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 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 /* TRANSLATORS: %s after `Cannot' is a function name, e.g. `Cannot open'.
553 Directly translating this to another language will not work, first because
554 %s itself is not translated.
555 Translate it as `%s: Function %s failed'. */
556 ERROR ((0, e, _("%s: Cannot %s"), quotearg_colon (name), call));
559 /* Report a fatal error associated with the system call CALL and
560 the optional file name NAME. */
562 call_arg_fatal (char const *call, char const *name)
565 /* TRANSLATORS: %s after `Cannot' is a function name, e.g. `Cannot open'.
566 Directly translating this to another language will not work, first because
567 %s itself is not translated.
568 Translate it as `%s: Function %s failed'. */
569 FATAL_ERROR ((0, e, _("%s: Cannot %s"), quotearg_colon (name), call));
572 /* Report a warning associated with the system call CALL and
573 the optional file name NAME. */
575 call_arg_warn (char const *call, char const *name)
578 /* TRANSLATORS: %s after `Cannot' is a function name, e.g. `Cannot open'.
579 Directly translating this to another language will not work, first because
580 %s itself is not translated.
581 Translate it as `%s: Function %s failed'. */
582 WARN ((0, e, _("%s: Warning: Cannot %s"), quotearg_colon (name), call));
586 chdir_fatal (char const *name)
588 call_arg_fatal ("chdir", name);
592 chmod_error_details (char const *name, mode_t mode)
596 decode_mode (mode, buf);
597 ERROR ((0, e, _("%s: Cannot change mode to %s"),
598 quotearg_colon (name), buf));
602 chown_error_details (char const *name, uid_t uid, gid_t gid)
605 ERROR ((0, e, _("%s: Cannot change ownership to uid %lu, gid %lu"),
606 quotearg_colon (name), (unsigned long) uid, (unsigned long) gid));
610 close_error (char const *name)
612 call_arg_error ("close", name);
616 close_warn (char const *name)
618 call_arg_warn ("close", name);
622 close_diag (char const *name)
624 if (ignore_failed_read_option)
631 exec_fatal (char const *name)
633 call_arg_fatal ("exec", name);
637 link_error (char const *target, char const *source)
640 ERROR ((0, e, _("%s: Cannot hard link to %s"),
641 quotearg_colon (source), quote_n (1, target)));
645 mkdir_error (char const *name)
647 call_arg_error ("mkdir", name);
651 mkfifo_error (char const *name)
653 call_arg_error ("mkfifo", name);
657 mknod_error (char const *name)
659 call_arg_error ("mknod", name);
663 open_error (char const *name)
665 call_arg_error ("open", name);
669 open_fatal (char const *name)
671 call_arg_fatal ("open", name);
675 open_warn (char const *name)
677 call_arg_warn ("open", name);
681 open_diag (char const *name)
683 if (ignore_failed_read_option)
690 read_error (char const *name)
692 call_arg_error ("read", name);
696 read_error_details (char const *name, off_t offset, size_t size)
698 char buf[UINTMAX_STRSIZE_BOUND];
701 ngettext ("%s: Read error at byte %s, while reading %lu byte",
702 "%s: Read error at byte %s, while reading %lu bytes",
704 quotearg_colon (name), STRINGIFY_BIGINT (offset, buf),
705 (unsigned long) size));
709 read_warn_details (char const *name, off_t offset, size_t size)
711 char buf[UINTMAX_STRSIZE_BOUND];
714 ngettext ("%s: Warning: Read error at byte %s, while reading %lu byte",
715 "%s: Warning: Read error at byte %s, while reading %lu bytes",
717 quotearg_colon (name), STRINGIFY_BIGINT (offset, buf),
718 (unsigned long) size));
722 read_diag_details (char const *name, off_t offset, size_t size)
724 if (ignore_failed_read_option)
725 read_warn_details (name, offset, size);
727 read_error_details (name, offset, size);
731 read_fatal (char const *name)
733 call_arg_fatal ("read", name);
737 read_fatal_details (char const *name, off_t offset, size_t size)
739 char buf[UINTMAX_STRSIZE_BOUND];
742 ngettext ("%s: Read error at byte %s, reading %lu byte",
743 "%s: Read error at byte %s, reading %lu bytes",
745 quotearg_colon (name), STRINGIFY_BIGINT (offset, buf),
746 (unsigned long) size));
750 readlink_error (char const *name)
752 call_arg_error ("readlink", name);
756 readlink_warn (char const *name)
758 call_arg_warn ("readlink", name);
762 readlink_diag (char const *name)
764 if (ignore_failed_read_option)
765 readlink_warn (name);
767 readlink_error (name);
771 savedir_error (char const *name)
773 call_arg_error ("savedir", name);
777 savedir_warn (char const *name)
779 call_arg_warn ("savedir", name);
783 savedir_diag (char const *name)
785 if (ignore_failed_read_option)
788 savedir_error (name);
792 seek_error (char const *name)
794 call_arg_error ("seek", name);
798 seek_error_details (char const *name, off_t offset)
800 char buf[UINTMAX_STRSIZE_BOUND];
802 ERROR ((0, e, _("%s: Cannot seek to %s"),
803 quotearg_colon (name),
804 STRINGIFY_BIGINT (offset, buf)));
808 seek_warn (char const *name)
810 call_arg_warn ("seek", name);
814 seek_warn_details (char const *name, off_t offset)
816 char buf[UINTMAX_STRSIZE_BOUND];
818 WARN ((0, e, _("%s: Warning: Cannot seek to %s"),
819 quotearg_colon (name),
820 STRINGIFY_BIGINT (offset, buf)));
824 seek_diag_details (char const *name, off_t offset)
826 if (ignore_failed_read_option)
827 seek_warn_details (name, offset);
829 seek_error_details (name, offset);
833 symlink_error (char const *contents, char const *name)
836 ERROR ((0, e, _("%s: Cannot create symlink to %s"),
837 quotearg_colon (name), quote_n (1, contents)));
841 stat_fatal (char const *name)
843 call_arg_fatal ("stat", name);
847 stat_error (char const *name)
849 call_arg_error ("stat", name);
853 stat_warn (char const *name)
855 call_arg_warn ("stat", name);
859 stat_diag (char const *name)
861 if (ignore_failed_read_option)
868 truncate_error (char const *name)
870 call_arg_error ("truncate", name);
874 truncate_warn (char const *name)
876 call_arg_warn ("truncate", name);
880 unlink_error (char const *name)
882 call_arg_error ("unlink", name);
886 utime_error (char const *name)
888 call_arg_error ("utime", name);
892 waitpid_error (char const *name)
894 call_arg_error ("waitpid", name);
898 write_error (char const *name)
900 call_arg_error ("write", name);
904 write_error_details (char const *name, size_t status, size_t size)
910 ngettext ("%s: Wrote only %lu of %lu byte",
911 "%s: Wrote only %lu of %lu bytes",
913 name, (unsigned long int) status, (unsigned long int) size));
917 write_fatal (char const *name)
919 call_arg_fatal ("write", name);
923 write_fatal_details (char const *name, ssize_t status, size_t size)
925 write_error_details (name, status, size);
930 /* Fork, aborting if unsuccessful. */
936 call_arg_fatal ("fork", _("child process"));
940 /* Create a pipe, aborting if unsuccessful. */
945 call_arg_fatal ("pipe", _("interprocess channel"));
948 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
949 ALIGNMENT must be nonzero. The caller must arrange for ((char *)
950 PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
954 ptr_align (void *ptr, size_t alignment)
957 char *p1 = p0 + alignment - 1;
958 return p1 - (size_t) p1 % alignment;
961 /* Return the address of a page-aligned buffer of at least SIZE bytes.
962 The caller should free *PTR when done with the buffer. */
965 page_aligned_alloc (void **ptr, size_t size)
967 size_t alignment = getpagesize ();
968 size_t size1 = size + alignment;
971 *ptr = xmalloc (size1);
972 return ptr_align (*ptr, alignment);