#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<string.h>
#include<sys/wait.h>

int main(int argc, char const *argv[])
{
	int fd[2];

    if (pipe(fd)==-1) exit(1);

    int pid = fork();
    if(pid == 0) {
    	close(fd[0]);
    	dup2(fd[1], 1);
    	close(fd[1]);
    	execlp("ls", "ls", (char *) 0);
    	exit(1);
    }
    else if (pid > 0) {
    	int pid2 = fork();
    	if(pid2 == 0) {
    		close(fd[1]);
    		dup2(fd[0], 0);
    		close(fd[0]);
    		execlp("wc", "wc", (char *) 0);
    		exit(1);

    	} else if(pid2 > 0) {
    		// Close both ends
    		close(fd[0]);
    		close(fd[1]);
    		wait(NULL);
    		wait(NULL);
    	} else exit(1);
    } else exit(1);

	return 0;
}