xref: /third_party/toybox/toys/posix/touch.c (revision 0f66f451) 
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