// file: hello_pipe.c
//
// Synopsis: Simple illustration of pipe
// 		from [Jumpstart].
//
// 	(1) Creates a pipe
//	(2) Writes "Hello World" into one end
//	(3) Reads from the other end
//	(4) Write the result of reading to std output.
//
//	THIS IS A TOY PROBLEM SINCE USUALLY PIPES
//	GOES BETWEEN TWO PROCESSES.
//
//	REMARK: THIS PROGRAM WORKS ON BOTH CYGWIN and SOLARIS.
// Chee Yap (Feb 10, 2005)

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

main()
{  char *message = "Hello World!\n";
   int length = strlen(message);
   char buf[1024];
   int fdv[2];
   int n;

   if (pipe(fdv) == -1)
	   perror("pipe");

   if (write(fdv[1], message, length) != length)
	   perror("write to pipe");

   n = read(fdv[0], buf, length);
   if (n != length) 
	   perror("read from pipe");
   write(STDOUT_FILENO, buf, n);
   exit(0);
}