1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/ctype.h> 41 #include <sys/limits.h> 42 43 /* 44 * Convert a string to a quad integer. 45 * 46 * Ignores `locale' stuff. Assumes that the upper and lower case 47 * alphabets and digits are each contiguous. 48 */ 49 quad_t 50 strtoq(const char *nptr, char **endptr, int base) 51 { 52 const char *s; 53 u_quad_t acc; 54 unsigned char c; 55 u_quad_t qbase, cutoff; 56 int neg, any, cutlim; 57 58 /* 59 * Skip white space and pick up leading +/- sign if any. 60 * If base is 0, allow 0x for hex and 0 for octal, else 61 * assume decimal; if base is already 16, allow 0x. 62 */ 63 s = nptr; 64 do { 65 c = *s++; 66 } while (isspace(c)); 67 if (c == '-') { 68 neg = 1; 69 c = *s++; 70 } else { 71 neg = 0; 72 if (c == '+') 73 c = *s++; 74 } 75 if ((base == 0 || base == 16) && 76 c == '0' && (*s == 'x' || *s == 'X')) { 77 c = s[1]; 78 s += 2; 79 base = 16; 80 } 81 if (base == 0) 82 base = c == '0' ? 8 : 10; 83 84 /* 85 * Compute the cutoff value between legal numbers and illegal 86 * numbers. That is the largest legal value, divided by the 87 * base. An input number that is greater than this value, if 88 * followed by a legal input character, is too big. One that 89 * is equal to this value may be valid or not; the limit 90 * between valid and invalid numbers is then based on the last 91 * digit. For instance, if the range for quads is 92 * [-9223372036854775808..9223372036854775807] and the input base 93 * is 10, cutoff will be set to 922337203685477580 and cutlim to 94 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 95 * accumulated a value > 922337203685477580, or equal but the 96 * next digit is > 7 (or 8), the number is too big, and we will 97 * return a range error. 98 * 99 * Set any if any `digits' consumed; make it negative to indicate 100 * overflow. 101 */ 102 qbase = (unsigned)base; 103 cutoff = neg ? (u_quad_t)-(QUAD_MIN + QUAD_MAX) + QUAD_MAX : QUAD_MAX; 104 cutlim = cutoff % qbase; 105 cutoff /= qbase; 106 for (acc = 0, any = 0;; c = *s++) { 107 if (!isascii(c)) 108 break; 109 if (isdigit(c)) 110 c -= '0'; 111 else if (isalpha(c)) 112 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 113 else 114 break; 115 if (c >= base) 116 break; 117 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 118 any = -1; 119 else { 120 any = 1; 121 acc *= qbase; 122 acc += c; 123 } 124 } 125 if (any < 0) { 126 acc = neg ? QUAD_MIN : QUAD_MAX; 127 } else if (neg) 128 acc = -acc; 129 if (endptr != NULL) 130 *endptr = __DECONST(char *, any ? s - 1 : nptr); 131 return (acc); 132 } 133