src/touch.c

   1 /* touch -- change modification and access times of files
   2    Copyright (C) 1987, 1989, 1990, 1991, 1995 Free Software Foundation Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 /* Options:
  19    -a, --time={atime,access,use}        Change access time only.
  20    -c, --no-create              Do not create files that do not exist.
  21    -d, --date=TIME              Specify time and date in various formats.
  22    -f                           Ignored.
  23    -m, --time={mtime,modify}    Change modification time only.
  24    -r, --reference=FILE         Use the time and date of reference file FILE.
  25    -t TIME                      Specify time and date in the form
  26                                 `MMDDhhmm[[CC]YY][.ss]'.
  27
  28    If no options are given, -am is the default, using the current time.
  29    The -r, -t, and -d options are mutually exclusive.  If a file does not
  30    exist, create it unless -c is given.
  31
  32    Written by Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie,
  33    and Randy Smith. */
  34
  35 #include <config.h>
  36 #include <stdio.h>
  37 #include <getopt.h>
  38 #include <sys/types.h>
  39
  40 #include "system.h"
  41 #include "error.h"
  42 #include "argmatch.h"
  43
  44 #ifndef STDC_HEADERS
  45 time_t mktime ();
  46 time_t time ();
  47 #endif
  48
  49 time_t get_date ();
  50 time_t posixtime ();
  51 int safe_read ();
  52 int full_write ();
  53 void invalid_arg ();
  54
  55 #ifndef HAVE_UTIME_NULL
  56 static int utime_now ();
  57 #endif
  58
  59 /* Bitmasks for `change_times'. */
  60 #define CH_ATIME 1
  61 #define CH_MTIME 2
  62
  63 /* The name by which this program was run. */
  64 char *program_name;
  65
  66 /* Which timestamps to change. */
  67 static int change_times;
  68
  69 /* (-c) If nonzero, don't create if not already there. */
  70 static int no_create;
  71
  72 /* (-d) If nonzero, date supplied on command line in get_date formats. */
  73 static int flexible_date;
  74
  75 /* (-r) If nonzero, use times from a reference file. */
  76 static int use_ref;
  77
  78 /* (-t) If nonzero, date supplied on command line in POSIX format. */
  79 static int posix_date;
  80
  81 /* If nonzero, the only thing we have to do is change both the
  82    modification and access time to the current time, so we don't
  83    have to own the file, just be able to read and write it.  */
  84 static int amtime_now;
  85
  86 /* New time to use when setting time. */
  87 static time_t newtime;
  88
  89 /* File to use for -r. */
  90 static char *ref_file;
  91
  92 /* Info about the reference file. */
  93 static struct stat ref_stats;
  94
  95 /* If nonzero, display usage information and exit.  */
  96 static int show_help;
  97
  98 /* If nonzero, print the version on standard output and exit.  */
  99 static int show_version;
 100
 101 static struct option const longopts[] =
 102 {
 103   {"time", required_argument, 0, 130},
 104   {"no-create", no_argument, 0, 'c'},
 105   {"date", required_argument, 0, 'd'},
 106   {"file", required_argument, 0, 'r'},
 107   {"reference", required_argument, 0, 'r'},
 108   {"help", no_argument, &show_help, 1},
 109   {"version", no_argument, &show_version, 1},
 110   {0, 0, 0, 0}
 111 };
 112
 113 /* Valid arguments to the `--time' option. */
 114 static char const* const time_args[] =
 115 {
 116   "atime", "access", "use", "mtime", "modify", 0
 117 };
 118
 119 /* The bits in `change_times' that those arguments set. */
 120 static int const time_masks[] =
 121 {
 122   CH_ATIME, CH_ATIME, CH_ATIME, CH_MTIME, CH_MTIME
 123 };
 124
 125 /* Update the time of file FILE according to the options given.
 126    Return 0 if successful, 1 if an error occurs. */
 127
 128 static int
 129 touch (char *file)
 130 {
 131   int status;
 132   struct stat sbuf;
 133   int fd;
 134
 135   if (stat (file, &sbuf))
 136     {
 137       if (errno != ENOENT)
 138         {
 139           error (0, errno, "%s", file);
 140           return 1;
 141         }
 142       if (no_create)
 143         return 0;
 144       fd = creat (file, 0666);
 145       if (fd == -1)
 146         {
 147           error (0, errno, "%s", file);
 148           return 1;
 149         }
 150       if (amtime_now)
 151         {
 152           if (close (fd) < 0)
 153             {
 154               error (0, errno, "%s", file);
 155               return 1;
 156             }
 157           return 0;             /* We've done all we have to. */
 158         }
 159       if (fstat (fd, &sbuf))
 160         {
 161           error (0, errno, "%s", file);
 162           close (fd);
 163           return 1;
 164         }
 165       if (close (fd) < 0)
 166         {
 167           error (0, errno, "%s", file);
 168           return 1;
 169         }
 170     }
 171
 172   if (amtime_now)
 173     {
 174 #ifndef HAVE_UTIME_NULL
 175       status = utime_now (file, sbuf.st_size);
 176 #else
 177       /* Pass NULL to utime so it will not fail if we just have
 178          write access to the file, but don't own it.  */
 179       status = utime (file, NULL);
 180 #endif
 181     }
 182   else
 183     {
 184       struct utimbuf utb;
 185
 186       if (use_ref)
 187         {
 188           utb.actime = ref_stats.st_atime;
 189           utb.modtime = ref_stats.st_mtime;
 190         }
 191       else
 192         utb.actime = utb.modtime = newtime;
 193
 194       if (!(change_times & CH_ATIME))
 195         utb.actime = sbuf.st_atime;
 196
 197       if (!(change_times & CH_MTIME))
 198         utb.modtime = sbuf.st_mtime;
 199
 200       status = utime (file, &utb);
 201     }
 202
 203   if (status)
 204     {
 205       error (0, errno, "%s", file);
 206       return 1;
 207     }
 208
 209   return 0;
 210 }
 211
 212 #ifndef HAVE_UTIME_NULL
 213 /* Emulate utime (file, NULL) for systems (like 4.3BSD) that do not
 214    interpret it to set the access and modification times of FILE to
 215    the current time.  FILESIZE is the correct size of FILE, used to
 216    make sure empty files are not lengthened to 1 byte.
 217    Return 0 if successful, -1 if not. */
 218
 219 static int
 220 utime_now (file, filesize)
 221      char *file;
 222      off_t filesize;
 223 {
 224   int fd;
 225   char c;
 226   int status = 0;
 227
 228   fd = open (file, O_RDWR, 0666);
 229   if (fd < 0
 230       || safe_read (fd, &c, sizeof (char)) < 0
 231       || lseek (fd, (off_t) 0, SEEK_SET) < 0
 232       || full_write (fd, &c, sizeof (char)) < 0
 233       || ftruncate (fd, filesize) < 0
 234       || close (fd) < 0)
 235     status = -1;
 236   return status;
 237 }
 238 #endif
 239
 240 static void
 241 usage (int status)
 242 {
 243   if (status != 0)
 244     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 245              program_name);
 246   else
 247     {
 248       printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
 249       printf (_("\
 250 Update the access and modification times of each FILE to the current time.\n\
 251 \n\
 252   -a                     change only the access time\n\
 253   -c                     do not create any files\n\
 254   -d, --date=STRING      parse STRING and use it instead of current time\n\
 255   -f                     (ignored)\n\
 256   -m                     change only the modification time\n\
 257   -r, --reference=FILE   use this file's times instead of current time\n\
 258   -t STAMP               use MMDDhhmm[[CC]YY][.ss] instead of current time\n\
 259       --time=WORD        access -a, atime -a, mtime -m, modify -m, use -a\n\
 260       --help             display this help and exit\n\
 261       --version          output version information and exit\n\
 262 \n\
 263 STAMP may be used without -t if none of -drt, nor --, are used.\n"));
 264     }
 265   exit (status);
 266 }
 267
 268 void
 269 main (int argc, char **argv)
 270 {
 271   int c, i;
 272   int date_set = 0;
 273   int err = 0;
 274
 275   program_name = argv[0];
 276   setlocale (LC_ALL, "");
 277   bindtextdomain (PACKAGE, LOCALEDIR);
 278   textdomain (PACKAGE);
 279
 280   change_times = no_create = use_ref = posix_date = flexible_date = 0;
 281   newtime = (time_t) -1;
 282
 283   while ((c = getopt_long (argc, argv, "acd:fmr:t:", longopts, (int *) 0))
 284          != EOF)
 285     {
 286       switch (c)
 287         {
 288         case 0:
 289           break;
 290
 291         case 'a':
 292           change_times |= CH_ATIME;
 293           break;
 294
 295         case 'c':
 296           no_create++;
 297           break;
 298
 299         case 'd':
 300           flexible_date++;
 301           newtime = get_date (optarg, NULL);
 302           if (newtime == (time_t) -1)
 303             error (1, 0, _("invalid date format `%s'"), optarg);
 304           date_set++;
 305           break;
 306
 307         case 'f':
 308           break;
 309
 310         case 'm':
 311           change_times |= CH_MTIME;
 312           break;
 313
 314         case 'r':
 315           use_ref++;
 316           ref_file = optarg;
 317           break;
 318
 319         case 't':
 320           posix_date++;
 321           newtime = posixtime (optarg);
 322           if (newtime == (time_t) -1)
 323             error (1, 0, _("invalid date format `%s'"), optarg);
 324           date_set++;
 325           break;
 326
 327         case 130:
 328           i = argmatch (optarg, time_args);
 329           if (i < 0)
 330             {
 331               invalid_arg (_("time selector"), optarg, i);
 332               usage (1);
 333             }
 334           change_times |= time_masks[i];
 335           break;
 336
 337         default:
 338           usage (1);
 339         }
 340     }
 341
 342   if (show_version)
 343     {
 344       printf ("touch - %s\n", PACKAGE_VERSION);
 345       exit (0);
 346     }
 347
 348   if (show_help)
 349     usage (0);
 350
 351   if (change_times == 0)
 352     change_times = CH_ATIME | CH_MTIME;
 353
 354   if ((use_ref && (posix_date || flexible_date))
 355       || (posix_date && flexible_date))
 356     {
 357       error (0, 0, _("cannot specify times from more than one source"));
 358       usage (1);
 359     }
 360
 361   if (use_ref)
 362     {
 363       if (stat (ref_file, &ref_stats))
 364         error (1, errno, "%s", ref_file);
 365       date_set++;
 366     }
 367
 368   if (!date_set && optind < argc && strcmp (argv[optind - 1], "--"))
 369     {
 370       newtime = posixtime (argv[optind]);
 371       if (newtime != (time_t) -1)
 372         {
 373           optind++;
 374           date_set++;
 375         }
 376     }
 377   if (!date_set)
 378     {
 379       if ((change_times & (CH_ATIME | CH_MTIME)) == (CH_ATIME | CH_MTIME))
 380         amtime_now = 1;
 381       else
 382         time (&newtime);
 383     }
 384
 385   if (optind == argc)
 386     {
 387       error (0, 0, _("file arguments missing"));
 388       usage (1);
 389     }
 390
 391   for (; optind < argc; ++optind)
 392     err += touch (argv[optind]);
 393
 394   exit (err != 0);
 395 }