/*

 * atoint - convert an ascii string to a signed long, with error checking

 */

#include <config.h>

#include <sys/types.h>

#include <ctype.h>

#include "ntp_types.h"

#include "ntp_stdlib.h"

int

atoint(

  const char *str,

  long *ival

  )

{

  register 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((unsigned char)*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 = -u;

  else 

      *ival = u;

  return 1;

}