#include "string.h"

void *memset( void *s, int c, size_t n )
{
	for( size_t i = 0; i < n; i++ ) {
		((char *)s)[i] = c;
	}
	
	return s;
}

void *memmove( void *d, const void *s, size_t n )
{
	const char *ss = (const char *)s;
	char *dd = (char *)d;
	
	if( dd == ss ) return d;
	
	if( dd <= ss ) {
		while( n > 0 ) {
			*dd++ = *ss++;
			n--;
		}
	} else {
		dd += n;
		ss += n;
		while( n > 0 ) {
			*--dd = *--ss;
			n--;
		}
	}
	
	return d;
}

void *memcpy( void *d, const void *s, size_t n )
{
	const char *ss = (const char *)s;
	char *dd = (char *)d;
	
	if( dd == ss ) return d;
	
	while( n > 0 ) {
		*dd++ = *ss++;
		n--;
	}
	
	return d;
}

size_t strlen( const char *s )
{
	size_t len;
	const char *p = s;
	
	for( len = 0; *p; len++, p++ );
	
	return len;
}

int strcmp( const char *s1, const char *s2 )
{
	while( *s1 && *s2 && *s1 == *s2 ) {
		s1++;
		s2++;
	}

	return *s1 - *s2;
}

size_t strlcpy( char *d, const char *s, size_t n )
{
	size_t len = 0;
	
	while( len < n && s[len] != '\0' ) {
		d[len] = s[len];
		len++;
	}
	d[len] = '\0';
	
	while( s[len] != '\0' ) {
		len++;
	}
	
	if( len >= n ) {
		d[n-1] = '\0';
	}
	
	return len;
}

size_t strlcat( char *d, const char *s, size_t n )
{
	size_t len = 0;
	const char *ss = s;
	char *dd = d;
	
	while( len < n && *dd != '\0' ) {
		len++;
		dd++;
	}
	
	if( len == n ) {
		return len + strlen( s );
	}
	
	while( len + 1 < n && ( *dd++ = *ss++ ) ) {
		len++;
	}
	
	*dd = '\0';
	
	return len;
}