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 <time.h>
  21
  22 #include "util.h"
  23
  24 /* Parse the given string (interpreted as seconds) into a
  25  * timespec.  On error NULL is returned.  The caller is responsible
  26  * to free the result.   The string may be NULL, in which case NULL
  27  * is returned, too. */
  28 struct timespec *parse_seconds(const char *s)
  29 {
  30   if (s == NULL) {
  31     return NULL;
  32   } else {
  33     char *n;
  34     struct timespec *t = calloc(sizeof *t, 1);
  35
  36     if (t == NULL)
  37       return NULL;
  38
  39     t->tv_sec = strtol(s, &n, 10);
  40
  41     if (*n != '\0' || t->tv_sec <= 0) {
  42       free(t);
  43       t = NULL;
  44     }
  45
  46     return t;
  47   }
  48 }
  49
  50 void fatal_error(const char *format, ...)
  51 {
  52   char *error;
  53   va_list ap;
  54   va_start(ap, format);
  55   if (vasprintf(&error, format, ap) < 0)
  56     error = "error while formatting error message";
  57   va_end(ap);
  58   fatal_error_free(error);
  59 }
  60
  61 void fatal_error_free(char *error)
  62 {
  63   fputs(error, stderr);
  64   fputc('\n', stderr);
  65   abort();
  66 }
  67
  68 void *ensure_malloc(size_t size)
  69 {
  70   void *r = malloc(size);
  71
  72   if (r == NULL)
  73     fatal_error("failed to allocate %d bytes", size);
  74
  75   return r;
  76 }
  77
  78 void *ensure_calloc(size_t number, size_t size)
  79 {
  80   void *r = calloc(number, size);
  81
  82   if (r == NULL)
  83     fatal_error("failed to allocate %d bytes", size);
  84
  85   return r;
  86 }
  87
  88 void *ensure_realloc(void *ptr, size_t size)
  89 {
  90   void *r = realloc(ptr, size);
  91
  92   if (size != 0 && r == NULL)
  93     fatal_error("failed to reallocate %d bytes at %p", size, ptr);
  94
  95   return r;
  96 }
  97
  98 void *ensure_not_null(void *data, const char *errmsg)
  99 {
 100   if (data == NULL)
 101     fatal_error(errmsg);
 102
 103   return data;
 104 }