From: Carlos <angus@...>
Date: 2001-09-25T03:11:50+09:00
Subject: [ruby-talk:21642] Re: opening a named pipe?

> > sendCmdToDiald( 'monitor', $STATUS_FIFO_NAME )
> > File.open($STATUS_FIFO_NAME,'r') do |status_fifo|
> >     # read from FIFO
> > end
> 
> Nope, tried that.  Diald doesn't like it when there's no one reading on
> the other end... it only starts writing if another process has *already*
> opened the pipe for read when it gets the command to start writing.
> I've confirmed this with tests on the command line, manually creating
> pipes and telling Diald to write to them.  If I have a 'cat' command
> pending on a pipe, and then tell diald to write to that pipe, it works
> and the 'cat' command starts displaying the diald output.  But if I tell
> diald to start writing, and then start 'cat /tmp/myfifo', (where
> /tmp/myfifo is a fifo I've already created with mkfifo) then diald
> complains: "could not open pipe /tmp/myfifo: No such device or address".

Maybe you can open the pipe non-blocking

	File.open($STATUS_FIFO_NAME, File::RDONLY | File::NONBLOCK)

or something like that (I don't have the necessary documentation; I only saw
this form of opening a file as an example of File.new in the Rubybook).