pid_t pid;
/* fork a child process */
pid = fork();
if(pid<0){
    /*error occurred */
    fprintf(stderr, "Fork Failed");
    return 1;
}
else if(pid==0){/* child process */
    execlp("/bin/ls" ,"ls" ,NULL);
}
else{/* parent process */
    /* parent will wait for the child to complete */
    wait(NULL);
    printf("Child Complete");
}
return 0;
}