test_read_pipe.cpp

/*
Copyright 2007, 2008, 2009, 2010, 2011 Instituto de Sistemas e Robotica, Instituto Superior Tecnico

This file is part of MeRMaID.

MeRMaID is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

MeRMaID is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with MeRMaID.  If not, see <http://www.gnu.org/licenses/>.
*/



#include "config.h"

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

#define PIPE_NAME "/tmp/test_read_pipe"
#define TEST_FILE "test_file.txt"
#define SIZE 1000

int main()
{
  // create named pipe
  mkfifo (PIPE_NAME, S_IWUSR);
  
#ifdef DEBUG
  fprintf (stderr, "Named pipe created with name: %s.\n", PIPE_NAME);
#endif
  
  // open named pipe
  int fd_pipe = open (PIPE_NAME, O_WRONLY | O_CREAT, S_IWUSR);
  FILE* fd_file = fopen (TEST_FILE, "r");
  
  if (fd_pipe == -1 || fd_file == 0) {
    // Error opening pipe or file
    return -1;
  }
  
#ifdef DEBUG
  fprintf (stderr, "Named pipe opened sucessfully.");
#endif
  
  char buf[SIZE];
  while (1) {
    int bytes_read = fread (buf, 1, SIZE, fd_file);
#ifdef DEBUG
    int bytes_written = write (fd_pipe, buf, bytes_read);
#else
    write (fd_pipe, buf, bytes_read);
#endif
    
#ifdef DEBUG
    fprintf (stderr, "%d bytes written\n", bytes_written);
#endif
    
    if (bytes_read < SIZE) break;
  }
  
  close (fd_pipe);
  fclose (fd_file);
  return 0;
}