strtoul.c revision 53648
152845Sphk/*- 252845Sphk * Copyright (c) 1990, 1993 352845Sphk * The Regents of the University of California. All rights reserved. 452845Sphk * 552845Sphk * This code is derived from software contributed to Berkeley by 652845Sphk * Chris Torek. 752845Sphk * 852845Sphk * Redistribution and use in source and binary forms, with or without 952845Sphk * modification, are permitted provided that the following conditions 1052845Sphk * are met: 1152845Sphk * 1. Redistributions of source code must retain the above copyright 1252845Sphk * notice, this list of conditions and the following disclaimer. 1352845Sphk * 2. Redistributions in binary form must reproduce the above copyright 1452845Sphk * notice, this list of conditions and the following disclaimer in the 1552845Sphk * documentation and/or other materials provided with the distribution. 1652845Sphk * 3. All advertising materials mentioning features or use of this software 1752845Sphk * must display the following acknowledgement: 1852845Sphk * This product includes software developed by the University of 1952845Sphk * California, Berkeley and its contributors. 2052845Sphk * 4. Neither the name of the University nor the names of its contributors 2152845Sphk * may be used to endorse or promote products derived from this software 2252845Sphk * without specific prior written permission. 2352845Sphk * 2452845Sphk * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2552845Sphk * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2652845Sphk * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2752845Sphk * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2852845Sphk * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2952845Sphk * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3052845Sphk * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3152845Sphk * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3252845Sphk * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3352845Sphk * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3452845Sphk * SUCH DAMAGE. 3552845Sphk * 3652845Sphk * From: static char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93"; 3752845Sphk * 3852845Sphk * $FreeBSD: head/sys/libkern/strtoul.c 53648 1999-11-24 01:03:08Z archie $ 3952845Sphk */ 4052845Sphk 4152845Sphk#include <sys/param.h> 4252845Sphk#include <sys/systm.h> 4352845Sphk#include <sys/ctype.h> 4452845Sphk#include <machine/limits.h> 4552845Sphk 4652845Sphk/* 4752845Sphk * Convert a string to an unsigned long integer. 4852845Sphk * 4952845Sphk * Ignores `locale' stuff. Assumes that the upper and lower case 5052845Sphk * alphabets and digits are each contiguous. 5152845Sphk */ 5252845Sphkunsigned long 5352845Sphkstrtoul(nptr, endptr, base) 5452845Sphk const char *nptr; 5553648Sarchie char **endptr; 5652845Sphk int base; 5752845Sphk{ 5852845Sphk const char *s = nptr; 5952845Sphk unsigned long acc; 6052845Sphk unsigned char c; 6152845Sphk unsigned long cutoff; 6252845Sphk int neg = 0, any, cutlim; 6352845Sphk 6452845Sphk /* 6552845Sphk * See strtol for comments as to the logic used. 6652845Sphk */ 6752845Sphk do { 6852845Sphk c = *s++; 6952845Sphk } while (isspace(c)); 7052845Sphk if (c == '-') { 7152845Sphk neg = 1; 7252845Sphk c = *s++; 7352845Sphk } else if (c == '+') 7452845Sphk c = *s++; 7552845Sphk if ((base == 0 || base == 16) && 7652845Sphk c == '0' && (*s == 'x' || *s == 'X')) { 7752845Sphk c = s[1]; 7852845Sphk s += 2; 7952845Sphk base = 16; 8052845Sphk } 8152845Sphk if (base == 0) 8252845Sphk base = c == '0' ? 8 : 10; 8352845Sphk cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; 8452845Sphk cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; 8552845Sphk for (acc = 0, any = 0;; c = *s++) { 8652845Sphk if (!isascii(c)) 8752845Sphk break; 8852845Sphk if (isdigit(c)) 8952845Sphk c -= '0'; 9052845Sphk else if (isalpha(c)) 9152845Sphk c -= isupper(c) ? 'A' - 10 : 'a' - 10; 9252845Sphk else 9352845Sphk break; 9452845Sphk if (c >= base) 9552845Sphk break; 9652845Sphk if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 9752845Sphk any = -1; 9852845Sphk else { 9952845Sphk any = 1; 10052845Sphk acc *= base; 10152845Sphk acc += c; 10252845Sphk } 10352845Sphk } 10452845Sphk if (any < 0) { 10552845Sphk acc = ULONG_MAX; 10652845Sphk } else if (neg) 10752845Sphk acc = -acc; 10852845Sphk if (endptr != 0) 10953648Sarchie *endptr = (char *)(any ? s - 1 : nptr); 11052845Sphk return (acc); 11152845Sphk} 112