freebsd-nq/usr.sbin/xntpd/lib/atouint.c
1993-12-21 18:36:48 +00:00

34 lines
589 B
C

/* atouint.c,v 3.1 1993/07/06 01:07:42 jbj Exp
* atouint - convert an ascii string to an unsigned long, with error checking
*/
#include <sys/types.h>
#include <ctype.h>
#include "ntp_types.h"
int
atouint(str, uval)
const char *str;
U_LONG *uval;
{
register U_LONG u;
register const char *cp;
cp = str;
if (*cp == '\0')
return 0;
u = 0;
while (*cp != '\0') {
if (!isdigit(*cp))
return 0;
if (u > 429496729 || (u == 429496729 && *cp >= '6'))
return 0; /* overflow */
u = (u << 3) + (u << 1);
u += *cp++ - '0'; /* ascii dependent */
}
*uval = u;
return 1;
}