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 static struct option const longopts[] =
  82 {
  83   {"time", required_argument, 0, CHAR_MAX + 1},
  84   {"no-create", no_argument, 0, 'c'},
  85   {"date", required_argument, 0, 'd'},
  86   {"file", required_argument, 0, 'r'}, /* FIXME: phase out --file */
  87   {"reference", required_argument, 0, 'r'},
  88   {GETOPT_HELP_OPTION_DECL},
  89   {GETOPT_VERSION_OPTION_DECL},
  90   {0, 0, 0, 0}
  91 };
  92
  93 /* Valid arguments to the `--time' option. */
  94 static char const* const time_args[] =
  95 {
  96   "atime", "access", "use", "mtime", "modify", 0
  97 };
  98
  99 /* The bits in `change_times' that those arguments set. */
 100 static int const time_masks[] =
 101 {
 102   CH_ATIME, CH_ATIME, CH_ATIME, CH_MTIME, CH_MTIME
 103 };
 104
 105 /* Update the time of file FILE according to the options given.
 106    Return 0 if successful, 1 if an error occurs. */
 107
 108 static int
 109 touch (const char *file)
 110 {
 111   int status;
 112   struct stat sbuf;
 113   int fd = -1;
 114
 115   if (! no_create)
 116     {
 117       /* Try to open FILE, creating it if necessary.  */
 118       fd = open (file, O_WRONLY | O_CREAT,
 119                  S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 120     }
 121
 122   if (! amtime_now)
 123     {
 124       /* We're setting only one of the time values.  stat the target to get
 125          the other one.  If we have the file descriptor already, use fstat.
 126          Otherwise, either we're in no-create mode (and hence didn't call open)
 127          or FILE is inaccessible or a directory, so we have to use stat.  */
 128       if (fd != -1 ? fstat (fd, &sbuf) : stat (file, &sbuf))
 129         {
 130           error (0, errno, "%s", file);
 131           close (fd);
 132           return 1;
 133         }
 134     }
 135
 136   if (fd != -1 && close (fd) < 0)
 137     {
 138       error (0, errno, "%s", file);
 139       return 1;
 140     }
 141
 142   if (amtime_now)
 143     {
 144       /* Pass NULL to utime so it will not fail if we just have
 145          write access to the file, but don't own it.  */
 146       status = utime (file, NULL);
 147     }
 148   else
 149     {
 150       struct utimbuf utb;
 151
 152       /* There's currently no interface to set file timestamps with
 153          better than 1-second resolution, so discard any fractional
 154          part of the source timestamp.  */
 155
 156       if (use_ref)
 157         {
 158           utb.actime = ref_stats.st_atime;
 159           utb.modtime = ref_stats.st_mtime;
 160         }
 161       else
 162         utb.actime = utb.modtime = newtime;
 163
 164       if (!(change_times & CH_ATIME))
 165         utb.actime = sbuf.st_atime;
 166
 167       if (!(change_times & CH_MTIME))
 168         utb.modtime = sbuf.st_mtime;
 169
 170       status = utime (file, &utb);
 171     }
 172
 173   if (status)
 174     {
 175       error (0, errno, "%s", file);
 176       return 1;
 177     }
 178
 179   return 0;
 180 }
 181
 182 void
 183 usage (int status)
 184 {
 185   if (status != 0)
 186     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 187              program_name);
 188   else
 189     {
 190       printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
 191       printf (_("  or : %s [-acm] MMDDhhmm[YY] FILE... (obsolescent)\n"),
 192               program_name);
 193       printf (_("\
 194 Update the access and modification times of each FILE to the current time.\n\
 195 \n\
 196   -a                     change only the access time\n\
 197   -c, --no-create        do not create any files\n\
 198   -d, --date=STRING      parse STRING and use it instead of current time\n\
 199   -f                     (ignored)\n\
 200   -m                     change only the modification time\n\
 201   -r, --reference=FILE   use this file's times instead of current time\n\
 202   -t STAMP               use [[CC]YY]MMDDhhmm[.ss] instead of current time\n\
 203   --time=WORD            set time given by WORD: access atime use (same as -a)\n\
 204                            modify mtime (same as -m)\n\
 205       --help             display this help and exit\n\
 206       --version          output version information and exit\n\
 207 \n\
 208 Note that the three time-date formats recognized for the -d and -t options\n\
 209 and for the obsolescent argument are all different.\n\
 210 "));
 211       puts (_("\nReport bugs to <bug-fileutils@gnu.org>."));
 212       close_stdout ();
 213     }
 214   exit (status);
 215 }
 216
 217 int
 218 main (int argc, char **argv)
 219 {
 220   int c;
 221   int date_set = 0;
 222   int err = 0;
 223
 224   program_name = argv[0];
 225   setlocale (LC_ALL, "");
 226   bindtextdomain (PACKAGE, LOCALEDIR);
 227   textdomain (PACKAGE);
 228
 229   change_times = no_create = use_ref = posix_date = flexible_date = 0;
 230   newtime = (time_t) -1;
 231
 232   while ((c = getopt_long (argc, argv, "acd:fmr:t:", longopts, NULL)) != -1)
 233     {
 234       switch (c)
 235         {
 236         case 0:
 237           break;
 238
 239         case 'a':
 240           change_times |= CH_ATIME;
 241           break;
 242
 243         case 'c':
 244           no_create++;
 245           break;
 246
 247         case 'd':
 248           flexible_date++;
 249           newtime = get_date (optarg, NULL);
 250           if (newtime == (time_t) -1)
 251             error (1, 0, _("invalid date format `%s'"), optarg);
 252           date_set++;
 253           break;
 254
 255         case 'f':
 256           break;
 257
 258         case 'm':
 259           change_times |= CH_MTIME;
 260           break;
 261
 262         case 'r':
 263           use_ref++;
 264           ref_file = optarg;
 265           break;
 266
 267         case 't':
 268           posix_date++;
 269           newtime = posixtime (optarg,
 270                                PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS);
 271           if (newtime == (time_t) -1)
 272             error (1, 0, _("invalid date format `%s'"), optarg);
 273           date_set++;
 274           break;
 275
 276         case CHAR_MAX + 1:      /* --time */
 277           change_times |= XARGMATCH ("--time", optarg,
 278                                      time_args, time_masks);
 279           break;
 280
 281         case_GETOPT_HELP_CHAR;
 282
 283         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 284
 285         default:
 286           usage (1);
 287         }
 288     }
 289
 290   if (change_times == 0)
 291     change_times = CH_ATIME | CH_MTIME;
 292
 293   if ((use_ref && (posix_date || flexible_date))
 294       || (posix_date && flexible_date))
 295     {
 296       error (0, 0, _("cannot specify times from more than one source"));
 297       usage (1);
 298     }
 299
 300   if (use_ref)
 301     {
 302       if (stat (ref_file, &ref_stats))
 303         error (1, errno, "%s", ref_file);
 304       date_set++;
 305     }
 306
 307   if (!date_set && optind < argc && !STREQ (argv[optind - 1], "--"))
 308     {
 309       newtime = posixtime (argv[optind], PDS_TRAILING_YEAR);
 310       if (newtime != (time_t) -1)
 311         {
 312           optind++;
 313           date_set++;
 314         }
 315     }
 316   if (!date_set)
 317     {
 318       if ((change_times & (CH_ATIME | CH_MTIME)) == (CH_ATIME | CH_MTIME))
 319         amtime_now = 1;
 320       else
 321         time (&newtime);
 322     }
 323
 324   if (optind == argc)
 325     {
 326       error (0, 0, _("file arguments missing"));
 327       usage (1);
 328     }
 329
 330   for (; optind < argc; ++optind)
 331     err += touch (argv[optind]);
 332
 333   exit (err != 0);
 334 }