A Simple Pipe

The Solaris C code below opens a pipe to itself via a call the the IPC function pipe. The array hPipe holds two "pointers," hPipe[0] is to access the pipe’s output and hPipe[1] is used for input.
 #include <stdio.h>
 #include <unistd.h>
 #include <errno.h>                                /* perror function */
 
  int hPipe[2];                                        /* Handle hPipe[0]=input, hPipe[1]=output */
 
main() 
{
   int count;
   char buff[200];
 
   char msg[] = "Hello World\n";
 
   if ( pipe( hPipe) <0)                                      /* create an anonymous pipe */
                    perror("pipe creation");
 
    printf(" msg size is %d, read fd = %d, write = %d \n", sizeof(msg), hPipe[0], hPipe[1]);
 
    count = write( hPipe[1], msg, sizeof(msg) );  /* send message to self via pipe */
    printf(" characters Written to pipe: %d\n", count);
 
    count = read( hPipe[0], buff, sizeof(buff) );
   printf(" characters Read back from pipe: %d\n", count);
 
   write(1, buff, count);                      /* printf( buff) or the non-buffered write */
}