oskit/oskit-20020317/libc/stdlib/strtoul.c

58 lines
1.6 KiB
C
Executable File

/*
* Copyright (c) 1994-1995, 1998 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
#include <ctype.h>
#include <string.h>
unsigned long strtoul(const char *p, char **out_p, int base)
{
unsigned long v = 0;
while (isspace(*p))
p++;
if (((base == 16) || (base == 0)) &&
((*p == '0') && ((p[1] == 'x') || (p[1] == 'X'))))
{
p += 2;
base = 16;
}
if (base == 0)
{
if (*p == '0')
base = 8;
else
base = 10;
}
while (1)
{
char c = *p;
if ((c >= '0') && (c <= '9') && (c - '0' < base))
v = (v * base) + (c - '0');
else if ((c >= 'a') && (c <= 'z') && (c - 'a' + 10 < base))
v = (v * base) + (c - 'a' + 10);
else if ((c >= 'A') && (c <= 'Z') && (c - 'A' + 10 < base))
v = (v * base) + (c - 'A' + 10);
else
break;
p++;
}
if (out_p) *out_p = (char*)p;
return v;
}