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 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #ifndef lint 39 static const char rcsid[] = 40 "$FreeBSD$"; 41 #endif 42 43 #include <limits.h> 44 #include <ctype.h> 45 #include <errno.h> 46 #include <stdlib.h> 47 48 /* 49 * Convert a string to an unsigned long integer. 50 * 51 * Assumes that the upper and lower case 52 * alphabets and digits are each contiguous. 53 */ 54 unsigned long 55 strtoul(nptr, endptr, base) 56 const char *nptr; 57 char **endptr; 58 register int base; 59 { 60 register const char *s; 61 register unsigned long acc; 62 register unsigned char c; 63 register unsigned long cutoff; 64 register int neg, any, cutlim; 65 66 /* 67 * See strtol for comments as to the logic used. 68 */ 69 s = nptr; 70 do { 71 c = *s++; 72 } while (isspace(c)); 73 if (c == '-') { 74 neg = 1; 75 c = *s++; 76 } else { 77 neg = 0; 78 if (c == '+') 79 c = *s++; 80 } 81 if ((base == 0 || base == 16) && 82 c == '0' && (*s == 'x' || *s == 'X')) { 83 c = s[1]; 84 s += 2; 85 base = 16; 86 } 87 if (base == 0) 88 base = c == '0' ? 8 : 10; 89 acc = any = 0; 90 if (base < 2 || base > 36) 91 goto noconv; 92 93 cutoff = ULONG_MAX / base; 94 cutlim = ULONG_MAX % base; 95 for ( ; ; c = *s++) { 96 if (!isascii(c)) 97 break; 98 if (isdigit(c)) 99 c -= '0'; 100 else if (isalpha(c)) 101 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 102 else 103 break; 104 if (c >= base) 105 break; 106 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 107 any = -1; 108 else { 109 any = 1; 110 acc *= base; 111 acc += c; 112 } 113 } 114 if (any < 0) { 115 acc = ULONG_MAX; 116 errno = ERANGE; 117 } else if (!any) { 118 noconv: 119 errno = EINVAL; 120 } else if (neg) 121 acc = -acc; 122 if (endptr != NULL) 123 *endptr = (char *)(any ? s - 1 : nptr); 124 return (acc); 125 } 126