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

int main() {
    char *command1[] = {"ls","ls", "-l", NULL};
    char *command2[] = {"wc","wc", "-l", NULL};
    int p[2];

    pipe(p);
    pid_t pid = fork();

    if (pid == 0) {
        close(p[1]);
        dup2(p[0], STDIN_FILENO);
        execvp(command2[0], command2+1);
        exit(-1);
    }
    else{
        close(p[0]);
        dup2(p[1], STDOUT_FILENO);
        execvp(command1[0], command1+1);
        exit(-1);
    }
    return 0;
}