);	/* XXX - loses coproc fds */
+#endif
+	    }
+	}
+      break;
+
+    case r_close_this:
+      if (flags & RX_ACTIVE)
+	{
+	  if (redirect->rflags & REDIR_VARASSIGN)
+	    {
+	      redirector = redir_varvalue (redirect);
+	      if (redirector < 0)
+		return AMBIGUOUS_REDIRECT;
+	    }
+
+	  r = 0;
+	  if (flags & RX_UNDOABLE)
+	    {
+	      if (fcntl (redirector, F_GETFD, 0) != -1)
+		r = add_undo_redirect (redirector, ri, -1);
+	      else
+		r = add_undo_close_redirect (redirector);
+	      REDIRECTION_ERROR (r, errno, redirector);
+	    }
+
+#if defined (COPROCESS_SUPPORT)
+	  coproc_fdchk (redirector);
+#endif
+	  xtrace_fdchk (redirector);
+
+#if defined (BUFFERED_INPUT)
+	  /* inhibit call to sync_buffered_stream() for async processes */
+	  if (redirector != 0 || (subshell_environment & SUBSHELL_ASYNC) == 0)
+	    check_bash_input (redirector);
+	  r = close_buffered_fd (redirector);
+#else /* !BUFFERED_INPUT */
+	  r = close (redirector);
+#endif /* !BUFFERED_INPUT */
+
+	  if (r < 0 && (flags & RX_INTERNAL) && (errno == EIO || errno == ENOSPC))
+	    REDIRECTION_ERROR (r, errno, -1);
+	}
+      break;
+
+    case r_duplicating_input_word:
+    case r_duplicating_output_word:
+    case r_move_input_word:
+    case r_move_output_word:
+      break;
+    }
+  return (0);
+}
+
+/* Remember the file descriptor associated with the slot FD,
+   on REDIRECTION_UNDO_LIST.  Note that the list will be reversed
+   before it is executed.  Any redirections that need to be undone
+   even if REDIRECTION_UNDO_LIST is discarded by the exec builtin
+   are also saved on EXEC_REDIRECTION_UNDO_LIST.  FDBASE says where to
+   start the duplicating.  If it's less than SHELL_FD_BASE, we're ok,
+   and can use SHELL_FD_BASE (-1 == don't care).  If it's >= SHELL_FD_BASE,
+   we have to make sure we don't use fdbase to save a file descriptor,
+   since we're going to use it later (e.g., make sure we don't save fd 0
+   to fd 10 if we have a redirection like 0<&10).  If the value of fdbase
+   puts the process over its fd limit, causing fcntl to fail, we try
+   again with SHELL_FD_BASE.  Return 0 on success, -1 on error. */
+static int
+add_undo_redirect (fd, ri, fdbase)
+     int fd;
+     enum r_instruction ri;
+     int fdbase;
+{
+  int new_fd, clexec_flag, savefd_flag;
+  REDIRECT *new_redirect, *closer, *dummy_redirect;
+  REDIRECTEE sd;
+
+  savefd_flag = 0;
+  new_fd = fcntl (fd, F_DUPFD, (fdbase < SHELL_FD_BASE) ? SHELL_FD_BASE : fdbase+1);
+  if (new_fd < 0)
+    new_fd = fcntl (fd, F_DUPFD, SHELL_FD_BASE);
+  if (new_fd < 0)
+    {
+      new_fd = fcntl (fd, F_DUPFD, 0);
+      savefd_flag = 1;
+    }
+
+  if (new_fd < 0)
+    {
+      sys_error (_("redirection error: cannot duplicate fd"));
+      return (-1);
+    }
+
+  clexec_flag = fcntl (fd, F_GETFD, 0);
+
+  sd.dest = new_fd;
+  rd.dest = 0;
+  closer = make_redirection (sd, r_close_this, rd, 0);
+  closer->flags |= RX_INTERNAL;
+  dummy_redirect = copy_redirects (closer);
+
+  sd.dest = fd;
+  rd.dest = new_fd;
+  if (fd == 0)
+    new_redirect = make_redirection (sd, r_duplicating_input, rd, 0);
+  else
+    new_redirect = make_redirection (sd, r_duplicating_output, rd, 0);
+  new_redirect->flags |= RX_INTERNAL;
+  if (savefd_flag)
+    new_redirect->flags |= RX_SAVEFD;
+  if (clexec_flag == 0 && fd >= 3 && (new_fd >= SHELL_FD_BASE || savefd_flag))
+    new_redirect->flags |= RX_SAVCLEXEC;
+  new_redirect->next = closer;
+
+  closer->next = redirection_undo_list;
+  redirection_undo_list = new_redirect;
+
+  /* Save redirections that need to be undone even if the undo list
+     is thrown away by the `exec' builtin. */
+  add_exec_redirect (dummy_redirect);
+
+  /* experimental:  if we're saving a redirection to undo for a file descriptor
+     above SHELL_FD_BASE, add a redirection to be undone if the exec builtin
+     causes redirections to be discarded.  There needs to be a difference
+     between fds that are used to save other fds and then are the target of
+     user redirections and fds that are just the target of user redirections.
+     We use the close-on-exec flag to tell the difference; fds > SHELL_FD_BASE
+     that have the close-on-exec flag set are assumed to be fds used internally
+     to save others. */
+  if (fd >= SHELL_FD_BASE && ri != r_close_this && clexec_flag)
+    {
+      sd.dest = fd;
+      rd.dest = new_fd;
+      new_redirect = make_redirection (sd, r_duplicating_output, rd, 0);
+      new_redirect->flags |= RX_INTERNAL;
+
+      add_exec_redirect (new_redirect);
+    }
+
+  /* File descriptors used only for saving others should always be
+     marked close-on-exec.  Unfortunately, we have to preserve the
+     close-on-exec state of the file descriptor we are saving, since
+     fcntl (F_DUPFD) sets the new file descriptor to remain open
+     across execs.  If, however, the file descriptor whose state we
+     are saving is <= 2, we can just set the close-on-exec flag,
+     because file descriptors 0-2 should always be open-on-exec,
+     and the restore above in do_redirection() will take care of it. */
+  if (clexec_flag || fd < 3)
+    SET_CLOSE_ON_EXEC (new_fd);
+  else if (redirection_undo_list->flags & RX_SAVCLEXEC)
+    SET_CLOSE_ON_EXEC (new_fd);
+
+  return (0);
+}
+
+/* Set up to close FD when we are finished with the current command
+   and its redirections.  Return 0 on success, -1 on error. */
+static int
+add_undo_close_redirect (fd)
+     int fd;
+{
+  REDIRECT *closer;
+  REDIRECTEE sd;
+
+  sd.dest = fd;
+  rd.dest = 0;
+  closer = make_redirection (sd, r_close_this, rd, 0);
+  closer->flags |= RX_INTERNAL;
+  closer->next = redirection_undo_list;
+  redirection_undo_list = closer;
+
+  return 0;
+}
+
+static void
+add_exec_redirect (dummy_redirect)
+     REDIRECT *dummy_redirect;
+{
+  dummy_redirect->next = exec_redirection_undo_list;
+  exec_redirection_undo_list = dummy_redirect;
+}
+
+/* Return 1 if the redirection specified by RI and REDIRECTOR alters the
+   standard input. */
+static int
+stdin_redirection (ri, redirector)
+     enum r_instruction ri;
+     int redirector;
+{
+  switch (ri)
+    {
+    case r_input_direction:
+    case r_inputa_direction:
+    case r_input_output:
+    case r_reading_until:
+    case r_deblank_reading_until:
+    case r_reading_string:
+      return (1);
+    case r_duplicating_input:
+    case r_duplicating_input_word:
+    case r_close_this:
+      return (redirector == 0);
+    case r_output_direction:
+    case r_appending_to:
+    case r_duplicating_output:
+    case r_err_and_out:
+    case r_append_err_and_out:
+    case r_output_force:
+    case r_duplicating_output_word:
+    case r_move_input:
+    case r_move_output:
+    case r_move_input_word:
+    case r_move_output_word:
+      return (0);
+    }
+  return (0);
+}
+
+/* Return non-zero if any of the redirections in REDIRS alter the standard
+   input. */
+int
+stdin_redirects (redirs)
+     REDIRECT *redirs;
+{
+  REDIRECT *rp;
+  int n;
+
+  for (n = 0, rp = redirs; rp; rp = rp->next)
+    if ((rp->rflags & REDIR_VARASSIGN) == 0)
+      n += stdin_redirection (rp->instruction, rp->redirector.dest);
+  return n;
+}
+/* bind_var_to_int handles array references */
+static int
+redir_varassign (redir, fd)
+     REDIRECT *redir;
+     int fd;
+{
+  WORD_DESC *w;
+  SHELL_VAR *v;
+
+  w = redir->redirector.filename;
+  v = bind_var_to_int (w->word, fd, 0);
+  if (v == 0 || readonly_p (v) || noassign_p (v))
+    return BADVAR_REDIRECT;
+
+  stupidly_hack_special_variables (w->word);
+  return 0;
+}
+
+/* Handles {array[ind]} for redirection words */
+static int
+redir_varvalue (redir)
+     REDIRECT *redir;
+{
+  SHELL_VAR *v;
+  char *val, *w;
+  intmax_t vmax;
+  int i;
+#if defined (ARRAY_VARS)
+  char *sub;
+  int len, vr;
+#endif
+
+  w = redir->redirector.filename->word;		/* shorthand */
+  /* XXX - handle set -u here? */
+#if defined (ARRAY_VARS)
+  if (vr = valid_array_reference (w, 0))
+    {
+      v = array_variable_part (w, 0, &sub, &len);
+    }
+  else
+#endif
+    {
+      v = find_variable (w);
+#if defined (ARRAY_VARS)
+      if (v == 0)
+	{
+	  v = find_variable_last_nameref (w, 0);
+	  if (v && nameref_p (v))
+	    {
+	      w = nameref_cell (v);
+	      if (vr = valid_array_reference (w, 0))
+		v = array_variable_part (w, 0, &sub, &len);
+	      else
+	        v = find_variable (w);
+	    }
+	}
+#endif
+    }
+	
+  if (v == 0 || invisible_p (v))
+    return -1;
+
+#if defined (ARRAY_VARS)
+  /* get_variable_value handles references to array variables without
+     subscripts */
+  if (vr && (array_p (v) || assoc_p (v)))
+    val = get_array_value (w, 0, (array_eltstate_t *)NULL);
+  else
+#endif
+  val = get_variable_value (v);
+  if (val == 0 || *val == 0)
+    return -1;
+
+  if (legal_number (val, &vmax) < 0)
+    return -1;
+
+  i = vmax;	/* integer truncation */
+  return i;
+}