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 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
  10  *
  11  * Previous version called open() and then utime().  While this will be
  12  * be necessary to implement -r and -t, it currently only makes things bigger.
  13  * Also, exiting on a failure was a bug.  All args should be processed.
  14  */
  15 //config:config TOUCH
  16 //config:       bool "touch (5.8 kb)"
  17 //config:       default y
  18 //config:       help
  19 //config:       touch is used to create or change the access and/or
  20 //config:       modification timestamp of specified files.
  21 //config:
  22 //config:config FEATURE_TOUCH_NODEREF
  23 //config:       bool "Add support for -h"
  24 //config:       default y
  25 //config:       depends on TOUCH
  26 //config:       help
  27 //config:       Enable touch to have the -h option.
  28 //config:       This requires libc support for lutimes() function.
  29 //config:
  30 //config:config FEATURE_TOUCH_SUSV3
  31 //config:       bool "Add support for SUSV3 features (-d -t -r)"
  32 //config:       default y
  33 //config:       depends on TOUCH
  34 //config:       help
  35 //config:       Enable touch to use a reference file or a given date/time argument.
  36
  37 //applet:IF_TOUCH(APPLET_NOFORK(touch, touch, BB_DIR_BIN, BB_SUID_DROP, touch))
  38
  39 //kbuild:lib-$(CONFIG_TOUCH) += touch.o
  40
  41 /* BB_AUDIT SUSv3 _NOT_ compliant -- options -a, -m not supported. */
  42 /* http://www.opengroup.org/onlinepubs/007904975/utilities/touch.html */
  43
  44 //usage:#define touch_trivial_usage
  45 //usage:       "[-c]" IF_FEATURE_TOUCH_SUSV3(" [-d DATE] [-t DATE] [-r FILE]") " FILE..."
  46 //usage:#define touch_full_usage "\n\n"
  47 //usage:       "Update the last-modified date on the given FILE[s]\n"
  48 //usage:     "\n        -c      Don't create files"
  49 //usage:        IF_FEATURE_TOUCH_NODEREF(
  50 //usage:     "\n        -h      Don't follow links"
  51 //usage:        )
  52 //usage:        IF_FEATURE_TOUCH_SUSV3(
  53 //usage:     "\n        -d DT   Date/time to use"
  54 //usage:     "\n        -t DT   Date/time to use"
  55 //usage:     "\n        -r FILE Use FILE's date/time"
  56 //usage:        )
  57 //usage:
  58 //usage:#define touch_example_usage
  59 //usage:       "$ ls -l /tmp/foo\n"
  60 //usage:       "/bin/ls: /tmp/foo: No such file or directory\n"
  61 //usage:       "$ touch /tmp/foo\n"
  62 //usage:       "$ ls -l /tmp/foo\n"
  63 //usage:       "-rw-rw-r--    1 andersen andersen        0 Apr 15 01:11 /tmp/foo\n"
  64
  65 /* coreutils implements:
  66  * -a   change only the access time
  67  * -c, --no-create
  68  *      do not create any files
  69  * -d, --date=STRING
  70  *      parse STRING and use it instead of current time
  71  * -f   (ignored, BSD compat)
  72  * -m   change only the modification time
  73  * -h, --no-dereference
  74  * -r, --reference=FILE
  75  *      use this file's times instead of current time
  76  * -t STAMP
  77  *      use [[CC]YY]MMDDhhmm[.ss] instead of current time
  78  * --time=WORD
  79  *      change the specified time: WORD is access, atime, or use
  80  */
  81
  82 #include "libbb.h"
  83
  84 int touch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  85 int touch_main(int argc UNUSED_PARAM, char **argv)
  86 {
  87         int fd;
  88         int status = EXIT_SUCCESS;
  89         int opts;
  90         enum {
  91                 OPT_c = (1 << 0),
  92                 OPT_r = (1 << 1) * ENABLE_FEATURE_TOUCH_SUSV3,
  93                 OPT_d = (1 << 2) * ENABLE_FEATURE_TOUCH_SUSV3,
  94                 OPT_t = (1 << 3) * ENABLE_FEATURE_TOUCH_SUSV3,
  95                 OPT_h = (1 << 4) * ENABLE_FEATURE_TOUCH_NODEREF,
  96         };
  97 #if ENABLE_FEATURE_TOUCH_SUSV3
  98 # if ENABLE_LONG_OPTS
  99         static const char touch_longopts[] ALIGN1 =
 100                 /* name, has_arg, val */
 101                 "no-create\0"         No_argument       "c"
 102                 "reference\0"         Required_argument "r"
 103                 "date\0"              Required_argument "d"
 104                 IF_FEATURE_TOUCH_NODEREF("no-dereference\0" No_argument "h")
 105         ;
 106 # endif
 107         char *reference_file = NULL;
 108         char *date_str = NULL;
 109         struct timeval timebuf[2];
 110         timebuf[1].tv_usec = timebuf[0].tv_usec = 0;
 111 #else
 112 # define reference_file NULL
 113 # define date_str       NULL
 114 # define timebuf        ((struct timeval*)NULL)
 115 #endif
 116
 117 #if ENABLE_FEATURE_TOUCH_SUSV3 && ENABLE_LONG_OPTS
 118         applet_long_options = touch_longopts;
 119 #endif
 120         /* -d and -t both set time. In coreutils,
 121          * accepted data format differs a bit between -d and -t.
 122          * We accept the same formats for both */
 123         opts = getopt32(argv, "c" IF_FEATURE_TOUCH_SUSV3("r:d:t:")
 124                                 IF_FEATURE_TOUCH_NODEREF("h")
 125                                 /*ignored:*/ "fma"
 126                                 IF_FEATURE_TOUCH_SUSV3(, &reference_file)
 127                                 IF_FEATURE_TOUCH_SUSV3(, &date_str)
 128                                 IF_FEATURE_TOUCH_SUSV3(, &date_str)
 129         );
 130
 131         argv += optind;
 132         if (!*argv) {
 133                 bb_show_usage();
 134         }
 135
 136         if (reference_file) {
 137                 struct stat stbuf;
 138                 xstat(reference_file, &stbuf);
 139                 timebuf[1].tv_sec = timebuf[0].tv_sec = stbuf.st_mtime;
 140                 /* Can use .st_mtim.tv_nsec
 141                  * (or is it .st_mtimensec?? see date.c)
 142                  * to set microseconds too.
 143                  */
 144         }
 145
 146         if (date_str) {
 147                 struct tm tm_time;
 148                 time_t t;
 149
 150                 //memset(&tm_time, 0, sizeof(tm_time));
 151                 /* Better than memset: makes "HH:MM" dates meaningful */
 152                 time(&t);
 153                 localtime_r(&t, &tm_time);
 154                 parse_datestr(date_str, &tm_time);
 155
 156                 /* Correct any day of week and day of year etc. fields */
 157                 tm_time.tm_isdst = -1;  /* Be sure to recheck dst */
 158                 t = validate_tm_time(date_str, &tm_time);
 159
 160                 timebuf[1].tv_sec = timebuf[0].tv_sec = t;
 161         }
 162
 163         do {
 164                 int result;
 165                 result = (
 166 #if ENABLE_FEATURE_TOUCH_NODEREF
 167                         (opts & OPT_h) ? lutimes :
 168 #endif
 169                         utimes)(*argv, (reference_file || date_str) ? timebuf : NULL);
 170                 if (result != 0) {
 171                         if (errno == ENOENT) { /* no such file? */
 172                                 if (opts & OPT_c) {
 173                                         /* Creation is disabled, so ignore */
 174                                         continue;
 175                                 }
 176                                 /* Try to create the file */
 177                                 fd = open(*argv, O_RDWR | O_CREAT, 0666);
 178                                 if (fd >= 0) {
 179                                         xclose(fd);
 180                                         if (reference_file || date_str)
 181                                                 utimes(*argv, timebuf);
 182                                         continue;
 183                                 }
 184                         }
 185                         status = EXIT_FAILURE;
 186                         bb_simple_perror_msg(*argv);
 187                 }
 188         } while (*++argv);
 189
 190         return status;
 191 }