49 lines
794 B
C
49 lines
794 B
C
/* atoint.c,v 3.1 1993/07/06 01:07:39 jbj Exp
|
|
* atoint - convert an ascii string to a signed long, with error checking
|
|
*/
|
|
#include <sys/types.h>
|
|
#include <ctype.h>
|
|
|
|
#include "ntp_types.h"
|
|
|
|
int
|
|
atoint(str, ival)
|
|
const char *str;
|
|
LONG *ival;
|
|
{
|
|
register U_LONG u;
|
|
register const char *cp;
|
|
register int isneg;
|
|
register int oflow_digit;
|
|
|
|
cp = str;
|
|
|
|
if (*cp == '-') {
|
|
cp++;
|
|
isneg = 1;
|
|
oflow_digit = '8';
|
|
} else {
|
|
isneg = 0;
|
|
oflow_digit = '7';
|
|
}
|
|
|
|
if (*cp == '\0')
|
|
return 0;
|
|
|
|
u = 0;
|
|
while (*cp != '\0') {
|
|
if (!isdigit(*cp))
|
|
return 0;
|
|
if (u > 214748364 || (u == 214748364 && *cp > oflow_digit))
|
|
return 0; /* overflow */
|
|
u = (u << 3) + (u << 1);
|
|
u += *cp++ - '0'; /* ascii dependent */
|
|
}
|
|
|
|
if (isneg)
|
|
*ival = -((LONG)u);
|
|
else
|
|
*ival = (LONG)u;
|
|
return 1;
|
|
}
|