compat/strtonum.c

   1 /*      $OpenBSD: strtonum.c,v 1.6 2004/08/03 19:38:01 millert Exp $    */
   2
   3 /*
   4  * Copyright (c) 2004 Ted Unangst and Todd Miller
   5  * All rights reserved.
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <stdlib.h>
  23
  24 #include "compat.h"
  25
  26 #define INVALID         1
  27 #define TOOSMALL        2
  28 #define TOOLARGE        3
  29
  30 long long
  31 strtonum(const char *numstr, long long minval, long long maxval,
  32     const char **errstrp)
  33 {
  34         long long ll = 0;
  35         char *ep;
  36         int error = 0;
  37         struct errval {
  38                 const char *errstr;
  39                 int err;
  40         } ev[4] = {
  41                 { NULL,         0 },
  42                 { "invalid",    EINVAL },
  43                 { "too small",  ERANGE },
  44                 { "too large",  ERANGE },
  45         };
  46
  47         ev[0].err = errno;
  48         errno = 0;
  49         if (minval > maxval)
  50                 error = INVALID;
  51         else {
  52                 ll = strtoll(numstr, &ep, 10);
  53                 if (numstr == ep || *ep != '\0')
  54                         error = INVALID;
  55                 else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)
  56                         error = TOOSMALL;
  57                 else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)
  58                         error = TOOLARGE;
  59         }
  60         if (errstrp != NULL)
  61                 *errstrp = ev[error].errstr;
  62         errno = ev[error].err;
  63         if (error)
  64                 ll = 0;
  65
  66         return (ll);
  67 }