1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * From: static char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93"; 37 * 38 * $FreeBSD: src/sys/libkern/strtoul.c,v 1.3 1999/12/01 22:56:51 archie Exp $ 39 * $DragonFly: src/sys/libkern/strtoul.c,v 1.3 2004/01/26 11:09:44 joerg Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/ctype.h> 45 #include <machine/limits.h> 46 47 /* 48 * Convert a string to an unsigned long integer. 49 * 50 * Ignores `locale' stuff. Assumes that the upper and lower case 51 * alphabets and digits are each contiguous. 52 */ 53 unsigned long 54 strtoul(const char *nptr, char **endptr, int base) 55 { 56 const char *s = nptr; 57 unsigned long acc; 58 unsigned char c; 59 unsigned long cutoff; 60 int neg = 0, any, cutlim; 61 62 /* 63 * See strtol for comments as to the logic used. 64 */ 65 do { 66 c = *s++; 67 } while (isspace(c)); 68 if (c == '-') { 69 neg = 1; 70 c = *s++; 71 } else if (c == '+') 72 c = *s++; 73 if ((base == 0 || base == 16) && 74 c == '0' && (*s == 'x' || *s == 'X')) { 75 c = s[1]; 76 s += 2; 77 base = 16; 78 } 79 if (base == 0) 80 base = c == '0' ? 8 : 10; 81 cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; 82 cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; 83 for (acc = 0, any = 0;; c = *s++) { 84 if (!isascii(c)) 85 break; 86 if (isdigit(c)) 87 c -= '0'; 88 else if (isalpha(c)) 89 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 90 else 91 break; 92 if (c >= base) 93 break; 94 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 95 any = -1; 96 else { 97 any = 1; 98 acc *= base; 99 acc += c; 100 } 101 } 102 if (any < 0) { 103 acc = ULONG_MAX; 104 } else if (neg) 105 acc = -acc; 106 if (endptr != 0) 107 *((const char **)endptr) = any ? s - 1 : nptr; 108 return (acc); 109 } 110