The PIPE filesystem arose in answer to the question: how can I save
all or part of a Linux system onto/ via a DOS computer or a Novell
fileserver? The PIPE filesystem was designed as a quick attempt to
solve this problem

In the PIPE filesystem either shell scripts or Linux programs can be
stored. These programs are treated on the client side (eg DOS) like
simple files. Opening these files via the client causes a popen of the
programs. The server passes as the first parameter either CREAT READ
or WRITE, depending on the mode of the corresponding openfile
operation. This allows the PIPE filesystem to provide a direct
interface between client applications and Linux programs.

The problem stated above could then be solved with the following
simple shell script, which was stored in the PIPE-filesystem:

#!/bin/sh
case "$1" in
'CREAT')
        ;;
'WRITE')
        cd /u3 && tar -xf -  2>> /tmp/tar.in
        # restore directory /u3/mar
        ;;
'READ')
        cd /u3 && tar -cf -  mar  2> /dev/null
        # save directory /u3/mar
        ;;
*)
	;;
esac


Under DOS this 'Pipe File' can now be 'copied' into a local file using
the Copy command (->save), or the local file can be copied into this
'Pipe File' (->restore).

A simple print operation can be achieved with the following script:

#!/bin/sh
case "$1" in
'WRITE')
        /usr/bin/lpr
        ;;
*)
	;;
esac



Various unix programs can be invoked with the following script, after
it has been linked with the required program name.

#!/bin/sh
case "$1" in
'READ')
        /usr/bin/`basename $0`
        ;;
*)
	;;
esac


I would appreciate hearing about further documented applications of
the PIPE filesystem or suggestions for other ways of using it.

Martin