bsd/libkern/strtol.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      Copyright (c) 1995 NeXT Computer, Inc.  All rights reserved.
  23  *
  24  * strol.c - The functions strtol() & strtoul() are exported as public API
  25  *           via the header file ~driverkit/generalFuncs.h
  26  *
  27  * HISTORY
  28  * 25-Oct-1995    Dean Reece at NeXT
  29  *      Created based on BSD4.4's strtol.c & strtoul.c.
  30  *      Removed dependency on _ctype_ by static versions of isupper()...
  31  *      Added support for "0b101..." binary constants.
  32  *      Commented out references to errno.
  33  */
  34
  35 /*-
  36  * Copyright (c) 1990, 1993
  37  *      The Regents of the University of California.  All rights reserved.
  38  *
  39  * Redistribution and use in source and binary forms, with or without
  40  * modification, are permitted provided that the following conditions
  41  * are met:
  42  * 1. Redistributions of source code must retain the above copyright
  43  *    notice, this list of conditions and the following disclaimer.
  44  * 2. Redistributions in binary form must reproduce the above copyright
  45  *    notice, this list of conditions and the following disclaimer in the
  46  *    documentation and/or other materials provided with the distribution.
  47  * 3. All advertising materials mentioning features or use of this software
  48  *    must display the following acknowledgement:
  49  *      This product includes software developed by the University of
  50  *      California, Berkeley and its contributors.
  51  * 4. Neither the name of the University nor the names of its contributors
  52  *    may be used to endorse or promote products derived from this software
  53  *    without specific prior written permission.
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  65  * SUCH DAMAGE.
  66  */
  67
  68
  69 static inline int
  70 isupper(char c)
  71 {
  72     return (c >= 'A' && c <= 'Z');
  73 }
  74
  75 static inline int
  76 isalpha(char c)
  77 {
  78     return ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'));
  79 }
  80
  81
  82 static inline int
  83 isspace(char c)
  84 {
  85     return (c == ' ' || c == '\t' || c == '\n' || c == '\12');
  86 }
  87
  88 static inline int
  89 isdigit(char c)
  90 {
  91     return (c >= '0' && c <= '9');
  92 }
  93
  94 /*
  95  * Convert a string to a long integer.
  96  *
  97  * Ignores `locale' stuff.  Assumes that the upper and lower case
  98  * alphabets and digits are each contiguous.
  99  */
 100 long
 101 strtol(nptr, endptr, base)
 102         const char *nptr;
 103         char **endptr;
 104         register int base;
 105 {
 106         register const char *s = nptr;
 107         register unsigned long acc;
 108         register int c;
 109         register unsigned long cutoff;
 110         register int neg = 0, any, cutlim;
 111
 112         /*
 113          * Skip white space and pick up leading +/- sign if any.
 114          * If base is 0, allow 0x for hex and 0 for octal, else
 115          * assume decimal; if base is already 16, allow 0x.
 116          */
 117         do {
 118                 c = *s++;
 119         } while (isspace(c));
 120         if (c == '-') {
 121                 neg = 1;
 122                 c = *s++;
 123         } else if (c == '+')
 124                 c = *s++;
 125         if ((base == 0 || base == 16) &&
 126             c == '0' && (*s == 'x' || *s == 'X')) {
 127                 c = s[1];
 128                 s += 2;
 129                 base = 16;
 130         } else if ((base == 0 || base == 2) &&
 131             c == '0' && (*s == 'b' || *s == 'B')) {
 132                 c = s[1];
 133                 s += 2;
 134                 base = 2;
 135         }
 136         if (base == 0)
 137                 base = c == '0' ? 8 : 10;
 138
 139         /*
 140          * Compute the cutoff value between legal numbers and illegal
 141          * numbers.  That is the largest legal value, divided by the
 142          * base.  An input number that is greater than this value, if
 143          * followed by a legal input character, is too big.  One that
 144          * is equal to this value may be valid or not; the limit
 145          * between valid and invalid numbers is then based on the last
 146          * digit.  For instance, if the range for longs is
 147          * [-2147483648..2147483647] and the input base is 10,
 148          * cutoff will be set to 214748364 and cutlim to either
 149          * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 150          * a value > 214748364, or equal but the next digit is > 7 (or 8),
 151          * the number is too big, and we will return a range error.
 152          *
 153          * Set any if any `digits' consumed; make it negative to indicate
 154          * overflow.
 155          */
 156         cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
 157         cutlim = cutoff % (unsigned long)base;
 158         cutoff /= (unsigned long)base;
 159         for (acc = 0, any = 0;; c = *s++) {
 160                 if (isdigit(c))
 161                         c -= '0';
 162                 else if (isalpha(c))
 163                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 164                 else
 165                         break;
 166                 if (c >= base)
 167                         break;
 168                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 169                         any = -1;
 170                 else {
 171                         any = 1;
 172                         acc *= base;
 173                         acc += c;
 174                 }
 175         }
 176         if (any < 0) {
 177                 acc = neg ? LONG_MIN : LONG_MAX;
 178 //              errno = ERANGE;
 179         } else if (neg)
 180                 acc = -acc;
 181         if (endptr != 0)
 182                 *endptr = (char *)(any ? s - 1 : nptr);
 183         return (acc);
 184 }
 185
 186 /*
 187  * Convert a string to an unsigned long integer.
 188  *
 189  * Ignores `locale' stuff.  Assumes that the upper and lower case
 190  * alphabets and digits are each contiguous.
 191  */
 192 unsigned long
 193 strtoul(nptr, endptr, base)
 194         const char *nptr;
 195         char **endptr;
 196         register int base;
 197 {
 198         register const char *s = nptr;
 199         register unsigned long acc;
 200         register int c;
 201         register unsigned long cutoff;
 202         register int neg = 0, any, cutlim;
 203
 204         /*
 205          * See strtol for comments as to the logic used.
 206          */
 207         do {
 208                 c = *s++;
 209         } while (isspace(c));
 210         if (c == '-') {
 211                 neg = 1;
 212                 c = *s++;
 213         } else if (c == '+')
 214                 c = *s++;
 215         if ((base == 0 || base == 16) &&
 216             c == '0' && (*s == 'x' || *s == 'X')) {
 217                 c = s[1];
 218                 s += 2;
 219                 base = 16;
 220         } else if ((base == 0 || base == 2) &&
 221             c == '0' && (*s == 'b' || *s == 'B')) {
 222                 c = s[1];
 223                 s += 2;
 224                 base = 2;
 225         }
 226         if (base == 0)
 227                 base = c == '0' ? 8 : 10;
 228         cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
 229         cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
 230         for (acc = 0, any = 0;; c = *s++) {
 231                 if (isdigit(c))
 232                         c -= '0';
 233                 else if (isalpha(c))
 234                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
 235                 else
 236                         break;
 237                 if (c >= base)
 238                         break;
 239                 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
 240                         any = -1;
 241                 else {
 242                         any = 1;
 243                         acc *= base;
 244                         acc += c;
 245                 }
 246         }
 247         if (any < 0) {
 248                 acc = ULONG_MAX;
 249 //              errno = ERANGE;
 250         } else if (neg)
 251                 acc = -acc;
 252         if (endptr != 0)
 253                 *endptr = (char *)(any ? s - 1 : nptr);
 254         return (acc);
 255 }