/contrib/ntp/libntp/atouint.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 35 lines · 27 code · 5 blank · 3 comment · 9 complexity · ac32de88587f9ac542487850b30321ac MD5 · raw file
- /*
- * atouint - convert an ascii string to an unsigned long, with error checking
- */
- #include <sys/types.h>
- #include <ctype.h>
- #include "ntp_types.h"
- #include "ntp_stdlib.h"
- int
- atouint(
- 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((int)*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;
- }