usr/src/lib/libc/port/gen/strtonum.c

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