IPC with pipes, also dup2 redirect stream handle

#include <stdio.h>

#include <sys/types.h>

#include <sys/wait.h>

#include <unistd.h>



int main()

{

        int fds[2];

        pid_t pid;



        pipe( fds );

        pid = fork();

        if( pid == (pid_t)0 )

        {

                close( fds[1] );

                dup2(fds[0], STDIN_FILENO );

                execlp( "sort", "sort", 0 );

        }

        else

        {

                FILE *stream;

                close(fds[0]);

                stream = fdopen( fds[1], "w" );

                fprintf( stream, "This is a test.\n" );

                fprintf( stream, "Hello, world.\n" );

                fprintf( stream, "My dog has fleas.\n" );

                fprintf( stream, "My dream will come true.\n");

                fflush( stream );

                close( fds[1] );

                waitpid( pid, NULL, 0 );

        }

}