src/util.c

   1 /* util.c -- utility routines for vlock, the VT locking program for linux
   2  *
   3  * This program is copyright (C) 2007 Frank Benkstein, and is free
   4  * software which is freely distributable under the terms of the
   5  * GNU General Public License version 2, included as the file COPYING in this
   6  * distribution.  It is NOT public domain software, and any
   7  * redistribution not permitted by the GNU General Public License is
   8  * expressly forbidden without prior written permission from
   9  * the author.
  10  *
  11  */
  12
  13 #if !defined(__FreeBSD__) && !defined(_GNU_SOURCE)
  14 #define _GNU_SOURCE
  15 #endif
  16
  17 #include <stdlib.h>
  18 #include <stdarg.h>
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <errno.h>
  22 #include <time.h>
  23
  24 #include "util.h"
  25
  26 /* Parse the given string (interpreted as seconds) into a
  27  * timespec.  On error NULL is returned.  The caller is responsible
  28  * to free the result.   The argument may be NULL, in which case NULL
  29  * is returned, too.  "0" is also parsed as NULL. */
  30 struct timespec *parse_seconds(const char *s)
  31 {
  32   if (s == NULL) {
  33     return NULL;
  34   } else {
  35     char *n;
  36     struct timespec *t = calloc(sizeof *t, 1);
  37
  38     if (t == NULL)
  39       return NULL;
  40
  41     t->tv_sec = strtol(s, &n, 10);
  42
  43     if (*n != '\0' || t->tv_sec <= 0) {
  44       free(t);
  45       t = NULL;
  46     }
  47
  48     return t;
  49   }
  50 }
  51