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 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>
28 #include <canonicalize.h>
34 # include <sys/filio.h>
38 /* Handling strings. */
40 /* Assign STRING to a copy of VALUE if not zero, or to zero. If
41 STRING was nonzero, it is freed first. */
43 assign_string (char **string
, const char *value
)
47 *string
= value
? xstrdup (value
) : 0;
50 /* Allocate a copy of the string quoted as in C, and returns that. If
51 the string does not have to be quoted, it returns a null pointer.
52 The allocated copy should normally be freed with free() after the
53 caller is done with it.
55 This is used in one context only: generating the directory file in
56 incremental dumps. The quoted string is not intended for human
57 consumption; it is intended only for unquote_string. The quoting
58 is locale-independent, so that users needn't worry about locale
59 when reading directory files. This means that we can't use
60 quotearg, as quotearg is locale-dependent and is meant for human
63 quote_copy_string (const char *string
)
65 const char *source
= string
;
66 char *destination
= 0;
72 int character
= *source
++;
79 size_t length
= (source
- string
) - 1;
82 buffer
= xmalloc (length
+ 2 + 2 * strlen (source
) + 1);
83 memcpy (buffer
, string
, length
);
84 destination
= buffer
+ length
;
86 *destination
++ = '\\';
87 *destination
++ = character
== '\\' ? '\\' : 'n';
92 *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
))
234 normalize_filename (const char *name
)
236 return zap_slashes (canonicalize_filename_mode (name
, CAN_MISSING
));
240 /* Handling numbers. */
242 /* Output fraction and trailing digits appropriate for a nanoseconds
243 count equal to NS, but don't output unnecessary '.' or trailing
247 code_ns_fraction (int ns
, char *p
)
266 p
[--i
] = '0' + ns
% 10;
275 code_timespec (struct timespec t
, char sbuf
[TIMESPEC_STRSIZE_BOUND
])
280 bool negative
= s
< 0;
282 if (negative
&& ns
!= 0)
288 np
= umaxtostr (negative
? - (uintmax_t) s
: (uintmax_t) s
, sbuf
+ 1);
291 code_ns_fraction (ns
, sbuf
+ UINTMAX_STRSIZE_BOUND
);
297 /* Saved names in case backup needs to be undone. */
298 static char *before_backup_name
;
299 static char *after_backup_name
;
301 /* Return 1 if FILE_NAME is obviously "." or "/". */
303 must_be_dot_or_slash (char const *file_name
)
305 file_name
+= FILE_SYSTEM_PREFIX_LEN (file_name
);
307 if (ISSLASH (file_name
[0]))
310 if (ISSLASH (file_name
[1]))
312 else if (file_name
[1] == '.'
313 && ISSLASH (file_name
[2 + (file_name
[2] == '.')]))
314 file_name
+= 2 + (file_name
[2] == '.');
316 return ! file_name
[1];
320 while (file_name
[0] == '.' && ISSLASH (file_name
[1]))
323 while (ISSLASH (*file_name
))
327 return ! file_name
[0] || (file_name
[0] == '.' && ! file_name
[1]);
331 /* Some implementations of rmdir let you remove '.' or '/'.
332 Report an error with errno set to zero for obvious cases of this;
333 otherwise call rmdir. */
335 safer_rmdir (const char *file_name
)
337 if (must_be_dot_or_slash (file_name
))
343 return rmdir (file_name
);
346 /* Remove FILE_NAME, returning 1 on success. If FILE_NAME is a directory,
347 then if OPTION is RECURSIVE_REMOVE_OPTION is set remove FILE_NAME
348 recursively; otherwise, remove it only if it is empty. If FILE_NAME is
349 a directory that cannot be removed (e.g., because it is nonempty)
350 and if OPTION is WANT_DIRECTORY_REMOVE_OPTION, then return -1.
351 Return 0 on error, with errno set; if FILE_NAME is obviously the working
352 directory return zero with errno set to zero. */
354 remove_any_file (const char *file_name
, enum remove_option option
)
356 /* Try unlink first if we cannot unlink directories, as this saves
357 us a system call in the common case where we're removing a
359 bool try_unlink_first
= cannot_unlink_dir ();
361 if (try_unlink_first
)
363 if (unlink (file_name
) == 0)
366 /* POSIX 1003.1-2001 requires EPERM when attempting to unlink a
367 directory without appropriate privileges, but many Linux
368 kernels return the more-sensible EISDIR. */
369 if (errno
!= EPERM
&& errno
!= EISDIR
)
373 if (safer_rmdir (file_name
) == 0)
379 return !try_unlink_first
&& unlink (file_name
) == 0;
383 #if defined ENOTEMPTY && ENOTEMPTY != EEXIST
388 case ORDINARY_REMOVE_OPTION
:
391 case WANT_DIRECTORY_REMOVE_OPTION
:
394 case RECURSIVE_REMOVE_OPTION
:
396 char *directory
= savedir (file_name
);
403 for (entry
= directory
;
404 (entrylen
= strlen (entry
)) != 0;
405 entry
+= entrylen
+ 1)
407 char *file_name_buffer
= new_name (file_name
, entry
);
408 int r
= remove_any_file (file_name_buffer
,
409 RECURSIVE_REMOVE_OPTION
);
411 free (file_name_buffer
);
422 return safer_rmdir (file_name
) == 0;
431 /* Check if FILE_NAME already exists and make a backup of it right now.
432 Return success (nonzero) only if the backup is either unneeded, or
433 successful. For now, directories are considered to never need
434 backup. If THIS_IS_THE_ARCHIVE is nonzero, this is the archive and
435 so, we do not have to backup block or character devices, nor remote
438 maybe_backup_file (const char *file_name
, bool this_is_the_archive
)
440 struct stat file_stat
;
442 assign_string (&before_backup_name
, file_name
);
444 /* A run situation may exist between Emacs or other GNU programs trying to
445 make a backup for the same file simultaneously. If theoretically
446 possible, real problems are unlikely. Doing any better would require a
447 convention, GNU-wide, for all programs doing backups. */
449 assign_string (&after_backup_name
, 0);
451 /* Check if we really need to backup the file. */
453 if (this_is_the_archive
&& _remdev (file_name
))
456 if (stat (file_name
, &file_stat
))
461 stat_error (file_name
);
465 if (S_ISDIR (file_stat
.st_mode
))
468 if (this_is_the_archive
469 && (S_ISBLK (file_stat
.st_mode
) || S_ISCHR (file_stat
.st_mode
)))
472 after_backup_name
= find_backup_file_name (file_name
, backup_type
);
473 if (! after_backup_name
)
476 if (rename (before_backup_name
, after_backup_name
) == 0)
479 fprintf (stdlis
, _("Renaming %s to %s\n"),
480 quote_n (0, before_backup_name
),
481 quote_n (1, after_backup_name
));
486 /* The backup operation failed. */
488 ERROR ((0, e
, _("%s: Cannot rename to %s"),
489 quotearg_colon (before_backup_name
),
490 quote_n (1, after_backup_name
)));
491 assign_string (&after_backup_name
, 0);
496 /* Try to restore the recently backed up file to its original name.
497 This is usually only needed after a failed extraction. */
499 undo_last_backup (void)
501 if (after_backup_name
)
503 if (rename (after_backup_name
, before_backup_name
) != 0)
506 ERROR ((0, e
, _("%s: Cannot rename to %s"),
507 quotearg_colon (after_backup_name
),
508 quote_n (1, before_backup_name
)));
511 fprintf (stdlis
, _("Renaming %s back to %s\n"),
512 quote_n (0, after_backup_name
),
513 quote_n (1, before_backup_name
));
514 assign_string (&after_backup_name
, 0);
518 /* Depending on DEREF, apply either stat or lstat to (NAME, BUF). */
520 deref_stat (bool deref
, char const *name
, struct stat
*buf
)
522 return deref
? stat (name
, buf
) : lstat (name
, buf
);
525 /* Set FD's (i.e., FILE's) access time to TIMESPEC[0]. If that's not
526 possible to do by itself, set its access and data modification
527 times to TIMESPEC[0] and TIMESPEC[1], respectively. */
529 set_file_atime (int fd
, char const *file
, struct timespec
const timespec
[2])
534 struct timeval timeval
;
535 timeval
.tv_sec
= timespec
[0].tv_sec
;
536 timeval
.tv_usec
= timespec
[0].tv_nsec
/ 1000;
537 if (ioctl (fd
, _FIOSATIME
, &timeval
) == 0)
542 return gl_futimens (fd
, file
, timespec
);
545 /* A description of a working directory. */
550 struct saved_cwd saved_cwd
;
553 /* A vector of chdir targets. wd[0] is the initial working directory. */
554 static struct wd
*wd
;
556 /* The number of working directories in the vector. */
557 static size_t wd_count
;
559 /* The allocated size of the vector. */
560 static size_t wd_alloc
;
570 /* DIR is the operand of a -C option; add it to vector of chdir targets,
571 and return the index of its location. */
573 chdir_arg (char const *dir
)
575 if (wd_count
== wd_alloc
)
580 wd
= xmalloc (sizeof *wd
* wd_alloc
);
583 wd
= x2nrealloc (wd
, &wd_alloc
, sizeof *wd
);
587 wd
[wd_count
].name
= ".";
588 wd
[wd_count
].saved
= 0;
593 /* Optimize the common special case of the working directory,
594 or the working directory as a prefix. */
597 while (dir
[0] == '.' && ISSLASH (dir
[1]))
598 for (dir
+= 2; ISSLASH (*dir
); dir
++)
600 if (! dir
[dir
[0] == '.'])
604 wd
[wd_count
].name
= dir
;
605 wd
[wd_count
].saved
= 0;
609 /* Change to directory I. If I is 0, change to the initial working
610 directory; otherwise, I must be a value returned by chdir_arg. */
618 struct wd
*prev
= &wd
[previous
];
619 struct wd
*curr
= &wd
[i
];
625 if (save_cwd (&prev
->saved_cwd
) != 0)
627 else if (0 <= prev
->saved_cwd
.desc
)
629 /* Make sure we still have at least one descriptor available. */
630 int fd1
= prev
->saved_cwd
.desc
;
634 else if (errno
== EMFILE
)
636 /* Force restore_cwd to use chdir_long. */
638 prev
->saved_cwd
.desc
= -1;
639 prev
->saved_cwd
.name
= xgetcwd ();
646 FATAL_ERROR ((0, err
, _("Cannot save working directory")));
651 if (restore_cwd (&curr
->saved_cwd
))
652 FATAL_ERROR ((0, 0, _("Cannot change working directory")));
656 if (i
&& ! ISSLASH (curr
->name
[0]))
658 if (chdir (curr
->name
) != 0)
659 chdir_fatal (curr
->name
);
667 close_diag (char const *name
)
669 if (ignore_failed_read_option
)
676 open_diag (char const *name
)
678 if (ignore_failed_read_option
)
685 read_diag_details (char const *name
, off_t offset
, size_t size
)
687 if (ignore_failed_read_option
)
688 read_warn_details (name
, offset
, size
);
690 read_error_details (name
, offset
, size
);
694 readlink_diag (char const *name
)
696 if (ignore_failed_read_option
)
697 readlink_warn (name
);
699 readlink_error (name
);
703 savedir_diag (char const *name
)
705 if (ignore_failed_read_option
)
708 savedir_error (name
);
712 seek_diag_details (char const *name
, off_t offset
)
714 if (ignore_failed_read_option
)
715 seek_warn_details (name
, offset
);
717 seek_error_details (name
, offset
);
721 stat_diag (char const *name
)
723 if (ignore_failed_read_option
)
730 write_fatal_details (char const *name
, ssize_t status
, size_t size
)
732 write_error_details (name
, status
, size
);
736 /* Fork, aborting if unsuccessful. */
742 call_arg_fatal ("fork", _("child process"));
746 /* Create a pipe, aborting if unsuccessful. */
751 call_arg_fatal ("pipe", _("interprocess channel"));
754 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
755 ALIGNMENT must be nonzero. The caller must arrange for ((char *)
756 PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
760 ptr_align (void *ptr
, size_t alignment
)
763 char *p1
= p0
+ alignment
- 1;
764 return p1
- (size_t) p1
% alignment
;
767 /* Return the address of a page-aligned buffer of at least SIZE bytes.
768 The caller should free *PTR when done with the buffer. */
771 page_aligned_alloc (void **ptr
, size_t size
)
773 size_t alignment
= getpagesize ();
774 size_t size1
= size
+ alignment
;
777 *ptr
= xmalloc (size1
);
778 return ptr_align (*ptr
, alignment
);