1 /* 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)strtoul.c 8.1 (Berkeley) 6/4/93 34 * $DragonFly: src/lib/libc/stdlib/strtoul.c,v 1.3 2003/09/06 08:10:46 asmodai Exp $ 35 */ 36 37 #include <limits.h> 38 #include <ctype.h> 39 #include <errno.h> 40 #include <stdlib.h> 41 42 /* 43 * Convert a string to an unsigned long integer. 44 * 45 * Ignores `locale' stuff. Assumes that the upper and lower case 46 * alphabets and digits are each contiguous. 47 */ 48 unsigned long 49 strtoul(nptr, endptr, base) 50 const char *nptr; 51 char **endptr; 52 int base; 53 { 54 const char *s = nptr; 55 unsigned long acc; 56 unsigned char c; 57 unsigned long cutoff; 58 int neg = 0, any, cutlim; 59 60 /* 61 * See strtol for comments as to the logic used. 62 */ 63 do { 64 c = *s++; 65 } while (isspace(c)); 66 if (c == '-') { 67 neg = 1; 68 c = *s++; 69 } else if (c == '+') 70 c = *s++; 71 if ((base == 0 || base == 16) && 72 c == '0' && (*s == 'x' || *s == 'X')) { 73 c = s[1]; 74 s += 2; 75 base = 16; 76 } 77 if (base == 0) 78 base = c == '0' ? 8 : 10; 79 cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; 80 cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; 81 for (acc = 0, any = 0;; c = *s++) { 82 if (!isascii(c)) 83 break; 84 if (isdigit(c)) 85 c -= '0'; 86 else if (isalpha(c)) 87 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 88 else 89 break; 90 if (c >= base) 91 break; 92 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 93 any = -1; 94 else { 95 any = 1; 96 acc *= base; 97 acc += c; 98 } 99 } 100 if (any < 0) { 101 acc = ULONG_MAX; 102 errno = ERANGE; 103 } else if (neg) 104 acc = -acc; 105 if (endptr != 0) 106 *endptr = (char *)(any ? s - 1 : nptr); 107 return (acc); 108 } 109