[Gllug] Convertng a disk (regular) file to a named pipe

[Bruce Richardson]

On Wed, Apr 30, 2003 at 11:36:13PM +0100, Adrian wrote:
 
> Why is it not a named pipe? I may well have got the nomeclture wrong (this is 
> a genuine question), but this:
> 
> http://wombat.doc.ic.ac.uk/foldoc/foldoc.cgi?named+pipe
> 
> suggests that I haven't afaics.

Applications use file read and write operations to send data to a named
pipe (or FIFO, as it is more often called in Linux) but nothing is ever
written to the actual filesystem.  Instead, any data written to the pipe
is passed by the kernel directly to whichever application is reading
from the pipe.  My ~/.signature file is a fifo with a script in a loop
feeding it.

A loopback device, otoh, may be a virtual device but it is a real file
with real contents.  Mount it and modify its contents and you are
writing data to the filesystem, no pipes involved (named or unnamed).
Unmount it, reboot the computer, re-mount it and the contents are still
there as you left them.

man fifo
man mkfifo

-- 
Bruce

I unfortunately do not know how to turn cheese into gold.
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