1 /* $OpenBSD: strtoll.c,v 1.8 2014/09/13 20:10:12 schwarze 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 */ 44 long long strtoll(const char * nptr,char ** endptr,int base)45 strtoll(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 * Ensure that base is between 2 and 36 inclusive, or the special 54 * value of 0. 55 */ 56 if (base < 0 || base == 1 || base > 36) { 57 if (endptr != 0) 58 *endptr = (char *)nptr; 59 errno = EINVAL; 60 return 0; 61 } 62 63 /* 64 * Skip white space and pick up leading +/- sign if any. 65 * If base is 0, allow 0x for hex and 0 for octal, else 66 * assume decimal; if base is already 16, allow 0x. 67 */ 68 s = nptr; 69 do { 70 c = (unsigned char) *s++; 71 } while (isspace(c)); 72 if (c == '-') { 73 neg = 1; 74 c = *s++; 75 } else { 76 neg = 0; 77 if (c == '+') 78 c = *s++; 79 } 80 if ((base == 0 || base == 16) && 81 c == '0' && (*s == 'x' || *s == 'X')) { 82 c = s[1]; 83 s += 2; 84 base = 16; 85 } 86 if (base == 0) 87 base = c == '0' ? 8 : 10; 88 89 /* 90 * Compute the cutoff value between legal numbers and illegal 91 * numbers. That is the largest legal value, divided by the 92 * base. An input number that is greater than this value, if 93 * followed by a legal input character, is too big. One that 94 * is equal to this value may be valid or not; the limit 95 * between valid and invalid numbers is then based on the last 96 * digit. For instance, if the range for long longs is 97 * [-9223372036854775808..9223372036854775807] and the input base 98 * is 10, cutoff will be set to 922337203685477580 and cutlim to 99 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 100 * accumulated a value > 922337203685477580, or equal but the 101 * next digit is > 7 (or 8), the number is too big, and we will 102 * return a range error. 103 * 104 * Set any if any `digits' consumed; make it negative to indicate 105 * overflow. 106 */ 107 cutoff = neg ? LLONG_MIN : LLONG_MAX; 108 cutlim = cutoff % base; 109 cutoff /= base; 110 if (neg) { 111 if (cutlim > 0) { 112 cutlim -= base; 113 cutoff += 1; 114 } 115 cutlim = -cutlim; 116 } 117 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 118 if (isdigit(c)) 119 c -= '0'; 120 else if (isalpha(c)) 121 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 122 else 123 break; 124 if (c >= base) 125 break; 126 if (any < 0) 127 continue; 128 if (neg) { 129 if (acc < cutoff || (acc == cutoff && c > cutlim)) { 130 any = -1; 131 acc = LLONG_MIN; 132 errno = ERANGE; 133 } else { 134 any = 1; 135 acc *= base; 136 acc -= c; 137 } 138 } else { 139 if (acc > cutoff || (acc == cutoff && c > cutlim)) { 140 any = -1; 141 acc = LLONG_MAX; 142 errno = ERANGE; 143 } else { 144 any = 1; 145 acc *= base; 146 acc += c; 147 } 148 } 149 } 150 if (endptr != 0) 151 *endptr = (char *) (any ? s - 1 : nptr); 152 return (acc); 153 } 154 155 __strong_alias(strtoq, strtoll); 156