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>
33 # include <sys/filio.h>
36 #ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
37 # define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
41 /* Handling strings. */
43 /* Assign STRING to a copy of VALUE if not zero, or to zero. If
44 STRING was nonzero, it is freed first. */
46 assign_string (char **string
, const char *value
)
50 *string
= value
? xstrdup (value
) : 0;
53 /* Allocate a copy of the string quoted as in C, and returns that. If
54 the string does not have to be quoted, it returns a null pointer.
55 The allocated copy should normally be freed with free() after the
56 caller is done with it.
58 This is used in one context only: generating the directory file in
59 incremental dumps. The quoted string is not intended for human
60 consumption; it is intended only for unquote_string. The quoting
61 is locale-independent, so that users needn't worry about locale
62 when reading directory files. This means that we can't use
63 quotearg, as quotearg is locale-dependent and is meant for human
66 quote_copy_string (const char *string
)
68 const char *source
= string
;
69 char *destination
= 0;
75 int character
= *source
++;
82 size_t length
= (source
- string
) - 1;
85 buffer
= xmalloc (length
+ 2 + 2 * strlen (source
) + 1);
86 memcpy (buffer
, string
, length
);
87 destination
= buffer
+ length
;
89 *destination
++ = '\\';
90 *destination
++ = character
== '\\' ? '\\' : 'n';
95 *destination
++ = character
;
107 /* Takes a quoted C string (like those produced by quote_copy_string)
108 and turns it back into the un-quoted original. This is done in
109 place. Returns 0 only if the string was not properly quoted, but
110 completes the unquoting anyway.
112 This is used for reading the saved directory file in incremental
113 dumps. It is used for decoding old `N' records (demangling names).
114 But also, it is used for decoding file arguments, would they come
115 from the shell or a -T file, and for decoding the --exclude
118 unquote_string (char *string
)
121 char *source
= string
;
122 char *destination
= string
;
124 /* Escape sequences other than \\ and \n are no longer generated by
125 quote_copy_string, but accept them for backwards compatibility,
126 and also because unquote_string is used for purposes other than
127 parsing the output of quote_copy_string. */
134 *destination
++ = '\\';
139 *destination
++ = '\a';
144 *destination
++ = '\b';
149 *destination
++ = '\f';
154 *destination
++ = '\n';
159 *destination
++ = '\r';
164 *destination
++ = '\t';
169 *destination
++ = '\v';
174 *destination
++ = 0177;
187 int value
= *source
++ - '0';
189 if (*source
< '0' || *source
> '7')
191 *destination
++ = value
;
194 value
= value
* 8 + *source
++ - '0';
195 if (*source
< '0' || *source
> '7')
197 *destination
++ = value
;
200 value
= value
* 8 + *source
++ - '0';
201 *destination
++ = value
;
207 *destination
++ = '\\';
209 *destination
++ = *source
++;
212 else if (source
!= destination
)
213 *destination
++ = *source
++;
215 source
++, destination
++;
217 if (source
!= destination
)
222 /* Zap trailing slashes. */
224 zap_slashes (char *name
)
228 if (!name
|| *name
== 0)
230 q
= name
+ strlen (name
) - 1;
231 while (q
> name
&& ISSLASH (*q
))
236 /* Normalize FILE_NAME by removing redundant slashes and "."
237 components, including redundant trailing slashes. Leave ".."
238 alone, as it may be significant in the presence of symlinks and on
239 platforms where "/.." != "/". Destructive version: modifies its
242 normalize_filename_x (char *file_name
)
244 char *name
= file_name
+ FILE_SYSTEM_PREFIX_LEN (file_name
);
249 /* Don't squeeze leading "//" to "/", on hosts where they're distinct. */
250 name
+= (DOUBLE_SLASH_IS_DISTINCT_ROOT
251 && ISSLASH (*name
) && ISSLASH (name
[1]) && ! ISSLASH (name
[2]));
253 /* Omit redundant leading "." components. */
254 for (q
= p
= name
; (*p
= *q
) == '.' && ISSLASH (q
[1]); p
+= !*q
)
255 for (q
+= 2; ISSLASH (*q
); q
++)
258 /* Copy components from Q to P, omitting redundant slashes and
259 internal "." components. */
260 while ((*p
++ = c
= *q
++) != '\0')
262 while (ISSLASH (q
[*q
== '.']))
263 q
+= (*q
== '.') + 1;
265 /* Omit redundant trailing "." component and slash. */
268 p
-= p
[-2] == '.' && ISSLASH (p
[-3]);
269 p
-= 2 < p
- name
&& ISSLASH (p
[-2]);
274 /* Normalize NAME by removing redundant slashes and "." components,
275 including redundant trailing slashes. Return a normalized
276 newly-allocated copy. */
279 normalize_filename (const char *name
)
283 if (IS_RELATIVE_FILE_NAME (name
))
285 /* Set COPY to the absolute file name if possible.
287 FIXME: There should be no need to get the absolute file name.
288 getcwd is slow, it might fail, and it does not necessarily
289 return a canonical name even when it succeeds. Perhaps we
290 can use dev+ino pairs instead of names? */
294 size_t copylen
= strlen (copy
);
295 bool need_separator
= ! (DOUBLE_SLASH_IS_DISTINCT_ROOT
296 && copylen
== 2 && ISSLASH (copy
[1]));
297 copy
= xrealloc (copy
, copylen
+ need_separator
+ strlen (name
) + 1);
298 copy
[copylen
] = DIRECTORY_SEPARATOR
;
299 strcpy (copy
+ copylen
+ need_separator
, name
);
302 WARN ((0, errno
, _("Cannot get working directory")));
306 copy
= xstrdup (name
);
307 normalize_filename_x (copy
);
313 replace_prefix (char **pname
, const char *samp
, size_t slen
,
314 const char *repl
, size_t rlen
)
317 size_t nlen
= strlen (name
);
318 if (nlen
> slen
&& memcmp (name
, samp
, slen
) == 0 && ISSLASH (name
[slen
]))
322 name
= xrealloc (name
, nlen
- slen
+ rlen
+ 1);
325 memmove (name
+ rlen
, name
+ slen
, nlen
- slen
+ 1);
326 memcpy (name
, repl
, rlen
);
331 /* Handling numbers. */
333 /* Output fraction and trailing digits appropriate for a nanoseconds
334 count equal to NS, but don't output unnecessary '.' or trailing
338 code_ns_fraction (int ns
, char *p
)
357 p
[--i
] = '0' + ns
% 10;
366 code_timespec (struct timespec t
, char sbuf
[TIMESPEC_STRSIZE_BOUND
])
371 bool negative
= s
< 0;
373 /* ignore invalid values of ns */
374 if (BILLION
<= ns
|| ns
< 0)
377 if (negative
&& ns
!= 0)
383 np
= umaxtostr (negative
? - (uintmax_t) s
: (uintmax_t) s
, sbuf
+ 1);
386 code_ns_fraction (ns
, sbuf
+ UINTMAX_STRSIZE_BOUND
);
392 /* Saved names in case backup needs to be undone. */
393 static char *before_backup_name
;
394 static char *after_backup_name
;
396 /* Return 1 if FILE_NAME is obviously "." or "/". */
398 must_be_dot_or_slash (char const *file_name
)
400 file_name
+= FILE_SYSTEM_PREFIX_LEN (file_name
);
402 if (ISSLASH (file_name
[0]))
405 if (ISSLASH (file_name
[1]))
407 else if (file_name
[1] == '.'
408 && ISSLASH (file_name
[2 + (file_name
[2] == '.')]))
409 file_name
+= 2 + (file_name
[2] == '.');
411 return ! file_name
[1];
415 while (file_name
[0] == '.' && ISSLASH (file_name
[1]))
418 while (ISSLASH (*file_name
))
422 return ! file_name
[0] || (file_name
[0] == '.' && ! file_name
[1]);
426 /* Some implementations of rmdir let you remove '.' or '/'.
427 Report an error with errno set to zero for obvious cases of this;
428 otherwise call rmdir. */
430 safer_rmdir (const char *file_name
)
432 if (must_be_dot_or_slash (file_name
))
438 return rmdir (file_name
);
441 /* Remove FILE_NAME, returning 1 on success. If FILE_NAME is a directory,
442 then if OPTION is RECURSIVE_REMOVE_OPTION is set remove FILE_NAME
443 recursively; otherwise, remove it only if it is empty. If FILE_NAME is
444 a directory that cannot be removed (e.g., because it is nonempty)
445 and if OPTION is WANT_DIRECTORY_REMOVE_OPTION, then return -1.
446 Return 0 on error, with errno set; if FILE_NAME is obviously the working
447 directory return zero with errno set to zero. */
449 remove_any_file (const char *file_name
, enum remove_option option
)
451 /* Try unlink first if we cannot unlink directories, as this saves
452 us a system call in the common case where we're removing a
454 bool try_unlink_first
= cannot_unlink_dir ();
456 if (try_unlink_first
)
458 if (unlink (file_name
) == 0)
461 /* POSIX 1003.1-2001 requires EPERM when attempting to unlink a
462 directory without appropriate privileges, but many Linux
463 kernels return the more-sensible EISDIR. */
464 if (errno
!= EPERM
&& errno
!= EISDIR
)
468 if (safer_rmdir (file_name
) == 0)
474 return !try_unlink_first
&& unlink (file_name
) == 0;
478 #if defined ENOTEMPTY && ENOTEMPTY != EEXIST
483 case ORDINARY_REMOVE_OPTION
:
486 case WANT_DIRECTORY_REMOVE_OPTION
:
489 case RECURSIVE_REMOVE_OPTION
:
491 char *directory
= savedir (file_name
);
498 for (entry
= directory
;
499 (entrylen
= strlen (entry
)) != 0;
500 entry
+= entrylen
+ 1)
502 char *file_name_buffer
= new_name (file_name
, entry
);
503 int r
= remove_any_file (file_name_buffer
,
504 RECURSIVE_REMOVE_OPTION
);
506 free (file_name_buffer
);
517 return safer_rmdir (file_name
) == 0;
526 /* Check if FILE_NAME already exists and make a backup of it right now.
527 Return success (nonzero) only if the backup is either unneeded, or
528 successful. For now, directories are considered to never need
529 backup. If THIS_IS_THE_ARCHIVE is nonzero, this is the archive and
530 so, we do not have to backup block or character devices, nor remote
533 maybe_backup_file (const char *file_name
, bool this_is_the_archive
)
535 struct stat file_stat
;
537 assign_string (&before_backup_name
, file_name
);
539 /* A run situation may exist between Emacs or other GNU programs trying to
540 make a backup for the same file simultaneously. If theoretically
541 possible, real problems are unlikely. Doing any better would require a
542 convention, GNU-wide, for all programs doing backups. */
544 assign_string (&after_backup_name
, 0);
546 /* Check if we really need to backup the file. */
548 if (this_is_the_archive
&& _remdev (file_name
))
551 if (stat (file_name
, &file_stat
))
556 stat_error (file_name
);
560 if (S_ISDIR (file_stat
.st_mode
))
563 if (this_is_the_archive
564 && (S_ISBLK (file_stat
.st_mode
) || S_ISCHR (file_stat
.st_mode
)))
567 after_backup_name
= find_backup_file_name (file_name
, backup_type
);
568 if (! after_backup_name
)
571 if (rename (before_backup_name
, after_backup_name
) == 0)
574 fprintf (stdlis
, _("Renaming %s to %s\n"),
575 quote_n (0, before_backup_name
),
576 quote_n (1, after_backup_name
));
581 /* The backup operation failed. */
583 ERROR ((0, e
, _("%s: Cannot rename to %s"),
584 quotearg_colon (before_backup_name
),
585 quote_n (1, after_backup_name
)));
586 assign_string (&after_backup_name
, 0);
591 /* Try to restore the recently backed up file to its original name.
592 This is usually only needed after a failed extraction. */
594 undo_last_backup (void)
596 if (after_backup_name
)
598 if (rename (after_backup_name
, before_backup_name
) != 0)
601 ERROR ((0, e
, _("%s: Cannot rename to %s"),
602 quotearg_colon (after_backup_name
),
603 quote_n (1, before_backup_name
)));
606 fprintf (stdlis
, _("Renaming %s back to %s\n"),
607 quote_n (0, after_backup_name
),
608 quote_n (1, before_backup_name
));
609 assign_string (&after_backup_name
, 0);
613 /* Depending on DEREF, apply either stat or lstat to (NAME, BUF). */
615 deref_stat (bool deref
, char const *name
, struct stat
*buf
)
617 return deref
? stat (name
, buf
) : lstat (name
, buf
);
620 /* Set FD's (i.e., FILE's) access time to TIMESPEC[0]. If that's not
621 possible to do by itself, set its access and data modification
622 times to TIMESPEC[0] and TIMESPEC[1], respectively. */
624 set_file_atime (int fd
, char const *file
, struct timespec
const timespec
[2])
629 struct timeval timeval
;
630 timeval
.tv_sec
= timespec
[0].tv_sec
;
631 timeval
.tv_usec
= timespec
[0].tv_nsec
/ 1000;
632 if (ioctl (fd
, _FIOSATIME
, &timeval
) == 0)
637 return gl_futimens (fd
, file
, timespec
);
640 /* A description of a working directory. */
643 /* The directory's name. */
646 /* A negative value if no attempt has been made to save the
647 directory, 0 if it was saved successfully, and a positive errno
648 value if it was not saved successfully. */
651 /* The saved version of the directory, if ERR == 0. */
652 struct saved_cwd saved_cwd
;
655 /* A vector of chdir targets. wd[0] is the initial working directory. */
656 static struct wd
*wd
;
658 /* The number of working directories in the vector. */
659 static size_t wd_count
;
661 /* The allocated size of the vector. */
662 static size_t wd_alloc
;
672 /* DIR is the operand of a -C option; add it to vector of chdir targets,
673 and return the index of its location. */
675 chdir_arg (char const *dir
)
677 if (wd_count
== wd_alloc
)
682 wd
= xmalloc (sizeof *wd
* wd_alloc
);
685 wd
= x2nrealloc (wd
, &wd_alloc
, sizeof *wd
);
689 wd
[wd_count
].name
= ".";
690 wd
[wd_count
].err
= -1;
695 /* Optimize the common special case of the working directory,
696 or the working directory as a prefix. */
699 while (dir
[0] == '.' && ISSLASH (dir
[1]))
700 for (dir
+= 2; ISSLASH (*dir
); dir
++)
702 if (! dir
[dir
[0] == '.'])
706 wd
[wd_count
].name
= dir
;
707 wd
[wd_count
].err
= -1;
711 /* Change to directory I. If I is 0, change to the initial working
712 directory; otherwise, I must be a value returned by chdir_arg. */
720 struct wd
*prev
= &wd
[previous
];
721 struct wd
*curr
= &wd
[i
];
726 if (save_cwd (&prev
->saved_cwd
) != 0)
728 else if (0 <= prev
->saved_cwd
.desc
)
730 /* Make sure we still have at least one descriptor available. */
731 int fd1
= prev
->saved_cwd
.desc
;
735 else if (errno
== EMFILE
)
737 /* Force restore_cwd to use chdir_long. */
739 prev
->saved_cwd
.desc
= -1;
740 prev
->saved_cwd
.name
= xgetcwd ();
741 if (! prev
->saved_cwd
.name
)
752 if (err
== 0 && restore_cwd (&curr
->saved_cwd
) != 0)
755 FATAL_ERROR ((0, err
, _("Cannot restore working directory")));
759 if (i
&& ! ISSLASH (curr
->name
[0]))
761 if (chdir (curr
->name
) != 0)
762 chdir_fatal (curr
->name
);
770 close_diag (char const *name
)
772 if (ignore_failed_read_option
)
779 open_diag (char const *name
)
781 if (ignore_failed_read_option
)
788 read_diag_details (char const *name
, off_t offset
, size_t size
)
790 if (ignore_failed_read_option
)
791 read_warn_details (name
, offset
, size
);
793 read_error_details (name
, offset
, size
);
797 readlink_diag (char const *name
)
799 if (ignore_failed_read_option
)
800 readlink_warn (name
);
802 readlink_error (name
);
806 savedir_diag (char const *name
)
808 if (ignore_failed_read_option
)
811 savedir_error (name
);
815 seek_diag_details (char const *name
, off_t offset
)
817 if (ignore_failed_read_option
)
818 seek_warn_details (name
, offset
);
820 seek_error_details (name
, offset
);
824 stat_diag (char const *name
)
826 if (ignore_failed_read_option
)
833 file_removed_diag (const char *name
, bool top_level
,
834 void (*diagfn
) (char const *name
))
836 if (!top_level
&& errno
== ENOENT
)
838 WARNOPT (WARN_FILE_REMOVED
,
839 (0, 0, _("%s: File removed before we read it"),
840 quotearg_colon (name
)));
841 set_exit_status (TAREXIT_DIFFERS
);
848 dir_removed_diag (const char *name
, bool top_level
,
849 void (*diagfn
) (char const *name
))
851 if (!top_level
&& errno
== ENOENT
)
853 WARNOPT (WARN_FILE_REMOVED
,
854 (0, 0, _("%s: Directory removed before we read it"),
855 quotearg_colon (name
)));
856 set_exit_status (TAREXIT_DIFFERS
);
863 write_fatal_details (char const *name
, ssize_t status
, size_t size
)
865 write_error_details (name
, status
, size
);
869 /* Fork, aborting if unsuccessful. */
875 call_arg_fatal ("fork", _("child process"));
879 /* Create a pipe, aborting if unsuccessful. */
884 call_arg_fatal ("pipe", _("interprocess channel"));
887 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
888 ALIGNMENT must be nonzero. The caller must arrange for ((char *)
889 PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
893 ptr_align (void *ptr
, size_t alignment
)
896 char *p1
= p0
+ alignment
- 1;
897 return p1
- (size_t) p1
% alignment
;
900 /* Return the address of a page-aligned buffer of at least SIZE bytes.
901 The caller should free *PTR when done with the buffer. */
904 page_aligned_alloc (void **ptr
, size_t size
)
906 size_t alignment
= getpagesize ();
907 size_t size1
= size
+ alignment
;
910 *ptr
= xmalloc (size1
);
911 return ptr_align (*ptr
, alignment
);
918 char *buffer
; /* directory, `/', and directory member */
919 size_t buffer_size
; /* allocated size of name_buffer */
920 size_t dir_length
; /* length of directory part in buffer */
924 namebuf_create (const char *dir
)
926 namebuf_t buf
= xmalloc (sizeof (*buf
));
927 buf
->buffer_size
= strlen (dir
) + 2;
928 buf
->buffer
= xmalloc (buf
->buffer_size
);
929 strcpy (buf
->buffer
, dir
);
930 buf
->dir_length
= strlen (buf
->buffer
);
931 if (!ISSLASH (buf
->buffer
[buf
->dir_length
- 1]))
932 buf
->buffer
[buf
->dir_length
++] = DIRECTORY_SEPARATOR
;
937 namebuf_free (namebuf_t buf
)
944 namebuf_name (namebuf_t buf
, const char *name
)
946 size_t len
= strlen (name
);
947 while (buf
->dir_length
+ len
+ 1 >= buf
->buffer_size
)
948 buf
->buffer
= x2realloc (buf
->buffer
, &buf
->buffer_size
);
949 strcpy (buf
->buffer
+ buf
->dir_length
, name
);