IPC Pipe in Linux C -

it's simple code makes 2 child processes communicate: first 1 execute "ls" , pass output myfd[1]; second 1 receives output myfd[0], , execute "sort"(and shows result). parent process waits these 2 processes.

but code doesn't work. gets stuck @ second child process. possible reason why? did use right "close" , "dump" in proper place?

my code:

#include <stdio.h> #include <string.h> #include <unistd.h> #include <stdlib.h> #include <sys/types.h>  int main(void) {     int pid;     int wpid;     int status = 0;      int myfd[2];      printf("parent's pid: %d\n",getpid());      pipe(myfd);      pid = fork();     if(pid == 0) // child 1 - execute "ls"     {         printf("child1's pid: %d\n",getpid());          close(1);         dup(myfd[1]);         close(0);         close(myfd[0]);          execlp("ls","child_process1",null);     }     else     {         pid = fork();         if(pid == 0) // child 2 - execute "sort"         {             printf("child2's pid: %d\n",getpid());              close(myfd[1]);             close(0);             dup(myfd[0]);              execlp("sort","child_process2",null);         }     }      // parent     while((wpid = wait(&status)) > 0)     {         // wait until 2 child processes finish     }     printf("done!\n"); }