utils-lib.c

   1 #define _GNU_SOURCE
   2
   3 #include "kerncompat.h"
   4 #include <unistd.h>
   5 #include <stdlib.h>
   6 #include <limits.h>
   7
   8 #if BTRFS_FLAT_INCLUDES
   9 #else
  10 #endif /* BTRFS_FLAT_INCLUDES */
  11
  12 /*
  13  * This function should be only used when parsing command arg, it won't return
  14  * error to its caller and rather exit directly just like usage().
  15  */
  16 u64 arg_strtou64(const char *str)
  17 {
  18         u64 value;
  19         char *ptr_parse_end = NULL;
  20
  21         value = strtoull(str, &ptr_parse_end, 0);
  22         if (ptr_parse_end && *ptr_parse_end != '\0') {
  23                 fprintf(stderr, "ERROR: %s is not a valid numeric value.\n",
  24                         str);
  25                 exit(1);
  26         }
  27
  28         /*
  29          * if we pass a negative number to strtoull, it will return an
  30          * unexpected number to us, so let's do the check ourselves.
  31          */
  32         if (str[0] == '-') {
  33                 fprintf(stderr, "ERROR: %s: negative value is invalid.\n",
  34                         str);
  35                 exit(1);
  36         }
  37         if (value == ULLONG_MAX) {
  38                 fprintf(stderr, "ERROR: %s is too large.\n", str);
  39                 exit(1);
  40         }
  41         return value;
  42 }