/* * hextoint - convert an ascii string in hex to an unsigned * long, with error checking */ #include #include "ntp_stdlib.h" int hextoint( const char *str, u_long *ival ) { register u_long u; register const char *cp; cp = str; if (*cp == '\0') return 0; u = 0; while (*cp != '\0') { if (!isxdigit((int)*cp)) return 0; if (u >= 0x10000000) return 0; /* overflow */ u <<= 4; if (*cp <= '9') /* very ascii dependent */ u += *cp++ - '0'; else if (*cp >= 'a') u += *cp++ - 'a' + 10; else u += *cp++ - 'A' + 10; } *ival = u; return 1; }