bsd/libkern/strtol.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*      Copyright (c) 1995 NeXT Computer, Inc.  All rights reserved.
  26  *
  27  * strol.c - The functions strtol() & strtoul() are exported as public API
  28  *           via the header file ~driverkit/generalFuncs.h
  29  *
  30  * HISTORY
  31  * 25-Oct-1995    Dean Reece at NeXT
  32  *      Created based on BSD4.4's strtol.c & strtoul.c.
  33  *      Removed dependency on _ctype_ by static versions of isupper()...
  34  *      Added support for "0b101..." binary constants.
  35  *      Commented out references to errno.
  36  */
  37
  38 /*-
  39  * Copyright (c) 1990, 1993
  40  *      The Regents of the University of California.  All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. All advertising materials mentioning features or use of this software
  51  *    must display the following acknowledgement:
  52  *      This product includes software developed by the University of
  53  *      California, Berkeley and its contributors.
  54  * 4. Neither the name of the University nor the names of its contributors
  55  *    may be used to endorse or promote products derived from this software
  56  *    without specific prior written permission.
  57  *
  58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  68  * SUCH DAMAGE.
  69  */
  70
  71
  72 static inline int
  73 isupper(char c)
  74 {
  75     return (c >= 'A' && c <= 'Z');
  76 }
  77
  78 static inline int
  79 isalpha(char c)
  80 {
  81     return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
  82 }
  83
  84
  85 static inline int
  86 isspace(char c)
  87 {
  88     return (c == ' ' || c == '\t' || c == '\n' || c == '\12');
  89 }
  90
  91 static inline int
  92 isdigit(char c)
  93 {
  94     return (c >= '0' && c <= '9');
  95 }
  96
  97 /*
  98  * Convert a string to a long integer.
  99  *
 100  * Ignores `locale' stuff.  Assumes that the upper and lower case
 101  * alphabets and digits are each contiguous.
 102  */
 103 long
 104 strtol(nptr, endptr, base)
 105         const char *nptr;
 106         char **endptr;
 107         register int base;
 108 {
 109         register const char *s = nptr;
 110         register unsigned long acc;
 111         register int c;
 112         register unsigned long cutoff;
 113         register int neg = 0, any, cutlim;
 114
 115         /*
 116          * Skip white space and pick up leading +/- sign if any.
 117          * If base is 0, allow 0x for hex and 0 for octal, else
 118          * assume decimal; if base is already 16, allow 0x.
 119          */
 120         do {
 121                 c = *s++;
 122         } while (isspace(c));
 123         if (c == '-') {
 124                 neg = 1;
 125                 c = *s++;
 126         } else if (c == '+')
 127                 c = *s++;
 128         if ((base == 0 || base == 16) &&
 129             c == '0' && (*s == 'x' || *s == 'X')) {
 130                 c = s[1];
 131                 s += 2;
 132                 base = 16;
 133         } else if ((base == 0 || base == 2) &&
 134             c == '0' && (*s == 'b' || *s == 'B')) {
 135                 c = s[1];
 136                 s += 2;
 137                 base = 2;
 138         }
 139         if (base == 0)
 140                 base = c == '0' ? 8 : 10;
 141
 142         /*
 143          * Compute the cutoff value between legal numbers and illegal
 144          * numbers.  That is the largest legal value, divided by the
 145          * base.  An input number that is greater than this value, if
 146          * followed by a legal input character, is too big.  One that
 147          * is equal to this value may be valid or not; the limit
 148          * between valid and invalid numbers is then based on the last
 149          * digit.  For instance, if the range for longs is
 150          * [-2147483648..2147483647] and the input base is 10,
 151          * cutoff will be set to 214748364 and cutlim to either
 152          * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 153          * a value > 214748364, or equal but the next digit is > 7 (or 8),
 154          * the number is too big, and we will return a range error.
 155          *
 156          * Set any if any `digits' consumed; make it negative to indicate
 157          * overflow.
 158          */
 159         cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
 160         cutlim = cutoff % (unsigned long)base;
 161         cutoff /= (unsigned long)base;
 162         for (acc = 0, any = 0;; c = *s++) {
 163                 if (isdigit(c))
 164                         c -= '0';
 165                 else if (isalpha(c))
 166                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 167                 else
 168                         break;
 169                 if (c >= base)
 170                         break;
 171                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 172                         any = -1;
 173                 else {
 174                         any = 1;
 175                         acc *= base;
 176                         acc += c;
 177                 }
 178         }
 179         if (any < 0) {
 180                 acc = neg ? LONG_MIN : LONG_MAX;
 181 //              errno = ERANGE;
 182         } else if (neg)
 183                 acc = -acc;
 184         if (endptr != 0)
 185                 *endptr = (char *)(any ? s - 1 : nptr);
 186         return (acc);
 187 }
 188
 189 /*
 190  * Convert a string to an unsigned long integer.
 191  *
 192  * Ignores `locale' stuff.  Assumes that the upper and lower case
 193  * alphabets and digits are each contiguous.
 194  */
 195 unsigned long
 196 strtoul(nptr, endptr, base)
 197         const char *nptr;
 198         char **endptr;
 199         register int base;
 200 {
 201         register const char *s = nptr;
 202         register unsigned long acc;
 203         register int c;
 204         register unsigned long cutoff;
 205         register int neg = 0, any, cutlim;
 206
 207         /*
 208          * See strtol for comments as to the logic used.
 209          */
 210         do {
 211                 c = *s++;
 212         } while (isspace(c));
 213         if (c == '-') {
 214                 neg = 1;
 215                 c = *s++;
 216         } else if (c == '+')
 217                 c = *s++;
 218         if ((base == 0 || base == 16) &&
 219             c == '0' && (*s == 'x' || *s == 'X')) {
 220                 c = s[1];
 221                 s += 2;
 222                 base = 16;
 223         } else if ((base == 0 || base == 2) &&
 224             c == '0' && (*s == 'b' || *s == 'B')) {
 225                 c = s[1];
 226                 s += 2;
 227                 base = 2;
 228         }
 229         if (base == 0)
 230                 base = c == '0' ? 8 : 10;
 231         cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
 232         cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
 233         for (acc = 0, any = 0;; c = *s++) {
 234                 if (isdigit(c))
 235                         c -= '0';
 236                 else if (isalpha(c))
 237                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 238                 else
 239                         break;
 240                 if (c >= base)
 241                         break;
 242                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 243                         any = -1;
 244                 else {
 245                         any = 1;
 246                         acc *= base;
 247                         acc += c;
 248                 }
 249         }
 250         if (any < 0) {
 251                 acc = ULONG_MAX;
 252 //              errno = ERANGE;
 253         } else if (neg)
 254                 acc = -acc;
 255         if (endptr != 0)
 256                 *endptr = (char *)(any ? s - 1 : nptr);
 257         return (acc);
 258 }