wmii/libcext/strtonum.c

66 lines
1.6 KiB
C

/*
* Copyright (c) 2004 Ted Unangst and Todd Miller
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
enum {
INVALID = 1,
TOOSMALL = 2,
TOOLARGE = 3
};
long long
cext_strtonum(const char *numstr, long long minval, long long maxval,
const char **errstrp)
{
long long ll = 0;
char *ep;
int error = 0;
struct errval {
const char *errstr;
int err;
} ev[4] = {
{NULL, 0},
{"invalid", EINVAL},
{"too small", ERANGE},
{"too large", ERANGE},
};
ev[0].err = errno;
errno = 0;
if(minval > maxval)
error = INVALID;
else {
ll = strtoll(numstr, &ep, 10);
if(numstr == ep || *ep != 0)
error = INVALID;
else if(errno == ERANGE || ll < minval)
error = TOOSMALL;
else if(errno == ERANGE || ll > maxval)
error = TOOLARGE;
}
if(errstrp != NULL)
*errstrp = ev[error].errstr;
errno = ev[error].err;
if(error)
ll = 0;
return (ll);
}