1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. 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 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/types.h> 39 40 #include <limits.h> 41 #include <errno.h> 42 #include <ctype.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 u_quad_t acc; 59 register unsigned char c; 60 register u_quad_t qbase, cutoff; 61 register int neg, any, cutlim; 62 63 /* 64 * Skip white space and pick up leading +/- sign if any. 65 * If base is 0, allow 0x for hex and 0 for octal, else 66 * assume decimal; if base is already 16, allow 0x. 67 */ 68 s = nptr; 69 do { 70 c = *s++; 71 } while (isspace(c)); 72 if (c == '-') { 73 neg = 1; 74 c = *s++; 75 } else { 76 neg = 0; 77 if (c == '+') 78 c = *s++; 79 } 80 if ((base == 0 || base == 16) && 81 c == '0' && (*s == 'x' || *s == 'X')) { 82 c = s[1]; 83 s += 2; 84 base = 16; 85 } 86 if (base == 0) 87 base = c == '0' ? 8 : 10; 88 89 /* 90 * Compute the cutoff value between legal numbers and illegal 91 * numbers. That is the largest legal value, divided by the 92 * base. An input number that is greater than this value, if 93 * followed by a legal input character, is too big. One that 94 * is equal to this value may be valid or not; the limit 95 * between valid and invalid numbers is then based on the last 96 * digit. For instance, if the range for quads is 97 * [-9223372036854775808..9223372036854775807] and the input base 98 * is 10, cutoff will be set to 922337203685477580 and cutlim to 99 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 100 * accumulated a value > 922337203685477580, or equal but the 101 * next digit is > 7 (or 8), the number is too big, and we will 102 * return a range error. 103 * 104 * Set any if any `digits' consumed; make it negative to indicate 105 * overflow. 106 */ 107 qbase = (unsigned)base; 108 cutoff = neg ? -(u_quad_t)QUAD_MIN : QUAD_MAX; 109 cutlim = cutoff % qbase; 110 cutoff /= qbase; 111 for (acc = 0, any = 0;; c = *s++) { 112 if (!isascii(c)) 113 break; 114 if (isdigit(c)) 115 c -= '0'; 116 else if (isalpha(c)) 117 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 118 else 119 break; 120 if (c >= base) 121 break; 122 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) 123 any = -1; 124 else { 125 any = 1; 126 acc *= qbase; 127 acc += c; 128 } 129 } 130 if (any < 0) { 131 acc = neg ? QUAD_MIN : QUAD_MAX; 132 errno = ERANGE; 133 } else if (neg) 134 acc = -acc; 135 if (endptr != 0) 136 *endptr = (char *)(any ? s - 1 : nptr); 137 return (acc); 138 } 139