1 /* $NetBSD: strtoq.c,v 1.15 2000/03/08 20:17:21 kleink 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 1.15 2000/03/08 20:17:21 kleink Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <sys/types.h> 46 47 #include <assert.h> 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 _DIAGASSERT(nptr != NULL); 71 /* endptr may be NULL */ 72 73 #ifdef __GNUC__ 74 /* This outrageous construct just to shut up a GCC warning. */ 75 (void) &acc; (void) &cutoff; 76 #endif 77 78 /* 79 * Skip white space and pick up leading +/- sign if any. 80 * If base is 0, allow 0x for hex and 0 for octal, else 81 * assume decimal; if base is already 16, allow 0x. 82 */ 83 s = nptr; 84 do { 85 c = (unsigned char) *s++; 86 } while (isspace(c)); 87 if (c == '-') { 88 neg = 1; 89 c = *s++; 90 } else { 91 neg = 0; 92 if (c == '+') 93 c = *s++; 94 } 95 if ((base == 0 || base == 16) && 96 c == '0' && (*s == 'x' || *s == 'X')) { 97 c = s[1]; 98 s += 2; 99 base = 16; 100 } 101 if (base == 0) 102 base = c == '0' ? 8 : 10; 103 104 /* 105 * Compute the cutoff value between legal numbers and illegal 106 * numbers. That is the largest legal value, divided by the 107 * base. An input number that is greater than this value, if 108 * followed by a legal input character, is too big. One that 109 * is equal to this value may be valid or not; the limit 110 * between valid and invalid numbers is then based on the last 111 * digit. For instance, if the range for quads is 112 * [-9223372036854775808..9223372036854775807] and the input base 113 * is 10, cutoff will be set to 922337203685477580 and cutlim to 114 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 115 * accumulated a value > 922337203685477580, or equal but the 116 * next digit is > 7 (or 8), the number is too big, and we will 117 * return a range error. 118 * 119 * Set any if any `digits' consumed; make it negative to indicate 120 * overflow. 121 */ 122 cutoff = neg ? QUAD_MIN : QUAD_MAX; 123 cutlim = (int)(cutoff % base); 124 cutoff /= base; 125 if (neg) { 126 if (cutlim > 0) { 127 cutlim -= base; 128 cutoff += 1; 129 } 130 cutlim = -cutlim; 131 } 132 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 133 if (isdigit(c)) 134 c -= '0'; 135 else if (isalpha(c)) 136 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 137 else 138 break; 139 if (c >= base) 140 break; 141 if (any < 0) 142 continue; 143 if (neg) { 144 if (acc < cutoff || (acc == cutoff && c > cutlim)) { 145 any = -1; 146 acc = QUAD_MIN; 147 errno = ERANGE; 148 } else { 149 any = 1; 150 acc *= base; 151 acc -= c; 152 } 153 } else { 154 if (acc > cutoff || (acc == cutoff && c > cutlim)) { 155 any = -1; 156 acc = QUAD_MAX; 157 errno = ERANGE; 158 } else { 159 any = 1; 160 acc *= base; 161 acc += c; 162 } 163 } 164 } 165 if (endptr != 0) 166 /* LINTED interface specification */ 167 *endptr = (char *)(any ? s - 1 : nptr); 168 return (acc); 169 } 170