C language Implementation string concatenation and string copy

string concatenation:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char *str_contact (const Char *,const char *);

Char *str_contact (const char *str1,const char *str2)
{
	char *result = (char*) malloc (strlen (str1) + strlen (str2) + 1);
    if (!result)
    {
    	printf ("Error:malloc failed in concat! \ n ");
    	Exit (exit_failure);
    }

    char *temp = result;
    while (*str1!= ' ")
    {
    	*result++ = *str1++;
    }

    while ((*result++ = *str2)!= ' ")
    {
    	;}
    return

    temp;
}


int main (void)
{
	char *ch1 = ' string_ ';
	char * CH2 = "_contact";
	char *result = NULL;
	result = Str_contact (CH1,CH2);
	Print ("result =%s\n", result);
	Free (result);
	result = NULL;
	return 0;
}

String copy:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

Char *strcpy (char *dst, const char *src)
{
	assert (*dst!= NULL && *src!=null);
	char *temp = DST;
	while (*src!= ' ")
	{
		*dst++ = *src++;
	}
	*DST = ' n ';

	return temp;
}

int main (void)
{
	char *ch1 = ' str_cpy ';
	char *ch2;
	Char *result = strcpy (ch2,ch1);
	printf ("result =%s\n", result);
	Free (result);
	result = NULL;
	return 0;
}