1 /* Miscellaneous functions, not really specific to GNU tar.
3 Copyright (C) 1988, 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
4 2003, 2004, 2005, 2006, 2007, 2009, 2010 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 3, 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 #include <unlinkdir.h>
29 #ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
30 # define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
34 /* Handling strings. */
36 /* Assign STRING to a copy of VALUE if not zero, or to zero. If
37 STRING was nonzero, it is freed first. */
39 assign_string (char **string
, const char *value
)
43 *string
= value
? xstrdup (value
) : 0;
47 /* This function is currently unused; perhaps it should be removed? */
49 /* Allocate a copy of the string quoted as in C, and returns that. If
50 the string does not have to be quoted, it returns a null pointer.
51 The allocated copy should normally be freed with free() after the
52 caller is done with it.
54 This is used in one context only: generating the directory file in
55 incremental dumps. The quoted string is not intended for human
56 consumption; it is intended only for unquote_string. The quoting
57 is locale-independent, so that users needn't worry about locale
58 when reading directory files. This means that we can't use
59 quotearg, as quotearg is locale-dependent and is meant for human
62 quote_copy_string (const char *string
)
64 const char *source
= string
;
65 char *destination
= 0;
71 int character
= *source
++;
78 size_t length
= (source
- string
) - 1;
81 buffer
= xmalloc (length
+ 2 + 2 * strlen (source
) + 1);
82 memcpy (buffer
, string
, length
);
83 destination
= buffer
+ length
;
85 *destination
++ = '\\';
86 *destination
++ = character
== '\\' ? '\\' : 'n';
91 *destination
++ = character
;
104 /* Takes a quoted C string (like those produced by quote_copy_string)
105 and turns it back into the un-quoted original. This is done in
106 place. Returns 0 only if the string was not properly quoted, but
107 completes the unquoting anyway.
109 This is used for reading the saved directory file in incremental
110 dumps. It is used for decoding old `N' records (demangling names).
111 But also, it is used for decoding file arguments, would they come
112 from the shell or a -T file, and for decoding the --exclude
115 unquote_string (char *string
)
118 char *source
= string
;
119 char *destination
= string
;
121 /* Escape sequences other than \\ and \n are no longer generated by
122 quote_copy_string, but accept them for backwards compatibility,
123 and also because unquote_string is used for purposes other than
124 parsing the output of quote_copy_string. */
131 *destination
++ = '\\';
136 *destination
++ = '\a';
141 *destination
++ = '\b';
146 *destination
++ = '\f';
151 *destination
++ = '\n';
156 *destination
++ = '\r';
161 *destination
++ = '\t';
166 *destination
++ = '\v';
171 *destination
++ = 0177;
184 int value
= *source
++ - '0';
186 if (*source
< '0' || *source
> '7')
188 *destination
++ = value
;
191 value
= value
* 8 + *source
++ - '0';
192 if (*source
< '0' || *source
> '7')
194 *destination
++ = value
;
197 value
= value
* 8 + *source
++ - '0';
198 *destination
++ = value
;
204 *destination
++ = '\\';
206 *destination
++ = *source
++;
209 else if (source
!= destination
)
210 *destination
++ = *source
++;
212 source
++, destination
++;
214 if (source
!= destination
)
219 /* Zap trailing slashes. */
221 zap_slashes (char *name
)
225 if (!name
|| *name
== 0)
227 q
= name
+ strlen (name
) - 1;
228 while (q
> name
&& ISSLASH (*q
))
233 /* Normalize FILE_NAME by removing redundant slashes and "."
234 components, including redundant trailing slashes. Leave ".."
235 alone, as it may be significant in the presence of symlinks and on
236 platforms where "/.." != "/". Destructive version: modifies its
239 normalize_filename_x (char *file_name
)
241 char *name
= file_name
+ FILE_SYSTEM_PREFIX_LEN (file_name
);
246 /* Don't squeeze leading "//" to "/", on hosts where they're distinct. */
247 name
+= (DOUBLE_SLASH_IS_DISTINCT_ROOT
248 && ISSLASH (*name
) && ISSLASH (name
[1]) && ! ISSLASH (name
[2]));
250 /* Omit redundant leading "." components. */
251 for (q
= p
= name
; (*p
= *q
) == '.' && ISSLASH (q
[1]); p
+= !*q
)
252 for (q
+= 2; ISSLASH (*q
); q
++)
255 /* Copy components from Q to P, omitting redundant slashes and
256 internal "." components. */
257 while ((*p
++ = c
= *q
++) != '\0')
259 while (ISSLASH (q
[*q
== '.']))
260 q
+= (*q
== '.') + 1;
262 /* Omit redundant trailing "." component and slash. */
265 p
-= p
[-2] == '.' && ISSLASH (p
[-3]);
266 p
-= 2 < p
- name
&& ISSLASH (p
[-2]);
271 /* Normalize NAME by removing redundant slashes and "." components,
272 including redundant trailing slashes. Return a normalized
273 newly-allocated copy. */
276 normalize_filename (const char *name
)
280 if (IS_RELATIVE_FILE_NAME (name
))
282 /* Set COPY to the absolute file name if possible.
284 FIXME: There should be no need to get the absolute file name.
285 getcwd is slow, it might fail, and it does not necessarily
286 return a canonical name even when it succeeds. Perhaps we
287 can use dev+ino pairs instead of names? */
291 size_t copylen
= strlen (copy
);
292 bool need_separator
= ! (DOUBLE_SLASH_IS_DISTINCT_ROOT
293 && copylen
== 2 && ISSLASH (copy
[1]));
294 copy
= xrealloc (copy
, copylen
+ need_separator
+ strlen (name
) + 1);
295 copy
[copylen
] = DIRECTORY_SEPARATOR
;
296 strcpy (copy
+ copylen
+ need_separator
, name
);
299 WARN ((0, errno
, _("Cannot get working directory")));
303 copy
= xstrdup (name
);
304 normalize_filename_x (copy
);
310 replace_prefix (char **pname
, const char *samp
, size_t slen
,
311 const char *repl
, size_t rlen
)
314 size_t nlen
= strlen (name
);
315 if (nlen
> slen
&& memcmp (name
, samp
, slen
) == 0 && ISSLASH (name
[slen
]))
319 name
= xrealloc (name
, nlen
- slen
+ rlen
+ 1);
322 memmove (name
+ rlen
, name
+ slen
, nlen
- slen
+ 1);
323 memcpy (name
, repl
, rlen
);
328 /* Handling numbers. */
330 /* Output fraction and trailing digits appropriate for a nanoseconds
331 count equal to NS, but don't output unnecessary '.' or trailing
335 code_ns_fraction (int ns
, char *p
)
354 p
[--i
] = '0' + ns
% 10;
363 code_timespec (struct timespec t
, char sbuf
[TIMESPEC_STRSIZE_BOUND
])
368 bool negative
= s
< 0;
370 /* ignore invalid values of ns */
371 if (BILLION
<= ns
|| ns
< 0)
374 if (negative
&& ns
!= 0)
380 np
= umaxtostr (negative
? - (uintmax_t) s
: (uintmax_t) s
, sbuf
+ 1);
383 code_ns_fraction (ns
, sbuf
+ UINTMAX_STRSIZE_BOUND
);
389 /* Saved names in case backup needs to be undone. */
390 static char *before_backup_name
;
391 static char *after_backup_name
;
393 /* Return 1 if FILE_NAME is obviously "." or "/". */
395 must_be_dot_or_slash (char const *file_name
)
397 file_name
+= FILE_SYSTEM_PREFIX_LEN (file_name
);
399 if (ISSLASH (file_name
[0]))
402 if (ISSLASH (file_name
[1]))
404 else if (file_name
[1] == '.'
405 && ISSLASH (file_name
[2 + (file_name
[2] == '.')]))
406 file_name
+= 2 + (file_name
[2] == '.');
408 return ! file_name
[1];
412 while (file_name
[0] == '.' && ISSLASH (file_name
[1]))
415 while (ISSLASH (*file_name
))
419 return ! file_name
[0] || (file_name
[0] == '.' && ! file_name
[1]);
423 /* Some implementations of rmdir let you remove '.' or '/'.
424 Report an error with errno set to zero for obvious cases of this;
425 otherwise call rmdir. */
427 safer_rmdir (const char *file_name
)
429 if (must_be_dot_or_slash (file_name
))
435 return rmdir (file_name
);
438 /* Remove FILE_NAME, returning 1 on success. If FILE_NAME is a directory,
439 then if OPTION is RECURSIVE_REMOVE_OPTION is set remove FILE_NAME
440 recursively; otherwise, remove it only if it is empty. If FILE_NAME is
441 a directory that cannot be removed (e.g., because it is nonempty)
442 and if OPTION is WANT_DIRECTORY_REMOVE_OPTION, then return -1.
443 Return 0 on error, with errno set; if FILE_NAME is obviously the working
444 directory return zero with errno set to zero. */
446 remove_any_file (const char *file_name
, enum remove_option option
)
448 /* Try unlink first if we cannot unlink directories, as this saves
449 us a system call in the common case where we're removing a
451 bool try_unlink_first
= cannot_unlink_dir ();
453 if (try_unlink_first
)
455 if (unlink (file_name
) == 0)
458 /* POSIX 1003.1-2001 requires EPERM when attempting to unlink a
459 directory without appropriate privileges, but many Linux
460 kernels return the more-sensible EISDIR. */
461 if (errno
!= EPERM
&& errno
!= EISDIR
)
465 if (safer_rmdir (file_name
) == 0)
471 return !try_unlink_first
&& unlink (file_name
) == 0;
475 #if defined ENOTEMPTY && ENOTEMPTY != EEXIST
480 case ORDINARY_REMOVE_OPTION
:
483 case WANT_DIRECTORY_REMOVE_OPTION
:
486 case RECURSIVE_REMOVE_OPTION
:
488 char *directory
= savedir (file_name
);
495 for (entry
= directory
;
496 (entrylen
= strlen (entry
)) != 0;
497 entry
+= entrylen
+ 1)
499 char *file_name_buffer
= new_name (file_name
, entry
);
500 int r
= remove_any_file (file_name_buffer
,
501 RECURSIVE_REMOVE_OPTION
);
503 free (file_name_buffer
);
514 return safer_rmdir (file_name
) == 0;
523 /* Check if FILE_NAME already exists and make a backup of it right now.
524 Return success (nonzero) only if the backup is either unneeded, or
525 successful. For now, directories are considered to never need
526 backup. If THIS_IS_THE_ARCHIVE is nonzero, this is the archive and
527 so, we do not have to backup block or character devices, nor remote
530 maybe_backup_file (const char *file_name
, bool this_is_the_archive
)
532 struct stat file_stat
;
534 assign_string (&before_backup_name
, file_name
);
536 /* A run situation may exist between Emacs or other GNU programs trying to
537 make a backup for the same file simultaneously. If theoretically
538 possible, real problems are unlikely. Doing any better would require a
539 convention, GNU-wide, for all programs doing backups. */
541 assign_string (&after_backup_name
, 0);
543 /* Check if we really need to backup the file. */
545 if (this_is_the_archive
&& _remdev (file_name
))
548 if (stat (file_name
, &file_stat
))
553 stat_error (file_name
);
557 if (S_ISDIR (file_stat
.st_mode
))
560 if (this_is_the_archive
561 && (S_ISBLK (file_stat
.st_mode
) || S_ISCHR (file_stat
.st_mode
)))
564 after_backup_name
= find_backup_file_name (file_name
, backup_type
);
565 if (! after_backup_name
)
568 if (rename (before_backup_name
, after_backup_name
) == 0)
571 fprintf (stdlis
, _("Renaming %s to %s\n"),
572 quote_n (0, before_backup_name
),
573 quote_n (1, after_backup_name
));
578 /* The backup operation failed. */
580 ERROR ((0, e
, _("%s: Cannot rename to %s"),
581 quotearg_colon (before_backup_name
),
582 quote_n (1, after_backup_name
)));
583 assign_string (&after_backup_name
, 0);
588 /* Try to restore the recently backed up file to its original name.
589 This is usually only needed after a failed extraction. */
591 undo_last_backup (void)
593 if (after_backup_name
)
595 if (rename (after_backup_name
, before_backup_name
) != 0)
598 ERROR ((0, e
, _("%s: Cannot rename to %s"),
599 quotearg_colon (after_backup_name
),
600 quote_n (1, before_backup_name
)));
603 fprintf (stdlis
, _("Renaming %s back to %s\n"),
604 quote_n (0, after_backup_name
),
605 quote_n (1, before_backup_name
));
606 assign_string (&after_backup_name
, 0);
610 /* Depending on DEREF, apply either stat or lstat to (NAME, BUF). */
612 deref_stat (bool deref
, char const *name
, struct stat
*buf
)
614 return deref
? stat (name
, buf
) : lstat (name
, buf
);
617 /* Set FD's (i.e., assuming the working directory is PARENTFD, FILE's)
618 access time to ATIME. ATFLAG controls symbolic-link following, in
619 the style of openat. */
621 set_file_atime (int fd
, int parentfd
, char const *file
, struct timespec atime
,
624 struct timespec ts
[2];
626 ts
[1].tv_nsec
= UTIME_OMIT
;
627 return fdutimensat (fd
, parentfd
, file
, ts
, atflag
);
630 /* A description of a working directory. */
633 /* The directory's name. */
636 /* A negative value if no attempt has been made to save the
637 directory, 0 if it was saved successfully, and a positive errno
638 value if it was not saved successfully. */
641 /* The saved version of the directory, if ERR == 0. */
642 struct saved_cwd saved_cwd
;
645 /* A vector of chdir targets. wd[0] is the initial working directory. */
646 static struct wd
*wd
;
648 /* The number of working directories in the vector. */
649 static size_t wd_count
;
651 /* The allocated size of the vector. */
652 static size_t wd_alloc
;
662 /* DIR is the operand of a -C option; add it to vector of chdir targets,
663 and return the index of its location. */
665 chdir_arg (char const *dir
)
667 if (wd_count
== wd_alloc
)
672 wd
= xmalloc (sizeof *wd
* wd_alloc
);
675 wd
= x2nrealloc (wd
, &wd_alloc
, sizeof *wd
);
679 wd
[wd_count
].name
= ".";
680 wd
[wd_count
].err
= -1;
685 /* Optimize the common special case of the working directory,
686 or the working directory as a prefix. */
689 while (dir
[0] == '.' && ISSLASH (dir
[1]))
690 for (dir
+= 2; ISSLASH (*dir
); dir
++)
692 if (! dir
[dir
[0] == '.'])
696 wd
[wd_count
].name
= dir
;
697 wd
[wd_count
].err
= -1;
701 /* Index of current directory. */
704 /* Change to directory I. If I is 0, change to the initial working
705 directory; otherwise, I must be a value returned by chdir_arg. */
709 if (chdir_current
!= i
)
711 struct wd
*prev
= &wd
[chdir_current
];
712 struct wd
*curr
= &wd
[i
];
717 if (save_cwd (&prev
->saved_cwd
) != 0)
719 else if (0 <= prev
->saved_cwd
.desc
)
721 /* Make sure we still have at least one descriptor available. */
722 int fd1
= prev
->saved_cwd
.desc
;
726 else if (errno
== EMFILE
)
728 /* Force restore_cwd to use chdir_long. */
730 prev
->saved_cwd
.desc
= -1;
731 prev
->saved_cwd
.name
= xgetcwd ();
732 if (! prev
->saved_cwd
.name
)
743 if (err
== 0 && restore_cwd (&curr
->saved_cwd
) != 0)
746 FATAL_ERROR ((0, err
, _("Cannot restore working directory")));
750 if (i
&& ! ISSLASH (curr
->name
[0]))
752 if (chdir (curr
->name
) != 0)
753 chdir_fatal (curr
->name
);
761 close_diag (char const *name
)
763 if (ignore_failed_read_option
)
770 open_diag (char const *name
)
772 if (ignore_failed_read_option
)
779 read_diag_details (char const *name
, off_t offset
, size_t size
)
781 if (ignore_failed_read_option
)
782 read_warn_details (name
, offset
, size
);
784 read_error_details (name
, offset
, size
);
788 readlink_diag (char const *name
)
790 if (ignore_failed_read_option
)
791 readlink_warn (name
);
793 readlink_error (name
);
797 savedir_diag (char const *name
)
799 if (ignore_failed_read_option
)
802 savedir_error (name
);
806 seek_diag_details (char const *name
, off_t offset
)
808 if (ignore_failed_read_option
)
809 seek_warn_details (name
, offset
);
811 seek_error_details (name
, offset
);
815 stat_diag (char const *name
)
817 if (ignore_failed_read_option
)
824 file_removed_diag (const char *name
, bool top_level
,
825 void (*diagfn
) (char const *name
))
827 if (!top_level
&& errno
== ENOENT
)
829 WARNOPT (WARN_FILE_REMOVED
,
830 (0, 0, _("%s: File removed before we read it"),
831 quotearg_colon (name
)));
832 set_exit_status (TAREXIT_DIFFERS
);
839 dir_removed_diag (const char *name
, bool top_level
,
840 void (*diagfn
) (char const *name
))
842 if (!top_level
&& errno
== ENOENT
)
844 WARNOPT (WARN_FILE_REMOVED
,
845 (0, 0, _("%s: Directory removed before we read it"),
846 quotearg_colon (name
)));
847 set_exit_status (TAREXIT_DIFFERS
);
854 write_fatal_details (char const *name
, ssize_t status
, size_t size
)
856 write_error_details (name
, status
, size
);
860 /* Fork, aborting if unsuccessful. */
866 call_arg_fatal ("fork", _("child process"));
870 /* Create a pipe, aborting if unsuccessful. */
875 call_arg_fatal ("pipe", _("interprocess channel"));
878 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
879 ALIGNMENT must be nonzero. The caller must arrange for ((char *)
880 PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
884 ptr_align (void *ptr
, size_t alignment
)
887 char *p1
= p0
+ alignment
- 1;
888 return p1
- (size_t) p1
% alignment
;
891 /* Return the address of a page-aligned buffer of at least SIZE bytes.
892 The caller should free *PTR when done with the buffer. */
895 page_aligned_alloc (void **ptr
, size_t size
)
897 size_t alignment
= getpagesize ();
898 size_t size1
= size
+ alignment
;
901 *ptr
= xmalloc (size1
);
902 return ptr_align (*ptr
, alignment
);
909 char *buffer
; /* directory, `/', and directory member */
910 size_t buffer_size
; /* allocated size of name_buffer */
911 size_t dir_length
; /* length of directory part in buffer */
915 namebuf_create (const char *dir
)
917 namebuf_t buf
= xmalloc (sizeof (*buf
));
918 buf
->buffer_size
= strlen (dir
) + 2;
919 buf
->buffer
= xmalloc (buf
->buffer_size
);
920 strcpy (buf
->buffer
, dir
);
921 buf
->dir_length
= strlen (buf
->buffer
);
922 if (!ISSLASH (buf
->buffer
[buf
->dir_length
- 1]))
923 buf
->buffer
[buf
->dir_length
++] = DIRECTORY_SEPARATOR
;
928 namebuf_free (namebuf_t buf
)
935 namebuf_name (namebuf_t buf
, const char *name
)
937 size_t len
= strlen (name
);
938 while (buf
->dir_length
+ len
+ 1 >= buf
->buffer_size
)
939 buf
->buffer
= x2realloc (buf
->buffer
, &buf
->buffer_size
);
940 strcpy (buf
->buffer
+ buf
->dir_length
, name
);