bsd/libkern/strtol.c

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*      Copyright (c) 1995 NeXT Computer, Inc.  All rights reserved.
  31  *
  32  * strol.c - The functions strtol() & strtoul() are exported as public API
  33  *           via the header file ~driverkit/generalFuncs.h
  34  *
  35  * HISTORY
  36  * 25-Oct-1995    Dean Reece at NeXT
  37  *      Created based on BSD4.4's strtol.c & strtoul.c.
  38  *      Removed dependency on _ctype_ by static versions of isupper()...
  39  *      Added support for "0b101..." binary constants.
  40  *      Commented out references to errno.
  41  */
  42
  43 /*-
  44  * Copyright (c) 1990, 1993
  45  *      The Regents of the University of California.  All rights reserved.
  46  *
  47  * Redistribution and use in source and binary forms, with or without
  48  * modification, are permitted provided that the following conditions
  49  * are met:
  50  * 1. Redistributions of source code must retain the above copyright
  51  *    notice, this list of conditions and the following disclaimer.
  52  * 2. Redistributions in binary form must reproduce the above copyright
  53  *    notice, this list of conditions and the following disclaimer in the
  54  *    documentation and/or other materials provided with the distribution.
  55  * 3. All advertising materials mentioning features or use of this software
  56  *    must display the following acknowledgement:
  57  *      This product includes software developed by the University of
  58  *      California, Berkeley and its contributors.
  59  * 4. Neither the name of the University nor the names of its contributors
  60  *    may be used to endorse or promote products derived from this software
  61  *    without specific prior written permission.
  62  *
  63  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  64  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  65  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  66  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  67  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  68  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  69  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  70  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  71  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  72  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  73  * SUCH DAMAGE.
  74  */
  75
  76
  77 static inline int
  78 isupper(char c)
  79 {
  80     return (c >= 'A' && c <= 'Z');
  81 }
  82
  83 static inline int
  84 isalpha(char c)
  85 {
  86     return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
  87 }
  88
  89
  90 static inline int
  91 isspace(char c)
  92 {
  93     return (c == ' ' || c == '\t' || c == '\n' || c == '\12');
  94 }
  95
  96 static inline int
  97 isdigit(char c)
  98 {
  99     return (c >= '0' && c <= '9');
 100 }
 101
 102 /*
 103  * Convert a string to a long integer.
 104  *
 105  * Ignores `locale' stuff.  Assumes that the upper and lower case
 106  * alphabets and digits are each contiguous.
 107  */
 108 long
 109 strtol(nptr, endptr, base)
 110         const char *nptr;
 111         char **endptr;
 112         register int base;
 113 {
 114         register const char *s = nptr;
 115         register unsigned long acc;
 116         register int c;
 117         register unsigned long cutoff;
 118         register int neg = 0, any, cutlim;
 119
 120         /*
 121          * Skip white space and pick up leading +/- sign if any.
 122          * If base is 0, allow 0x for hex and 0 for octal, else
 123          * assume decimal; if base is already 16, allow 0x.
 124          */
 125         do {
 126                 c = *s++;
 127         } while (isspace(c));
 128         if (c == '-') {
 129                 neg = 1;
 130                 c = *s++;
 131         } else if (c == '+')
 132                 c = *s++;
 133         if ((base == 0 || base == 16) &&
 134             c == '0' && (*s == 'x' || *s == 'X')) {
 135                 c = s[1];
 136                 s += 2;
 137                 base = 16;
 138         } else if ((base == 0 || base == 2) &&
 139             c == '0' && (*s == 'b' || *s == 'B')) {
 140                 c = s[1];
 141                 s += 2;
 142                 base = 2;
 143         }
 144         if (base == 0)
 145                 base = c == '0' ? 8 : 10;
 146
 147         /*
 148          * Compute the cutoff value between legal numbers and illegal
 149          * numbers.  That is the largest legal value, divided by the
 150          * base.  An input number that is greater than this value, if
 151          * followed by a legal input character, is too big.  One that
 152          * is equal to this value may be valid or not; the limit
 153          * between valid and invalid numbers is then based on the last
 154          * digit.  For instance, if the range for longs is
 155          * [-2147483648..2147483647] and the input base is 10,
 156          * cutoff will be set to 214748364 and cutlim to either
 157          * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 158          * a value > 214748364, or equal but the next digit is > 7 (or 8),
 159          * the number is too big, and we will return a range error.
 160          *
 161          * Set any if any `digits' consumed; make it negative to indicate
 162          * overflow.
 163          */
 164         cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
 165         cutlim = cutoff % (unsigned long)base;
 166         cutoff /= (unsigned long)base;
 167         for (acc = 0, any = 0;; c = *s++) {
 168                 if (isdigit(c))
 169                         c -= '0';
 170                 else if (isalpha(c))
 171                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 172                 else
 173                         break;
 174                 if (c >= base)
 175                         break;
 176                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 177                         any = -1;
 178                 else {
 179                         any = 1;
 180                         acc *= base;
 181                         acc += c;
 182                 }
 183         }
 184         if (any < 0) {
 185                 acc = neg ? LONG_MIN : LONG_MAX;
 186 //              errno = ERANGE;
 187         } else if (neg)
 188                 acc = -acc;
 189         if (endptr != 0)
 190                 *endptr = (char *)(any ? s - 1 : nptr);
 191         return (acc);
 192 }
 193
 194 /*
 195  * Convert a string to an unsigned long integer.
 196  *
 197  * Ignores `locale' stuff.  Assumes that the upper and lower case
 198  * alphabets and digits are each contiguous.
 199  */
 200 unsigned long
 201 strtoul(nptr, endptr, base)
 202         const char *nptr;
 203         char **endptr;
 204         register int base;
 205 {
 206         register const char *s = nptr;
 207         register unsigned long acc;
 208         register int c;
 209         register unsigned long cutoff;
 210         register int neg = 0, any, cutlim;
 211
 212         /*
 213          * See strtol for comments as to the logic used.
 214          */
 215         do {
 216                 c = *s++;
 217         } while (isspace(c));
 218         if (c == '-') {
 219                 neg = 1;
 220                 c = *s++;
 221         } else if (c == '+')
 222                 c = *s++;
 223         if ((base == 0 || base == 16) &&
 224             c == '0' && (*s == 'x' || *s == 'X')) {
 225                 c = s[1];
 226                 s += 2;
 227                 base = 16;
 228         } else if ((base == 0 || base == 2) &&
 229             c == '0' && (*s == 'b' || *s == 'B')) {
 230                 c = s[1];
 231                 s += 2;
 232                 base = 2;
 233         }
 234         if (base == 0)
 235                 base = c == '0' ? 8 : 10;
 236         cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
 237         cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
 238         for (acc = 0, any = 0;; c = *s++) {
 239                 if (isdigit(c))
 240                         c -= '0';
 241                 else if (isalpha(c))
 242                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 243                 else
 244                         break;
 245                 if (c >= base)
 246                         break;
 247                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 248                         any = -1;
 249                 else {
 250                         any = 1;
 251                         acc *= base;
 252                         acc += c;
 253                 }
 254         }
 255         if (any < 0) {
 256                 acc = ULONG_MAX;
 257 //              errno = ERANGE;
 258         } else if (neg)
 259                 acc = -acc;
 260         if (endptr != 0)
 261                 *endptr = (char *)(any ? s - 1 : nptr);
 262         return (acc);
 263 }