.\"  -*- nroff -*-
.\"
.\" zssh.1
.\"
.\" Author: Matthieu Lucotte <gounter@users.sourceforge.net>
.\"
.\" Copyright (c) 2000 Matthieu Lucotte <gounter@users.sourceforge.net> France
.\"                    All rights reserved
.\"
.\" Created: Mon Jun 26 23:18:13 2000
.TH ZSSH 1 "June 26, 2000" "ZSSH" "ZSSH"

.SH NAME
zssh \- interactive file transfer wrapper for ssh

.SH SYNOPSIS

.B zssh [zssh options] [--] [ssh options]
.br
.B ztelnet [zssh options] [--] [telnet options]

.SH DESCRIPTION 
.LP
.B zssh
(Zmodem SSH) is a program for interactively transferring files to a remote
machine while using the secure shell (
.B ssh
). It is intended to be a
convenient alternative to
.B scp
, allowing to transfer files without having to
open another session and re-authenticate oneself.

zssh is an interactive wrapper for ssh used to switch the ssh connection
between the remote shell and file transfers. This is achieved by using
another tty/pty pair between the user and the local ssh process to plug
either the user's tty (remote shell mode) or another process (file transfer
mode) on the ssh connection.

ztelnet behaves similarly to zssh, except telnet is used instead of ssh.
It is equivalent to 'zssh -s "telnet -8 -E"'

Files are transferred through the 
.I zmodem
protocol, using the
.B rz
and
.B sz
commands.

zssh behaves as an usual ssh session until the escape sequence is depressed
( default is  
.B ^@
which can be produced by pressing C-space, or C-2, or C-` ), which enables
file transfer mode. A new prompt is then
displayed, and commands can be executed locally to initiate file transfers
(among other things). It roughly behaves as a local shell featuring line
edition, history and completion (thanks to libreadline), globbing, and
escape characters ( " ' and \\ ).

The following builtins are handled by zssh itself:
.B ?
,
.B cd
,
.B disconnect
,
.B escape
,
.B exit
,
.B help
,
.B hook
,
.B quit
,
.B repeat
,
.B rz
,
.B suspend
,
.B sz
,
.B version

.PP
.PD 0

.TP 20
.B cd <dir>
change current directory

.TP 20
.B disconnect
disconnect and exit

.TP 20
.B escape [^X]
Change escape key to ^X. Without argument, print current escape key

.TP 20
.B exit
exit file transfer mode. ^D may also be used for this purpose.

.TP 20
.B help
print help and tips
.TP
.B ?

.TP 20
.B hook prg [args]
Hook program 'prg' on the the pty. Its standard input and output will go
through the ssh channel.
.br 
typing 'sz'/'rz' is in fact equivalent to 'hook sz'/'hook rz'
.br 
A weird imagination is most useful to gain full advantage of this feature.

.TP 20
.B quit
same as exit.
  
.TP 20
.B repeat
repeats cmd forever (^C to interrupt). Useful for example if you use a
remote script invoking "sz" and you don't want to be typing "rz" each
time...
Remember however that several files can be transferred by a single
sz/rz pair so this is not usually necessary to use repeat.

.TP 20
.B rz
Receive files from the remote machine. runs rz and plugs the process on the ssh connection.
running sz on the REMOTE machine is required :
.TP 25
.B \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 1)
run `sz <remote_file> ...' from the remote machine shell
.TP
.B \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 2)
press the escape sequence (C-space) to enter file transfer mode
.TP
.B \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 3)
run the `rz' builtin

.TP 20
.B suspend
suspend zssh (back to the local machine shell)

.TP 20
.B sz <file> ...
Send files to the remote machine. runs sz and plugs the process on the ssh connection.
There is no need to manually run rz on the remote side.

.TP 20
.B version
print version information


.PD
.PP

builtins
.B rz
, 
.B sz
,
.B hook
and 
.B exit
return to shell mode after completion.

.SH OPTIONS
.LP

.PP
.PD 0

.TP 20
.B -f
.TP
.B --force
Do not ask user any question
.TP

.B -h
.TP
.B --help
show basic help
.TP

.B -s cmd
.TP
.B --shell cmd
run cmd as remote shell instead of the default 
"ssh -e none" (zssh) or "telnet -8 -E" (ztelnet)
.br
ex: zssh -s "rsh -x"
.TP

.B -V
.TP
.B --version
show version
.TP

.B -z ^X
.TP
.B --zssh-escape ^X
set escape sequence to ^X

.PD
.PP

.B --
may be used to separate zssh options from ssh ones
.br 
Other arguments are passed verbatim to ssh/telnet/whatever.

.SH ENVIRONMENT
.LP

.PP
.PD 0

.TP 10
.B ZSSHESCAPE
Setting the ZSSHESCAPE environment variable allows to override the default
escape sequence. ZSSHESCAPE should contain only two characters of the form
`^X', meaning that ^X is to be the new escape sequence.

.PD
.PP

.SH REQUIREMENTS
.LP

the following binaries need to be properly installed for zssh to work :
.TP 10
.B ssh/telnet/...
the remote shell to be executed (local machine)
.TP
.B sz rz
zmodem send and receive programs. Should be both on local and remote machine, and
(hopefully) of compatible versions.
.LP

.SH TIPS
.LP

If file transfer is initiated but never completes
.br
( ie a line like :
    Bytes Sent:  38144/4610624   BPS:3424     ETA 22:15
  or
    Bytes Sent:      0/    513   BPS:0        ETA 00:00  Retry 0: Got ZCAN
  can be seen, but transfer never completes
.br
)
.br
Chances are the pty/tty on one of the systems are not 8-bit clean.
(Linux is 8-bit clean, NetBSD is not).
.br
Using the -e (escape) option of rz should solve this problem.

Transfers can be interrupted with ^C (somewhat experimental =)

If you get stuck in rz/sz (for example you've just ran rz, but you then
decided not to transmit anything), hit a dozen ^X (Ctrl-X, not the zssh escape!) to stop it

Use `sz -y <files>' to overwrite files on the other side


.SH BUGS / LIMITATIONS
.LP

You may sometimes have to hit return 2 or 3 times after file transfer
completion in order get back to the shell. Some digits are usually
displayed; don't worry it won't harm (you or your term) ...

the tty may (sometimes) be somewhat upset after an interrupted transfer (
using ^C ). typing `reset' in this case should help.

no pipe, redirection (and other stuff) support in shell ...
but after all there are already wonderful shells around =)

.SH CREDITS

ttssh's author - Robert O'Callahan - for the original idea

The sourceforge team. 

.SH AUTHOR

Matthieu Lucotte <gounter@users.sourceforge.net>

zssh homepage: http://zssh.sourceforge.net

.SH SEE ALSO
.BR ssh (1),
.BR telnet (1),
.BR scp (1),
.BR sz (1),
.BR rz (1),
.BR readline (3),