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-rw-r--r--redir.c1505
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diff --git a/redir.c b/redir.c
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+++ b/redir.c
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+/* redir.c -- Functions to perform input and output redirection. */
+
+/* Copyright (C) 1997-2020 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;
+
+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 defined (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)
+ {
+ 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
+ closes N. */
+ 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)
+ {
+ /* Only setup to undo it if the thing to undo is active. */
+ 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)
+ {
+ /* Only setup to undo it if the thing to undo is active. */
+ 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)
+ {
+ /* Only setup to undo it if the thing to undo is active. */
+ 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;
+ /* XXX - only if REDIR_VARASSIGN not set? */
+ 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);
+ 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, (int *)NULL, (arrayind_t *)0);
+ 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;
+}