1 /* $NetBSD: strtoq.c,v 1.14 1999/09/20 04:39:42 lukem 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 1.14 1999/09/20 04:39:42 lukem Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/types.h> 47 48 #include <assert.h> 49 #include <ctype.h> 50 #include <errno.h> 51 #include <limits.h> 52 #include <stdlib.h> 53 54 #ifdef __weak_alias 55 __weak_alias(strtoq, _strtoq) 56 #endif 57 58 /* 59 * Convert a string to a quad integer. 60 * 61 * Ignores `locale' stuff. Assumes that the upper and lower case 62 * alphabets and digits are each contiguous. 63 */ 64 quad_t 65 _strtoq(nptr, endptr, base) 66 const char *nptr; 67 char **endptr; 68 int base; 69 { 70 const char *s; 71 quad_t acc, cutoff; 72 int c; 73 int neg, any, cutlim; 74 75 _DIAGASSERT(nptr != NULL); 76 /* endptr may be NULL */ 77 78 #ifdef __GNUC__ 79 /* This outrageous construct just to shut up a GCC warning. */ 80 (void) &acc; (void) &cutoff; 81 #endif 82 83 /* 84 * Skip white space and pick up leading +/- sign if any. 85 * If base is 0, allow 0x for hex and 0 for octal, else 86 * assume decimal; if base is already 16, allow 0x. 87 */ 88 s = nptr; 89 do { 90 c = (unsigned char) *s++; 91 } while (isspace(c)); 92 if (c == '-') { 93 neg = 1; 94 c = *s++; 95 } else { 96 neg = 0; 97 if (c == '+') 98 c = *s++; 99 } 100 if ((base == 0 || base == 16) && 101 c == '0' && (*s == 'x' || *s == 'X')) { 102 c = s[1]; 103 s += 2; 104 base = 16; 105 } 106 if (base == 0) 107 base = c == '0' ? 8 : 10; 108 109 /* 110 * Compute the cutoff value between legal numbers and illegal 111 * numbers. That is the largest legal value, divided by the 112 * base. An input number that is greater than this value, if 113 * followed by a legal input character, is too big. One that 114 * is equal to this value may be valid or not; the limit 115 * between valid and invalid numbers is then based on the last 116 * digit. For instance, if the range for quads is 117 * [-9223372036854775808..9223372036854775807] and the input base 118 * is 10, cutoff will be set to 922337203685477580 and cutlim to 119 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 120 * accumulated a value > 922337203685477580, or equal but the 121 * next digit is > 7 (or 8), the number is too big, and we will 122 * return a range error. 123 * 124 * Set any if any `digits' consumed; make it negative to indicate 125 * overflow. 126 */ 127 cutoff = neg ? QUAD_MIN : QUAD_MAX; 128 cutlim = (int)(cutoff % base); 129 cutoff /= base; 130 if (neg) { 131 if (cutlim > 0) { 132 cutlim -= base; 133 cutoff += 1; 134 } 135 cutlim = -cutlim; 136 } 137 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 138 if (isdigit(c)) 139 c -= '0'; 140 else if (isalpha(c)) 141 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 142 else 143 break; 144 if (c >= base) 145 break; 146 if (any < 0) 147 continue; 148 if (neg) { 149 if (acc < cutoff || (acc == cutoff && c > cutlim)) { 150 any = -1; 151 acc = QUAD_MIN; 152 errno = ERANGE; 153 } else { 154 any = 1; 155 acc *= base; 156 acc -= c; 157 } 158 } else { 159 if (acc > cutoff || (acc == cutoff && c > cutlim)) { 160 any = -1; 161 acc = QUAD_MAX; 162 errno = ERANGE; 163 } else { 164 any = 1; 165 acc *= base; 166 acc += c; 167 } 168 } 169 } 170 if (endptr != 0) 171 /* LINTED interface specification */ 172 *endptr = (char *)(any ? s - 1 : nptr); 173 return (acc); 174 } 175