Annotation of prex/usr/lib/libc/stdlib/strtoul.c, Revision 1.1
1.1 ! nbrk 1: /*
! 2: * Copyright (c) 1990, 1993
! 3: * The Regents of the University of California. All rights reserved.
! 4: *
! 5: * Redistribution and use in source and binary forms, with or without
! 6: * modification, are permitted provided that the following conditions
! 7: * are met:
! 8: * 1. Redistributions of source code must retain the above copyright
! 9: * notice, this list of conditions and the following disclaimer.
! 10: * 2. Redistributions in binary form must reproduce the above copyright
! 11: * notice, this list of conditions and the following disclaimer in the
! 12: * documentation and/or other materials provided with the distribution.
! 13: * 3. Neither the name of the University nor the names of its contributors
! 14: * may be used to endorse or promote products derived from this software
! 15: * without specific prior written permission.
! 16: *
! 17: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 20: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 27: * SUCH DAMAGE.
! 28: */
! 29:
! 30: #include <limits.h>
! 31: #include <ctype.h>
! 32: #include <errno.h>
! 33: #include <stdlib.h>
! 34:
! 35: /*
! 36: * Convert a string to an unsigned long integer.
! 37: *
! 38: * Ignores `locale' stuff. Assumes that the upper and lower case
! 39: * alphabets and digits are each contiguous.
! 40: */
! 41: unsigned long
! 42: strtoul(nptr, endptr, base)
! 43: const char *nptr;
! 44: char **endptr;
! 45: register int base;
! 46: {
! 47: const char *s;
! 48: unsigned long acc, cutoff;
! 49: int c;
! 50: int neg, any, cutlim;
! 51:
! 52: /*
! 53: * See strtol for comments as to the logic used.
! 54: */
! 55: s = nptr;
! 56: do {
! 57: c = (unsigned char) *s++;
! 58: } while (isspace(c));
! 59: if (c == '-') {
! 60: neg = 1;
! 61: c = *s++;
! 62: } else {
! 63: neg = 0;
! 64: if (c == '+')
! 65: c = *s++;
! 66: }
! 67: if ((base == 0 || base == 16) &&
! 68: c == '0' && (*s == 'x' || *s == 'X')) {
! 69: c = s[1];
! 70: s += 2;
! 71: base = 16;
! 72: }
! 73: if (base == 0)
! 74: base = c == '0' ? 8 : 10;
! 75:
! 76: cutoff = ULONG_MAX / (unsigned long)base;
! 77: cutlim = (int)(ULONG_MAX % (unsigned long)base);
! 78: for (acc = 0, any = 0;; c = (unsigned char) *s++) {
! 79: if (isdigit(c))
! 80: c -= '0';
! 81: else if (isalpha(c))
! 82: c -= isupper(c) ? 'A' - 10 : 'a' - 10;
! 83: else
! 84: break;
! 85: if (c >= base)
! 86: break;
! 87: if (any < 0)
! 88: continue;
! 89: if (acc > cutoff || (acc == cutoff && c > cutlim)) {
! 90: any = -1;
! 91: acc = ULONG_MAX;
! 92: errno = ERANGE;
! 93: } else {
! 94: any = 1;
! 95: acc *= (unsigned long)base;
! 96: acc += c;
! 97: }
! 98: }
! 99: if (neg && any > 0)
! 100: acc = -acc;
! 101: if (endptr != 0)
! 102: /* LINTED interface specification */
! 103: *endptr = (char *)(any ? s - 1 : nptr);
! 104: return (acc);
! 105: }
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