1/* $OpenBSD: strtoll.c,v 1.7 2013/03/28 18:09:38 martynas Exp $ */ 2/*- 3 * Copyright (c) 1992 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31#include <sys/types.h> 32 33#include <ctype.h> 34#include <errno.h> 35#include <limits.h> 36#include <stdlib.h> 37 38/* 39 * Convert a string to a long long. 40 * 41 * Ignores `locale' stuff. Assumes that the upper and lower case 42 * alphabets and digits are each contiguous. 43 */ 44long long 45strtoll(const char *nptr, char **endptr, int base) 46{ 47 const char *s; 48 long long acc, cutoff; 49 int c; 50 int neg, any, cutlim; 51 52 /* 53 * Skip white space and pick up leading +/- sign if any. 54 * If base is 0, allow 0x for hex and 0 for octal, else 55 * assume decimal; if base is already 16, allow 0x. 56 */ 57 s = nptr; 58 do { 59 c = (unsigned char) *s++; 60 } while (isspace(c)); 61 if (c == '-') { 62 neg = 1; 63 c = *s++; 64 } else { 65 neg = 0; 66 if (c == '+') 67 c = *s++; 68 } 69 if ((base == 0 || base == 16) && 70 c == '0' && (*s == 'x' || *s == 'X')) { 71 c = s[1]; 72 s += 2; 73 base = 16; 74 } 75 if (base == 0) 76 base = c == '0' ? 8 : 10; 77 78 /* 79 * Compute the cutoff value between legal numbers and illegal 80 * numbers. That is the largest legal value, divided by the 81 * base. An input number that is greater than this value, if 82 * followed by a legal input character, is too big. One that 83 * is equal to this value may be valid or not; the limit 84 * between valid and invalid numbers is then based on the last 85 * digit. For instance, if the range for long longs is 86 * [-9223372036854775808..9223372036854775807] and the input base 87 * is 10, cutoff will be set to 922337203685477580 and cutlim to 88 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 89 * accumulated a value > 922337203685477580, or equal but the 90 * next digit is > 7 (or 8), the number is too big, and we will 91 * return a range error. 92 * 93 * Set any if any `digits' consumed; make it negative to indicate 94 * overflow. 95 */ 96 cutoff = neg ? LLONG_MIN : LLONG_MAX; 97 cutlim = cutoff % base; 98 cutoff /= base; 99 if (neg) { 100 if (cutlim > 0) { 101 cutlim -= base; 102 cutoff += 1; 103 } 104 cutlim = -cutlim; 105 } 106 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 107 if (isdigit(c)) 108 c -= '0'; 109 else if (isalpha(c)) 110 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 111 else 112 break; 113 if (c >= base) 114 break; 115 if (any < 0) 116 continue; 117 if (neg) { 118 if (acc < cutoff || (acc == cutoff && c > cutlim)) { 119 any = -1; 120 acc = LLONG_MIN; 121 errno = ERANGE; 122 } else { 123 any = 1; 124 acc *= base; 125 acc -= c; 126 } 127 } else { 128 if (acc > cutoff || (acc == cutoff && c > cutlim)) { 129 any = -1; 130 acc = LLONG_MAX; 131 errno = ERANGE; 132 } else { 133 any = 1; 134 acc *= base; 135 acc += c; 136 } 137 } 138 } 139 if (endptr != 0) 140 *endptr = (char *) (any ? s - 1 : nptr); 141 return (acc); 142} 143 144__strong_alias(strtoq, strtoll); 145