strtol.c revision 140536
11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1990, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * Redistribution and use in source and binary forms, with or without 61573Srgrimes * modification, are permitted provided that the following conditions 71573Srgrimes * are met: 81573Srgrimes * 1. Redistributions of source code must retain the above copyright 91573Srgrimes * notice, this list of conditions and the following disclaimer. 101573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111573Srgrimes * notice, this list of conditions and the following disclaimer in the 121573Srgrimes * documentation and/or other materials provided with the distribution. 131573Srgrimes * 3. All advertising materials mentioning features or use of this software 141573Srgrimes * must display the following acknowledgement: 151573Srgrimes * This product includes software developed by the University of 161573Srgrimes * California, Berkeley and its contributors. 171573Srgrimes * 4. Neither the name of the University nor the names of its contributors 181573Srgrimes * may be used to endorse or promote products derived from this software 191573Srgrimes * without specific prior written permission. 201573Srgrimes * 211573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311573Srgrimes * SUCH DAMAGE. 321573Srgrimes */ 331573Srgrimes 341573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 351573Srgrimesstatic char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93"; 361573Srgrimes#endif /* LIBC_SCCS and not lint */ 3792986Sobrien#include <sys/cdefs.h> 3892986Sobrien__FBSDID("$FreeBSD: head/lib/libc/stdlib/strtol.c 140536 2005-01-21 00:42:13Z ache $"); 391573Srgrimes 401573Srgrimes#include <limits.h> 411573Srgrimes#include <ctype.h> 421573Srgrimes#include <errno.h> 431573Srgrimes#include <stdlib.h> 441573Srgrimes 451573Srgrimes 461573Srgrimes/* 471573Srgrimes * Convert a string to a long integer. 481573Srgrimes * 4982975Sache * Assumes that the upper and lower case 501573Srgrimes * alphabets and digits are each contiguous. 511573Srgrimes */ 521573Srgrimeslong 53103012Stjrstrtol(const char * __restrict nptr, char ** __restrict endptr, int base) 541573Srgrimes{ 5587016Sache const char *s; 5687016Sache unsigned long acc; 5787494Sache char c; 5887016Sache unsigned long cutoff; 5987494Sache int neg, any, cutlim; 601573Srgrimes 611573Srgrimes /* 621573Srgrimes * Skip white space and pick up leading +/- sign if any. 631573Srgrimes * If base is 0, allow 0x for hex and 0 for octal, else 641573Srgrimes * assume decimal; if base is already 16, allow 0x. 651573Srgrimes */ 6682975Sache s = nptr; 671573Srgrimes do { 681573Srgrimes c = *s++; 6987494Sache } while (isspace((unsigned char)c)); 701573Srgrimes if (c == '-') { 711573Srgrimes neg = 1; 721573Srgrimes c = *s++; 7382975Sache } else { 7482975Sache neg = 0; 7582975Sache if (c == '+') 7682975Sache c = *s++; 7782975Sache } 781573Srgrimes if ((base == 0 || base == 16) && 79140536Sache c == '0' && (*s == 'x' || *s == 'X') && 80140536Sache ((s[1] >= 'a' && s[1] <= 'f') || 81140536Sache (s[1] >= 'A' && s[1] <= 'F') || 82140536Sache (s[1] >= '0' && s[1] <= '9')) 83140536Sache ) { 841573Srgrimes c = s[1]; 851573Srgrimes s += 2; 861573Srgrimes base = 16; 871573Srgrimes } 881573Srgrimes if (base == 0) 891573Srgrimes base = c == '0' ? 8 : 10; 9082982Sache acc = any = 0; 9187023Sfenner if (base < 2 || base > 36) 9282975Sache goto noconv; 931573Srgrimes 941573Srgrimes /* 951573Srgrimes * Compute the cutoff value between legal numbers and illegal 961573Srgrimes * numbers. That is the largest legal value, divided by the 971573Srgrimes * base. An input number that is greater than this value, if 981573Srgrimes * followed by a legal input character, is too big. One that 991573Srgrimes * is equal to this value may be valid or not; the limit 1001573Srgrimes * between valid and invalid numbers is then based on the last 1011573Srgrimes * digit. For instance, if the range for longs is 1021573Srgrimes * [-2147483648..2147483647] and the input base is 10, 1031573Srgrimes * cutoff will be set to 214748364 and cutlim to either 1041573Srgrimes * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 1051573Srgrimes * a value > 214748364, or equal but the next digit is > 7 (or 8), 1061573Srgrimes * the number is too big, and we will return a range error. 1071573Srgrimes * 10882975Sache * Set 'any' if any `digits' consumed; make it negative to indicate 1091573Srgrimes * overflow. 1101573Srgrimes */ 11187016Sache cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX 11282975Sache : LONG_MAX; 11382975Sache cutlim = cutoff % base; 11482975Sache cutoff /= base; 11582982Sache for ( ; ; c = *s++) { 11687494Sache if (c >= '0' && c <= '9') 11787494Sache c -= '0'; 11887494Sache else if (c >= 'A' && c <= 'Z') 11987494Sache c -= 'A' - 10; 12087494Sache else if (c >= 'a' && c <= 'z') 12187494Sache c -= 'a' - 10; 1221573Srgrimes else 1231573Srgrimes break; 12487494Sache if (c >= base) 1251573Srgrimes break; 12687494Sache if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 1271573Srgrimes any = -1; 1281573Srgrimes else { 1291573Srgrimes any = 1; 1301573Srgrimes acc *= base; 13187494Sache acc += c; 1321573Srgrimes } 1331573Srgrimes } 1341573Srgrimes if (any < 0) { 1351573Srgrimes acc = neg ? LONG_MIN : LONG_MAX; 1361573Srgrimes errno = ERANGE; 13782975Sache } else if (!any) { 13882975Sachenoconv: 13982975Sache errno = EINVAL; 1401573Srgrimes } else if (neg) 1411573Srgrimes acc = -acc; 14282975Sache if (endptr != NULL) 1431573Srgrimes *endptr = (char *)(any ? s - 1 : nptr); 1441573Srgrimes return (acc); 1451573Srgrimes} 146