1 /* $NetBSD: strtoq.c,v 1.11 1998/11/15 17:13:52 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1992, 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 <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)strtoq.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: strtoq.c,v 1.11 1998/11/15 17:13:52 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/types.h> 47 48 #include <ctype.h> 49 #include <errno.h> 50 #include <limits.h> 51 #include <stdlib.h> 52 53 /* 54 * Convert a string to a quad integer. 55 * 56 * Ignores `locale' stuff. Assumes that the upper and lower case 57 * alphabets and digits are each contiguous. 58 */ 59 quad_t 60 _strtoq(nptr, endptr, base) 61 const char *nptr; 62 char **endptr; 63 int base; 64 { 65 const char *s; 66 quad_t acc, cutoff; 67 int c; 68 int neg, any, cutlim; 69 70 #ifdef __GNUC__ 71 /* This outrageous construct just to shut up a GCC warning. */ 72 (void) &acc; (void) &cutoff; 73 #endif 74 75 /* 76 * Skip white space and pick up leading +/- sign if any. 77 * If base is 0, allow 0x for hex and 0 for octal, else 78 * assume decimal; if base is already 16, allow 0x. 79 */ 80 s = nptr; 81 do { 82 c = (unsigned char) *s++; 83 } while (isspace(c)); 84 if (c == '-') { 85 neg = 1; 86 c = *s++; 87 } else { 88 neg = 0; 89 if (c == '+') 90 c = *s++; 91 } 92 if ((base == 0 || base == 16) && 93 c == '0' && (*s == 'x' || *s == 'X')) { 94 c = s[1]; 95 s += 2; 96 base = 16; 97 } 98 if (base == 0) 99 base = c == '0' ? 8 : 10; 100 101 /* 102 * Compute the cutoff value between legal numbers and illegal 103 * numbers. That is the largest legal value, divided by the 104 * base. An input number that is greater than this value, if 105 * followed by a legal input character, is too big. One that 106 * is equal to this value may be valid or not; the limit 107 * between valid and invalid numbers is then based on the last 108 * digit. For instance, if the range for quads is 109 * [-9223372036854775808..9223372036854775807] and the input base 110 * is 10, cutoff will be set to 922337203685477580 and cutlim to 111 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 112 * accumulated a value > 922337203685477580, or equal but the 113 * next digit is > 7 (or 8), the number is too big, and we will 114 * return a range error. 115 * 116 * Set any if any `digits' consumed; make it negative to indicate 117 * overflow. 118 */ 119 cutoff = neg ? QUAD_MIN : QUAD_MAX; 120 cutlim = (int)(cutoff % base); 121 cutoff /= base; 122 if (neg) { 123 if (cutlim > 0) { 124 cutlim -= base; 125 cutoff += 1; 126 } 127 cutlim = -cutlim; 128 } 129 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 130 if (isdigit(c)) 131 c -= '0'; 132 else if (isalpha(c)) 133 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 134 else 135 break; 136 if (c >= base) 137 break; 138 if (any < 0) 139 continue; 140 if (neg) { 141 if (acc < cutoff || (acc == cutoff && c > cutlim)) { 142 any = -1; 143 acc = QUAD_MIN; 144 errno = ERANGE; 145 } else { 146 any = 1; 147 acc *= base; 148 acc -= c; 149 } 150 } else { 151 if (acc > cutoff || (acc == cutoff && c > cutlim)) { 152 any = -1; 153 acc = QUAD_MAX; 154 errno = ERANGE; 155 } else { 156 any = 1; 157 acc *= base; 158 acc += c; 159 } 160 } 161 } 162 if (endptr != 0) 163 /* LINTED interface specification */ 164 *endptr = (char *)(any ? s - 1 : nptr); 165 return (acc); 166 } 167