LXR toybox/toys/posix/touch.c

   1/* touch.c : change timestamp of a file
   2 *
   3 * Copyright 2012 Choubey Ji <warior.linux@gmail.com>
   4 *
   5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/touch.html
   6 *
   7 * -f is ignored for BSD/macOS compatibility. busybox/coreutils also support
   8 * this, but only coreutils documents it in --help output.
   9
  10USE_TOUCH(NEWTOY(touch, "<1acd:fmr:t:h[!dtr]", TOYFLAG_BIN))
  11
  12config TOUCH
  13  bool "touch"
  14  default y
  15  help
  16    usage: touch [-amch] [-d DATE] [-t TIME] [-r FILE] FILE...
  17
  18    Update the access and modification times of each FILE to the current time.
  19
  20    -a  Change access time
  21    -m  Change modification time
  22    -c  Don't create file
  23    -h  Change symlink
  24    -d  Set time to DATE (in YYYY-MM-DDThh:mm:SS[.frac][tz] format)
  25    -t  Set time to TIME (in [[CC]YY]MMDDhhmm[.ss][frac] format)
  26    -r  Set time same as reference FILE
  27*/
  28
  29#define FOR_touch
  30#include "toys.h"
  31
  32GLOBALS(
  33  char *t, *r, *d;
  34)
  35
  36void touch_main(void)
  37{
  38  struct timespec ts[2];
  39  char **ss;
  40  int fd, i;
  41
  42  // use current time if no -t or -d
  43  ts[0].tv_nsec = UTIME_NOW;
  44
  45  if (FLAG(t) || FLAG(d)) {
  46    time_t t = time(0);
  47    unsigned nano;
  48
  49    xparsedate(TT.t ? TT.t : TT.d, &t, &nano, 0);
  50    ts->tv_sec = t;
  51    ts->tv_nsec = nano;
  52  }
  53  ts[1]=ts[0];
  54
  55  if (TT.r) {
  56    struct stat st;
  57
  58    xstat(TT.r, &st);
  59    ts[0] = st.st_atim;
  60    ts[1] = st.st_mtim;
  61  }
  62
  63  // Which time(s) should we actually change?
  64  i = toys.optflags & (FLAG_a|FLAG_m);
  65  if (i && i!=(FLAG_a|FLAG_m)) ts[i!=FLAG_m].tv_nsec = UTIME_OMIT;
  66
  67  // Loop through files on command line
  68  for (ss = toys.optargs; *ss;) {
  69    char *s = *ss++;
  70
  71    if (!strcmp(s, "-")) {
  72      if (!futimens(1, ts)) continue;
  73    } else {
  74      // cheat: FLAG_h is rightmost flag, so its value is 1
  75      if (!utimensat(AT_FDCWD, s, ts, FLAG(h)*AT_SYMLINK_NOFOLLOW)) continue;
  76      if (FLAG(c)) continue;
  77      if (access(s, F_OK) && (-1!=(fd = open(s, O_CREAT, 0666)))) {
  78        close(fd);
  79        if (toys.optflags) ss--;
  80        continue;
  81      }
  82    }
  83    perror_msg("'%s'", s);
  84  }
  85}
  86