1 /* 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Copyright (c) 2011 The FreeBSD Foundation 6 * All rights reserved. 7 * Portions of this software were developed by David Chisnall 8 * under sponsorship from the FreeBSD Foundation. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)strtoul.c 8.1 (Berkeley) 6/4/93 35 * $FreeBSD: head/lib/libstand/strtoul.c 247001 2013-02-19 17:09:23Z kientzle $ 36 */ 37 38 #include "stand.h" 39 #include <limits.h> 40 41 /* 42 * Convert a string to an unsigned long integer. 43 * 44 * Assumes that the upper and lower case 45 * alphabets and digits are each contiguous. 46 */ 47 unsigned long 48 strtoul(const char * __restrict nptr, char ** __restrict endptr, int base) 49 { 50 const char *s; 51 unsigned long acc; 52 char c; 53 unsigned long cutoff; 54 int neg, any, cutlim; 55 56 /* 57 * See strtol for comments as to the logic used. 58 */ 59 s = nptr; 60 do { 61 c = *s++; 62 } while (isspace((unsigned char)c)); 63 if (c == '-') { 64 neg = 1; 65 c = *s++; 66 } else { 67 neg = 0; 68 if (c == '+') 69 c = *s++; 70 } 71 if ((base == 0 || base == 16) && 72 c == '0' && (*s == 'x' || *s == 'X') && 73 ((s[1] >= '0' && s[1] <= '9') || 74 (s[1] >= 'A' && s[1] <= 'F') || 75 (s[1] >= 'a' && s[1] <= 'f'))) { 76 c = s[1]; 77 s += 2; 78 base = 16; 79 } 80 if (base == 0) 81 base = c == '0' ? 8 : 10; 82 acc = any = 0; 83 if (base < 2 || base > 36) 84 goto noconv; 85 86 cutoff = ULONG_MAX / base; 87 cutlim = ULONG_MAX % base; 88 for ( ; ; c = *s++) { 89 if (c >= '0' && c <= '9') 90 c -= '0'; 91 else if (c >= 'A' && c <= 'Z') 92 c -= 'A' - 10; 93 else if (c >= 'a' && c <= 'z') 94 c -= 'a' - 10; 95 else 96 break; 97 if (c >= base) 98 break; 99 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 100 any = -1; 101 else { 102 any = 1; 103 acc *= base; 104 acc += c; 105 } 106 } 107 if (any < 0) { 108 acc = ULONG_MAX; 109 errno = ERANGE; 110 } else if (!any) { 111 noconv: 112 errno = EINVAL; 113 } else if (neg) 114 acc = -acc; 115 if (endptr != NULL) 116 *endptr = (char *)(any ? s - 1 : nptr); 117 return (acc); 118 } 119