diff options
Diffstat (limited to 'sys/libkern/strtoul.c')
-rw-r--r-- | sys/libkern/strtoul.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/sys/libkern/strtoul.c b/sys/libkern/strtoul.c new file mode 100644 index 0000000..0f7e703 --- /dev/null +++ b/sys/libkern/strtoul.c @@ -0,0 +1,111 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Chris Torek. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * From: static char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93"; + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/ctype.h> +#include <machine/limits.h> + +/* + * Convert a string to an unsigned long integer. + * + * Ignores `locale' stuff. Assumes that the upper and lower case + * alphabets and digits are each contiguous. + */ +unsigned long +strtoul(nptr, endptr, base) + const char *nptr; + const char **endptr; + int base; +{ + const char *s = nptr; + unsigned long acc; + unsigned char c; + unsigned long cutoff; + int neg = 0, any, cutlim; + + /* + * See strtol for comments as to the logic used. + */ + do { + c = *s++; + } while (isspace(c)); + if (c == '-') { + neg = 1; + c = *s++; + } else if (c == '+') + c = *s++; + if ((base == 0 || base == 16) && + c == '0' && (*s == 'x' || *s == 'X')) { + c = s[1]; + s += 2; + base = 16; + } + if (base == 0) + base = c == '0' ? 8 : 10; + cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; + cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; + for (acc = 0, any = 0;; c = *s++) { + if (!isascii(c)) + break; + if (isdigit(c)) + c -= '0'; + else if (isalpha(c)) + c -= isupper(c) ? 'A' - 10 : 'a' - 10; + else + break; + if (c >= base) + break; + if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) + any = -1; + else { + any = 1; + acc *= base; + acc += c; + } + } + if (any < 0) { + acc = ULONG_MAX; + } else if (neg) + acc = -acc; + if (endptr != 0) + *endptr = (const char *)(any ? s - 1 : nptr); + return (acc); +} |