PLUMBER(8) PLUMBER(8)
NAME
plumber - plumber for interapplication message routing
SYNOPSIS
plumber [ -v ] [ -w ] [ -c wmchan ] [ rulefile ... ]
DESCRIPTION
Plumber provides high-level message-passing between applica-
tions. In a plumbed environment, applications can receive
messages on an input port, which is given a logical name.
Messages are not sent directly between applications but are
routed via the plumber, following user-specified rules.
Plumber is typically started by wm(1)'s startup script. It
reads each rulefile (default: /usr/user/lib/plumbing) in
turn. Each file has the form described in plumbing(6); the
rules direct the routing of each message plumber receives.
Plumber then lurks in the background with its mate, awaiting
plumbing requests sent by plumbmsg(2), by windowing applica-
tions in response to events such as button clicks or drag-
and-drop, or by plumb(1).
When a message arrives, plumber applies the rules to decide
how to route it. It forwards the message to the selected
application's input port, starting it if necessary. If no
rule applies (or some other error occurs), plumber returns
an error to the message's sender. The -v option causes
plumber to log the contents of messages it receives, to help
debug plumbing rules and applications.
Plumber normally starts applications directly. For use on
devices that have specialised window managers, not wm(1),
the -w option causes plumber to start applications indi-
rectly, by sending a message to a window manager listening
on /chan/wm, allowing the window manager to track every
application started. The -c option can select an alterna-
tive wmchan to /chan/wm.
FILES
/usr/user/lib/plumbing default plumbing rules for user
SOURCE
/appl/cmd/plumber.b
/appl/lib/plumbing.b
SEE ALSO
plumb(1), wm(1), plumbmsg(2), plumbing(6)
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