bsd/libkern/strtol.c

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