1 /* redir.c -- Functions to perform input and output redirection. */
3 /* Copyright (C) 1997-2015 Free Software Foundation, Inc.
5 This file is part of GNU Bash, the Bourne Again SHell.
7 Bash is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 Bash is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with Bash. If not, see <http://www.gnu.org/licenses/>.
23 #if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX)
25 #endif /* _AIX && RISC6000 && !__GNUC__ */
28 #include "bashtypes.h"
29 #if !defined (_MINIX) && defined (HAVE_SYS_FILE_H)
30 # include <sys/file.h>
33 #include "posixstat.h"
35 #if defined (HAVE_UNISTD_H)
49 #define NEED_FPURGE_DECL
53 #include "execute_cmd.h"
57 #if defined (BUFFERED_INPUT)
61 #define SHELL_FD_BASE 10
65 extern int posixly_correct
;
66 extern int last_command_exit_value
;
67 extern int executing_builtin
;
68 extern REDIRECT
*redirection_undo_list
;
69 extern REDIRECT
*exec_redirection_undo_list
;
71 /* Static functions defined and used in this file. */
72 static void add_exec_redirect
__P((REDIRECT
*));
73 static int add_undo_redirect
__P((int, enum r_instruction
, int));
74 static int add_undo_close_redirect
__P((int));
75 static int expandable_redirection_filename
__P((REDIRECT
*));
76 static int stdin_redirection
__P((enum r_instruction
, int));
77 static int undoablefd
__P((int));
78 static int do_redirection_internal
__P((REDIRECT
*, int));
80 static int write_here_document
__P((int, WORD_DESC
*));
81 static int write_here_string
__P((int, WORD_DESC
*));
82 static int here_document_to_fd
__P((WORD_DESC
*, enum r_instruction
));
84 static int redir_special_open
__P((int, char *, int, int, enum r_instruction
));
85 static int noclobber_open
__P((char *, int, int, enum r_instruction
));
86 static int redir_open
__P((char *, int, int, enum r_instruction
));
88 static int redir_varassign
__P((REDIRECT
*, int));
89 static int redir_varvalue
__P((REDIRECT
*));
91 /* Spare redirector used when translating [N]>&WORD[-] or [N]<&WORD[-] to
92 a new redirection and when creating the redirection undo list. */
95 /* Set to errno when a here document cannot be created for some reason.
96 Used to print a reasonable error message. */
97 static int heredoc_errno
;
99 #define REDIRECTION_ERROR(r, e, fd) \
105 last_command_exit_value = EXECUTION_FAILURE;\
106 return ((e) == 0 ? EINVAL : (e));\
111 redirection_error (temp
, error
)
115 char *filename
, *allocname
;
119 if ((temp
->rflags
& REDIR_VARASSIGN
) && error
< 0)
120 filename
= allocname
= savestring (temp
->redirector
.filename
->word
);
121 else if ((temp
->rflags
& REDIR_VARASSIGN
) == 0 && temp
->redirector
.dest
< 0)
122 /* This can happen when read_token_word encounters overflow, like in
124 filename
= _("file descriptor out of range");
126 /* This error can never involve NOCLOBBER */
127 else if (error
!= NOCLOBBER_REDIRECT
&& temp
->redirector
.dest
>= 0 && error
== EBADF
)
129 /* If we're dealing with two file descriptors, we have to guess about
130 which one is invalid; in the cases of r_{duplicating,move}_input and
131 r_{duplicating,move}_output we're here because dup2() failed. */
132 switch (temp
->instruction
)
134 case r_duplicating_input
:
135 case r_duplicating_output
:
138 filename
= allocname
= itos (temp
->redirectee
.dest
);
140 case r_duplicating_input_word
:
141 if (temp
->redirector
.dest
== 0) /* Guess */
142 filename
= temp
->redirectee
.filename
->word
; /* XXX */
144 filename
= allocname
= itos (temp
->redirector
.dest
);
146 case r_duplicating_output_word
:
147 if (temp
->redirector
.dest
== 1) /* Guess */
148 filename
= temp
->redirectee
.filename
->word
; /* XXX */
150 filename
= allocname
= itos (temp
->redirector
.dest
);
153 filename
= allocname
= itos (temp
->redirector
.dest
);
158 else if (expandable_redirection_filename (temp
))
161 oflags
= temp
->redirectee
.filename
->flags
;
162 if (posixly_correct
&& interactive_shell
== 0)
163 temp
->redirectee
.filename
->flags
|= W_NOGLOB
;
164 temp
->redirectee
.filename
->flags
|= W_NOCOMSUB
;
165 filename
= allocname
= redirection_expand (temp
->redirectee
.filename
);
166 temp
->redirectee
.filename
->flags
= oflags
;
168 filename
= temp
->redirectee
.filename
->word
;
170 else if (temp
->redirectee
.dest
< 0)
171 filename
= _("file descriptor out of range");
173 filename
= allocname
= itos (temp
->redirectee
.dest
);
177 case AMBIGUOUS_REDIRECT
:
178 internal_error (_("%s: ambiguous redirect"), filename
);
181 case NOCLOBBER_REDIRECT
:
182 internal_error (_("%s: cannot overwrite existing file"), filename
);
185 #if defined (RESTRICTED_SHELL)
186 case RESTRICTED_REDIRECT
:
187 internal_error (_("%s: restricted: cannot redirect output"), filename
);
189 #endif /* RESTRICTED_SHELL */
191 case HEREDOC_REDIRECT
:
192 internal_error (_("cannot create temp file for here-document: %s"), strerror (heredoc_errno
));
195 case BADVAR_REDIRECT
:
196 internal_error (_("%s: cannot assign fd to variable"), filename
);
200 internal_error ("%s: %s", filename
, strerror (error
));
207 /* Perform the redirections on LIST. If flags & RX_ACTIVE, then actually
208 make input and output file descriptors, otherwise just do whatever is
209 necessary for side effecting. flags & RX_UNDOABLE says to remember
210 how to undo the redirections later, if non-zero. If flags & RX_CLEXEC
211 is non-zero, file descriptors opened in do_redirection () have their
212 close-on-exec flag set. */
214 do_redirections (list
, flags
)
221 if (flags
& RX_UNDOABLE
)
223 if (redirection_undo_list
)
225 dispose_redirects (redirection_undo_list
);
226 redirection_undo_list
= (REDIRECT
*)NULL
;
228 if (exec_redirection_undo_list
)
229 dispose_exec_redirects ();
232 for (temp
= list
; temp
; temp
= temp
->next
)
234 error
= do_redirection_internal (temp
, flags
);
237 redirection_error (temp
, error
);
244 /* Return non-zero if the redirection pointed to by REDIRECT has a
245 redirectee.filename that can be expanded. */
247 expandable_redirection_filename (redirect
)
250 switch (redirect
->instruction
)
252 case r_output_direction
:
254 case r_input_direction
:
255 case r_inputa_direction
:
257 case r_append_err_and_out
:
260 case r_duplicating_input_word
:
261 case r_duplicating_output_word
:
262 case r_move_input_word
:
263 case r_move_output_word
:
271 /* Expand the word in WORD returning a string. If WORD expands to
272 multiple words (or no words), then return NULL. */
274 redirection_expand (word
)
278 WORD_LIST
*tlist1
, *tlist2
;
282 w
= copy_word (word
);
284 w
->flags
|= W_NOSPLIT
;
286 tlist1
= make_word_list (w
, (WORD_LIST
*)NULL
);
288 /* Now that we've changed the variable search order to ignore the temp
289 environment, see if we need to change the cached IFS values. */
291 tlist2
= expand_words_no_vars (tlist1
);
293 /* Now we need to change the variable search order back to include the temp
294 environment. We force the temp environment search by forcing
295 executing_builtin to 1. This is what makes `read' get the right values
296 for the IFS-related cached variables, for example. */
297 old
= executing_builtin
;
298 executing_builtin
= 1;
300 executing_builtin
= old
;
301 dispose_words (tlist1
);
303 if (tlist2
== 0 || tlist2
->next
)
305 /* We expanded to no words, or to more than a single word.
306 Dispose of the word list and return NULL. */
308 dispose_words (tlist2
);
309 return ((char *)NULL
);
311 result
= string_list (tlist2
); /* XXX savestring (tlist2->word->word)? */
312 dispose_words (tlist2
);
317 write_here_string (fd
, redirectee
)
319 WORD_DESC
*redirectee
;
322 int herelen
, n
, e
, old
;
325 /* Now that we've changed the variable search order to ignore the temp
326 environment, see if we need to change the cached IFS values. */
328 herestr
= expand_string_unsplit_to_string (redirectee
->word
, 0);
330 /* Now we need to change the variable search order back to include the temp
331 environment. We force the temp environment search by forcing
332 executing_builtin to 1. This is what makes `read' get the right values
333 for the IFS-related cached variables, for example. */
334 old
= executing_builtin
;
335 executing_builtin
= 1;
337 executing_builtin
= old
;
339 herelen
= STRLEN (herestr
);
341 n
= write (fd
, herestr
, herelen
);
344 n
= write (fd
, "\n", 1);
358 /* Write the text of the here document pointed to by REDIRECTEE to the file
359 descriptor FD, which is already open to a temp file. Return 0 if the
360 write is successful, otherwise return errno. */
362 write_here_document (fd
, redirectee
)
364 WORD_DESC
*redirectee
;
367 int document_len
, fd2
, old
;
369 register WORD_LIST
*t
, *tlist
;
371 /* Expand the text if the word that was specified had
372 no quoting. The text that we expand is treated
373 exactly as if it were surrounded by double quotes. */
375 if (redirectee
->flags
& W_QUOTED
)
377 document
= redirectee
->word
;
378 document_len
= strlen (document
);
379 /* Set errno to something reasonable if the write fails. */
380 if (write (fd
, document
, document_len
) < document_len
)
391 /* Now that we've changed the variable search order to ignore the temp
392 environment, see if we need to change the cached IFS values. */
394 tlist
= expand_string (redirectee
->word
, Q_HERE_DOCUMENT
);
396 /* Now we need to change the variable search order back to include the temp
397 environment. We force the temp environment search by forcing
398 executing_builtin to 1. This is what makes `read' get the right values
399 for the IFS-related cached variables, for example. */
400 old
= executing_builtin
;
401 executing_builtin
= 1;
403 executing_builtin
= old
;
407 /* Try using buffered I/O (stdio) and writing a word
408 at a time, letting stdio do the work of buffering
409 for us rather than managing our own strings. Most
410 stdios are not particularly fast, however -- this
411 may need to be reconsidered later. */
412 if ((fd2
= dup (fd
)) < 0 || (fp
= fdopen (fd2
, "w")) == NULL
)
417 dispose_words (tlist
);
422 for (t
= tlist
; t
; t
= t
->next
)
424 /* This is essentially the body of
425 string_list_internal expanded inline. */
426 document
= t
->word
->word
;
427 document_len
= strlen (document
);
429 putc (' ', fp
); /* separator */
430 fwrite (document
, document_len
, 1, fp
);
437 dispose_words (tlist
);
441 dispose_words (tlist
);
442 if (fclose (fp
) != 0)
452 /* Create a temporary file holding the text of the here document pointed to
453 by REDIRECTEE, and return a file descriptor open for reading to the temp
454 file. Return -1 on any error, and make sure errno is set appropriately. */
456 here_document_to_fd (redirectee
, ri
)
457 WORD_DESC
*redirectee
;
458 enum r_instruction ri
;
463 fd
= sh_mktmpfd ("sh-thd", MT_USERANDOM
|MT_USETMPDIR
, &filename
);
465 /* If we failed for some reason other than the file existing, abort */
472 errno
= r
= 0; /* XXX */
473 /* write_here_document returns 0 on success, errno on failure. */
474 if (redirectee
->word
)
475 r
= (ri
!= r_reading_string
) ? write_here_document (fd
, redirectee
)
476 : write_here_string (fd
, redirectee
);
487 /* In an attempt to avoid races, we close the first fd only after opening
489 /* Make the document really temporary. Also make it the input. */
490 fd2
= open (filename
, O_RDONLY
|O_BINARY
, 0600);
503 if (unlink (filename
) < 0)
517 #define RF_DEVSTDERR 2
518 #define RF_DEVSTDIN 3
519 #define RF_DEVSTDOUT 4
523 /* A list of pattern/value pairs for filenames that the redirection
524 code handles specially. */
525 static STRING_INT_ALIST _redir_special_filenames
[] = {
526 #if !defined (HAVE_DEV_FD)
527 { "/dev/fd/[0-9]*", RF_DEVFD
},
529 #if !defined (HAVE_DEV_STDIN)
530 { "/dev/stderr", RF_DEVSTDERR
},
531 { "/dev/stdin", RF_DEVSTDIN
},
532 { "/dev/stdout", RF_DEVSTDOUT
},
534 #if defined (NETWORK_REDIRECTIONS)
535 { "/dev/tcp/*/*", RF_DEVTCP
},
536 { "/dev/udp/*/*", RF_DEVUDP
},
542 redir_special_open (spec
, filename
, flags
, mode
, ri
)
546 enum r_instruction ri
;
549 #if !defined (HAVE_DEV_FD)
556 #if !defined (HAVE_DEV_FD)
558 if (all_digits (filename
+8) && legal_number (filename
+8, &lfd
) && lfd
== (int)lfd
)
561 fd
= fcntl (fd
, F_DUPFD
, SHELL_FD_BASE
);
564 fd
= AMBIGUOUS_REDIRECT
;
568 #if !defined (HAVE_DEV_STDIN)
570 fd
= fcntl (0, F_DUPFD
, SHELL_FD_BASE
);
573 fd
= fcntl (1, F_DUPFD
, SHELL_FD_BASE
);
576 fd
= fcntl (2, F_DUPFD
, SHELL_FD_BASE
);
580 #if defined (NETWORK_REDIRECTIONS)
583 #if defined (HAVE_NETWORK)
584 fd
= netopen (filename
);
586 internal_warning (_("/dev/(tcp|udp)/host/port not supported without networking"));
587 fd
= open (filename
, flags
, mode
);
590 #endif /* NETWORK_REDIRECTIONS */
596 /* Open FILENAME with FLAGS in noclobber mode, hopefully avoiding most
597 race conditions and avoiding the problem where the file is replaced
598 between the stat(2) and open(2). */
600 noclobber_open (filename
, flags
, mode
, ri
)
603 enum r_instruction ri
;
606 struct stat finfo
, finfo2
;
608 /* If the file exists and is a regular file, return an error
610 r
= stat (filename
, &finfo
);
611 if (r
== 0 && (S_ISREG (finfo
.st_mode
)))
612 return (NOCLOBBER_REDIRECT
);
614 /* If the file was not present (r != 0), make sure we open it
615 exclusively so that if it is created before we open it, our open
616 will fail. Make sure that we do not truncate an existing file.
617 Note that we don't turn on O_EXCL unless the stat failed -- if
618 the file was not a regular file, we leave O_EXCL off. */
622 fd
= open (filename
, flags
|O_EXCL
, mode
);
623 return ((fd
< 0 && errno
== EEXIST
) ? NOCLOBBER_REDIRECT
: fd
);
625 fd
= open (filename
, flags
, mode
);
627 /* If the open failed, return the file descriptor right away. */
629 return (errno
== EEXIST
? NOCLOBBER_REDIRECT
: fd
);
631 /* OK, the open succeeded, but the file may have been changed from a
632 non-regular file to a regular file between the stat and the open.
633 We are assuming that the O_EXCL open handles the case where FILENAME
634 did not exist and is symlinked to an existing file between the stat
637 /* If we can open it and fstat the file descriptor, and neither check
638 revealed that it was a regular file, and the file has not been replaced,
639 return the file descriptor. */
640 if ((fstat (fd
, &finfo2
) == 0) && (S_ISREG (finfo2
.st_mode
) == 0) &&
641 r
== 0 && (S_ISREG (finfo
.st_mode
) == 0) &&
642 same_file (filename
, filename
, &finfo
, &finfo2
))
645 /* The file has been replaced. badness. */
648 return (NOCLOBBER_REDIRECT
);
652 redir_open (filename
, flags
, mode
, ri
)
655 enum r_instruction ri
;
659 r
= find_string_in_alist (filename
, _redir_special_filenames
, 1);
661 return (redir_special_open (r
, filename
, flags
, mode
, ri
));
663 /* If we are in noclobber mode, you are not allowed to overwrite
664 existing files. Check before opening. */
665 if (noclobber
&& CLOBBERING_REDIRECT (ri
))
667 fd
= noclobber_open (filename
, flags
, mode
, ri
);
668 if (fd
== NOCLOBBER_REDIRECT
)
669 return (NOCLOBBER_REDIRECT
);
675 fd
= open (filename
, flags
, mode
);
677 if (fd
< 0 && e
== EINTR
)
680 run_pending_traps ();
684 while (fd
< 0 && errno
== EINTR
);
687 if ((fd
< 0) && (errno
== EACCES
))
689 fd
= open (filename
, flags
& ~O_CREAT
, mode
);
690 errno
= EACCES
; /* restore errno */
704 clexec
= fcntl (fd
, F_GETFD
, 0);
705 if (clexec
== -1 || (fd
>= SHELL_FD_BASE
&& clexec
== 1))
710 /* Do the specific redirection requested. Returns errno or one of the
711 special redirection errors (*_REDIRECT) in case of error, 0 on success.
712 If flags & RX_ACTIVE is zero, then just do whatever is necessary to
713 produce the appropriate side effects. flags & RX_UNDOABLE, if non-zero,
714 says to remember how to undo each redirection. If flags & RX_CLEXEC is
715 non-zero, then we set all file descriptors > 2 that we open to be
718 do_redirection_internal (redirect
, flags
)
722 WORD_DESC
*redirectee
;
723 int redir_fd
, fd
, redirector
, r
, oflags
;
725 char *redirectee_word
;
726 enum r_instruction ri
;
727 REDIRECT
*new_redirect
;
730 redirectee
= redirect
->redirectee
.filename
;
731 redir_fd
= redirect
->redirectee
.dest
;
732 redirector
= redirect
->redirector
.dest
;
733 ri
= redirect
->instruction
;
735 if (redirect
->flags
& RX_INTERNAL
)
736 flags
|= RX_INTERNAL
;
738 if (TRANSLATE_REDIRECT (ri
))
740 /* We have [N]>&WORD[-] or [N]<&WORD[-] (or {V}>&WORD[-] or {V}<&WORD-).
741 and WORD, then translate the redirection into a new one and
743 redirectee_word
= redirection_expand (redirectee
);
745 /* XXX - what to do with [N]<&$w- where w is unset or null? ksh93
747 if (redirectee_word
== 0)
748 return (AMBIGUOUS_REDIRECT
);
749 else if (redirectee_word
[0] == '-' && redirectee_word
[1] == '\0')
751 sd
= redirect
->redirector
;
753 new_redirect
= make_redirection (sd
, r_close_this
, rd
, 0);
755 else if (all_digits (redirectee_word
))
757 sd
= redirect
->redirector
;
758 if (legal_number (redirectee_word
, &lfd
) && (int)lfd
== lfd
)
761 rd
.dest
= -1; /* XXX */
764 case r_duplicating_input_word
:
765 new_redirect
= make_redirection (sd
, r_duplicating_input
, rd
, 0);
767 case r_duplicating_output_word
:
768 new_redirect
= make_redirection (sd
, r_duplicating_output
, rd
, 0);
770 case r_move_input_word
:
771 new_redirect
= make_redirection (sd
, r_move_input
, rd
, 0);
773 case r_move_output_word
:
774 new_redirect
= make_redirection (sd
, r_move_output
, rd
, 0);
778 else if (ri
== r_duplicating_output_word
&& (redirect
->rflags
& REDIR_VARASSIGN
) == 0 && redirector
== 1)
780 sd
= redirect
->redirector
;
781 rd
.filename
= make_bare_word (redirectee_word
);
782 new_redirect
= make_redirection (sd
, r_err_and_out
, rd
, 0);
786 free (redirectee_word
);
787 return (AMBIGUOUS_REDIRECT
);
790 free (redirectee_word
);
792 /* Set up the variables needed by the rest of the function from the
794 if (new_redirect
->instruction
== r_err_and_out
)
798 /* Copy the word without allocating any memory that must be
800 redirectee
= (WORD_DESC
*)alloca (sizeof (WORD_DESC
));
801 xbcopy ((char *)new_redirect
->redirectee
.filename
,
802 (char *)redirectee
, sizeof (WORD_DESC
));
804 alloca_hack
= (char *)
805 alloca (1 + strlen (new_redirect
->redirectee
.filename
->word
));
806 redirectee
->word
= alloca_hack
;
807 strcpy (redirectee
->word
, new_redirect
->redirectee
.filename
->word
);
810 /* It's guaranteed to be an integer, and shouldn't be freed. */
811 redirectee
= new_redirect
->redirectee
.filename
;
813 redir_fd
= new_redirect
->redirectee
.dest
;
814 redirector
= new_redirect
->redirector
.dest
;
815 ri
= new_redirect
->instruction
;
817 /* Overwrite the flags element of the old redirect with the new value. */
818 redirect
->flags
= new_redirect
->flags
;
819 dispose_redirects (new_redirect
);
824 case r_output_direction
:
826 case r_input_direction
:
827 case r_inputa_direction
:
828 case r_err_and_out
: /* command &>filename */
829 case r_append_err_and_out
: /* command &>> filename */
832 if (posixly_correct
&& interactive_shell
== 0)
834 oflags
= redirectee
->flags
;
835 redirectee
->flags
|= W_NOGLOB
;
837 redirectee_word
= redirection_expand (redirectee
);
838 if (posixly_correct
&& interactive_shell
== 0)
839 redirectee
->flags
= oflags
;
841 if (redirectee_word
== 0)
842 return (AMBIGUOUS_REDIRECT
);
844 #if defined (RESTRICTED_SHELL)
845 if (restricted
&& (WRITE_REDIRECT (ri
)))
847 free (redirectee_word
);
848 return (RESTRICTED_REDIRECT
);
850 #endif /* RESTRICTED_SHELL */
852 fd
= redir_open (redirectee_word
, redirect
->flags
, 0666, ri
);
853 free (redirectee_word
);
855 if (fd
== NOCLOBBER_REDIRECT
)
861 if (flags
& RX_ACTIVE
)
863 if (redirect
->rflags
& REDIR_VARASSIGN
)
865 redirector
= fcntl (fd
, F_DUPFD
, SHELL_FD_BASE
); /* XXX try this for now */
868 sys_error (_("redirection error: cannot duplicate fd"));
869 REDIRECTION_ERROR (redirector
, r
, fd
);
872 if ((flags
& RX_UNDOABLE
) && (redirect
->rflags
& REDIR_VARASSIGN
) == 0)
874 /* Only setup to undo it if the thing to undo is active. */
875 if ((fd
!= redirector
) && (fcntl (redirector
, F_GETFD
, 0) != -1))
876 r
= add_undo_redirect (redirector
, ri
, -1);
878 r
= add_undo_close_redirect (redirector
);
879 REDIRECTION_ERROR (r
, errno
, fd
);
882 #if defined (BUFFERED_INPUT)
883 /* inhibit call to sync_buffered_stream() for async processes */
884 if (redirector
!= 0 || (subshell_environment
& SUBSHELL_ASYNC
) == 0)
885 check_bash_input (redirector
);
888 /* Make sure there is no pending output before we change the state
889 of the underlying file descriptor, since the builtins use stdio
891 if (redirector
== 1 && fileno (stdout
) == redirector
)
896 else if (redirector
== 2 && fileno (stderr
) == redirector
)
902 if (redirect
->rflags
& REDIR_VARASSIGN
)
904 if ((r
= redir_varassign (redirect
, redirector
)) < 0)
908 return (r
); /* XXX */
911 else if ((fd
!= redirector
) && (dup2 (fd
, redirector
) < 0))
913 close (fd
); /* dup2 failed? must be fd limit issue */
917 #if defined (BUFFERED_INPUT)
918 /* Do not change the buffered stream for an implicit redirection
919 of /dev/null to fd 0 for asynchronous commands without job
920 control (r_inputa_direction). */
921 if (ri
== r_input_direction
|| ri
== r_input_output
)
922 duplicate_buffered_stream (fd
, redirector
);
923 #endif /* BUFFERED_INPUT */
926 * If we're remembering, then this is the result of a while, for
927 * or until loop with a loop redirection, or a function/builtin
928 * executing in the parent shell with a redirection. In the
929 * function/builtin case, we want to set all file descriptors > 2
930 * to be close-on-exec to duplicate the effect of the old
931 * for i = 3 to NOFILE close(i) loop. In the case of the loops,
932 * both sh and ksh leave the file descriptors open across execs.
933 * The Posix standard mentions only the exec builtin.
935 if ((flags
& RX_CLEXEC
) && (redirector
> 2))
936 SET_CLOSE_ON_EXEC (redirector
);
939 if (fd
!= redirector
)
941 #if defined (BUFFERED_INPUT)
942 if (INPUT_REDIRECT (ri
))
943 close_buffered_fd (fd
);
945 #endif /* !BUFFERED_INPUT */
946 close (fd
); /* Don't close what we just opened! */
949 /* If we are hacking both stdout and stderr, do the stderr
950 redirection here. XXX - handle {var} here? */
951 if (ri
== r_err_and_out
|| ri
== r_append_err_and_out
)
953 if (flags
& RX_ACTIVE
)
955 if (flags
& RX_UNDOABLE
)
956 add_undo_redirect (2, ri
, -1);
963 case r_reading_until
:
964 case r_deblank_reading_until
:
965 case r_reading_string
:
966 /* REDIRECTEE is a pointer to a WORD_DESC containing the text of
967 the new input. Place it in a temporary file. */
970 fd
= here_document_to_fd (redirectee
, ri
);
974 heredoc_errno
= errno
;
975 return (HEREDOC_REDIRECT
);
978 if (redirect
->rflags
& REDIR_VARASSIGN
)
980 redirector
= fcntl (fd
, F_DUPFD
, SHELL_FD_BASE
); /* XXX try this for now */
983 sys_error (_("redirection error: cannot duplicate fd"));
984 REDIRECTION_ERROR (redirector
, r
, fd
);
987 if (flags
& RX_ACTIVE
)
989 if ((flags
& RX_UNDOABLE
) && (redirect
->rflags
& REDIR_VARASSIGN
) == 0)
991 /* Only setup to undo it if the thing to undo is active. */
992 if ((fd
!= redirector
) && (fcntl (redirector
, F_GETFD
, 0) != -1))
993 r
= add_undo_redirect (redirector
, ri
, -1);
995 r
= add_undo_close_redirect (redirector
);
996 REDIRECTION_ERROR (r
, errno
, fd
);
999 #if defined (BUFFERED_INPUT)
1000 check_bash_input (redirector
);
1002 if (redirect
->rflags
& REDIR_VARASSIGN
)
1004 if ((r
= redir_varassign (redirect
, redirector
)) < 0)
1008 return (r
); /* XXX */
1011 else if (fd
!= redirector
&& dup2 (fd
, redirector
) < 0)
1018 #if defined (BUFFERED_INPUT)
1019 duplicate_buffered_stream (fd
, redirector
);
1022 if ((flags
& RX_CLEXEC
) && (redirector
> 2))
1023 SET_CLOSE_ON_EXEC (redirector
);
1026 if (fd
!= redirector
)
1027 #if defined (BUFFERED_INPUT)
1028 close_buffered_fd (fd
);
1035 case r_duplicating_input
:
1036 case r_duplicating_output
:
1039 if ((flags
& RX_ACTIVE
) && (redirect
->rflags
& REDIR_VARASSIGN
))
1041 redirector
= fcntl (redir_fd
, F_DUPFD
, SHELL_FD_BASE
); /* XXX try this for now */
1044 sys_error (_("redirection error: cannot duplicate fd"));
1045 REDIRECTION_ERROR (redirector
, r
, -1);
1048 if ((flags
& RX_ACTIVE
) && (redir_fd
!= redirector
))
1050 if ((flags
& RX_UNDOABLE
) && (redirect
->rflags
& REDIR_VARASSIGN
) == 0)
1052 /* Only setup to undo it if the thing to undo is active. */
1053 if (fcntl (redirector
, F_GETFD
, 0) != -1)
1054 r
= add_undo_redirect (redirector
, ri
, redir_fd
);
1056 r
= add_undo_close_redirect (redirector
);
1057 REDIRECTION_ERROR (r
, errno
, -1);
1059 if ((flags
& RX_UNDOABLE
) && (ri
== r_move_input
|| ri
== r_move_output
))
1061 /* r_move_input and r_move_output add an additional close()
1062 that needs to be undone */
1063 if (fcntl (redirector
, F_GETFD
, 0) != -1)
1065 r
= add_undo_redirect (redir_fd
, r_close_this
, -1);
1066 REDIRECTION_ERROR (r
, errno
, -1);
1069 #if defined (BUFFERED_INPUT)
1070 /* inhibit call to sync_buffered_stream() for async processes */
1071 if (redirector
!= 0 || (subshell_environment
& SUBSHELL_ASYNC
) == 0)
1072 check_bash_input (redirector
);
1074 if (redirect
->rflags
& REDIR_VARASSIGN
)
1076 if ((r
= redir_varassign (redirect
, redirector
)) < 0)
1079 return (r
); /* XXX */
1082 /* This is correct. 2>&1 means dup2 (1, 2); */
1083 else if (dup2 (redir_fd
, redirector
) < 0)
1086 #if defined (BUFFERED_INPUT)
1087 if (ri
== r_duplicating_input
|| ri
== r_move_input
)
1088 duplicate_buffered_stream (redir_fd
, redirector
);
1089 #endif /* BUFFERED_INPUT */
1091 /* First duplicate the close-on-exec state of redirectee. dup2
1092 leaves the flag unset on the new descriptor, which means it
1093 stays open. Only set the close-on-exec bit for file descriptors
1094 greater than 2 in any case, since 0-2 should always be open
1095 unless closed by something like `exec 2<&-'. It should always
1096 be safe to set fds > 2 to close-on-exec if they're being used to
1097 save file descriptors < 2, since we don't need to preserve the
1098 state of the close-on-exec flag for those fds -- they should
1100 /* if ((already_set || set_unconditionally) && (ok_to_set))
1103 if (((fcntl (redir_fd
, F_GETFD
, 0) == 1) || redir_fd
< 2 || (flags
& RX_CLEXEC
)) &&
1106 if (((fcntl (redir_fd
, F_GETFD
, 0) == 1) || (redir_fd
< 2 && (flags
& RX_INTERNAL
)) || (flags
& RX_CLEXEC
)) &&
1109 SET_CLOSE_ON_EXEC (redirector
);
1111 /* When undoing saving of non-standard file descriptors (>=3) using
1112 file descriptors >= SHELL_FD_BASE, we set the saving fd to be
1113 close-on-exec and use a flag to decide how to set close-on-exec
1114 when the fd is restored. */
1115 if ((redirect
->flags
& RX_INTERNAL
) && (redirect
->flags
& RX_SAVCLEXEC
) && redirector
>= 3 && (redir_fd
>= SHELL_FD_BASE
|| (redirect
->flags
& RX_SAVEFD
)))
1116 SET_OPEN_ON_EXEC (redirector
);
1118 /* dup-and-close redirection */
1119 if (ri
== r_move_input
|| ri
== r_move_output
)
1121 xtrace_fdchk (redir_fd
);
1124 #if defined (COPROCESS_SUPPORT)
1125 coproc_fdchk (redir_fd
); /* XXX - loses coproc fds */
1132 if (flags
& RX_ACTIVE
)
1134 if (redirect
->rflags
& REDIR_VARASSIGN
)
1136 redirector
= redir_varvalue (redirect
);
1138 return AMBIGUOUS_REDIRECT
;
1142 /* XXX - only if REDIR_VARASSIGN not set? */
1143 if ((flags
& RX_UNDOABLE
) && (fcntl (redirector
, F_GETFD
, 0) != -1))
1145 r
= add_undo_redirect (redirector
, ri
, -1);
1146 REDIRECTION_ERROR (r
, errno
, redirector
);
1149 #if defined (COPROCESS_SUPPORT)
1150 coproc_fdchk (redirector
);
1152 xtrace_fdchk (redirector
);
1154 #if defined (BUFFERED_INPUT)
1155 /* inhibit call to sync_buffered_stream() for async processes */
1156 if (redirector
!= 0 || (subshell_environment
& SUBSHELL_ASYNC
) == 0)
1157 check_bash_input (redirector
);
1158 r
= close_buffered_fd (redirector
);
1159 #else /* !BUFFERED_INPUT */
1160 r
= close (redirector
);
1161 #endif /* !BUFFERED_INPUT */
1163 if (r
< 0 && (flags
& RX_INTERNAL
) && (errno
== EIO
|| errno
== ENOSPC
))
1164 REDIRECTION_ERROR (r
, errno
, -1);
1168 case r_duplicating_input_word
:
1169 case r_duplicating_output_word
:
1175 /* Remember the file descriptor associated with the slot FD,
1176 on REDIRECTION_UNDO_LIST. Note that the list will be reversed
1177 before it is executed. Any redirections that need to be undone
1178 even if REDIRECTION_UNDO_LIST is discarded by the exec builtin
1179 are also saved on EXEC_REDIRECTION_UNDO_LIST. FDBASE says where to
1180 start the duplicating. If it's less than SHELL_FD_BASE, we're ok,
1181 and can use SHELL_FD_BASE (-1 == don't care). If it's >= SHELL_FD_BASE,
1182 we have to make sure we don't use fdbase to save a file descriptor,
1183 since we're going to use it later (e.g., make sure we don't save fd 0
1184 to fd 10 if we have a redirection like 0<&10). If the value of fdbase
1185 puts the process over its fd limit, causing fcntl to fail, we try
1186 again with SHELL_FD_BASE. Return 0 on success, -1 on error. */
1188 add_undo_redirect (fd
, ri
, fdbase
)
1190 enum r_instruction ri
;
1193 int new_fd
, clexec_flag
, savefd_flag
;
1194 REDIRECT
*new_redirect
, *closer
, *dummy_redirect
;
1198 new_fd
= fcntl (fd
, F_DUPFD
, (fdbase
< SHELL_FD_BASE
) ? SHELL_FD_BASE
: fdbase
+1);
1200 new_fd
= fcntl (fd
, F_DUPFD
, SHELL_FD_BASE
);
1203 new_fd
= fcntl (fd
, F_DUPFD
, 0);
1209 sys_error (_("redirection error: cannot duplicate fd"));
1213 clexec_flag
= fcntl (fd
, F_GETFD
, 0);
1217 closer
= make_redirection (sd
, r_close_this
, rd
, 0);
1218 closer
->flags
|= RX_INTERNAL
;
1219 dummy_redirect
= copy_redirects (closer
);
1224 new_redirect
= make_redirection (sd
, r_duplicating_input
, rd
, 0);
1226 new_redirect
= make_redirection (sd
, r_duplicating_output
, rd
, 0);
1227 new_redirect
->flags
|= RX_INTERNAL
;
1229 new_redirect
->flags
|= RX_SAVEFD
;
1230 if (clexec_flag
== 0 && fd
>= 3 && (new_fd
>= SHELL_FD_BASE
|| savefd_flag
))
1231 new_redirect
->flags
|= RX_SAVCLEXEC
;
1232 new_redirect
->next
= closer
;
1234 closer
->next
= redirection_undo_list
;
1235 redirection_undo_list
= new_redirect
;
1237 /* Save redirections that need to be undone even if the undo list
1238 is thrown away by the `exec' builtin. */
1239 add_exec_redirect (dummy_redirect
);
1241 /* experimental: if we're saving a redirection to undo for a file descriptor
1242 above SHELL_FD_BASE, add a redirection to be undone if the exec builtin
1243 causes redirections to be discarded. There needs to be a difference
1244 between fds that are used to save other fds and then are the target of
1245 user redirections and fds that are just the target of user redirections.
1246 We use the close-on-exec flag to tell the difference; fds > SHELL_FD_BASE
1247 that have the close-on-exec flag set are assumed to be fds used internally
1249 if (fd
>= SHELL_FD_BASE
&& ri
!= r_close_this
&& clexec_flag
)
1253 new_redirect
= make_redirection (sd
, r_duplicating_output
, rd
, 0);
1254 new_redirect
->flags
|= RX_INTERNAL
;
1256 add_exec_redirect (new_redirect
);
1259 /* File descriptors used only for saving others should always be
1260 marked close-on-exec. Unfortunately, we have to preserve the
1261 close-on-exec state of the file descriptor we are saving, since
1262 fcntl (F_DUPFD) sets the new file descriptor to remain open
1263 across execs. If, however, the file descriptor whose state we
1264 are saving is <= 2, we can just set the close-on-exec flag,
1265 because file descriptors 0-2 should always be open-on-exec,
1266 and the restore above in do_redirection() will take care of it. */
1267 if (clexec_flag
|| fd
< 3)
1268 SET_CLOSE_ON_EXEC (new_fd
);
1269 else if (redirection_undo_list
->flags
& RX_SAVCLEXEC
)
1270 SET_CLOSE_ON_EXEC (new_fd
);
1275 /* Set up to close FD when we are finished with the current command
1276 and its redirections. Return 0 on success, -1 on error. */
1278 add_undo_close_redirect (fd
)
1286 closer
= make_redirection (sd
, r_close_this
, rd
, 0);
1287 closer
->flags
|= RX_INTERNAL
;
1288 closer
->next
= redirection_undo_list
;
1289 redirection_undo_list
= closer
;
1295 add_exec_redirect (dummy_redirect
)
1296 REDIRECT
*dummy_redirect
;
1298 dummy_redirect
->next
= exec_redirection_undo_list
;
1299 exec_redirection_undo_list
= dummy_redirect
;
1302 /* Return 1 if the redirection specified by RI and REDIRECTOR alters the
1305 stdin_redirection (ri
, redirector
)
1306 enum r_instruction ri
;
1311 case r_input_direction
:
1312 case r_inputa_direction
:
1313 case r_input_output
:
1314 case r_reading_until
:
1315 case r_deblank_reading_until
:
1316 case r_reading_string
:
1318 case r_duplicating_input
:
1319 case r_duplicating_input_word
:
1321 return (redirector
== 0);
1322 case r_output_direction
:
1323 case r_appending_to
:
1324 case r_duplicating_output
:
1326 case r_append_err_and_out
:
1327 case r_output_force
:
1328 case r_duplicating_output_word
:
1334 /* Return non-zero if any of the redirections in REDIRS alter the standard
1337 stdin_redirects (redirs
)
1343 for (n
= 0, rp
= redirs
; rp
; rp
= rp
->next
)
1344 if ((rp
->rflags
& REDIR_VARASSIGN
) == 0)
1345 n
+= stdin_redirection (rp
->instruction
, rp
->redirector
.dest
);
1348 /* bind_var_to_int handles array references */
1350 redir_varassign (redir
, fd
)
1357 w
= redir
->redirector
.filename
;
1358 v
= bind_var_to_int (w
->word
, fd
);
1359 if (v
== 0 || readonly_p (v
) || noassign_p (v
))
1360 return BADVAR_REDIRECT
;
1362 stupidly_hack_special_variables (w
->word
);
1366 /* Handles {array[ind]} for redirection words */
1368 redir_varvalue (redir
)
1375 #if defined (ARRAY_VARS)
1380 w
= redir
->redirector
.filename
->word
; /* shorthand */
1381 /* XXX - handle set -u here? */
1382 #if defined (ARRAY_VARS)
1383 if (vr
= valid_array_reference (w
, 0))
1385 v
= array_variable_part (w
, &sub
, &len
);
1390 v
= find_variable (w
);
1391 #if defined (ARRAY_VARS)
1394 v
= find_variable_last_nameref (w
, 0);
1395 if (v
&& nameref_p (v
))
1397 w
= nameref_cell (v
);
1398 if (vr
= valid_array_reference (w
, 0))
1399 v
= array_variable_part (w
, &sub
, &len
);
1401 v
= find_variable (w
);
1407 if (v
== 0 || invisible_p (v
))
1410 #if defined (ARRAY_VARS)
1411 /* get_variable_value handles references to array variables without
1413 if (vr
&& (array_p (v
) || assoc_p (v
)))
1414 val
= get_array_value (w
, 0, (int *)NULL
, (arrayind_t
*)0);
1417 val
= get_variable_value (v
);
1418 if (val
== 0 || *val
== 0)
1421 if (legal_number (val
, &vmax
) < 0)
1424 i
= vmax
; /* integer truncation */