summaryrefslogtreecommitdiff
path: root/src/touch.c
blob: 3d6d9fac26becae106eb63a0b2dfba821bcacf26 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
/* touch -- change modification and access times of files
   Copyright (C) 87, 1989-1991, 1995-2005, 2007-2009
   Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie,
   and Randy Smith. */

#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>

#include "system.h"
#include "argmatch.h"
#include "error.h"
#include "fd-reopen.h"
#include "getdate.h"
#include "posixtm.h"
#include "posixver.h"
#include "quote.h"
#include "stat-time.h"
#include "utimens.h"

/* The official name of this program (e.g., no `g' prefix).  */
#define PROGRAM_NAME "touch"

#define AUTHORS \
  proper_name ("Paul Rubin"), \
  proper_name ("Arnold Robbins"), \
  proper_name ("Jim Kingdon"), \
  proper_name ("David MacKenzie"), \
  proper_name ("Randy Smith")

/* Bitmasks for `change_times'. */
#define CH_ATIME 1
#define CH_MTIME 2

/* Which timestamps to change. */
static int change_times;

/* (-c) If true, don't create if not already there.  */
static bool no_create;

/* (-r) If true, use times from a reference file.  */
static bool use_ref;

/* If true, the only thing we have to do is change both the
   modification and access time to the current time, so we don't
   have to own the file, just be able to read and write it.
   On some systems, we can do this if we own the file, even though
   we have neither read nor write access to it.  */
static bool amtime_now;

/* New access and modification times to use when setting time.  */
static struct timespec newtime[2];

/* File to use for -r. */
static char *ref_file;

/* For long options that have no equivalent short option, use a
   non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
enum
{
  TIME_OPTION = CHAR_MAX + 1
};

static struct option const longopts[] =
{
  {"time", required_argument, NULL, TIME_OPTION},
  {"no-create", no_argument, NULL, 'c'},
  {"date", required_argument, NULL, 'd'},
  {"file", required_argument, NULL, 'r'}, /* FIXME: remove --file in 2010 */
  {"reference", required_argument, NULL, 'r'},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {NULL, 0, NULL, 0}
};

/* Valid arguments to the `--time' option. */
static char const* const time_args[] =
{
  "atime", "access", "use", "mtime", "modify", NULL
};

/* The bits in `change_times' that those arguments set. */
static int const time_masks[] =
{
  CH_ATIME, CH_ATIME, CH_ATIME, CH_MTIME, CH_MTIME
};

/* Store into *RESULT the result of interpreting FLEX_DATE as a date,
   relative to NOW.  If NOW is null, use the current time.  */

static void
get_reldate (struct timespec *result,
	     char const *flex_date, struct timespec const *now)
{
  if (! get_date (result, flex_date, now))
    error (EXIT_FAILURE, 0, _("invalid date format %s"), quote (flex_date));
}

/* Update the time of file FILE according to the options given.
   Return true if successful.  */

static bool
touch (const char *file)
{
  bool ok;
  struct stat sbuf;
  int fd = -1;
  int open_errno = 0;
  struct timespec timespec[2];
  struct timespec const *t;

  if (STREQ (file, "-"))
    fd = STDOUT_FILENO;
  else if (! no_create)
    {
      /* Try to open FILE, creating it if necessary.  */
      fd = fd_reopen (STDIN_FILENO, file,
		      O_WRONLY | O_CREAT | O_NONBLOCK | O_NOCTTY,
		      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);

      /* Don't save a copy of errno if it's EISDIR, since that would lead
	 touch to give a bogus diagnostic for e.g., `touch /' (assuming
	 we don't own / or have write access to it).  On Solaris 5.6,
	 and probably other systems, it is EINVAL.  On SunOS4, it's EPERM.  */
      if (fd == -1 && errno != EISDIR && errno != EINVAL && errno != EPERM)
	open_errno = errno;
    }

  if (change_times != (CH_ATIME | CH_MTIME))
    {
      /* We're setting only one of the time values.  stat the target to get
	 the other one.  If we have the file descriptor already, use fstat.
	 Otherwise, either we're in no-create mode (and hence didn't call open)
	 or FILE is inaccessible or a directory, so we have to use stat.  */
      if (fd != -1 ? fstat (fd, &sbuf) : stat (file, &sbuf))
	{
	  if (open_errno)
	    error (0, open_errno, _("creating %s"), quote (file));
	  else
	    {
	      if (no_create && (errno == ENOENT || errno == EBADF))
		return true;
	      error (0, errno, _("failed to get attributes of %s"),
		     quote (file));
	    }
	  if (fd == STDIN_FILENO)
	    close (fd);
	  return false;
	}
    }

  if (amtime_now)
    {
      /* Pass NULL to futimens so it will not fail if we have
	 write access to the file, but don't own it.  */
      t = NULL;
    }
  else
    {
      timespec[0] = (change_times & CH_ATIME
		     ? newtime[0]
		     : get_stat_atime (&sbuf));
      timespec[1] = (change_times & CH_MTIME
		     ? newtime[1]
		     : get_stat_mtime (&sbuf));
      t = timespec;
    }

  ok = (gl_futimens (fd, (fd == STDOUT_FILENO ? NULL : file), t) == 0);

  if (fd == STDIN_FILENO)
    {
      if (close (STDIN_FILENO) != 0)
	{
	  error (0, errno, _("closing %s"), quote (file));
	  return false;
	}
    }
  else if (fd == STDOUT_FILENO)
    {
      /* Do not diagnose "touch -c - >&-".  */
      if (!ok && errno == EBADF && no_create
	  && change_times == (CH_ATIME | CH_MTIME))
	return true;
    }

  if (!ok)
    {
      if (open_errno)
	{
	  /* The wording of this diagnostic should cover at least two cases:
	     - the file does not exist, but the parent directory is unwritable
	     - the file exists, but it isn't writable
	     I think it's not worth trying to distinguish them.  */
	  error (0, open_errno, _("cannot touch %s"), quote (file));
	}
      else
	{
	  if (no_create && errno == ENOENT)
	    return true;
	  error (0, errno, _("setting times of %s"), quote (file));
	}
      return false;
    }

  return true;
}

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
	     program_name);
  else
    {
      printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
      fputs (_("\
Update the access and modification times of each FILE to the current time.\n\
\n\
A FILE argument that does not exist is created empty.\n\
\n\
A FILE argument string of - is handled specially and causes touch to\n\
change the times of the file associated with standard output.\n\
\n\
"), stdout);
      fputs (_("\
Mandatory arguments to long options are mandatory for short options too.\n\
"), stdout);
      fputs (_("\
  -a                     change only the access time\n\
  -c, --no-create        do not create any files\n\
  -d, --date=STRING      parse STRING and use it instead of current time\n\
  -f                     (ignored)\n\
  -m                     change only the modification time\n\
"), stdout);
      fputs (_("\
  -r, --reference=FILE   use this file's times instead of current time\n\
  -t STAMP               use [[CC]YY]MMDDhhmm[.ss] instead of current time\n\
  --time=WORD            change the specified time:\n\
                           WORD is access, atime, or use: equivalent to -a\n\
                           WORD is modify or mtime: equivalent to -m\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
Note that the -d and -t options accept different time-date formats.\n\
"), stdout);
      emit_bug_reporting_address ();
    }
  exit (status);
}

int
main (int argc, char **argv)
{
  int c;
  bool date_set = false;
  bool ok = true;
  char const *flex_date = NULL;
  int long_idx; /* FIXME: remove in 2010, when --file is removed */

  initialize_main (&argc, &argv);
  set_program_name (argv[0]);
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  change_times = 0;
  no_create = use_ref = false;

  while ((c = getopt_long (argc, argv, "acd:fmr:t:", longopts, &long_idx)) != -1)
    {
      switch (c)
	{
	case 'a':
	  change_times |= CH_ATIME;
	  break;

	case 'c':
	  no_create = true;
	  break;

	case 'd':
	  flex_date = optarg;
	  break;

	case 'f':
	  break;

	case 'm':
	  change_times |= CH_MTIME;
	  break;

	case 'r':
	  if (long_idx == 3)
	    error (0, 0,
		   _("warning: the --%s option is obsolete; use --reference"),
		   longopts[long_idx].name);
	  use_ref = true;
	  ref_file = optarg;
	  break;

	case 't':
	  if (! posixtime (&newtime[0].tv_sec, optarg,
			   PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS))
	    error (EXIT_FAILURE, 0, _("invalid date format %s"),
		   quote (optarg));
	  newtime[0].tv_nsec = 0;
	  newtime[1] = newtime[0];
	  date_set = true;
	  break;

	case TIME_OPTION:	/* --time */
	  change_times |= XARGMATCH ("--time", optarg,
				     time_args, time_masks);
	  break;

	case_GETOPT_HELP_CHAR;

	case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);

	default:
	  usage (EXIT_FAILURE);
	}
    }

  if (change_times == 0)
    change_times = CH_ATIME | CH_MTIME;

  if (date_set && (use_ref || flex_date))
    {
      error (0, 0, _("cannot specify times from more than one source"));
      usage (EXIT_FAILURE);
    }

  if (use_ref)
    {
      struct stat ref_stats;
      if (stat (ref_file, &ref_stats))
	error (EXIT_FAILURE, errno,
	       _("failed to get attributes of %s"), quote (ref_file));
      newtime[0] = get_stat_atime (&ref_stats);
      newtime[1] = get_stat_mtime (&ref_stats);
      date_set = true;
      if (flex_date)
	{
	  if (change_times & CH_ATIME)
	    get_reldate (&newtime[0], flex_date, &newtime[0]);
	  if (change_times & CH_MTIME)
	    get_reldate (&newtime[1], flex_date, &newtime[1]);
	}
    }
  else
    {
      if (flex_date)
	{
	  struct timespec now;
	  gettime (&now);
	  get_reldate (&newtime[0], flex_date, &now);
	  newtime[1] = newtime[0];
	  date_set = true;

	  /* If neither -a nor -m is specified, treat "-d now" as if
	     it were absent; this lets "touch" succeed more often in
	     the presence of restrictive permissions.  */
	  if (change_times == (CH_ATIME | CH_MTIME)
	      && newtime[0].tv_sec == now.tv_sec
	      && newtime[0].tv_nsec == now.tv_nsec)
	    {
	      /* Check that it really was "-d now", and not a time
		 stamp that just happens to be the current time.  */
	      struct timespec notnow, notnow1;
	      notnow.tv_sec = now.tv_sec ^ 1;
	      notnow.tv_nsec = now.tv_nsec;
	      get_reldate (&notnow1, flex_date, &notnow);
	      if (notnow1.tv_sec == notnow.tv_sec
		  && notnow1.tv_nsec == notnow.tv_nsec)
		date_set = false;
	    }
	}
    }

  /* The obsolete `MMDDhhmm[YY]' form is valid IFF there are
     two or more non-option arguments.  */
  if (!date_set && 2 <= argc - optind && posix2_version () < 200112
      && posixtime (&newtime[0].tv_sec, argv[optind],
		    PDS_TRAILING_YEAR | PDS_PRE_2000))
    {
      newtime[0].tv_nsec = 0;
      newtime[1] = newtime[0];
      date_set = true;

      if (! getenv ("POSIXLY_CORRECT"))
	{
	  struct tm const *tm = localtime (&newtime[0].tv_sec);
	  error (0, 0,
		 _("warning: `touch %s' is obsolete; use "
		   "`touch -t %04ld%02d%02d%02d%02d.%02d'"),
		 argv[optind],
		 tm->tm_year + 1900L, tm->tm_mon + 1, tm->tm_mday,
		 tm->tm_hour, tm->tm_min, tm->tm_sec);
	}

      optind++;
    }

  if (!date_set)
    {
      if (change_times == (CH_ATIME | CH_MTIME))
	amtime_now = true;
      else
	{
	  gettime (&newtime[0]);
	  newtime[1] = newtime[0];
	}
    }

  if (optind == argc)
    {
      error (0, 0, _("missing file operand"));
      usage (EXIT_FAILURE);
    }

  for (; optind < argc; ++optind)
    ok &= touch (argv[optind]);

  exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
}