coreutils/touch.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini touch implementation for busybox
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9
  10 /* BB_AUDIT SUSv3 _NOT_ compliant -- options -a, -m, -r, -t not supported. */
  11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/touch.html */
  12
  13 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
  14  *
  15  * Previous version called open() and then utime().  While this will be
  16  * be necessary to implement -r and -t, it currently only makes things bigger.
  17  * Also, exiting on a failure was a bug.  All args should be processed.
  18  */
  19
  20 #include "libbb.h"
  21
  22 //config:config TOUCH
  23 //config:       bool "touch"
  24 //config:       default y
  25 //config:       help
  26 //config:         touch is used to create or change the access and/or
  27 //config:         modification timestamp of specified files.
  28
  29 //applet:IF_TOUCH(APPLET_NOFORK(touch, touch, BB_DIR_BIN, BB_SUID_DROP, touch))
  30
  31 //kbuild:lib-$(CONFIG_TOUCH) += touch.o
  32
  33 //usage:#define touch_trivial_usage
  34 //usage:       "[-c]" IF_DESKTOP(" [-d DATE] [-r FILE]") " FILE [FILE]..."
  35 //usage:#define touch_full_usage "\n\n"
  36 //usage:       "Update the last-modified date on the given FILE[s]\n"
  37 //usage:     "\n        -c      Don't create files"
  38 //usage:        IF_DESKTOP(
  39 //usage:     "\n        -d DT   Date/time to use"
  40 //usage:     "\n        -r FILE Use FILE's date/time"
  41 //usage:        )
  42 //usage:
  43 //usage:#define touch_example_usage
  44 //usage:       "$ ls -l /tmp/foo\n"
  45 //usage:       "/bin/ls: /tmp/foo: No such file or directory\n"
  46 //usage:       "$ touch /tmp/foo\n"
  47 //usage:       "$ ls -l /tmp/foo\n"
  48 //usage:       "-rw-rw-r--    1 andersen andersen        0 Apr 15 01:11 /tmp/foo\n"
  49
  50 /* This is a NOFORK applet. Be very careful! */
  51
  52 /* coreutils implements:
  53  * -a   change only the access time
  54  * -c, --no-create
  55  *      do not create any files
  56  * -d, --date=STRING
  57  *      parse STRING and use it instead of current time
  58  * -f   (ignored, BSD compat)
  59  * -m   change only the modification time
  60  * -r, --reference=FILE
  61  *      use this file's times instead of current time
  62  * -t STAMP
  63  *      use [[CC]YY]MMDDhhmm[.ss] instead of current time
  64  * --time=WORD
  65  *      change the specified time: WORD is access, atime, or use
  66  */
  67
  68 int touch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  69 int touch_main(int argc UNUSED_PARAM, char **argv)
  70 {
  71         int fd;
  72         int status = EXIT_SUCCESS;
  73         int opts;
  74 #if ENABLE_DESKTOP
  75 # if ENABLE_LONG_OPTS
  76         static const char touch_longopts[] ALIGN1 =
  77                 /* name, has_arg, val */
  78                 "no-create\0"         No_argument       "c"
  79                 "reference\0"         Required_argument "r"
  80                 "date\0"              Required_argument "d"
  81         ;
  82 # endif
  83         char *reference_file = NULL;
  84         char *date_str = NULL;
  85         struct timeval timebuf[2];
  86         timebuf[1].tv_usec = timebuf[0].tv_usec = 0;
  87 #else
  88 # define reference_file NULL
  89 # define date_str       NULL
  90 # define timebuf        ((struct timeval*)NULL)
  91 #endif
  92
  93 #if ENABLE_DESKTOP && ENABLE_LONG_OPTS
  94         applet_long_options = touch_longopts;
  95 #endif
  96         /* -d and -t both set time. In coreutils,
  97          * accepted data format differs a bit between -d and -t.
  98          * We accept the same formats for both */
  99         opts = getopt32(argv, "c" IF_DESKTOP("r:d:t:")
 100                                 /*ignored:*/ "fma"
 101                                 IF_DESKTOP(, &reference_file)
 102                                 IF_DESKTOP(, &date_str)
 103                                 IF_DESKTOP(, &date_str)
 104         );
 105
 106         opts &= 1; /* only -c bit is left */
 107         argv += optind;
 108         if (!*argv) {
 109                 bb_show_usage();
 110         }
 111
 112         if (reference_file) {
 113                 struct stat stbuf;
 114                 xstat(reference_file, &stbuf);
 115                 timebuf[1].tv_sec = timebuf[0].tv_sec = stbuf.st_mtime;
 116         }
 117
 118         if (date_str) {
 119                 struct tm tm_time;
 120                 time_t t;
 121
 122                 //memset(&tm_time, 0, sizeof(tm_time));
 123                 /* Better than memset: makes "HH:MM" dates meaningful */
 124                 time(&t);
 125                 localtime_r(&t, &tm_time);
 126                 parse_datestr(date_str, &tm_time);
 127
 128                 /* Correct any day of week and day of year etc. fields */
 129                 tm_time.tm_isdst = -1;  /* Be sure to recheck dst */
 130                 t = validate_tm_time(date_str, &tm_time);
 131
 132                 timebuf[1].tv_sec = timebuf[0].tv_sec = t;
 133         }
 134
 135         do {
 136                 if (utimes(*argv, (reference_file || date_str) ? timebuf : NULL) != 0) {
 137                         if (errno == ENOENT) { /* no such file */
 138                                 if (opts) { /* creation is disabled, so ignore */
 139                                         continue;
 140                                 }
 141                                 /* Try to create the file */
 142                                 fd = open(*argv, O_RDWR | O_CREAT, 0666);
 143                                 if (fd >= 0) {
 144                                         xclose(fd);
 145                                         if (reference_file || date_str)
 146                                                 utimes(*argv, timebuf);
 147                                         continue;
 148                                 }
 149                         }
 150                         status = EXIT_FAILURE;
 151                         bb_simple_perror_msg(*argv);
 152                 }
 153         } while (*++argv);
 154
 155         return status;
 156 }