1 /* 2 * Copyright (c) 1990 Regents of the University of California. 3 * 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 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char *rcsid = "$OpenBSD: strtoul.c,v 1.4 1996/08/19 08:33:52 tholo Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <ctype.h> 39 #include <errno.h> 40 #include <limits.h> 41 #include <stdlib.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 register int base; 54 { 55 register const char *s; 56 register unsigned long acc, cutoff; 57 register int c; 58 register int neg, any, cutlim; 59 60 /* 61 * See strtol for comments as to the logic used. 62 */ 63 s = nptr; 64 do { 65 c = (unsigned char) *s++; 66 } while (isspace(c)); 67 if (c == '-') { 68 neg = 1; 69 c = *s++; 70 } else { 71 neg = 0; 72 if (c == '+') 73 c = *s++; 74 } 75 if ((base == 0 || base == 16) && 76 c == '0' && (*s == 'x' || *s == 'X')) { 77 c = s[1]; 78 s += 2; 79 base = 16; 80 } 81 if (base == 0) 82 base = c == '0' ? 8 : 10; 83 84 cutoff = ULONG_MAX / (unsigned long)base; 85 cutlim = ULONG_MAX % (unsigned long)base; 86 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 87 if (isdigit(c)) 88 c -= '0'; 89 else if (isalpha(c)) 90 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 91 else 92 break; 93 if (c >= base) 94 break; 95 if (any < 0) 96 continue; 97 if (acc > cutoff || acc == cutoff && c > cutlim) { 98 any = -1; 99 acc = ULONG_MAX; 100 errno = ERANGE; 101 } else { 102 any = 1; 103 acc *= (unsigned long)base; 104 acc += c; 105 } 106 } 107 if (neg && any > 0) 108 acc = -acc; 109 if (endptr != 0) 110 *endptr = (char *) (any ? s - 1 : nptr); 111 return (acc); 112 } 113