1/* $NetBSD$ */ 2 3/*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include "config.h" 37 38#if defined(LIBC_SCCS) && !defined(lint) 39static const char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93"; 40#endif /* LIBC_SCCS and not lint */ 41 42#include <limits.h> 43#include <ctype.h> 44#include <errno.h> 45#include <stdlib.h> 46 47/* 48 * Convert a string to a long integer. 49 * 50 * Ignores `locale' stuff. Assumes that the upper and lower case 51 * alphabets and digits are each contiguous. 52 * 53 * PUBLIC: #ifndef HAVE_STRTOL 54 * PUBLIC: long strtol __P((const char *, char **, int)); 55 * PUBLIC: #endif 56 */ 57long 58strtol(const char *nptr, char **endptr, register int base) 59{ 60 register const char *s = nptr; 61 register unsigned long acc; 62 register int c; 63 register unsigned long cutoff; 64 register int neg = 0, any, cutlim; 65 66 /* 67 * Skip white space and pick up leading +/- sign if any. 68 * If base is 0, allow 0x for hex and 0 for octal, else 69 * assume decimal; if base is already 16, allow 0x. 70 */ 71 do { 72 c = *s++; 73 } while (isspace(c)); 74 if (c == '-') { 75 neg = 1; 76 c = *s++; 77 } else if (c == '+') 78 c = *s++; 79 if ((base == 0 || base == 16) && 80 c == '0' && (*s == 'x' || *s == 'X')) { 81 c = s[1]; 82 s += 2; 83 base = 16; 84 } 85 if (base == 0) 86 base = c == '0' ? 8 : 10; 87 88 /* 89 * Compute the cutoff value between legal numbers and illegal 90 * numbers. That is the largest legal value, divided by the 91 * base. An input number that is greater than this value, if 92 * followed by a legal input character, is too big. One that 93 * is equal to this value may be valid or not; the limit 94 * between valid and invalid numbers is then based on the last 95 * digit. For instance, if the range for longs is 96 * [-2147483648..2147483647] and the input base is 10, 97 * cutoff will be set to 214748364 and cutlim to either 98 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 99 * a value > 214748364, or equal but the next digit is > 7 (or 8), 100 * the number is too big, and we will return a range error. 101 * 102 * Set any if any `digits' consumed; make it negative to indicate 103 * overflow. 104 */ 105 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX; 106 cutlim = cutoff % (unsigned long)base; 107 cutoff /= (unsigned long)base; 108 for (acc = 0, any = 0;; c = *s++) { 109 if (isdigit(c)) 110 c -= '0'; 111 else if (isalpha(c)) 112 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 113 else 114 break; 115 if (c >= base) 116 break; 117 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) 118 any = -1; 119 else { 120 any = 1; 121 acc *= base; 122 acc += c; 123 } 124 } 125 if (any < 0) { 126 acc = neg ? LONG_MIN : LONG_MAX; 127 errno = ERANGE; 128 } else if (neg) 129 acc = -acc; 130 if (endptr != 0) 131 *endptr = (char *)(any ? s - 1 : nptr); 132 return (acc); 133} 134