strtoq.c revision 28640
1139823Simp/*- 21541Srgrimes * Copyright (c) 1992, 1993 3180305Srwatson * The Regents of the University of California. All rights reserved. 4180305Srwatson * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3150477Speter * SUCH DAMAGE. 321541Srgrimes */ 331541Srgrimes 341541Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 3596972Stanimurastatic char sccsid[] = "@(#)strtoq.c 8.1 (Berkeley) 6/4/93"; 36130387Srwatson#endif /* LIBC_SCCS and not lint */ 37180390Srwatson 3829024Sbde#include <sys/types.h> 39130387Srwatson 4096972Stanimura#include <limits.h> 411541Srgrimes#include <errno.h> 421541Srgrimes#include <ctype.h> 43180390Srwatson#include <stdlib.h> 4497093Sbde 451541Srgrimes/* 46183550Szec * Convert a string to a quad integer. 471541Srgrimes * 48185571Sbz * Ignores `locale' stuff. Assumes that the upper and lower case 491541Srgrimes * alphabets and digits are each contiguous. 501541Srgrimes */ 518876Srgrimesquad_t 521541Srgrimesstrtoq(nptr, endptr, base) 531541Srgrimes const char *nptr; 541541Srgrimes char **endptr; 551541Srgrimes register int base; 561541Srgrimes{ 571541Srgrimes register const char *s; 581541Srgrimes register u_quad_t acc; 59130514Srwatson register unsigned char c; 60195699Srwatson register u_quad_t qbase, cutoff; 6124936Sphk register int neg, any, cutlim; 62227309Sed 63227309Sed /* 641541Srgrimes * Skip white space and pick up leading +/- sign if any. 65180390Srwatson * If base is 0, allow 0x for hex and 0 for octal, else 66180390Srwatson * assume decimal; if base is already 16, allow 0x. 67180390Srwatson */ 68180390Srwatson s = nptr; 69180390Srwatson do { 70180390Srwatson c = *s++; 71180390Srwatson } while (isspace(c)); 72180390Srwatson if (c == '-') { 731541Srgrimes neg = 1; 74180305Srwatson c = *s++; 75180305Srwatson } else { 761541Srgrimes neg = 0; 771541Srgrimes if (c == '+') 78180305Srwatson c = *s++; 791541Srgrimes } 80180305Srwatson if ((base == 0 || base == 16) && 811541Srgrimes c == '0' && (*s == 'x' || *s == 'X')) { 821541Srgrimes c = s[1]; 831541Srgrimes s += 2; 84180391Srwatson base = 16; 85180391Srwatson } 86180391Srwatson if (base == 0) 87180391Srwatson base = c == '0' ? 8 : 10; 881541Srgrimes 89180391Srwatson /* 90180391Srwatson * Compute the cutoff value between legal numbers and illegal 913443Sphk * numbers. That is the largest legal value, divided by the 923443Sphk * base. An input number that is greater than this value, if 931541Srgrimes * followed by a legal input character, is too big. One that 941541Srgrimes * is equal to this value may be valid or not; the limit 951541Srgrimes * between valid and invalid numbers is then based on the last 961541Srgrimes * digit. For instance, if the range for quads is 97130514Srwatson * [-9223372036854775808..9223372036854775807] and the input base 98181803Sbz * is 10, cutoff will be set to 922337203685477580 and cutlim to 99130514Srwatson * either 7 (neg==0) or 8 (neg==1), meaning that if we have 1001541Srgrimes * accumulated a value > 922337203685477580, or equal but the 1011541Srgrimes * next digit is > 7 (or 8), the number is too big, and we will 1021541Srgrimes * return a range error. 1031541Srgrimes * 104180305Srwatson * Set any if any `digits' consumed; make it negative to indicate 1051541Srgrimes * overflow. 1061541Srgrimes */ 107180305Srwatson qbase = (unsigned)base; 1081541Srgrimes cutoff = neg ? (u_quad_t)-(QUAD_MIN + QUAD_MAX) + QUAD_MAX : QUAD_MAX; 1091541Srgrimes cutlim = cutoff % qbase; 1101541Srgrimes cutoff /= qbase; 111157370Srwatson for (acc = 0, any = 0;; c = *s++) { 112157370Srwatson if (!isascii(c)) 113157370Srwatson break; 114140775Srwatson if (isdigit(c)) 11524936Sphk c -= '0'; 116140775Srwatson else if (isalpha(c)) 1171541Srgrimes c -= isupper(c) ? 'A' - 10 : 'a' - 10; 1181541Srgrimes else 119 break; 120 if (c >= base) 121 break; 122 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 123 any = -1; 124 else { 125 any = 1; 126 acc *= qbase; 127 acc += c; 128 } 129 } 130 if (any < 0) { 131 acc = neg ? QUAD_MIN : QUAD_MAX; 132 errno = ERANGE; 133 } else if (neg) 134 acc = -acc; 135 if (endptr != 0) 136 *endptr = (char *)(any ? s - 1 : nptr); 137 return (acc); 138} 139