1 /*- 2 * Copyright (c) 1990, 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 #include "config.h" 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 static const char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93"; 38 #endif /* LIBC_SCCS and not lint */ 39 #else 40 __RCSID("$NetBSD: strtol.c,v 1.2 2014/01/26 21:43:45 christos Exp $"); 41 #endif 42 43 #include <limits.h> 44 #include <ctype.h> 45 #include <errno.h> 46 #include <stdlib.h> 47 48 /* 49 * Convert a string to a long integer. 50 * 51 * Ignores `locale' stuff. Assumes that the upper and lower case 52 * alphabets and digits are each contiguous. 53 * 54 * PUBLIC: #ifndef HAVE_STRTOL 55 * PUBLIC: long strtol __P((const char *, char **, int)); 56 * PUBLIC: #endif 57 */ 58 long 59 strtol(const char *nptr, char **endptr, register int base) 60 { 61 register const char *s = nptr; 62 register unsigned long acc; 63 register int c; 64 register unsigned long cutoff; 65 register int neg = 0, any, cutlim; 66 67 /* 68 * Skip white space and pick up leading +/- sign if any. 69 * If base is 0, allow 0x for hex and 0 for octal, else 70 * assume decimal; if base is already 16, allow 0x. 71 */ 72 do { 73 c = *s++; 74 } while (isspace(c)); 75 if (c == '-') { 76 neg = 1; 77 c = *s++; 78 } else if (c == '+') 79 c = *s++; 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 longs is 97 * [-2147483648..2147483647] and the input base is 10, 98 * cutoff will be set to 214748364 and cutlim to either 99 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 100 * a value > 214748364, or equal but the next digit is > 7 (or 8), 101 * the number is too big, and we will return a range error. 102 * 103 * Set any if any `digits' consumed; make it negative to indicate 104 * overflow. 105 */ 106 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX; 107 cutlim = cutoff % (unsigned long)base; 108 cutoff /= (unsigned long)base; 109 for (acc = 0, any = 0;; c = *s++) { 110 if (isdigit(c)) 111 c -= '0'; 112 else if (isalpha(c)) 113 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 114 else 115 break; 116 if (c >= base) 117 break; 118 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) 119 any = -1; 120 else { 121 any = 1; 122 acc *= base; 123 acc += c; 124 } 125 } 126 if (any < 0) { 127 acc = neg ? LONG_MIN : LONG_MAX; 128 errno = ERANGE; 129 } else if (neg) 130 acc = -acc; 131 if (endptr != 0) 132 *endptr = (char *)(any ? s - 1 : nptr); 133 return (acc); 134 } 135