.TH PORTFS 4
.SH NAME
portfs, sendfs, youps \- we deliver events and messages for Plan B
.SH SYNOPSIS
.B portfs
[
.B -abcAD]
]
[
.B -m
.I mnt
]
[
.B -s
.I srv
]
[
.B -n
.I addr
]
[
.B -V
.I vol
]
.PP
.B sendfs
[
.B -d
]
[
.B -p
.I portfile
]
.PP
.B
youps
.SH DESCRIPTION
The
.I youps
program suite (pronounced
.IR you-p-s )
receives, examines, rewrites, and dispatches
.IR plumb (6)
messages to ports provided by machines owned by the user.
Its behaviour is similar to 
.IR plumber (4),
when used in a centralized setting.
.PP
.I Portfs
implements a file system that provides message ports. A port can be created
by creating a file. Data written to a port is delivered to all processes
reading from the port. Data uses to be
.I plumb
messages, but it may be any other thing. Once a port has ben read, when
all readers of a port close the port, the port is removed. By default,
.I portfs
mounts itself at
.BR /devs/ports
and listens for network clients at
.BR tcp!*!11002 .
Options are similar to those of most file servers, as described in
.IR planb (4).
.PP
.I Sendfs
delivers events to ports. The program services are mounted on the directory
.B /mnt/plumb
and consists of two
pre-defined files:
.BR send .
and
.BR rules .
.PP
Programs use
.B write
(see
.IR read (2))
to deliver messages to the
.B send
file, and
.I sendfs
decides, looking at its configuration, to which port the message should be sent.
The behaviour and configuration is like in
.IR plumber (4).
Beware that commands used within a plumb rule should supply the
.B -p
option to any
.I plumb (1)
command issued within the rule. Otherwise,
.I plumb
will not be able to deliver the message because there is no
.B send
file in the file system as seen by the command (That file is implemented
by
.I sendfs
only as a front-end for the user).
.PP
The file
.BR rules
behaves like in
.IR plumber (4)
and permits configuration of the service.
.PP
.I youps
is a convenience script that starts the service by running
.I portfs
and
.I sendfs
after mounting a union of all user ports at
.BR /mnt/plumb .
.SH FILES
.TF /usr/$user/lib/plumbing
.TP
.B /usr/$user/lib/plumbing
default rules file
.TP
.B /sys/lib/plumb
directory to search for files in
.B include
statements.
.TP
.B /mnt/plumb
mount point for the send file and the union of all ports. The
ports of the local machine are mounted above those of others.
.TP
.B /devs/ports
ports serviced by the local machine.
.SH SOURCE
.B /sys/src/cmd/youps
.SH "SEE ALSO"
.IR plumber (4),
.IR plumb (1),
.IR plumb (2),
.IR plumb (6)
.SH BUGS
The delivery of messages across the network is not secured.