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/*
* strtoul.c --
*
* Source code for the "strtoul" library procedure.
*
* Copyright (c) 1988 The Regents of the University of California.
* Copyright (c) 1994 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*/
#include "tclInt.h"
/*
* The table below is used to convert from ASCII digits to a numerical
* equivalent. It maps from '0' through 'z' to integers (100 for non-digit
* characters).
*/
static const char cvtIn[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* '0' - '9' */
100, 100, 100, 100, 100, 100, 100, /* punctuation */
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'A' - 'Z' */
20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
30, 31, 32, 33, 34, 35,
100, 100, 100, 100, 100, 100, /* punctuation */
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'a' - 'z' */
20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
30, 31, 32, 33, 34, 35};
/*
*----------------------------------------------------------------------
*
* strtoul --
*
* Convert an ASCII string into an integer.
*
* Results:
* The return value is the integer equivalent of string. If endPtr is
* non-NULL, then *endPtr is filled in with the character after the last
* one that was part of the integer. If string doesn't contain a valid
* integer value, then zero is returned and *endPtr is set to string.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
unsigned long int
strtoul(
const char *string, /* String of ASCII digits, possibly preceded
* by white space. For bases greater than 10,
* either lower- or upper-case digits may be
* used. */
char **endPtr, /* Where to store address of terminating
* character, or NULL. */
int base) /* Base for conversion. Must be less than 37.
* If 0, then the base is chosen from the
* leading characters of string: "0x" means
* hex, "0" means octal, anything else means
* decimal. */
{
const char *p;
unsigned long int result = 0;
unsigned digit;
int anyDigits = 0;
int negative=0;
int overflow=0;
/*
* Skip any leading blanks.
*/
p = string;
while (isspace(UCHAR(*p))) {
p += 1;
}
if (*p == '-') {
negative = 1;
p += 1;
} else {
if (*p == '+') {
p += 1;
}
}
/*
* If no base was provided, pick one from the leading characters of the
* string.
*/
if (base == 0) {
if (*p == '0') {
p += 1;
if ((*p == 'x') || (*p == 'X')) {
p += 1;
base = 16;
} else {
/*
* Must set anyDigits here, otherwise "0" produces a "no
* digits" error.
*/
anyDigits = 1;
base = 8;
}
} else {
base = 10;
}
} else if (base == 16) {
/*
* Skip a leading "0x" from hex numbers.
*/
if ((p[0] == '0') && ((p[1] == 'x') || (p[1] == 'X'))) {
p += 2;
}
}
/*
* Sorry this code is so messy, but speed seems important. Do different
* things for base 8, 10, 16, and other.
*/
if (base == 8) {
unsigned long maxres = ULONG_MAX >> 3;
for ( ; ; p += 1) {
digit = *p - '0';
if (digit > 7) {
break;
}
if (result > maxres) { overflow = 1; }
result = (result << 3);
if (digit > (ULONG_MAX - result)) { overflow = 1; }
result += digit;
anyDigits = 1;
}
} else if (base == 10) {
unsigned long maxres = ULONG_MAX / 10;
for ( ; ; p += 1) {
digit = *p - '0';
if (digit > 9) {
break;
}
if (result > maxres) { overflow = 1; }
result *= 10;
if (digit > (ULONG_MAX - result)) { overflow = 1; }
result += digit;
anyDigits = 1;
}
} else if (base == 16) {
unsigned long maxres = ULONG_MAX >> 4;
for ( ; ; p += 1) {
digit = *p - '0';
if (digit > ('z' - '0')) {
break;
}
digit = cvtIn[digit];
if (digit > 15) {
break;
}
if (result > maxres) { overflow = 1; }
result = (result << 4);
if (digit > (ULONG_MAX - result)) { overflow = 1; }
result += digit;
anyDigits = 1;
}
} else if (base >= 2 && base <= 36) {
unsigned long maxres = ULONG_MAX / base;
for ( ; ; p += 1) {
digit = *p - '0';
if (digit > ('z' - '0')) {
break;
}
digit = cvtIn[digit];
if (digit >= ( (unsigned) base )) {
break;
}
if (result > maxres) { overflow = 1; }
result *= base;
if (digit > (ULONG_MAX - result)) { overflow = 1; }
result += digit;
anyDigits = 1;
}
}
/*
* See if there were any digits at all.
*/
if (!anyDigits) {
p = string;
}
if (endPtr != 0) {
/* unsafe, but required by the strtoul prototype */
*endPtr = (char *) p;
}
if (overflow) {
errno = ERANGE;
return ULONG_MAX;
}
if (negative) {
return -result;
}
return result;
}
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