Safe-memory-functions

safe_function.c

/*
 * safe_malloc ()
 * 
 * Call calloc () and abort if the specified amount of memory cannot be
 * allocated.
 */

void           *
safe_malloc(size_t size)
{
   void *mem_block = NULL;

   if ((mem_block = calloc(1, size)) == NULL) {
      fprintf(stderr, "ERROR: safe_malloc(%zu) cannot allocate memory.", size);
      exit(EXIT_FAILURE);
   }
   return (mem_block);
}

/*
 * safe_realloc ()
 * 
 * Call realloc () and abort if the specified amount of memory cannot be
 * allocated.
 */

void *
safe_realloc(void *old_mem, size_t new_size)
{
   if ((old_mem = realloc(old_mem, new_size)) == NULL) {
      fprintf(stderr, "ERROR: safe_realloc() cannot allocate"
      "%zu blocks of memory.\n", new_size);
      exit(EXIT_FAILURE);
   }
   return (old_mem);
}

/*
 * safe_strdup ()
 * 
 * Safe version of strdup avoid buffer overflow, etc.
 * 
 */

char *
safe_strdup(const char *str)
{
   char *copy = NULL;

   if (str == NULL) {
      fprintf(stderr, "ERROR safe_strdup(): str == NULL");
      exit(EXIT_FAILURE);
    }
    copy = safe_malloc((strlen(str) + 1) * sizeof(char));

   (void) strcpy(copy, str);

   return (copy);
}

char *
safe_strcat(char *str1, const char *str2)
{
   char *rv = NULL;
   size_t len = 0;

   if (str1 == NULL || str2 == NULL) {
      fprintf(stderr, "ERROR safe_strcat_new(): str == NULL");
      exit(EXIT_FAILURE);
   }
   len = strlen(str1) + strlen(str2) + 1;
   rv = safe_malloc(len * sizeof(char));
   (void) strcpy(rv, str1);
   rv = strcat(rv, str2);

   return (rv);
}