bsd/libkern/strtol.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*      Copyright (c) 1995 NeXT Computer, Inc.  All rights reserved.
  29  *
  30  * strol.c - The functions strtol() & strtoul() are exported as public API
  31  *           via the header file ~driverkit/generalFuncs.h
  32  *
  33  * HISTORY
  34  * 25-Oct-1995    Dean Reece at NeXT
  35  *      Created based on BSD4.4's strtol.c & strtoul.c.
  36  *      Removed dependency on _ctype_ by static versions of isupper()...
  37  *      Added support for "0b101..." binary constants.
  38  *      Commented out references to errno.
  39  */
  40
  41 /*-
  42  * Copyright (c) 1990, 1993
  43  *      The Regents of the University of California.  All rights reserved.
  44  *
  45  * Redistribution and use in source and binary forms, with or without
  46  * modification, are permitted provided that the following conditions
  47  * are met:
  48  * 1. Redistributions of source code must retain the above copyright
  49  *    notice, this list of conditions and the following disclaimer.
  50  * 2. Redistributions in binary form must reproduce the above copyright
  51  *    notice, this list of conditions and the following disclaimer in the
  52  *    documentation and/or other materials provided with the distribution.
  53  * 3. All advertising materials mentioning features or use of this software
  54  *    must display the following acknowledgement:
  55  *      This product includes software developed by the University of
  56  *      California, Berkeley and its contributors.
  57  * 4. Neither the name of the University nor the names of its contributors
  58  *    may be used to endorse or promote products derived from this software
  59  *    without specific prior written permission.
  60  *
  61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  71  * SUCH DAMAGE.
  72  */
  73
  74
  75 static inline int
  76 isupper(char c)
  77 {
  78     return (c >= 'A' && c <= 'Z');
  79 }
  80
  81 static inline int
  82 isalpha(char c)
  83 {
  84     return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
  85 }
  86
  87
  88 static inline int
  89 isspace(char c)
  90 {
  91     return (c == ' ' || c == '\t' || c == '\n' || c == '\12');
  92 }
  93
  94 static inline int
  95 isdigit(char c)
  96 {
  97     return (c >= '0' && c <= '9');
  98 }
  99
 100 /*
 101  * Convert a string to a long integer.
 102  *
 103  * Ignores `locale' stuff.  Assumes that the upper and lower case
 104  * alphabets and digits are each contiguous.
 105  */
 106 long
 107 strtol(nptr, endptr, base)
 108         const char *nptr;
 109         char **endptr;
 110         register int base;
 111 {
 112         register const char *s = nptr;
 113         register unsigned long acc;
 114         register int c;
 115         register unsigned long cutoff;
 116         register int neg = 0, any, cutlim;
 117
 118         /*
 119          * Skip white space and pick up leading +/- sign if any.
 120          * If base is 0, allow 0x for hex and 0 for octal, else
 121          * assume decimal; if base is already 16, allow 0x.
 122          */
 123         do {
 124                 c = *s++;
 125         } while (isspace(c));
 126         if (c == '-') {
 127                 neg = 1;
 128                 c = *s++;
 129         } else if (c == '+')
 130                 c = *s++;
 131         if ((base == 0 || base == 16) &&
 132             c == '0' && (*s == 'x' || *s == 'X')) {
 133                 c = s[1];
 134                 s += 2;
 135                 base = 16;
 136         } else if ((base == 0 || base == 2) &&
 137             c == '0' && (*s == 'b' || *s == 'B')) {
 138                 c = s[1];
 139                 s += 2;
 140                 base = 2;
 141         }
 142         if (base == 0)
 143                 base = c == '0' ? 8 : 10;
 144
 145         /*
 146          * Compute the cutoff value between legal numbers and illegal
 147          * numbers.  That is the largest legal value, divided by the
 148          * base.  An input number that is greater than this value, if
 149          * followed by a legal input character, is too big.  One that
 150          * is equal to this value may be valid or not; the limit
 151          * between valid and invalid numbers is then based on the last
 152          * digit.  For instance, if the range for longs is
 153          * [-2147483648..2147483647] and the input base is 10,
 154          * cutoff will be set to 214748364 and cutlim to either
 155          * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 156          * a value > 214748364, or equal but the next digit is > 7 (or 8),
 157          * the number is too big, and we will return a range error.
 158          *
 159          * Set any if any `digits' consumed; make it negative to indicate
 160          * overflow.
 161          */
 162         cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
 163         cutlim = cutoff % (unsigned long)base;
 164         cutoff /= (unsigned long)base;
 165         for (acc = 0, any = 0;; c = *s++) {
 166                 if (isdigit(c))
 167                         c -= '0';
 168                 else if (isalpha(c))
 169                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 170                 else
 171                         break;
 172                 if (c >= base)
 173                         break;
 174                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 175                         any = -1;
 176                 else {
 177                         any = 1;
 178                         acc *= base;
 179                         acc += c;
 180                 }
 181         }
 182         if (any < 0) {
 183                 acc = neg ? LONG_MIN : LONG_MAX;
 184 //              errno = ERANGE;
 185         } else if (neg)
 186                 acc = -acc;
 187         if (endptr != 0)
 188                 *endptr = (char *)(any ? s - 1 : nptr);
 189         return (acc);
 190 }
 191
 192 /*
 193  * Convert a string to an unsigned long integer.
 194  *
 195  * Ignores `locale' stuff.  Assumes that the upper and lower case
 196  * alphabets and digits are each contiguous.
 197  */
 198 unsigned long
 199 strtoul(nptr, endptr, base)
 200         const char *nptr;
 201         char **endptr;
 202         register int base;
 203 {
 204         register const char *s = nptr;
 205         register unsigned long acc;
 206         register int c;
 207         register unsigned long cutoff;
 208         register int neg = 0, any, cutlim;
 209
 210         /*
 211          * See strtol for comments as to the logic used.
 212          */
 213         do {
 214                 c = *s++;
 215         } while (isspace(c));
 216         if (c == '-') {
 217                 neg = 1;
 218                 c = *s++;
 219         } else if (c == '+')
 220                 c = *s++;
 221         if ((base == 0 || base == 16) &&
 222             c == '0' && (*s == 'x' || *s == 'X')) {
 223                 c = s[1];
 224                 s += 2;
 225                 base = 16;
 226         } else if ((base == 0 || base == 2) &&
 227             c == '0' && (*s == 'b' || *s == 'B')) {
 228                 c = s[1];
 229                 s += 2;
 230                 base = 2;
 231         }
 232         if (base == 0)
 233                 base = c == '0' ? 8 : 10;
 234         cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
 235         cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
 236         for (acc = 0, any = 0;; c = *s++) {
 237                 if (isdigit(c))
 238                         c -= '0';
 239                 else if (isalpha(c))
 240                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 241                 else
 242                         break;
 243                 if (c >= base)
 244                         break;
 245                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 246                         any = -1;
 247                 else {
 248                         any = 1;
 249                         acc *= base;
 250                         acc += c;
 251                 }
 252         }
 253         if (any < 0) {
 254                 acc = ULONG_MAX;
 255 //              errno = ERANGE;
 256         } else if (neg)
 257                 acc = -acc;
 258         if (endptr != 0)
 259                 *endptr = (char *)(any ? s - 1 : nptr);
 260         return (acc);
 261 }