eduOS/libkern/string.c

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/*
* Written by the Chair for Operating Systems, RWTH Aachen University
*
* NO Copyright (C) 2010-2011, Stefan Lankes
* consider these trivial functions to be public domain.
*
* These functions are distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*/
#include <eduos/string.h>
#ifndef HAVE_ARCH_MEMCPY
void *memcpy(void *dest, const void *src, size_t count)
{
size_t i;
if (BUILTIN_EXPECT(!dest || !src, 0))
return dest;
for (i = 0; i < count; i++)
((char*)dest)[i] = ((char*)src)[i];
return dest;
}
#endif
#ifndef HAVE_ARCH_MEMSET
void *memset(void *dest, int val, size_t count)
{
size_t i;
if (BUILTIN_EXPECT(!dest, 0))
return dest;
for (i = 0; i < count; i++)
((char*) dest)[i] = (char) val;
return dest;
}
#endif
#ifndef HAVE_ARCH_STRLEN
size_t strlen(const char *str)
{
size_t len = 0;
if (BUILTIN_EXPECT(!str, 0))
return len;
while (str[len] != '\0')
len++;
return len;
}
#endif
#ifndef HAVE_ARCH_STRNCPY
char* strncpy(char *dest, const char *src, size_t n)
{
size_t i;
if (BUILTIN_EXPECT(!dest || !src, 0))
return dest;
for (i = 0 ; i < n && src[i] != '\0' ; i++)
dest[i] = src[i];
if (i < n)
dest[i] = '\0';
else
dest[n-1] = '\0';
return dest;
}
#endif
#ifndef HAVE_ARCH_STRCPY
char* strcpy(char *dest, const char *src)
{
size_t i;
if (BUILTIN_EXPECT(!dest || !src, 0))
return dest;
for (i = 0 ; src[i] != '\0' ; i++)
dest[i] = src[i];
dest[i] = '\0';
return dest;
}
#endif
#ifndef HAVE_ARCH_STRCMP
int strcmp(const char *s1, const char *s2)
{
while (*s1 != '\0' && *s1 == *s2) {
s1++;
s2++;
}
return (*(unsigned char *) s1) - (*(unsigned char *) s2);
}
#endif
#ifndef HAVE_ARCH_STRNCMP
int strncmp(const char *s1, const char *s2, size_t n)
{
if (BUILTIN_EXPECT(n == 0, 0))
return 0;
while (n-- != 0 && *s1 == *s2) {
if (n == 0 || *s1 == '\0')
break;
s1++;
s2++;
}
return (*(unsigned char *) s1) - (*(unsigned char *) s2);
}
#endif