Implementation of ls | wc command

// C code to implement ls | wc command
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include<errno.h>
#include<sys/wait.h>
#include <unistd.h>
int main(){

    // array of 2 size a[0] is for
    // reading and a[1] is for
    // writing over a pipe    
    int a[2];

    // using pipe for inter
    // process communication
    pipe(a);

    if(!fork())
    {
        // closing normal stdout
        close(1);
        
        // making stdout same as a[1]
        dup(a[1]);
        
        // closing reading part of pipe
        // we don't need of it at this time
        close(a[0]);
        
        // executing ls 
        execlp("ls","ls",NULL);
    }
    else
    {
        // closing normal stdin
        close(0);
        
        // making stdin same as a[0]
        dup(a[0]);
        
        // closing writing part in parent,
        // we don't need of it at this time
        close(a[1]);
        
        // executing wc
        execlp("wc","wc",NULL);
    }
}