#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#define INVALID 1
#define TOOSMALL 2
#define TOOLARGE 3
long long
strtonum(const char *numstr, long long minval, long long maxval,
const char **errstrp)
{
long long ll = 0;
int error = 0;
char *ep;
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 (errno == EINVAL || numstr == ep || *ep != '\0')
error = INVALID;
else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)
error = TOOSMALL;
else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)
error = TOOLARGE;
}
if (errstrp != NULL)
*errstrp = ev[error].errstr;
errno = ev[error].err;
if (error)
ll = 0;
return (ll);
}