DaniWeb Forum Index > Software Development > C++

Named Pipe (FIFO)

Please support our C++ advertiser: Intel Parallel Studio Home

•

Join Date: Feb 2005

Posts: 78

Reputation: nanodano is an unknown quantity at this point

Solved Threads: 2

nanodano

Offline

Junior Poster in Training

Named Pipe (FIFO)

Feb 13th, 2007

Hi,
I'm trying to write a program using named pipes, and I'm having trouble opening it. In another program I call this line:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
  mkfifo("./fife", 0777);
  mkfifo("./fife", 0777);

So my named pipe exists and I see it in my list of files. Then I run the program I included below, but I can not get past the open call. Any help would be appreciated for I can not find a lot of resources on this subject.

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <iostream>
 
#define MSGSIZE 14
 
void main() {
  char *message = "Hello, world!";
 
  int fd;
  fd = open("fife", O_WRONLY);
 // Can not get past this point!
 
  cout << "fd: " << fd << endl;
 
  if (write(fd, message, MSGSIZE) < 0)
    cout << "error writing" << endl;
 
  close(fd);
}
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <iostream>

#define MSGSIZE 14

void main() {
  char *message = "Hello, world!";

  int fd;
  fd = open("fife", O_WRONLY);
 // Can not get past this point!

  cout << "fd: " << fd << endl;

  if (write(fd, message, MSGSIZE) < 0)
    cout << "error writing" << endl;

  close(fd);
}

•

Join Date: Dec 2005

Posts: 5,850

Reputation: Salem has a reputation beyond repute

Solved Threads: 749

Salem

Offline

Void main'ers are DOOMed

Re: Named Pipe (FIFO)

Feb 13th, 2007

Look at the errno which open sets, when it returns with a failure?

•

Join Date: Feb 2005

Posts: 78

Reputation: nanodano is an unknown quantity at this point

Solved Threads: 2

nanodano

Offline

Junior Poster in Training

Re: Named Pipe (FIFO)

Feb 14th, 2007

I found out the problem. It waits because it wants another program to handle the other end of the pipe.

I fixed my codes up and I wrote a script like this to fix the problem:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#!/bin/bash
echo "Running clients..."
./client &
./client &
 
echo "Running server..."
./server
# The & runs the program in the background, so you can run another program, playing client and server in the same console
#!/bin/bash
echo "Running clients..."
./client &
./client &

echo "Running server..."
./server
# The & runs the program in the background, so you can run another program, playing client and server in the same console

•

Join Date: May 2008

Posts: 1

Reputation: mustihi is an unknown quantity at this point

Solved Threads: 0

mustihi

Offline

Newbie Poster

Re: Named Pipe (FIFO)

May 21st, 2008

can you post the client program (reading program) too?

Last edited by mustihi; May 21st, 2008 at 8:58 am.

•

Join Date: Dec 2005

Posts: 5,850

Reputation: Salem has a reputation beyond repute

Solved Threads: 749

Salem

Offline

Void main'ers are DOOMed

Re: Named Pipe (FIFO)

May 21st, 2008

a) you're too late - by at least a year, check the dates.
b) try programming something for yourself.
c) start your own thread when you've got something to show.