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dpipe

NAME

dpipe - bi-directional pipe command

SYNOPSIS

dpipe [ command [ args ] ] = [ command [ args ] ]
dpipe [ command [ args ] ] = [ command [ args ] ] [ = [ command [ args ] ] ]

DESCRIPTION

dpipe is a general tool to run two commands diverting the standard output of the first command into the standard input of the second and viceversa. It is the bi-directional extension of the | (pipe) syntax used by all the shells. The = has been chosen as a metaphore of two parallel communication lines between the commands. It is also possible to catenate several tools. Itermediate programs communicate using standard input and stardard output with the preceding tool and alternate standard input and output (respectively file descriptors number 3 and 4) towards the following tool. If an intermediate tool should process only the data flowing in one direction use { or } as suffix for the preceding = and prefix of the following one.
This tool has been written as a tool for the Virtual Distributed Ethernet.

EXAMPLE

dpipe a = b
processes a and b are bidirectionally connected: stdin of a is connected to stdout of b and viceversa
dpipe a = b = c
a and b are connected as above. alternate stdin of b is connected to stdout of c and alternate stdout of b to stdin of c
dpipe a =} b }= c
This is a cycle of pipes: stdout of a is connected to stdin of b, stdout of b with stdin of c, and stdout of c to stdin of a
dpipe a =} b }={ c {= d = e
all the notations can be mixed together. this is a -> b -> d -> c and back to a; alternate ports of d are connected to e

OPTIONS

no options.

NOTICE

Virtual Distributed Ethernet is not related in any way with www.vde.com ("Verband der Elektrotechnik, Elektronik und Informationstechnik" i.e. the German "Association for Electrical, Electronic & Information Technologies").

SEE ALSO

vde_switch(1), vde_plug(1), vde_plug2tap(1), vdeq(1). wirefilter(1).

AUTHOR

VDE is a project by Renzo Davoli <renzo@cs.unibo.it>.