1 /*- 2 * Copyright (c) 1992 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)strtoq.c 5.1 (Berkeley) 6/26/92"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/types.h> 39 40 #include <ctype.h> 41 #include <errno.h> 42 #include <limits.h> 43 #include <stdlib.h> 44 45 /* 46 * Convert a string to a quad integer. 47 * 48 * Ignores `locale' stuff. Assumes that the upper and lower case 49 * alphabets and digits are each contiguous. 50 */ 51 quad_t 52 strtoq(nptr, endptr, base) 53 const char *nptr; 54 char **endptr; 55 register int base; 56 { 57 register const char *s; 58 register quad_t acc, cutoff; 59 register int c; 60 register int neg, any, cutlim; 61 62 /* 63 * Skip white space and pick up leading +/- sign if any. 64 * If base is 0, allow 0x for hex and 0 for octal, else 65 * assume decimal; if base is already 16, allow 0x. 66 */ 67 s = nptr; 68 do { 69 c = (unsigned char) *s++; 70 } while (isspace(c)); 71 if (c == '-') { 72 neg = 1; 73 c = *s++; 74 } else { 75 neg = 0; 76 if (c == '+') 77 c = *s++; 78 } 79 if ((base == 0 || base == 16) && 80 c == '0' && (*s == 'x' || *s == 'X')) { 81 c = s[1]; 82 s += 2; 83 base = 16; 84 } 85 if (base == 0) 86 base = c == '0' ? 8 : 10; 87 88 /* 89 * Compute the cutoff value between legal numbers and illegal 90 * numbers. That is the largest legal value, divided by the 91 * base. An input number that is greater than this value, if 92 * followed by a legal input character, is too big. One that 93 * is equal to this value may be valid or not; the limit 94 * between valid and invalid numbers is then based on the last 95 * digit. For instance, if the range for quads is 96 * [-9223372036854775808..9223372036854775807] and the input base 97 * is 10, cutoff will be set to 922337203685477580 and cutlim to 98 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 99 * accumulated a value > 922337203685477580, or equal but the 100 * next digit is > 7 (or 8), the number is too big, and we will 101 * return a range error. 102 * 103 * Set any if any `digits' consumed; make it negative to indicate 104 * overflow. 105 */ 106 cutoff = neg ? QUAD_MIN : QUAD_MAX; 107 cutlim = cutoff % base; 108 cutoff /= base; 109 if (neg) { 110 if (cutlim > 0) { 111 cutlim -= base; 112 cutoff += 1; 113 } 114 cutlim = -cutlim; 115 } 116 for (acc = 0, any = 0;; c = (unsigned char) *s++) { 117 if (isdigit(c)) 118 c -= '0'; 119 else if (isalpha(c)) 120 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 121 else 122 break; 123 if (c >= base) 124 break; 125 if (any < 0) 126 continue; 127 if (neg) { 128 if (acc < cutoff || acc == cutoff && c > cutlim) { 129 any = -1; 130 acc = QUAD_MIN; 131 errno = ERANGE; 132 } else { 133 any = 1; 134 acc *= base; 135 acc -= c; 136 } 137 } else { 138 if (acc > cutoff || acc == cutoff && c > cutlim) { 139 any = -1; 140 acc = QUAD_MAX; 141 errno = ERANGE; 142 } else { 143 any = 1; 144 acc *= base; 145 acc += c; 146 } 147 } 148 } 149 if (endptr != 0) 150 *endptr = (char *) (any ? s - 1 : nptr); 151 return (acc); 152 } 153