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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * From: @(#)strtoul.c 8.1 (Berkeley) 6/4/93 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/ctype.h> 41 #include <sys/limits.h> 42 43 /* 44 * Convert a string to an unsigned long integer. 45 * 46 * Ignores `locale' stuff. Assumes that the upper and lower case 47 * alphabets and digits are each contiguous. 48 */ 49 unsigned long 50 strtoul(nptr, endptr, base) 51 const char *nptr; 52 char **endptr; 53 int base; 54 { 55 const char *s = nptr; 56 unsigned long acc; 57 unsigned char c; 58 unsigned long cutoff; 59 int neg = 0, any, cutlim; 60 61 /* 62 * See strtol for comments as to the logic used. 63 */ 64 do { 65 c = *s++; 66 } while (isspace(c)); 67 if (c == '-') { 68 neg = 1; 69 c = *s++; 70 } else if (c == '+') 71 c = *s++; 72 if ((base == 0 || base == 16) && 73 c == '0' && (*s == 'x' || *s == 'X')) { 74 c = s[1]; 75 s += 2; 76 base = 16; 77 } 78 if (base == 0) 79 base = c == '0' ? 8 : 10; 80 cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; 81 cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; 82 for (acc = 0, any = 0;; c = *s++) { 83 if (!isascii(c)) 84 break; 85 if (isdigit(c)) 86 c -= '0'; 87 else if (isalpha(c)) 88 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 89 else 90 break; 91 if (c >= base) 92 break; 93 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 94 any = -1; 95 else { 96 any = 1; 97 acc *= base; 98 acc += c; 99 } 100 } 101 if (any < 0) { 102 acc = ULONG_MAX; 103 } else if (neg) 104 acc = -acc; 105 if (endptr != NULL) 106 *endptr = __DECONST(char *, any ? s - 1 : nptr); 107 return (acc); 108 } 109