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freebsd/contrib/ntp/libntp/atouint.c
Cy Schubert 2b15cb3d09 MFV ntp 4.2.8p1 (r258945, r275970, r276091, r276092, r276093, r278284)
Thanks to roberto for providing pointers to wedge this into HEAD.

Approved by:	roberto
2015-03-30 13:30:15 +00:00

43 lines
885 B
C

#include <config.h>
#include <sys/types.h>
#include <ctype.h>
#include "ntp_types.h"
#include "ntp_stdlib.h"
/*
* atouint() - convert an ascii string representing a whole base 10
* number to u_long *uval, returning TRUE if successful.
* Does not modify *uval and returns FALSE if str is not
* a positive base10 integer or is too large for a u_int32.
* this function uses u_long but should use u_int32, and
* probably be renamed.
*/
int
atouint(
const char *str,
u_long *uval
)
{
u_long u;
const char *cp;
cp = str;
if ('\0' == *cp)
return 0;
u = 0;
while ('\0' != *cp) {
if (!isdigit((unsigned char)*cp))
return 0;
if (u > 429496729 || (u == 429496729 && *cp >= '6'))
return 0; /* overflow */
/* hand-optimized u *= 10; */
u = (u << 3) + (u << 1);
u += *cp++ - '0'; /* not '\0' */
}
*uval = u;
return 1;
}