1 /* $NetBSD: strtol.c,v 1.2 2009/03/14 15:36:08 dsl Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 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 38 #if defined(LIBC_SCCS) && !defined(lint) 39 static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <lib/libsa/stand.h> 43 #include <lib/libkern/libkern.h> 44 45 #include <machine/limits.h> 46 47 #include "bootstrap.h" 48 49 /* 50 * Convert a string to a long integer. 51 * 52 * Ignores `locale' stuff. Assumes that the upper and lower case 53 * alphabets and digits are each contiguous. 54 */ 55 long 56 strtol(const char *nptr, char **endptr, int base) 57 { 58 const char *s; 59 unsigned long acc; 60 unsigned char c; 61 unsigned long cutoff; 62 int neg = 0, any, cutlim; 63 64 /* Be sensible about NULL strings */ 65 if (nptr == NULL) 66 nptr = ""; 67 s = nptr; 68 69 /* 70 * Skip white space and pick up leading +/- sign if any. 71 * If base is 0, allow 0x for hex and 0 for octal, else 72 * assume decimal; if base is already 16, allow 0x. 73 */ 74 do { 75 c = *s++; 76 } while (isspace(c)); 77 if (c == '-') { 78 neg = 1; 79 c = *s++; 80 } else if (c == '+') 81 c = *s++; 82 if ((base == 0 || base == 16) && 83 c == '0' && (*s == 'x' || *s == 'X')) { 84 c = s[1]; 85 s += 2; 86 base = 16; 87 } 88 if (base == 0) 89 base = c == '0' ? 8 : 10; 90 91 /* 92 * Compute the cutoff value between legal numbers and illegal 93 * numbers. That is the largest legal value, divided by the 94 * base. An input number that is greater than this value, if 95 * followed by a legal input character, is too big. One that 96 * is equal to this value may be valid or not; the limit 97 * between valid and invalid numbers is then based on the last 98 * digit. For instance, if the range for longs is 99 * [-2147483648..2147483647] and the input base is 10, 100 * cutoff will be set to 214748364 and cutlim to either 101 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 102 * a value > 214748364, or equal but the next digit is > 7 (or 8), 103 * the number is too big, and we will return a range error. 104 * 105 * Set any if any `digits' consumed; make it negative to indicate 106 * overflow. 107 */ 108 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX; 109 cutlim = cutoff % (unsigned long)base; 110 cutoff /= (unsigned long)base; 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 *= base; 127 acc += c; 128 } 129 } 130 if (any < 0) { 131 acc = neg ? LONG_MIN : LONG_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