3 plumber \- file system for interprocess messaging
16 is a user-level file server that receives, examines, rewrites, and dispatches
18 messages between programs.
19 Its behavior is programmed by a
22 .BR $HOME/lib/plumbing )
26 Its services are posted via
37 for dispatching messages to applications.
43 to deliver messages to the
47 to receive them from the corresponding port.
53 command cause a message to be sent to
56 in turn reads from, by convention,
58 to receive messages about files to open.
60 A copy of each message is sent to each client that has the corresponding port open.
61 If none has it open, and the rule has a
67 rule, that rule is applied.
71 rule causes the specified command to be run
72 and the message to be held for delivery when the port is opened.
76 rule runs the command but discards the message.
81 is specified and the port is not open,
82 the message is discarded and a write error is returned to the sender.
84 The set of output ports is determined dynamically by the
85 specification in the plumbing rules file: a port is created for each unique
91 The set of rules currently active may be examined by reading the file
93 appending to this file adds new rules to the set, while
94 creating it (opening it with
97 Thus the rule set may be edited dynamically with a traditional text editor.
98 However, ports are never deleted dynamically; if a new set of rules does not
99 include a port that was defined in earlier rules, that port will still exist (although
100 no new messages will be delivered there).
104 option causes the process to run in the foreground.
106 .TF $HOME/lib/plumbing
108 .B $HOME/lib/plumbing
112 directory to search for files in
127 .\" file name space is fixed, so it is difficult to plumb
128 .\" messages that involve files in newly mounted services.