gonzui

    1: /* $OpenBSD: strtoll.c,v 1.6 2005/11/10 10:00:17 espie Exp $ */
    2: /*-
    3:  * Copyright (c) 1992 The Regents of the University of California.
    4:  * All rights reserved.
    5:  *
    6:  * Redistribution and use in source and binary forms, with or without
    7:  * modification, are permitted provided that the following conditions
    8:  * are met:
    9:  * 1. Redistributions of source code must retain the above copyright
   10:  *    notice, this list of conditions and the following disclaimer.
   11:  * 2. Redistributions in binary form must reproduce the above copyright
   12:  *    notice, this list of conditions and the following disclaimer in the
   13:  *    documentation and/or other materials provided with the distribution.
   14:  * 3. Neither the name of the University nor the names of its contributors
   15:  *    may be used to endorse or promote products derived from this software
   16:  *    without specific prior written permission.
   17:  *
   18:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   19:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   20:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   21:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   22:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   23:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   24:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   25:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   26:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   27:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   28:  * SUCH DAMAGE.
   29:  */
   30: 
   31: #include <sys/types.h>
   32: 
   33: #include <ctype.h>
   34: #include <errno.h>
   35: #include <limits.h>
   36: #include <stdlib.h>
   37: 
   38: /*
   39:  * Convert a string to a long long.
   40:  *
   41:  * Ignores `locale' stuff.  Assumes that the upper and lower case
   42:  * alphabets and digits are each contiguous.
   43:  */
   44: long long
   45: strtoll(const char *nptr, char **endptr, int base)
   46: {
   47:         const char *s;
   48:         long long acc, cutoff;
   49:         int c;
   50:         int neg, any, cutlim;
   51: 
   52:         /*
   53:          * Skip white space and pick up leading +/- sign if any.
   54:          * If base is 0, allow 0x for hex and 0 for octal, else
   55:          * assume decimal; if base is already 16, allow 0x.
   56:          */
   57:         s = nptr;
   58:         do {
   59:                 c = (unsigned char) *s++;
   60:         } while (isspace(c));
   61:         if (c == '-') {
   62:                 neg = 1;
   63:                 c = *s++;
   64:         } else {
   65:                 neg = 0;
   66:                 if (c == '+')
   67:                         c = *s++;
   68:         }
   69:         if ((base == 0 || base == 16) &&
   70:             c == '0' && (*s == 'x' || *s == 'X')) {
   71:                 c = s[1];
   72:                 s += 2;
   73:                 base = 16;
   74:         }
   75:         if (base == 0)
   76:                 base = c == '0' ? 8 : 10;
   77: 
   78:         /*
   79:          * Compute the cutoff value between legal numbers and illegal
   80:          * numbers.  That is the largest legal value, divided by the
   81:          * base.  An input number that is greater than this value, if
   82:          * followed by a legal input character, is too big.  One that
   83:          * is equal to this value may be valid or not; the limit
   84:          * between valid and invalid numbers is then based on the last
   85:          * digit.  For instance, if the range for long longs is
   86:          * [-9223372036854775808..9223372036854775807] and the input base
   87:          * is 10, cutoff will be set to 922337203685477580 and cutlim to
   88:          * either 7 (neg==0) or 8 (neg==1), meaning that if we have
   89:          * accumulated a value > 922337203685477580, or equal but the
   90:          * next digit is > 7 (or 8), the number is too big, and we will
   91:          * return a range error.
   92:          *
   93:          * Set any if any `digits' consumed; make it negative to indicate
   94:          * overflow.
   95:          */
   96:         cutoff = neg ? LLONG_MIN : LLONG_MAX;
   97:         cutlim = cutoff % base;
   98:         cutoff /= base;
   99:         if (neg) {
  100:                 if (cutlim > 0) {
  101:                         cutlim -= base;
  102:                         cutoff += 1;
  103:                 }
  104:                 cutlim = -cutlim;
  105:         }
  106:         for (acc = 0, any = 0;; c = (unsigned char) *s++) {
  107:                 if (isdigit(c))
  108:                         c -= '0';
  109:                 else if (isalpha(c))
  110:                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
  111:                 else
  112:                         break;
  113:                 if (c >= base)
  114:                         break;
  115:                 if (any < 0)
  116:                         continue;
  117:                 if (neg) {
  118:                         if (acc < cutoff || (acc == cutoff && c > cutlim)) {
  119:                                 any = -1;
  120:                                 acc = LLONG_MIN;
  121:                                 /*errno = ERANGE*/;
  122:                         } else {
  123:                                 any = 1;
  124:                                 acc *= base;
  125:                                 acc -= c;
  126:                         }
  127:                 } else {
  128:                         if (acc > cutoff || (acc == cutoff && c > cutlim)) {
  129:                                 any = -1;
  130:                                 acc = LLONG_MAX;
  131:                                 /*errno = ERANGE*/;
  132:                         } else {
  133:                                 any = 1;
  134:                                 acc *= base;
  135:                                 acc += c;
  136:                         }
  137:                 }
  138:         }
  139:         if (endptr != 0)
  140:                 *endptr = (char *) (any ? s - 1 : nptr);
  141:         return (acc);
  142: }
  143: 
  144: #ifdef __weak_alias
  145: __weak_alias(strtoq, strtoll);
  146: #else
  147: quad_t
  148: strtoq(const char *nptr, char **endptr, int base)
  149: {
  150: 
  151:         return ((quad_t)strtoll(nptr, endptr, base));
  152: }
  153: #endif