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redir.c
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redir.c
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/* 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);