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
   7USE_TOUCH(NEWTOY(touch, "<1acd:mr:t:h[!dtr]", TOYFLAG_BIN))
   8
   9config TOUCH
  10  bool "touch"
  11  default y
  12  help
  13    usage: touch [-amch] [-d DATE] [-t TIME] [-r FILE] FILE...
  14
  15    Update the access and modification times of each FILE to the current time.
  16
  17    -a  change access time
  18    -m  change modification time
  19    -c  don't create file
  20    -h  change symlink
  21    -d  set time to DATE (in YYYY-MM-DDThh:mm:SS[.frac][tz] format)
  22    -t  set time to TIME (in [[CC]YY]MMDDhhmm[.ss][frac] format)
  23    -r  set time same as reference FILE
  24*/
  25
  26#define FOR_touch
  27#include "toys.h"
  28
  29GLOBALS(
  30  char *time;
  31  char *file;
  32  char *date;
  33)
  34
  35void touch_main(void)
  36{
  37  struct timespec ts[2];
  38  char **ss;
  39  int fd, i;
  40
  41  // use current time if no -t or -d
  42  ts[0].tv_nsec = UTIME_NOW;
  43  if (toys.optflags & (FLAG_t|FLAG_d)) {
  44    char *s, *date, **format;
  45    struct tm tm;
  46    int len = 0;
  47
  48    // Initialize default values for time fields
  49    ts->tv_sec = time(0);
  50    ts->tv_nsec = 0;
  51
  52    // List of search types
  53    if (toys.optflags & FLAG_d) {
  54      format = (char *[]){"%Y-%m-%dT%T", "%Y-%m-%d %T", 0};
  55      date = TT.date;
  56    } else {
  57      format = (char *[]){"%m%d%H%M", "%y%m%d%H%M", "%C%y%m%d%H%M", 0};
  58      date = TT.time;
  59    }
  60
  61    // Trailing Z means UTC timezone, don't expect libc to know this.
  62    i = strlen(s = date);
  63    if (i && toupper(date[i-1])=='Z') {
  64      date[i-1] = 0;
  65      setenv("TZ", "UTC0", 1);
  66    }
  67
  68    while (*format) {
  69      if (toys.optflags&FLAG_t) {
  70        s = strchr(date, '.');
  71        if ((s ? s-date : strlen(date)) != strlen(*format)) {
  72          format++;
  73          continue;
  74        }
  75      }
  76      localtime_r(&(ts->tv_sec), &tm);
  77      // Adjusting for daylight savings time gives the wrong answer.
  78      tm.tm_isdst = 0;
  79      tm.tm_sec = 0;
  80      s = strptime(date, *format++, &tm);
  81
  82      // parse nanoseconds
  83      if (s && *s=='.' && isdigit(s[1])) {
  84        s++;
  85        if (toys.optflags&FLAG_t)
  86          if (1 == sscanf(s, "%2u%n", &(tm.tm_sec), &len)) s += len;
  87        if (1 == sscanf(s, "%lu%n", &ts->tv_nsec, &len)) {
  88          s += len;
  89          if (ts->tv_nsec > 999999999) s = 0;
  90          else while (len++ < 9) ts->tv_nsec *= 10;
  91        }
  92      }
  93      if (s && !*s) break;
  94    }
  95
  96    errno = 0;
  97    ts->tv_sec = mktime(&tm);
  98    if (!s || *s || ts->tv_sec == -1) perror_exit("bad '%s'", date);
  99  }
 100  ts[1]=ts[0];
 101
 102  // Set time from -r?
 103
 104  if (TT.file) {
 105    struct stat st;
 106
 107    xstat(TT.file, &st);
 108    ts[0] = st.st_atim;
 109    ts[1] = st.st_mtim;
 110  }
 111
 112  // Which time(s) should we actually change?
 113  i = toys.optflags & (FLAG_a|FLAG_m);
 114  if (i && i!=(FLAG_a|FLAG_m)) ts[i!=FLAG_m].tv_nsec = UTIME_OMIT;
 115
 116  // Loop through files on command line
 117  for (ss = toys.optargs; *ss;) {
 118    char *s = *ss++;
 119
 120    if (!strcmp(s, "-")) {
 121      if (!futimens(1, ts)) continue;
 122    } else {
 123      // cheat: FLAG_h is rightmost flag, so its value is 1
 124      if (!utimensat(AT_FDCWD, s, ts,
 125          (toys.optflags & FLAG_h)*AT_SYMLINK_NOFOLLOW)) continue;
 126      if (toys.optflags & FLAG_c) continue;
 127      if (access(s, F_OK) && (-1!=(fd = open(s, O_CREAT, 0666)))) {
 128        close(fd);
 129        if (toys.optflags) ss--;
 130        continue;
 131      }
 132    }
 133    perror_msg("'%s'", s);
 134  }
 135}
 136