Ubuntu Manpage: zssh - interactive file transfer wrapper for ssh

NAME

       zssh - interactive file transfer wrapper for ssh

SYNOPSIS

       zssh [zssh options] [--] [ssh options]
       ztelnet [zssh options] [--] [telnet options]

DESCRIPTION

zssh (Zmodem SSH) is a program for interactively transferring files to a remote machine
while using the secure shell ( ssh ). It is intended to be a convenient alternative to 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 zmodem protocol, using the rz and sz commands.

zssh behaves as an usual ssh session until the escape sequence is depressed ( default is
^@ 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: ? , cd , disconnect , escape , exit ,
help , hook , quit , repeat , rz , suspend , sz , version

cd <dir> change current directory

disconnect disconnect and exit

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

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

help print help and tips
?

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

quit same as exit.

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.

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 :
1) run `sz <remote_file> ...' from the remote machine shell
2) press the escape sequence (C-space) to enter file transfer mode
3) run the `rz' builtin

suspend suspend zssh (back to the local machine shell)

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.

version print version information

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

OPTIONS

       -f
       --force             Do not ask user any question

       -h
       --help              show basic help

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

       -V
       --version           show version

       -z ^X
       --zssh-escape ^X    set escape sequence to ^X

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

ENVIRONMENT

       ZSSHESCAPE
                 Setting  the  ZSSHESCAPE environment variable allows one 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.

REQUIREMENTS

       the following binaries need to be properly installed for zssh to work :

       ssh/telnet/...
                 the remote shell to be executed (local machine)

       sz rz     zmodem  send  and  receive programs. Should be both on local and remote machine,
                 and (hopefully) of compatible versions.

TIPS

       If file transfer is initiated but never completes
       ( 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
       )
       Chances are the pty/tty on one of the systems are not 8-bit clean.  (Linux is 8-bit clean,
       NetBSD is not).
       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

BUGS / LIMITATIONS

       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 =)

CREDITS

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

       The sourceforge team.

AUTHOR

       Matthieu Lucotte <gounter@users.sourceforge.net>

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