/*********************************************************
 *
 *    pipe.c
 *
 *    4/15/04 Jeff Ondich
 *
 *    Adapted from "UNIX Network Programming," W. Richard
 *    Stevens, Prentice Hall 1990, p.102.
 *
 *********************************************************/

#include    <stdio.h>
#include    <stdlib.h>
#include    <unistd.h>
#include    <sys/types.h>
#include    <sys/stat.h>
#include    <fcntl.h>
#include    <ctype.h>

int main()
{
    pid_t pid;
    int fd[2];
    
    if( pipe( fd ) < 0 )
    {
        perror( "Trouble creating pipe.\n" );
        exit( 1 );
    }

    printf( "fd[0] = %d, fd[1] = %d\n", fd[0], fd[1] );

    pid = fork();
    if( pid < 0 )
    {
        perror( "Trouble forking.\n" );
        exit( 1 );
    }

    if( pid != 0 )
    {
        close( fd[0] );
        if( dup2( fd[1], STDOUT_FILENO ) == -1 )
            perror( "Trouble redirecting stdout." );
        close( fd[1] );

        execlp( "cat", "cat", "moose.txt", NULL );
        perror( "Parent: we shouldn't get here." );
    }
    else
    {
        close( fd[1] );
        if( dup2( fd[0], STDIN_FILENO ) == -1 )
            perror( "Trouble redirecting stdin." );
        close( fd[0] );

        execlp( "wc", "wc", NULL );
        perror( "Child: we shouldn't get here." );
    }

    return 0;
}