.TH IMPORT 4
.SH NAME
import \- import a name space from a remote system
.SH SYNOPSIS
.B import
[
.I options
]
.I system
.I file
[
.I mountpoint
]
.PP
.B import
.B -B
[
.I options
]
.I mountpoint
[
.I cmd
[
.I args ...
]
]
.SH DESCRIPTION
This tool is deprecated and has been replaced by
.I rimport
(see
.IR rcpu (1)).
.PP
.I Import
allows an arbitrary
.I file
on a remote
.I system
to be imported into the local name space.
Usually
.I file
is a directory, so the complete
file tree under the directory is made available.
.PP
A process is started on the
remote machine, with authority of the user of
.IR import ,
to perform work for the local machine using the
.IR exportfs (4)
service.
The default port used is TCP 17007.
If
.I mountpoint
is omitted
.I import
uses the name of the remote
.I file
as the local mount point.
.PP
The options are:
.TF "-s namexxx"
.PD
.TP
.B -a -b -c -C
Control the construction of union directories, as in
.I mount
and
.IR bind (1).
Only valid when 
.I file
is a directory.
.TP
.B -A
Skip the authentication protocol.
This is useful for connecting to foreign systems like Inferno.
.TP
.B -z
Bypass the initial protocol request for which remote tree to serve.
This is necessary when the remote 
.IR exportfs (4) 
is running with the 
.B -r 
or 
.B -S 
options which pre-select a file tree to serve. The exception is if both sides are
operating in the
.B -B
backwards mode.
.TP
.B -B
Run in ``backwards'' mode, described below.
.TP
.B -E \fIenc
Push an encryption protocol on its network connection.
The supported protocols are
.B clear
(the default, no protocol)
and
.BR ssl .
There are plans to make
.B tls
available.
.TP
.B -e '\fIenc hash\fR'
Specify the encryption and hash algorithms to use for
encrypting and authenticating the wire traffic
(see
.IR ssl (3)).
The defaults are
.B rc4_256
and
.BR sha1 .
.TP
.B -k \fIkeypattern
Use
.I keypattern
to select a key to authenticate to the remote side
(see
.IR auth (2)).
.TP
.B -p
Push the
.IR aan (8)
filter onto the connection to protect against
temporary network outages.
.TP
.B -n
Specify announce string for
.IR aan (8)
filter when run in ``backwards'' mode.
.TP
.B -s \fIname
Post the connection's mountable file descriptor as
.BI /srv/ name\fR.
.PD
.PP
The 
.B -B
option runs
.I import
in ``backwards'' mode.
In this mode,
.I import
runs a
.I p9any
authentication (as server) over its file descriptor 0
(expected to be an incoming network connection from
.B exportfs
.BR -B ),
mounts the connection onto
.IR mntpt ,
and optionally runs
.I cmd
.IR args .
.SH EXAMPLES
Assume a machine
.B kremvax
that has IP interfaces for the company intranet and the global
internet mounted on
.I /net
and
.I /net.alt
respectively.
Any machine inside the company can get telnet out to the global
internet using:
.IP
.EX
import -a kremvax /net.alt
telnet /net.alt/tcp!ucbvax
.EE
.PP
Suppose that the machine
.B moscvax
has access to a private file server containing public web pages
that need to be served by the less-trusted server
.BR webvax .
.B Webvax
runs the following listener 
(see
.IR listen (8))
on TCP port 999:
.IP
.EX
#!/bin/rc
import -B -s rowebfs /usr/web /bin/restarthttpd
.EE
.PP
When
.B moscvax
boots, it runs
.IP
.EX
exportfs -R -r /usr/web -B tcp!webvax!999
.EE
.PP
to serve a read-only copy of
.B /usr/web
to
.BR webvax .
When
.B webvax
gets the call, 
.B import
mounts the served tree onto its own
.B /usr/web
and then runs
.B /bin/restarthttpd
to restart
.IR httpd (8).
.SH SOURCE
.B /sys/src/cmd/import.c
.SH SEE ALSO
.IR rcpu (1),
.IR bind (1),
.IR ssl (3),
.IR exportfs (4),
.IR srv (4),
.IR aan (8),
.IR listen (8),
.B cs
in
.IR ndb (8)