shithub: purgatorio

ref: 5611a46d8fb04ec3fd60c05a1486743cea98a311
dir: /man/6/plumbing/

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.TH PLUMBING 6
.SH NAME
plumbing \- plumbing rules
.SH DESCRIPTION
Plumbing rules tell
.IR plumber (8)
how to route plumbing messages
generated by applications using
.IR plumbmsg (2).
.PP
The file is a set of rules separated by blank lines.
Each
rule
is a set of patterns followed by a set of actions.
The rules are interpreted in order.
The first rule whose patterns all match is applied, and no further
rules are examined.
Comments start with
.B #
and continue to end of line.
Single quotes protect special characters (use
.B ''
to get a single quote).
.PP
A
pattern
has the general form:
.IP
.I "field verb arg"
.PP
Each
.I field
corresponds to a field in the incoming plumbing message:
.RS
.TP
.B src
Source application
.TP
.B dst
Destination port
.TP
.B dir
Working directory
.TP
.B kind
Format of the data (eg,
.B text
or
.BR image )
.TP
.B attr
A line of
.IB name = value
pairs
.TP
.B data
The message data (an array of bytes)
.RE
.PP
The verbs are:
.RS
.TF matches
.PD
.TP
.B is
Exact string comparison with
.I arg
.TP
.B matches
Regular expression comparison with
.I arg
.TP
.B isdir
.I Arg
must name an existing directory
.TP
.B isfile
.I Arg
must name an existing file
.TP
.B set
Set the value of the
.I field
to
.IR arg .
This verb operates in place, so put it after all other patterns in the rule.
.RE
.PP
The
.I arg
can refer to one of the following variables:
.RS
.TF "$0 to $9 "
.PD
.TP
.BR $0 " to " $9
Substrings resulting from the most recent regular expression match:
.B $0
is the entire substring;
.B $1
the first parenthesised substring, etc.
.TP
.B $file
The file name examined by the last
.B isfile
verb.
.TP
.B $dir
The directory name examined by the last
.B isdir
verb.
.RE
.PP
The following actions are provided:
.RS
.TP
.BI "plumb to" " port"
Route the message to the given plumbing
.IR port .
.TP
.BI "plumb start" " command arg ..."
If no program is currently listening on the current rule's
.IR port ,
start the
.I command
with the given arguments.
The
.RB ` $ '
variables listed above can be used, to include part
of the message in the command line arguments to the program.
They are replaced in the command string by their actual values.
.RE
.PP
For example, the following rule sends the names of module files\-
file names ending with suffix
.RB ` .m '\-
to
.IR wm-brutus (1),
starting it if it is not already running:
.IP
.EX
kind is text
data matches '([a-zA-Z0-9]+\.m)(:[0-9]+)?'
data isfile     /module/$1
data set        /module/$0
plumb to edit
plumb start /dis/wm/brutus.dis $file$2
.EE
.PP
Note the use of
.B $2
in the
.B start
action to pass
.B brutus
the line number selected by the second parenthesised
expression in the pattern.
.SH FILES
.BI /usr/ user /lib/plumbing
.SH SEE ALSO
.IR plumb (1),
.IR plumbmsg (2),
.IR plumber (8)