1 /* OPENBSD ORIGINAL: lib/libc/stdlib/strtoul.c */ 2 3 /* 4 * Copyright (c) 1990 Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include "includes.h" 33 #ifndef HAVE_STRTOUL 34 35 #if defined(LIBC_SCCS) && !defined(lint) 36 static char *rcsid = "$OpenBSD: strtoul.c,v 1.5 2003/06/02 20:18:38 millert Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <ctype.h> 40 #include <errno.h> 41 #include <limits.h> 42 #include <stdlib.h> 43 44 /* 45 * Convert a string to an unsigned long integer. 46 * 47 * Ignores `locale' stuff. Assumes that the upper and lower case 48 * alphabets and digits are each contiguous. 49 */ 50 unsigned long 51 strtoul(nptr, endptr, base) 52 const char *nptr; 53 char **endptr; 54 register int base; 55 { 56 register const char *s; 57 register unsigned long acc, cutoff; 58 register int c; 59 register int neg, any, cutlim; 60 61 /* 62 * See strtol for comments as to the logic used. 63 */ 64 s = nptr; 65 do { 66 c = (unsigned char) *s++; 67 } while (isspace(c)); 68 if (c == '-') { 69 neg = 1; 70 c = *s++; 71 } else { 72 neg = 0; 73 if (c == '+') 74 c = *s++; 75 } 76 if ((base == 0 || base == 16) && 77 c == '0' && (*s == 'x' || *s == 'X')) { 78 c = s[1]; 79 s += 2; 80 base = 16; 81 } 82 if (base == 0) 83 base = c == '0' ? 8 : 10; 84 85 cutoff = ULONG_MAX / (unsigned long)base; 86 cutlim = ULONG_MAX % (unsigned long)base; 87 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 88 if (isdigit(c)) 89 c -= '0'; 90 else if (isalpha(c)) 91 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 92 else 93 break; 94 if (c >= base) 95 break; 96 if (any < 0) 97 continue; 98 if (acc > cutoff || acc == cutoff && c > cutlim) { 99 any = -1; 100 acc = ULONG_MAX; 101 errno = ERANGE; 102 } else { 103 any = 1; 104 acc *= (unsigned long)base; 105 acc += c; 106 } 107 } 108 if (neg && any > 0) 109 acc = -acc; 110 if (endptr != 0) 111 *endptr = (char *) (any ? s - 1 : nptr); 112 return (acc); 113 } 114 #endif /* !HAVE_STRTOUL */ 115