1 /* Miscellaneous functions, not really specific to GNU tar.
3 Copyright (C) 1988, 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
4 2003, 2004 Free Software Foundation, Inc.
6 This program is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any later
11 This program is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
14 Public License for more details.
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
26 static void call_arg_fatal (char const *, char const *)
27 __attribute__ ((noreturn
));
29 /* Handling strings. */
31 /* Assign STRING to a copy of VALUE if not zero, or to zero. If
32 STRING was nonzero, it is freed first. */
34 assign_string (char **string
, const char *value
)
38 *string
= value
? xstrdup (value
) : 0;
41 /* Allocate a copy of the string quoted as in C, and returns that. If
42 the string does not have to be quoted, it returns a null pointer.
43 The allocated copy should normally be freed with free() after the
44 caller is done with it.
46 This is used in one context only: generating the directory file in
47 incremental dumps. The quoted string is not intended for human
48 consumption; it is intended only for unquote_string. The quoting
49 is locale-independent, so that users needn't worry about locale
50 when reading directory files. This means that we can't use
51 quotearg, as quotearg is locale-dependent and is meant for human
54 quote_copy_string (const char *string
)
56 const char *source
= string
;
57 char *destination
= 0;
63 int character
= *source
++;
70 size_t length
= (source
- string
) - 1;
73 buffer
= xmalloc (length
+ 2 + 2 * strlen (source
) + 1);
74 memcpy (buffer
, string
, length
);
75 destination
= buffer
+ length
;
77 *destination
++ = '\\';
78 *destination
++ = character
== '\\' ? '\\' : 'n';
83 *destination
++ = character
;
95 /* Takes a quoted C string (like those produced by quote_copy_string)
96 and turns it back into the un-quoted original. This is done in
97 place. Returns 0 only if the string was not properly quoted, but
98 completes the unquoting anyway.
100 This is used for reading the saved directory file in incremental
101 dumps. It is used for decoding old `N' records (demangling names).
102 But also, it is used for decoding file arguments, would they come
103 from the shell or a -T file, and for decoding the --exclude
106 unquote_string (char *string
)
109 char *source
= string
;
110 char *destination
= string
;
112 /* Escape sequences other than \\ and \n are no longer generated by
113 quote_copy_string, but accept them for backwards compatibility,
114 and also because unquote_string is used for purposes other than
115 parsing the output of quote_copy_string. */
122 *destination
++ = '\\';
127 *destination
++ = '\a';
132 *destination
++ = '\b';
137 *destination
++ = '\f';
142 *destination
++ = '\n';
147 *destination
++ = '\r';
152 *destination
++ = '\t';
157 *destination
++ = '\v';
162 *destination
++ = 0177;
175 int value
= *source
++ - '0';
177 if (*source
< '0' || *source
> '7')
179 *destination
++ = value
;
182 value
= value
* 8 + *source
++ - '0';
183 if (*source
< '0' || *source
> '7')
185 *destination
++ = value
;
188 value
= value
* 8 + *source
++ - '0';
189 *destination
++ = value
;
195 *destination
++ = '\\';
197 *destination
++ = *source
++;
200 else if (source
!= destination
)
201 *destination
++ = *source
++;
203 source
++, destination
++;
205 if (source
!= destination
)
212 /* Saved names in case backup needs to be undone. */
213 static char *before_backup_name
;
214 static char *after_backup_name
;
216 /* Return 1 if FILE_NAME is obviously "." or "/". */
218 must_be_dot_or_slash (char const *file_name
)
220 file_name
+= FILE_SYSTEM_PREFIX_LEN (file_name
);
222 if (ISSLASH (file_name
[0]))
225 if (ISSLASH (file_name
[1]))
227 else if (file_name
[1] == '.'
228 && ISSLASH (file_name
[2 + (file_name
[2] == '.')]))
229 file_name
+= 2 + (file_name
[2] == '.');
231 return ! file_name
[1];
235 while (file_name
[0] == '.' && ISSLASH (file_name
[1]))
238 while (ISSLASH (*file_name
))
242 return ! file_name
[0] || (file_name
[0] == '.' && ! file_name
[1]);
246 /* Some implementations of rmdir let you remove '.' or '/'.
247 Report an error with errno set to zero for obvious cases of this;
248 otherwise call rmdir. */
250 safer_rmdir (const char *file_name
)
252 if (must_be_dot_or_slash (file_name
))
258 return rmdir (file_name
);
261 /* Remove FILE_NAME, returning 1 on success. If FILE_NAME is a directory,
262 then if OPTION is RECURSIVE_REMOVE_OPTION is set remove FILE_NAME
263 recursively; otherwise, remove it only if it is empty. If FILE_NAME is
264 a directory that cannot be removed (e.g., because it is nonempty)
265 and if OPTION is WANT_DIRECTORY_REMOVE_OPTION, then return -1.
266 Return 0 on error, with errno set; if FILE_NAME is obviously the working
267 directory return zero with errno set to zero. */
269 remove_any_file (const char *file_name
, enum remove_option option
)
271 /* Try unlink first if we are not root, as this saves us a system
272 call in the common case where we're removing a non-directory. */
275 if (unlink (file_name
) == 0)
278 /* POSIX 1003.1-2001 requires EPERM when attempting to unlink a
279 directory without appropriate privileges, but many Linux
280 kernels return the more-sensible EISDIR. */
281 if (errno
!= EPERM
&& errno
!= EISDIR
)
285 if (safer_rmdir (file_name
) == 0)
291 return we_are_root
&& unlink (file_name
) == 0;
295 #if defined ENOTEMPTY && ENOTEMPTY != EEXIST
300 case ORDINARY_REMOVE_OPTION
:
303 case WANT_DIRECTORY_REMOVE_OPTION
:
306 case RECURSIVE_REMOVE_OPTION
:
308 char *directory
= savedir (file_name
);
315 for (entry
= directory
;
316 (entrylen
= strlen (entry
)) != 0;
317 entry
+= entrylen
+ 1)
319 char *file_name_buffer
= new_name (file_name
, entry
);
320 int r
= remove_any_file (file_name_buffer
,
321 RECURSIVE_REMOVE_OPTION
);
323 free (file_name_buffer
);
334 return safer_rmdir (file_name
) == 0;
343 /* Check if FILE_NAME already exists and make a backup of it right now.
344 Return success (nonzero) only if the backup is either unneeded, or
345 successful. For now, directories are considered to never need
346 backup. If THIS_IS_THE_ARCHIVE is nonzero, this is the archive and
347 so, we do not have to backup block or character devices, nor remote
350 maybe_backup_file (const char *file_name
, int this_is_the_archive
)
352 struct stat file_stat
;
354 /* Check if we really need to backup the file. */
356 if (this_is_the_archive
&& _remdev (file_name
))
359 if (stat (file_name
, &file_stat
))
364 stat_error (file_name
);
368 if (S_ISDIR (file_stat
.st_mode
))
371 if (this_is_the_archive
372 && (S_ISBLK (file_stat
.st_mode
) || S_ISCHR (file_stat
.st_mode
)))
375 assign_string (&before_backup_name
, file_name
);
377 /* A run situation may exist between Emacs or other GNU programs trying to
378 make a backup for the same file simultaneously. If theoretically
379 possible, real problems are unlikely. Doing any better would require a
380 convention, GNU-wide, for all programs doing backups. */
382 assign_string (&after_backup_name
, 0);
383 after_backup_name
= find_backup_file_name (file_name
, backup_type
);
384 if (! after_backup_name
)
387 if (rename (before_backup_name
, after_backup_name
) == 0)
390 fprintf (stdlis
, _("Renaming %s to %s\n"),
391 quote_n (0, before_backup_name
),
392 quote_n (1, after_backup_name
));
397 /* The backup operation failed. */
399 ERROR ((0, e
, _("%s: Cannot rename to %s"),
400 quotearg_colon (before_backup_name
),
401 quote_n (1, after_backup_name
)));
402 assign_string (&after_backup_name
, 0);
407 /* Try to restore the recently backed up file to its original name.
408 This is usually only needed after a failed extraction. */
410 undo_last_backup (void)
412 if (after_backup_name
)
414 if (rename (after_backup_name
, before_backup_name
) != 0)
417 ERROR ((0, e
, _("%s: Cannot rename to %s"),
418 quotearg_colon (after_backup_name
),
419 quote_n (1, before_backup_name
)));
422 fprintf (stdlis
, _("Renaming %s back to %s\n"),
423 quote_n (0, after_backup_name
),
424 quote_n (1, before_backup_name
));
425 assign_string (&after_backup_name
, 0);
429 /* Depending on DEREF, apply either stat or lstat to (NAME, BUF). */
431 deref_stat (bool deref
, char const *name
, struct stat
*buf
)
433 return deref
? stat (name
, buf
) : lstat (name
, buf
);
436 /* A description of a working directory. */
441 struct saved_cwd saved_cwd
;
444 /* A vector of chdir targets. wd[0] is the initial working directory. */
445 static struct wd
*wd
;
447 /* The number of working directories in the vector. */
450 /* The allocated size of the vector. */
451 static size_t wd_alloc
;
453 /* DIR is the operand of a -C option; add it to vector of chdir targets,
454 and return the index of its location. */
456 chdir_arg (char const *dir
)
460 wd_alloc
= 2 * (wd_alloc
+ 1);
461 wd
= xrealloc (wd
, sizeof *wd
* wd_alloc
);
470 /* Optimize the common special case of the working directory,
471 or the working directory as a prefix. */
474 while (dir
[0] == '.' && ISSLASH (dir
[1]))
475 for (dir
+= 2; ISSLASH (*dir
); dir
++)
477 if (! dir
[dir
[0] == '.'])
486 /* Change to directory I. If I is 0, change to the initial working
487 directory; otherwise, I must be a value returned by chdir_arg. */
495 struct wd
*prev
= &wd
[previous
];
496 struct wd
*curr
= &wd
[i
];
501 if (save_cwd (&prev
->saved_cwd
) != 0)
502 FATAL_ERROR ((0, 0, _("Cannot save working directory")));
507 if (restore_cwd (&curr
->saved_cwd
))
508 FATAL_ERROR ((0, 0, _("Cannot change working directory")));
512 if (i
&& ! ISSLASH (curr
->name
[0]))
514 if (chdir (curr
->name
) != 0)
515 chdir_fatal (curr
->name
);
522 /* Decode MODE from its binary form in a stat structure, and encode it
523 into a 9-byte string STRING, terminated with a NUL. */
526 decode_mode (mode_t mode
, char *string
)
528 *string
++ = mode
& S_IRUSR
? 'r' : '-';
529 *string
++ = mode
& S_IWUSR
? 'w' : '-';
530 *string
++ = (mode
& S_ISUID
531 ? (mode
& S_IXUSR
? 's' : 'S')
532 : (mode
& S_IXUSR
? 'x' : '-'));
533 *string
++ = mode
& S_IRGRP
? 'r' : '-';
534 *string
++ = mode
& S_IWGRP
? 'w' : '-';
535 *string
++ = (mode
& S_ISGID
536 ? (mode
& S_IXGRP
? 's' : 'S')
537 : (mode
& S_IXGRP
? 'x' : '-'));
538 *string
++ = mode
& S_IROTH
? 'r' : '-';
539 *string
++ = mode
& S_IWOTH
? 'w' : '-';
540 *string
++ = (mode
& S_ISVTX
541 ? (mode
& S_IXOTH
? 't' : 'T')
542 : (mode
& S_IXOTH
? 'x' : '-'));
546 /* Report an error associated with the system call CALL and the
547 optional name NAME. */
549 call_arg_error (char const *call
, char const *name
)
552 ERROR ((0, e
, _("%s: Cannot %s"), quotearg_colon (name
), call
));
555 /* Report a fatal error associated with the system call CALL and
556 the optional file name NAME. */
558 call_arg_fatal (char const *call
, char const *name
)
561 FATAL_ERROR ((0, e
, _("%s: Cannot %s"), quotearg_colon (name
), call
));
564 /* Report a warning associated with the system call CALL and
565 the optional file name NAME. */
567 call_arg_warn (char const *call
, char const *name
)
570 WARN ((0, e
, _("%s: Warning: Cannot %s"), quotearg_colon (name
), call
));
574 chdir_fatal (char const *name
)
576 call_arg_fatal ("chdir", name
);
580 chmod_error_details (char const *name
, mode_t mode
)
584 decode_mode (mode
, buf
);
585 ERROR ((0, e
, _("%s: Cannot change mode to %s"),
586 quotearg_colon (name
), buf
));
590 chown_error_details (char const *name
, uid_t uid
, gid_t gid
)
593 ERROR ((0, e
, _("%s: Cannot change ownership to uid %lu, gid %lu"),
594 quotearg_colon (name
), (unsigned long) uid
, (unsigned long) gid
));
598 close_error (char const *name
)
600 call_arg_error ("close", name
);
604 close_warn (char const *name
)
606 call_arg_warn ("close", name
);
610 close_diag (char const *name
)
612 if (ignore_failed_read_option
)
619 exec_fatal (char const *name
)
621 call_arg_fatal ("exec", name
);
625 link_error (char const *target
, char const *source
)
628 ERROR ((0, e
, _("%s: Cannot hard link to %s"),
629 quotearg_colon (source
), quote_n (1, target
)));
633 mkdir_error (char const *name
)
635 call_arg_error ("mkdir", name
);
639 mkfifo_error (char const *name
)
641 call_arg_error ("mkfifo", name
);
645 mknod_error (char const *name
)
647 call_arg_error ("mknod", name
);
651 open_error (char const *name
)
653 call_arg_error ("open", name
);
657 open_fatal (char const *name
)
659 call_arg_fatal ("open", name
);
663 open_warn (char const *name
)
665 call_arg_warn ("open", name
);
669 open_diag (char const *name
)
671 if (ignore_failed_read_option
)
678 read_error (char const *name
)
680 call_arg_error ("read", name
);
684 read_error_details (char const *name
, off_t offset
, size_t size
)
686 char buf
[UINTMAX_STRSIZE_BOUND
];
689 ngettext ("%s: Read error at byte %s, reading %lu byte",
690 "%s: Read error at byte %s, reading %lu bytes",
692 quotearg_colon (name
), STRINGIFY_BIGINT (offset
, buf
),
693 (unsigned long) size
));
697 read_warn_details (char const *name
, off_t offset
, size_t size
)
699 char buf
[UINTMAX_STRSIZE_BOUND
];
702 ngettext ("%s: Warning: Read error at byte %s, reading %lu byte",
703 "%s: Warning: Read error at byte %s, reading %lu bytes",
705 quotearg_colon (name
), STRINGIFY_BIGINT (offset
, buf
),
706 (unsigned long) size
));
710 read_diag_details (char const *name
, off_t offset
, size_t size
)
712 if (ignore_failed_read_option
)
713 read_warn_details (name
, offset
, size
);
715 read_error_details (name
, offset
, size
);
719 read_fatal (char const *name
)
721 call_arg_fatal ("read", name
);
725 read_fatal_details (char const *name
, off_t offset
, size_t size
)
727 char buf
[UINTMAX_STRSIZE_BOUND
];
730 ngettext ("%s: Read error at byte %s, reading %lu byte",
731 "%s: Read error at byte %s, reading %lu bytes",
733 quotearg_colon (name
), STRINGIFY_BIGINT (offset
, buf
),
734 (unsigned long) size
));
738 readlink_error (char const *name
)
740 call_arg_error ("readlink", name
);
744 readlink_warn (char const *name
)
746 call_arg_warn ("readlink", name
);
750 readlink_diag (char const *name
)
752 if (ignore_failed_read_option
)
753 readlink_warn (name
);
755 readlink_error (name
);
759 savedir_error (char const *name
)
761 call_arg_error ("savedir", name
);
765 savedir_warn (char const *name
)
767 call_arg_warn ("savedir", name
);
771 savedir_diag (char const *name
)
773 if (ignore_failed_read_option
)
776 savedir_error (name
);
780 seek_error (char const *name
)
782 call_arg_error ("seek", name
);
786 seek_error_details (char const *name
, off_t offset
)
788 char buf
[UINTMAX_STRSIZE_BOUND
];
790 ERROR ((0, e
, _("%s: Cannot seek to %s"),
791 quotearg_colon (name
),
792 STRINGIFY_BIGINT (offset
, buf
)));
796 seek_warn (char const *name
)
798 call_arg_warn ("seek", name
);
802 seek_warn_details (char const *name
, off_t offset
)
804 char buf
[UINTMAX_STRSIZE_BOUND
];
806 WARN ((0, e
, _("%s: Warning: Cannot seek to %s"),
807 quotearg_colon (name
),
808 STRINGIFY_BIGINT (offset
, buf
)));
812 seek_diag_details (char const *name
, off_t offset
)
814 if (ignore_failed_read_option
)
815 seek_warn_details (name
, offset
);
817 seek_error_details (name
, offset
);
821 symlink_error (char const *contents
, char const *name
)
824 ERROR ((0, e
, _("%s: Cannot create symlink to %s"),
825 quotearg_colon (name
), quote_n (1, contents
)));
829 stat_error (char const *name
)
831 call_arg_error ("stat", name
);
835 stat_warn (char const *name
)
837 call_arg_warn ("stat", name
);
841 stat_diag (char const *name
)
843 if (ignore_failed_read_option
)
850 truncate_error (char const *name
)
852 call_arg_error ("truncate", name
);
856 truncate_warn (char const *name
)
858 call_arg_warn ("truncate", name
);
862 unlink_error (char const *name
)
864 call_arg_error ("unlink", name
);
868 utime_error (char const *name
)
870 call_arg_error ("utime", name
);
874 waitpid_error (char const *name
)
876 call_arg_error ("waitpid", name
);
880 write_error (char const *name
)
882 call_arg_error ("write", name
);
886 write_error_details (char const *name
, size_t status
, size_t size
)
892 ngettext ("%s: Wrote only %lu of %lu byte",
893 "%s: Wrote only %lu of %lu bytes",
895 name
, (unsigned long int) status
, (unsigned long int) size
));
899 write_fatal (char const *name
)
901 call_arg_fatal ("write", name
);
905 write_fatal_details (char const *name
, ssize_t status
, size_t size
)
907 write_error_details (name
, status
, size
);
912 /* Fork, aborting if unsuccessful. */
918 call_arg_fatal ("fork", _("child process"));
922 /* Create a pipe, aborting if unsuccessful. */
927 call_arg_fatal ("pipe", _("interprocess channel"));
930 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
931 ALIGNMENT must be nonzero. The caller must arrange for ((char *)
932 PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
936 ptr_align (void *ptr
, size_t alignment
)
939 char *p1
= p0
+ alignment
- 1;
940 return p1
- (size_t) p1
% alignment
;
943 /* Return the address of a page-aligned buffer of at least SIZE bytes.
944 The caller should free *PTR when done with the buffer. */
947 page_aligned_alloc (void **ptr
, size_t size
)
949 size_t alignment
= getpagesize ();
950 size_t size1
= size
+ alignment
;
953 *ptr
= xmalloc (size1
);
954 return ptr_align (*ptr
, alignment
);