usr.bin/sdiff/strtonum.c

   1 /*      $NetBSD$        */
   2 /*      $OpenBSD: strtonum.c,v 1.6 2004/08/03 19:38:01 millert Exp $    */
   3
   4 /*
   5  * Copyright (c) 2004 Ted Unangst and Todd Miller
   6  * All rights reserved.
   7  *
   8  * Permission to use, copy, modify, and distribute this software for any
   9  * purpose with or without fee is hereby granted, provided that the above
  10  * copyright notice and this permission notice appear in all copies.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  19  */
  20
  21 #include <errno.h>
  22 #include <limits.h>
  23 #include <stdlib.h>
  24
  25 #include "common.h"
  26
  27 #define INVALID         1
  28 #define TOOSMALL        2
  29 #define TOOLARGE        3
  30
  31 long long
  32 strtonum(const char *numstr, long long minval, long long maxval,
  33     const char **errstrp)
  34 {
  35         long long ll = 0;
  36         char *ep;
  37         int error = 0;
  38         struct errval {
  39                 const char *errstr;
  40                 int err;
  41         } ev[4] = {
  42                 { NULL,         0 },
  43                 { "invalid",    EINVAL },
  44                 { "too small",  ERANGE },
  45                 { "too large",  ERANGE },
  46         };
  47
  48         ev[0].err = errno;
  49         errno = 0;
  50         if (minval > maxval)
  51                 error = INVALID;
  52         else {
  53                 ll = strtoll(numstr, &ep, 10);
  54                 if (numstr == ep || *ep != '\0')
  55                         error = INVALID;
  56                 else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)
  57                         error = TOOSMALL;
  58                 else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)
  59                         error = TOOLARGE;
  60         }
  61         if (errstrp != NULL)
  62                 *errstrp = ev[error].errstr;
  63         errno = ev[error].err;
  64         if (error)
  65                 ll = 0;
  66
  67         return (ll);
  68 }