cLK/lk/lib/libc/atoi.c
2011-03-25 23:39:33 +02:00

106 lines
2.4 KiB
C

/*
** Copyright 2001, Travis Geiselbrecht. All rights reserved.
** Distributed under the terms of the NewOS License.
*/
/*
* Copyright (c) 2008 Travis Geiselbrecht
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <stdlib.h>
#include <ctype.h>
#define LONG_IS_INT 1
static int hexval(char c)
{
if (c >= '0' && c <= '9')
return c - '0';
else if (c >= 'a' && c <= 'f')
return c - 'a' + 10;
else if (c >= 'A' && c <= 'F')
return c - 'A' + 10;
return 0;
}
int atoi(const char *num)
{
#if !LONG_IS_INT
// XXX fail
#else
return atol(num);
#endif
}
unsigned int atoui(const char *num)
{
#if !LONG_IS_INT
// XXX fail
#else
return atoul(num);
#endif
}
long atol(const char *num)
{
long value = 0;
int neg = 0;
if (num[0] == '0' && num[1] == 'x') {
// hex
num += 2;
while (*num && isxdigit(*num))
value = value * 16 + hexval(*num++);
} else {
// decimal
if (num[0] == '-') {
neg = 1;
num++;
}
while (*num && isdigit(*num))
value = value * 10 + *num++ - '0';
}
if (neg)
value = -value;
return value;
}
unsigned long atoul(const char *num)
{
unsigned long value = 0;
if (num[0] == '0' && num[1] == 'x') {
// hex
num += 2;
while (*num && isxdigit(*num))
value = value * 16 + hexval(*num++);
} else {
// decimal
while (*num && isdigit(*num))
value = value * 10 + *num++ - '0';
}
return value;
}