/* * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands. * See the copyright notice in the ACK home directory, in the file "Copyright". */ /* $Id$ */ #include #include #include #include static unsigned long string2long(register const char *nptr, char **endptr, int base, int is_signed); long int strtol(register const char *nptr, char **endptr, int base) { return (signed long)string2long(nptr, endptr, base, 1); } unsigned long int strtoul(register const char *nptr, char **endptr, int base) { return (unsigned long)string2long(nptr, endptr, base, 0); } static unsigned long string2long(register const char *nptr, char ** const endptr, int base, int is_signed) { register unsigned int v; register unsigned long val = 0; register int c; int ovfl = 0, sign = 1; const char *startnptr = nptr, *nrstart; if (endptr) *endptr = (char *)nptr; while (isspace(*nptr)) nptr++; c = *nptr; if (c == '-' || c == '+') { if (c == '-') sign = -1; nptr++; } nrstart = nptr; /* start of the number */ /* When base is 0, the syntax determines the actual base */ if (base == 0) if (*nptr == '0') if (*++nptr == 'x' || *nptr == 'X') { base = 16; nptr++; } else base = 8; else base = 10; else if (base==16 && *nptr=='0' && (*++nptr =='x' || *nptr =='X')) nptr++; while (isdigit(c = *nptr) || isalpha(c)) { if (!ovfl) { if (isalpha(c)) v = 10 + (isupper(c) ? c - 'A' : c - 'a'); else v = c - '0'; if (v >= base) break; if (val > (ULONG_MAX - v) / base) ++ovfl; else val = (val * base) + v; } nptr++; } if (endptr) { if (nrstart == nptr) *endptr = (char *)startnptr; else *endptr = (char *)nptr; } if (!ovfl) { /* Overflow is only possible when converting a signed long. * The "-(LONG_MIN+1)+(unsigned long) 1" construction is there * to prevent overflow warnings on -LONG_MIN. */ if (is_signed && ( (sign < 0 && val > -(LONG_MIN+1)+(unsigned long) 1) || (sign > 0 && val > LONG_MAX))) ovfl++; } if (ovfl) { errno = ERANGE; if (is_signed) if (sign < 0) return LONG_MIN; else return LONG_MAX; else return ULONG_MAX; } return (sign * val); }