src/touch.c

   1 /* touch -- change modification and access times of files
   2    Copyright (C) 87, 1989-1991, 1995-1999 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 Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie,
  19    and Randy Smith. */
  20
  21 #include <config.h>
  22 #include <stdio.h>
  23 #include <getopt.h>
  24 #include <sys/types.h>
  25
  26 #include "system.h"
  27 #include "argmatch.h"
  28 #include "error.h"
  29 #include "getdate.h"
  30 #include "posixtm.h"
  31 #include "safe-read.h"
  32
  33 /* The official name of this program (e.g., no `g' prefix).  */
  34 #define PROGRAM_NAME "touch"
  35
  36 #define AUTHORS \
  37   "Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, and Randy Smith"
  38
  39 #ifndef STDC_HEADERS
  40 time_t time ();
  41 #endif
  42
  43 /* Bitmasks for `change_times'. */
  44 #define CH_ATIME 1
  45 #define CH_MTIME 2
  46
  47 /* The name by which this program was run. */
  48 char *program_name;
  49
  50 /* Which timestamps to change. */
  51 static int change_times;
  52
  53 /* (-c) If nonzero, don't create if not already there. */
  54 static int no_create;
  55
  56 /* (-d) If nonzero, date supplied on command line in get_date formats. */
  57 static int flexible_date;
  58
  59 /* (-r) If nonzero, use times from a reference file. */
  60 static int use_ref;
  61
  62 /* (-t) If nonzero, date supplied on command line in POSIX format. */
  63 static int posix_date;
  64
  65 /* If nonzero, the only thing we have to do is change both the
  66    modification and access time to the current time, so we don't
  67    have to own the file, just be able to read and write it.
  68    On some systems, we can do this if we own the file, even though
  69    we have neither read nor write access to it.  */
  70 static int amtime_now;
  71
  72 /* New time to use when setting time. */
  73 static time_t newtime;
  74
  75 /* File to use for -r. */
  76 static char *ref_file;
  77
  78 /* Info about the reference file. */
  79 static struct stat ref_stats;
  80
  81 /* For long options that have no equivalent short option, use a
  82    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  83 enum
  84 {
  85   TIME_OPTION = CHAR_MAX + 1
  86 };
  87
  88 static struct option const longopts[] =
  89 {
  90   {"time", required_argument, 0, TIME_OPTION},
  91   {"no-create", no_argument, 0, 'c'},
  92   {"date", required_argument, 0, 'd'},
  93   {"file", required_argument, 0, 'r'}, /* FIXME: phase out --file */
  94   {"reference", required_argument, 0, 'r'},
  95   {GETOPT_HELP_OPTION_DECL},
  96   {GETOPT_VERSION_OPTION_DECL},
  97   {0, 0, 0, 0}
  98 };
  99
 100 /* Valid arguments to the `--time' option. */
 101 static char const* const time_args[] =
 102 {
 103   "atime", "access", "use", "mtime", "modify", 0
 104 };
 105
 106 /* The bits in `change_times' that those arguments set. */
 107 static int const time_masks[] =
 108 {
 109   CH_ATIME, CH_ATIME, CH_ATIME, CH_MTIME, CH_MTIME
 110 };
 111
 112 /* Update the time of file FILE according to the options given.
 113    Return 0 if successful, 1 if an error occurs. */
 114
 115 static int
 116 touch (const char *file)
 117 {
 118   int status;
 119   struct stat sbuf;
 120   int fd = -1;
 121   int open_errno = 0;
 122
 123   if (! no_create)
 124     {
 125       /* Try to open FILE, creating it if necessary.  */
 126       fd = open (file, O_WRONLY | O_CREAT,
 127                  S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 128       if (fd == -1)
 129         open_errno = errno;
 130     }
 131
 132   if (! amtime_now)
 133     {
 134       /* We're setting only one of the time values.  stat the target to get
 135          the other one.  If we have the file descriptor already, use fstat.
 136          Otherwise, either we're in no-create mode (and hence didn't call open)
 137          or FILE is inaccessible or a directory, so we have to use stat.  */
 138       if (fd != -1 ? fstat (fd, &sbuf) : stat (file, &sbuf))
 139         {
 140           error (0, open_errno ? open_errno : errno, "%s", file);
 141           close (fd);
 142           return 1;
 143         }
 144     }
 145
 146   if (fd != -1 && close (fd) < 0)
 147     {
 148       error (0, errno, "%s", file);
 149       return 1;
 150     }
 151
 152   if (amtime_now)
 153     {
 154       /* Pass NULL to utime so it will not fail if we just have
 155          write access to the file, but don't own it.  */
 156       status = utime (file, NULL);
 157     }
 158   else
 159     {
 160       struct utimbuf utb;
 161
 162       /* There's currently no interface to set file timestamps with
 163          better than 1-second resolution, so discard any fractional
 164          part of the source timestamp.  */
 165
 166       if (use_ref)
 167         {
 168           utb.actime = ref_stats.st_atime;
 169           utb.modtime = ref_stats.st_mtime;
 170         }
 171       else
 172         utb.actime = utb.modtime = newtime;
 173
 174       if (!(change_times & CH_ATIME))
 175         utb.actime = sbuf.st_atime;
 176
 177       if (!(change_times & CH_MTIME))
 178         utb.modtime = sbuf.st_mtime;
 179
 180       status = utime (file, &utb);
 181     }
 182
 183   if (status)
 184     {
 185       error (0, open_errno ? open_errno : errno, "%s", file);
 186       return 1;
 187     }
 188
 189   return 0;
 190 }
 191
 192 void
 193 usage (int status)
 194 {
 195   if (status != 0)
 196     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 197              program_name);
 198   else
 199     {
 200       printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
 201       printf (_("  or : %s [-acm] MMDDhhmm[YY] FILE... (obsolescent)\n"),
 202               program_name);
 203       printf (_("\
 204 Update the access and modification times of each FILE to the current time.\n\
 205 \n\
 206   -a                     change only the access time\n\
 207   -c, --no-create        do not create any files\n\
 208   -d, --date=STRING      parse STRING and use it instead of current time\n\
 209   -f                     (ignored)\n\
 210   -m                     change only the modification time\n\
 211   -r, --reference=FILE   use this file's times instead of current time\n\
 212   -t STAMP               use [[CC]YY]MMDDhhmm[.ss] instead of current time\n\
 213   --time=WORD            set time given by WORD: access atime use (same as -a)\n\
 214                            modify mtime (same as -m)\n\
 215       --help             display this help and exit\n\
 216       --version          output version information and exit\n\
 217 \n\
 218 Note that the three time-date formats recognized for the -d and -t options\n\
 219 and for the obsolescent argument are all different.\n\
 220 "));
 221       puts (_("\nReport bugs to <bug-fileutils@gnu.org>."));
 222       close_stdout ();
 223     }
 224   exit (status);
 225 }
 226
 227 int
 228 main (int argc, char **argv)
 229 {
 230   int c;
 231   int date_set = 0;
 232   int err = 0;
 233
 234   program_name = argv[0];
 235   setlocale (LC_ALL, "");
 236   bindtextdomain (PACKAGE, LOCALEDIR);
 237   textdomain (PACKAGE);
 238
 239   change_times = no_create = use_ref = posix_date = flexible_date = 0;
 240   newtime = (time_t) -1;
 241
 242   while ((c = getopt_long (argc, argv, "acd:fmr:t:", longopts, NULL)) != -1)
 243     {
 244       switch (c)
 245         {
 246         case 0:
 247           break;
 248
 249         case 'a':
 250           change_times |= CH_ATIME;
 251           break;
 252
 253         case 'c':
 254           no_create++;
 255           break;
 256
 257         case 'd':
 258           flexible_date++;
 259           newtime = get_date (optarg, NULL);
 260           if (newtime == (time_t) -1)
 261             error (1, 0, _("invalid date format `%s'"), optarg);
 262           date_set++;
 263           break;
 264
 265         case 'f':
 266           break;
 267
 268         case 'm':
 269           change_times |= CH_MTIME;
 270           break;
 271
 272         case 'r':
 273           use_ref++;
 274           ref_file = optarg;
 275           break;
 276
 277         case 't':
 278           posix_date++;
 279           newtime = posixtime (optarg,
 280                                PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS);
 281           if (newtime == (time_t) -1)
 282             error (1, 0, _("invalid date format `%s'"), optarg);
 283           date_set++;
 284           break;
 285
 286         case TIME_OPTION:       /* --time */
 287           change_times |= XARGMATCH ("--time", optarg,
 288                                      time_args, time_masks);
 289           break;
 290
 291         case_GETOPT_HELP_CHAR;
 292
 293         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 294
 295         default:
 296           usage (1);
 297         }
 298     }
 299
 300   if (change_times == 0)
 301     change_times = CH_ATIME | CH_MTIME;
 302
 303   if ((use_ref && (posix_date || flexible_date))
 304       || (posix_date && flexible_date))
 305     {
 306       error (0, 0, _("cannot specify times from more than one source"));
 307       usage (1);
 308     }
 309
 310   if (use_ref)
 311     {
 312       if (stat (ref_file, &ref_stats))
 313         error (1, errno, "%s", ref_file);
 314       date_set++;
 315     }
 316
 317   if (!date_set && optind < argc && !STREQ (argv[optind - 1], "--"))
 318     {
 319       newtime = posixtime (argv[optind], PDS_TRAILING_YEAR);
 320       if (newtime != (time_t) -1)
 321         {
 322           optind++;
 323           date_set++;
 324         }
 325     }
 326   if (!date_set)
 327     {
 328       if ((change_times & (CH_ATIME | CH_MTIME)) == (CH_ATIME | CH_MTIME))
 329         amtime_now = 1;
 330       else
 331         time (&newtime);
 332     }
 333
 334   if (optind == argc)
 335     {
 336       error (0, 0, _("file arguments missing"));
 337       usage (1);
 338     }
 339
 340   for (; optind < argc; ++optind)
 341     err += touch (argv[optind]);
 342
 343   exit (err != 0);
 344 }