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