#include <stdio.h>

#include <stdlib.h>

#include <string.h>

char *my_strcat(char *dest, const char *src);

char *my_strncat(char *dest, const char *src, int n);

int main(int argc, char *argv[]){

char *a = "hello world";

char *b = " yes";

char c[50] = "\0";

my_strcat(c, a);

printf("%s\n", c);

my_strncat(c, b, 2);

printf("%s\n", c);

return 0;

}

char *my_strcat(char *dest, const char *src){

char *address;

if((dest == NULL)||(src == NULL)){

printf("NULL address\n");

exit(1);

}

address = dest;

while(*dest != '\0')

++dest;

while((*dest++ = *src++) != '\0')

;

return address;

}

char *my_strncat(char *dest, const char *src, int n){

char *address;

int i = 0;

if((dest == NULL)||(src == NULL)){

printf("NULL address\n");

exit(1);

}

address = dest;

while(*dest != '\0')

++dest;

while(((*dest++ = *src++) != '\0')&&(++i <n));

return address;

}