File: screen.info, Node: Top, Next: Overview, Prev: (dir), Up: (dir)
Screen
******
This file documents the `Screen' virtual terminal manager, version
4.0.2.
* Menu:
* Overview:: Preliminary information.
* Getting Started:: An introduction to `screen'.
* Invoking Screen:: Command line options for `screen'.
* Customization:: The `.screenrc' file.
* Commands:: List all of the commands.
* New Window:: Running a program in a new window.
* Selecting:: Selecting a window to display.
* Session Management:: Suspend/detach, grant access, connect sessions.
* Regions:: Split-screen commands.
* Window Settings:: Titles, logging, etc.
* Virtual Terminal:: Controlling the `screen' VT100 emulation.
* Copy and Paste:: Exchanging text between windows and sessions.
* Subprocess Execution:: I/O filtering with `exec'.
* Key Binding:: Binding commands to keys.
* Flow Control:: Trap or pass flow control characters.
* Termcap:: Tweaking your terminal's termcap entry.
* Message Line:: The `screen' message line.
* Logging:: Keeping a record of your session.
* Startup:: Functions only useful at `screen' startup.
* Miscellaneous:: Various other commands.
* String Escapes:: Inserting current information into strings
* Environment:: Environment variables used by `screen'.
* Files:: Files used by `screen'.
* Credits:: Who's who of `screen'.
* Bugs:: What to do if you find a bug.
* Installation:: Getting `screen' running on your system.
* Concept Index:: Index of concepts.
* Command Index:: Index of all `screen' commands.
* Keystroke Index:: Index of default key bindings.
File: screen.info, Node: Overview, Next: Getting Started, Prev: Top, Up: Top
Overview
********
Screen is a full-screen window manager that multiplexes a physical
terminal between several processes, typically interactive shells. Each
virtual terminal provides the functions of the DEC VT100 terminal and,
in addition, several control functions from the ISO 6429 (ECMA 48, ANSI
X3.64) and ISO 2022 standards (e.g. insert/delete line and support for
multiple character sets). There is a scrollback history buffer for
each virtual terminal and a copy-and-paste mechanism that allows the
user to move text regions between windows.
When `screen' is called, it creates a single window with a shell in
it (or the specified command) and then gets out of your way so that you
can use the program as you normally would. Then, at any time, you can
create new (full-screen) windows with other programs in them (including
more shells), kill the current window, view a list of the active
windows, turn output logging on and off, copy text between windows, view
the scrollback history, switch between windows, etc. All windows run
their programs completely independent of each other. Programs continue
to run when their window is currently not visible and even when the
whole screen session is detached from the user's terminal.
When a program terminates, `screen' (per default) kills the window
that contained it. If this window was in the foreground, the display
switches to the previously displayed window; if none are left, `screen'
exits.
Everything you type is sent to the program running in the current
window. The only exception to this is the one keystroke that is used to
initiate a command to the window manager. By default, each command
begins with a control-a (abbreviated `C-a' from now on), and is
followed by one other keystroke. The command character (*note Command
Character::) and all the key bindings (*note Key Binding::) can be fully
customized to be anything you like, though they are always two
characters in length.
`Screen' does not understand the prefix `C-' to mean control.
Please use the caret notation (`^A' instead of `C-a') as arguments to
e.g. the `escape' command or the `-e' option. `Screen' will also print
out control characters in caret notation.
The standard way to create a new window is to type `C-a c'. This
creates a new window running a shell and switches to that window
immediately, regardless of the state of the process running in the
current window. Similarly, you can create a new window with a custom
command in it by first binding the command to a keystroke (in your
`.screenrc' file or at the `C-a :' command line) and then using it just
like the `C-a c' command. In addition, new windows can be created by
running a command like:
screen emacs prog.c
from a shell prompt within a previously created window. This will not
run another copy of `screen', but will instead supply the command name
and its arguments to the window manager (specified in the $STY
environment variable) who will use it to create the new window. The
above example would start the `emacs' editor (editing `prog.c') and
switch to its window.
If `/etc/utmp' is writable by `screen', an appropriate record will
be written to this file for each window, and removed when the window is
closed. This is useful for working with `talk', `script', `shutdown',
`rsend', `sccs' and other similar programs that use the utmp file to
determine who you are. As long as `screen' is active on your terminal,
the terminal's own record is removed from the utmp file. *Note Login::.
File: screen.info, Node: Getting Started, Next: Invoking Screen, Prev: Overview, Up: Top
Getting Started
***************
Before you begin to use `screen' you'll need to make sure you have
correctly selected your terminal type, just as you would for any other
termcap/terminfo program. (You can do this by using `tset', `qterm',
or just `set term=mytermtype', for example.)
If you're impatient and want to get started without doing a lot more
reading, you should remember this one command: `C-a ?' (*note Key
Binding::). Typing these two characters will display a list of the
available `screen' commands and their bindings. Each keystroke is
discussed in the section on keystrokes (*note Default Key Bindings::).
Another section (*note Customization::) deals with the contents of your
`.screenrc'.
If your terminal is a "true" auto-margin terminal (it doesn't allow
the last position on the screen to be updated without scrolling the
screen) consider using a version of your terminal's termcap that has
automatic margins turned _off_. This will ensure an accurate and
optimal update of the screen in all circumstances. Most terminals
nowadays have "magic" margins (automatic margins plus usable last
column). This is the VT100 style type and perfectly suited for
`screen'. If all you've got is a "true" auto-margin terminal `screen'
will be content to use it, but updating a character put into the last
position on the screen may not be possible until the screen scrolls or
the character is moved into a safe position in some other way. This
delay can be shortened by using a terminal with insert-character
capability.
*Note Special Capabilities::, for more information about telling
`screen' what kind of terminal you have.
File: screen.info, Node: Invoking Screen, Next: Customization, Prev: Getting Started, Up: Top
Invoking `Screen'
*****************
Screen has the following command-line options:
`-a'
Include _all_ capabilities (with some minor exceptions) in each
window's termcap, even if `screen' must redraw parts of the display
in order to implement a function.
`-A'
Adapt the sizes of all windows to the size of the display. By
default, `screen' may try to restore its old window sizes when
attaching to resizable terminals (those with `WS' in their
descriptions, e.g. `suncmd' or some varieties of `xterm').
`-c FILE'
Use FILE as the user's configuration file instead of the default
of `$HOME/.screenrc'.
`-d [PID.SESSIONNAME]'
`-D [PID.SESSIONNAME]'
Do not start `screen', but instead detach a `screen' session
running elsewhere (*note Detach::). `-d' has the same effect as
typing `C-a d' from the controlling terminal for the session.
`-D' is the equivalent to the power detach key. If no session can
be detached, this option is ignored. In combination with the
`-r'/`-R' option more powerful effects can be achieved:
`-d -r'
Reattach a session and if necessary detach it first.
`-d -R'
Reattach a session and if necessary detach or even create
it first.
`-d -RR'
Reattach a session and if necessary detach or create it. Use
the first session if more than one session is available.
`-D -r'
Reattach a session. If necessary detach and logout remotely
first.
`-D -R'
Attach here and now. In detail this means: If a session is
running, then reattach. If necessary detach and logout
remotely first. If it was not running create it and notify
the user. This is the author's favorite.
`-D -RR'
Attach here and now. Whatever that means, just do it.
_Note_: It is a good idea to check the status of your sessions
with `screen -list' before using this option.
`-e XY'
Set the command character to X, and the character generating a
literal command character (when typed after the command character)
to Y. The defaults are `C-a' and `a', which can be specified as
`-e^Aa'. When creating a `screen' session, this option sets the
default command character. In a multiuser session all users added
will start off with this command character. But when attaching to
an already running session, this option only changes the command
character of the attaching user. This option is equivalent to the
commands `defescape' or `escape' respectively. (*note Command
Character::).
`-f'
`-fn'
`-fa'
Set flow-control to on, off, or automatic switching mode,
respectively. This option is equivalent to the `defflow' command
(*note Flow Control::).
`-h NUM'
Set the history scrollback buffer to be NUM lines high.
Equivalent to the `defscrollback' command (*note Copy::).
`-i'
Cause the interrupt key (usually `C-c') to interrupt the display
immediately when flow control is on. This option is equivalent to
the `interrupt' argument to the `defflow' command (*note Flow
Control::). Its use is discouraged.
`-l'
`-ln'
Turn login mode on or off (for `/etc/utmp' updating). This option
is equivalent to the `deflogin' command (*note Login::).
`-ls [MATCH]'
`-list [MATCH]'
Do not start `screen', but instead print a list of session
identification strings (usually of the form PID.TTY.HOST; *note
Session Name::). Sessions marked `detached' can be resumed with
`screen -r'. Those marked `attached' are running and have a
controlling terminal. If the session runs in multiuser mode, it
is marked `multi'. Sessions marked as `unreachable' either live
on a different host or are dead. An unreachable session is
considered dead, when its name matches either the name of the
local host, or the specified parameter, if any. See the `-r' flag
for a description how to construct matches. Sessions marked as
`dead' should be thoroughly checked and removed. Ask your system
administrator if you are not sure. Remove sessions with the
`-wipe' option.
`-L'
Tell `screen' to turn on automatic output logging for the windows.
`-m'
Tell `screen' to ignore the `$STY' environment variable. When
this option is used, a new session will always be created,
regardless of whether `screen' is being called from within another
`screen' session or not. This flag has a special meaning in
connection with the `-d' option:
`-d -m'
Start `screen' in _detached_ mode. This creates a new session
but doesn't attach to it. This is useful for system startup
scripts.
`-D -m'
This also starts `screen' in _detached_ mode, but doesn't fork
a new process. The command exits if the session terminates.
`-p NAME_OR_NUMBER'
Preselect a window. This is usefull when you want to reattach to a
specific windor or you want to send a command via the `-X' option
to a specific window. As with screen's select commant, `-' selects
the blank window. As a special case for reattach, `=' brings up
the windowlist on the blank window.
`-q'
Suppress printing of error messages. In combination with `-ls' the
exit value is set as follows: 9 indicates a directory without
sessions. 10 indicates a directory with running but not attachable
sessions. 11 (or more) indicates 1 (or more) usable sessions. In
combination with `-r' the exit value is as follows: 10 indicates
that there is no session to resume. 12 (or more) indicates that
there are 2 (or more) sessions to resume and you should specify
which one to choose. In all other cases `-q' has no effect.
`-r [PID.SESSIONNAME]'
`-r SESSIONOWNER/[PID.SESSIONNAME]'
Resume a detached `screen' session. No other options (except
combinations with `-d' or `-D') may be specified, though the
session name (*note Session Name::) may be needed to distinguish
between multiple detached `screen' sessions. The second form is
used to connect to another user's screen session which runs in
multiuser mode. This indicates that screen should look for
sessions in another user's directory. This requires setuid-root.
`-R'
Resume the first appropriate detached `screen' session. If
successful, all other command-line options are ignored. If no
detached session exists, start a new session using the specified
options, just as if `-R' had not been specified. This option is
set by default if screen is run as a login-shell (actually screen
uses `-xRR' in that case). For combinations with the `-D'/`-d'
option see there.
`-s PROGRAM'
Set the default shell to be PROGRAM. By default, `screen' uses
the value of the environment variable `$SHELL', or `/bin/sh' if it
is not defined. This option is equivalent to the `shell' command
(*note Shell::).
`-S SESSIONNAME'
Set the name of the new session to SESSIONNAME. This option can
be used to specify a meaningful name for the session in place of
the default TTY.HOST suffix. This name identifies the session for
the `screen -list' and `screen -r' commands. This option is
equivalent to the `sessionname' command (*note Session Name::).
`-t NAME'
Set the title (name) for the default shell or specified program.
This option is equivalent to the `shelltitle' command (*note
Shell::).
`-U'
Run screen in UTF-8 mode. This option tells screen that your
terminal sends and understands UTF-8 encoded characters. It also
sets the default encoding for new windows to `utf8'.
`-v'
Print the version number.
`-wipe [MATCH]'
List available screens like `screen -ls', but remove destroyed
sessions instead of marking them as `dead'. An unreachable
session is considered dead, when its name matches either the name
of the local host, or the explicitly given parameter, if any. See
the `-r' flag for a description how to construct matches.
`-x'
Attach to a session which is already attached elsewhere
(multi-display mode).
`-X'
Send the specified command to a running screen session. You can use
the `-d' or `-r' option to tell screen to look only for attached
or detached screen sessions. Note that this command doesn't work
if the session is password protected.
File: screen.info, Node: Customization, Next: Commands, Prev: Invoking Screen, Up: Top
Customizing `Screen'
********************
You can modify the default settings for `screen' to fit your tastes
either through a personal `.screenrc' file which contains commands to
be executed at startup, or on the fly using the `colon' command.
* Menu:
* Startup Files:: The `.screenrc' file.
* Source:: Read commands from a file.
* Colon:: Entering customization commands interactively.
File: screen.info, Node: Startup Files, Next: Source, Up: Customization
The `.screenrc' file
====================
When `screen' is invoked, it executes initialization commands from
the files `.screenrc' in the user's home directory and
`/usr/local/etc/screenrc'. These defaults can be overridden in the
following ways: For the global screenrc file `screen' searches for the
environment variable `$SYSSCREENRC' (this override feature may be
disabled at compile-time). The user specific screenrc file is searched
for in `$SCREENRC', then ``$HOME'/.screenrc'. The command line option
`-c' specifies which file to use (*note Invoking Screen::. Commands in
these files are used to set options, bind commands to keys, and to
automatically establish one or more windows at the beginning of your
`screen' session. Commands are listed one per line, with empty lines
being ignored. A command's arguments are separated by tabs or spaces,
and may be surrounded by single or double quotes. A `#' turns the rest
of the line into a comment, except in quotes. Unintelligible lines are
warned about and ignored. Commands may contain references to
environment variables. The syntax is the shell-like `$VAR' or
`${VAR}'. Note that this causes incompatibility with previous `screen'
versions, as now the '$'-character has to be protected with '\' if no
variable substitution is intended. A string in single-quotes is also
protected from variable substitution.
Two configuration files are shipped as examples with your screen
distribution: `etc/screenrc' and `etc/etcscreenrc'. They contain a
number of useful examples for various commands.
File: screen.info, Node: Source, Next: Colon, Prev: Startup Files, Up: Customization
Source
======
- Command: source file
(none)
Read and execute commands from file FILE. Source commands may be
nested to a maximum recursion level of ten. If FILE is not an
absolute path and screen is already processing a source
command, the parent directory of the running source command file
is used to search for the new command file before screen's
current directory.
Note that termcap/terminfo/termcapinfo commands only work at
startup and reattach time, so they must be reached via the
default screenrc files to have an effect.
File: screen.info, Node: Colon, Prev: Source, Up: Customization
Colon
=====
Customization can also be done online, with this command:
- Command: colon
(`C-a :')
Allows you to enter `.screenrc' command lines. Useful for
on-the-fly modification of key bindings, specific window creation
and changing settings. Note that the `set' keyword no longer
exists, as of version 3.3. Change default settings with commands
starting with `def'. You might think of this as the `ex' command
mode of `screen', with `copy' as its `vi' command mode (*note Copy
and Paste::).
File: screen.info, Node: Commands, Next: New Window, Prev: Customization, Up: Top
Commands
********
A command in `screen' can either be bound to a key, invoked from a
screenrc file, or called from the `colon' prompt (*note
Customization::). As of version 3.3, all commands can be bound to
keys, although some may be less useful than others. For a number of
real life working examples of the most important commands see the files
`etc/screenrc' and `etc/etcscreenrc' of your screen distribution.
In this manual, a command definition looks like this:
- Command: command [-n] ARG1 [ARG2] ...
(KEYBINDINGS)
This command does something, but I can't remember what.
An argument in square brackets (`[]') is optional. Many commands
take an argument of `on' or `off', which is indicated as STATE in the
definition.
* Menu:
* Default Key Bindings:: `screen' keyboard commands.
* Command Summary:: List of all commands.
File: screen.info, Node: Default Key Bindings, Next: Command Summary, Up: Commands
Default Key Bindings
====================
As mentioned previously, each keyboard command consists of a `C-a'
followed by one other character. For your convenience, all commands
that are bound to lower-case letters are also bound to their control
character counterparts (with the exception of `C-a a'; see below).
Thus, both `C-a c' and `C-a C-c' can be used to create a window.
The following table shows the default key bindings:
`C-a ''
(select)
Prompt for a window identifier and switch. *Note Selecting::.
`C-a "'
(windowlist -b)
Present a list of all windows for selection. *Note Selecting::.
`C-a 0...9, -'
(select 0...select 9, select -)
Switch to window number 0...9, or the blank window. *Note
Selecting::.
`C-a <Tab>'
(focus)
Switch the input focus to the next region. *Note Regions::.
`C-a C-a'
(other)
Toggle to the window displayed previously. If this window does no
longer exist, `other' has the same effect as `next'. *Note
Selecting::.
`C-a a'
(meta)
Send the command character (C-a) to window. See `escape' command.
*Note Command Character::.
`C-a A'
(title)
Allow the user to enter a title for the current window. *Note
Naming Windows::.
`C-a b'
`C-a C-b'
(break)
Send a break to the tty. *Note Break::.
`C-a B'
(pow_break)
Close and reopen the tty-line. *Note Break::.
`C-a c'
`C-a C-c'
(screen)
Create a new window with a shell and switch to that window. *Note
Screen Command::.
`C-a C'
(clear)
Clear the screen. *Note Clear::.
`C-a d'
`C-a C-d'
(detach)
Detach `screen' from this terminal. *Note Detach::.
`C-a D D'
(pow_detach)
Detach and logout. *Note Power Detach::.
`C-a f'
`C-a C-f'
(flow)
Cycle flow among `on', `off' or `auto'. *Note Flow::.
`C-a F'
(fit)
Resize the window to the current region size. *Note Window Size::.
`C-a C-g'
(vbell)
Toggle visual bell mode. *Note Bell::.
`C-a h'
(hardcopy)
Write a hardcopy of the current window to the file "hardcopy.N".
*Note Hardcopy::.
`C-a H'
(log)
Toggle logging of the current window to the file "screenlog.N".
*Note Log::.
`C-a i'
`C-a C-i'
(info)
Show info about the current window. *Note Info::.
`C-a k'
`C-a C-k'
(kill)
Destroy the current window. *Note Kill::.
`C-a l'
`C-a C-l'
(redisplay)
Fully refresh the current window. *Note Redisplay::.
`C-a L'
(login)
Toggle the current window's login state. *Note Login::.
`C-a m'
`C-a C-m'
(lastmsg)
Repeat the last message displayed in the message line. *Note Last
Message::.
`C-a M'
(monitor) Toggle monitoring of the current window. *Note
Monitor::.
`C-a <SPC>'
`C-a n'
`C-a C-n'
(next)
Switch to the next window. *Note Selecting::.
`C-a N'
(number)
Show the number (and title) of the current window. *Note Number::.
`C-a p'
`C-a C-p'
`C-a C-h'
`C-a <BackSpace>'
(prev)
Switch to the previous window (opposite of `C-a n'). *Note
Selecting::.
`C-a q'
`C-a C-q'
(xon)
Send a ^Q (ASCII XON) to the current window. *Note XON/XOFF::.
`C-a Q'
(only)
Delete all regions but the current one. *Note Regions::.
`C-a r'
`C-a C-r'
(wrap)
Toggle the current window's line-wrap setting (turn the current
window's automatic margins on or off). *Note Wrap::.
`C-a s'
`C-a C-s'
(xoff)
Send a ^S (ASCII XOFF) to the current window. *Note XON/XOFF::.
`C-a S'
(split)
Split the current region into two new ones. *Note Regions::.
`C-a t'
`C-a C-t'
(time)
Show the load average and xref. *Note Time::.
`C-a v'
(version)
Display the version and compilation date. *Note Version::.
`C-a C-v'
(digraph)
Enter digraph. *Note Digraph::.
`C-a w'
`C-a C-w'
(windows)
Show a list of active windows. *Note Windows::.
`C-a W'
(width)
Toggle between 80 and 132 columns. *Note Window Size::.
`C-a x'
`C-a C-x'
(lockscreen)
Lock your terminal. *Note Lock::.
`C-a X'
(remove)
Kill the current region. *Note Regions::.
`C-a z'
`C-a C-z'
(suspend)
Suspend `screen'. *Note Suspend::.
`C-a Z'
(reset)
Reset the virtual terminal to its "power-on" values. *Note
Reset::.
`C-a .'
(dumptermcap)
Write out a `.termcap' file. *Note Dump Termcap::.
`C-a ?'
(help)
Show key bindings. *Note Help::.
`C-a C-\'
(quit)
Kill all windows and terminate `screen'. *Note Quit::.
`C-a :'
(colon)
Enter a command line. *Note Colon::.
`C-a ['
`C-a C-['
`C-a <ESC>'
(copy)
Enter copy/scrollback mode. *Note Copy::.
`C-a ]'
`C-a C-]'
(paste .)
Write the contents of the paste buffer to the stdin queue of the
current window. *Note Paste::.
`C-a {'
`C-a }'
(history)
Copy and paste a previous (command) line. *Note History::.
`C-a >'
(writebuf)
Write the paste buffer out to the screen-exchange file. *Note
Screen Exchange::.
`C-a <'
(readbuf)
Read the screen-exchange file into the paste buffer. *Note Screen
Exchange::.
`C-a ='
(removebuf)
Delete the screen-exchange file. *Note Screen Exchange::.
`C-a _'
(silence)
Start/stop monitoring the current window for inactivity. *Note
Silence::,
`C-a ,'
(license)
Show the copyright page.
`C-a *'
(displays)
Show the listing of attached displays.
File: screen.info, Node: Command Summary, Prev: Default Key Bindings, Up: Commands
Command Summary
===============
`acladd USERNAMES'
Allow other users in this session. *Note Multiuser Session::.
`aclchg USERNAMES PERMBITS LIST'
Change a user's permissions. *Note Multiuser Session::.
`acldel USERNAME'
Disallow other user in this session. *Note Multiuser Session::.
`aclgrp USRNAME [GROUPNAME]'
Inherit permissions granted to a group leader. *Note Multiuser
Session::.
`aclumask [USERS]+/-BITS ...'
Predefine access to new windows. *Note Umask::.
`activity MESSAGE'
Set the activity notification message. *Note Monitor::.
`addacl USERNAMES'
Synonym to `acladd'. *Note Multiuser Session::.
`allpartial STATE'
Set all windows to partial refresh. *Note Redisplay::.
`altscreen STATE'
Enables support for the "alternate screen" terminal capability.
*Note Redisplay::.
`at [IDENT][#|*|%] COMMAND [ARGS]'
Execute a command at other displays or windows. *Note At::.
`attrcolor ATTRIB [ATTRIBUTE/COLOR-MODIFIER]'
Map attributes to colors. *Note Attrcolor::.
`autodetach STATE'
Automatically detach the session on SIGHUP. *Note Detach::.
`autonuke STATE'
Enable a clear screen to discard unwritten output. *Note
Autonuke::.
`backtick ID LIFESPAN AUTOREFRESH COMMAND [ARGS]'
Define a command for the backtick string escape. *Note Backtick::.
`bce [STATE]'
Change background color erase. *Note Character Processing::.
`bell_msg [MESSAGE]'
Set the bell notification message. *Note Bell::.
`bind [-c CLASS] KEY [COMMAND [ARGS]]'
Bind a command to a key. *Note Bind::.
`bindkey [OPTS] [STRING [CMD ARGS]]'
Bind a string to a series of keystrokes. *Note Bindkey::.
`blanker'
Blank the screen. *Note Screen Saver::.
`blankerprg'
Define a blanker program. *Note Screen Saver::.
`break [DURATION]'
Send a break signal to the current window. *Note Break::.
`breaktype [TCSENDBREAK | TCSBRK | TIOCSBRK]'
Specify how to generate breaks. *Note Break::.
`bufferfile [EXCHANGE-FILE]'
Select a file for screen-exchange. *Note Screen Exchange::.
`c1 [STATE]'
Change c1 code processing. *Note Character Processing::.
`caption MODE [STRING]'
Change caption mode and string. *Note Regions::.
`chacl USERNAMES PERMBITS LIST'
Synonym to `aclchg'. *Note Multiuser Session::.
`charset SET'
Change character set slot designation. *Note Character
Processing::.
`chdir [DIRECTORY]'
Change the current directory for future windows. *Note Chdir::.
`clear'
Clear the window screen. *Note Clear::.
`colon'
Enter a `screen' command. *Note Colon::.
`command [-c CLASS]'
Simulate the screen escape key. *Note Command Character::.
`compacthist [STATE]'
Selects compaction of trailing empty lines. *Note Scrollback::.
`console [STATE]'
Grab or ungrab console output. *Note Console::.
`copy'
Enter copy mode. *Note Copy::.
`copy_reg [KEY]'
Removed. Use `paste' instead. *Note Registers::.
`crlf STATE'
Select line break behavior for copying. *Note Line Termination::.
`debug STATE'
Suppress/allow debugging output. *Note Debug::.
`defautonuke STATE'
Select default autonuke behavior. *Note Autonuke::.
`defbce STATE'
Select background color erase. *Note Character Processing::.
`defbreaktype [TCSENDBREAK | TCSBRK | TIOCSBRK]'
Specify the default for generating breaks. *Note Break::.
`defc1 STATE'
Select default c1 processing behavior. *Note Character
Processing::.
`defcharset [SET]'
Change defaul character set slot designation. *Note Character
Processing::.
`defencoding ENC'
Select default window encoding. *Note Character Processing::.
`defescape XY'
Set the default command and `meta' characters. *Note Command
Character::.
`defflow FSTATE'
Select default flow control behavior. *Note Flow::.
`defgr STATE'
Select default GR processing behavior. *Note Character
Processing::.
`defhstatus [STATUS]'
Select default window hardstatus line. *Note Hardstatus::.
`deflog STATE'
Select default window logging behavior. *Note Log::.
`deflogin STATE'
Select default utmp logging behavior. *Note Login::.
`defmode MODE'
Select default file mode for ptys. *Note Mode::.
`defmonitor STATE'
Select default activity monitoring behavior. *Note Monitor::.
`defnonblock STATE|NUMSECS'
Select default nonblock mode. *Note Nonblock::.
`defobuflimit LIMIT'
Select default output buffer limit. *Note Obuflimit::.
`defscrollback NUM'
Set default lines of scrollback. *Note Scrollback::.
`defshell COMMAND'
Set the default program for new windows. *Note Shell::.
`defsilence STATE'
Select default idle monitoring behavior. *Note Silence::.
`defslowpaste MSEC'
Select the default inter-character timeout when pasting. *Note
Paste::.
`defutf8 STATE'
Select default character encoding. *Note Character Processing::.
`defwrap STATE'
Set default line-wrapping behavior. *Note Wrap::.
`defwritelock ON|OFF|AUTO'
Set default writelock behavior. *Note Multiuser Session::.
`defzombie [KEYS]'
Keep dead windows. *Note Zombie::.
`detach [-h]'
Disconnect `screen' from the terminal. *Note Detach::.
`digraph'
Enter digraph sequence. *Note Digraph::.
`dinfo'
Display terminal information. *Note Info::.
`displays'
List currently active user interfaces. *Note Displays::.
`dumptermcap'
Write the window's termcap entry to a file. *Note Dump Termcap::.
`echo [-n] MESSAGE'
Display a message on startup. *Note Startup::.
`encoding ENC [DENC]'
Set the encoding of a window. *Note Character Processing::.
`escape XY'
Set the command and `meta' characters. *Note Command Character::.
`eval COMMAND1 [COMMAND2 ...]'
Parse and execute each argument. *Note Eval::.
`exec [[FDPAT] COMMAND [ARGS ...]]'
Run a subprocess (filter). *Note Exec::.
`fit'
Change window size to current display size. *Note Window Size::.
`flow [FSTATE]'
Set flow control behavior. *Note Flow::.
`focus'
Move focus to next region. *Note Regions::.
`gr [STATE]'
Change GR charset processing. *Note Character Processing::.
`hardcopy [-h] [FILE]'
Write out the contents of the current window. *Note Hardcopy::.
`hardcopy_append STATE'
Append to hardcopy files. *Note Hardcopy::.
`hardcopydir DIRECTORY'
Place, where to dump hardcopy files. *Note Hardcopy::.
`hardstatus [STATE]'
Use the hardware status line. *Note Hardware Status Line::.
`height [LINES [COLS]]'
Set display height. *Note Window Size::.
`help [-c CLASS]'
Display current key bindings. *Note Help::.
`history'
Find previous command beginning .... *Note History::.
`hstatus STATUS'
Change the window's hardstatus line. *Note Hardstatus::.
`idle [TIMEOUT [CMD ARGS]]'
Define a screen saver command. *Note Screen Saver::.
`ignorecase [STATE]'
Ignore character case in searches. *Note Searching::.
`info'
Display window settings. *Note Info::.
`ins_reg [KEY]'
Removed, use `paste' instead. *Note Registers::.
`kill'
Destroy the current window. *Note Kill::.
`lastmsg'
Redisplay the last message. *Note Last Message::.
`license'
Display licensing information. *Note Startup::.
`lockscreen'
Lock the controlling terminal. *Note Lock::.
`log [STATE]'
Log all output in the current window. *Note Log::.
`logfile FILENAME'
Place where to collect logfiles. *Note Log::.
`login [STATE]'
Log the window in `/etc/utmp'. *Note Login::.
`logtstamp [STATE]'
Configure logfile time-stamps. *Note Log::.
`mapdefault'
Use only the default mapping table for the next keystroke. *Note
Bindkey Control::.
`mapnotnext'
Don't try to do keymapping on the next keystroke. *Note Bindkey
Control::.
`maptimeout TIMO'
Set the inter-character timeout used for keymapping. *Note Bindkey
Control::.
`markkeys STRING'
Rebind keys in copy mode. *Note Copy Mode Keys::.
`maxwin N'
Set the maximum window number. *Note Maxwin::.
`meta'
Insert the command character. *Note Command Character::.
`monitor [STATE]'
Monitor activity in window. *Note Monitor::.
`msgminwait SEC'
Set minimum message wait. *Note Message Wait::.
`msgwait SEC'
Set default message wait. *Note Message Wait::.
`multiuser STATE'
Go into single or multi user mode. *Note Multiuser Session::.
`nethack STATE'
Use `nethack'-like error messages. *Note Nethack::.
`next'
Switch to the next window. *Note Selecting::.
`nonblock [STATE|NUMSECS]'
Disable flow control to the current display. *Note
Nonblock::.|NUMSECS]
`number [N]'
Change/display the current window's number. *Note Number::.
`obuflimit [LIMIT]'
Select output buffer limit. *Note Obuflimit::.
`only'
Kill all other regions. *Note Regions::.
`other'
Switch to the window you were in last. *Note Selecting::.
`partial STATE'
Set window to partial refresh. *Note Redisplay::.
`password [CRYPTED_PW]'
Set reattach password. *Note Detach::.
`paste [SRC_REGS [DEST_REG]]'
Paste contents of paste buffer or registers somewhere. *Note
Paste::.
`pastefont [STATE]'
Include font information in the paste buffer. *Note Paste::.
`pow_break'
Close and Reopen the window's terminal. *Note Break::.
`pow_detach'
Detach and hang up. *Note Power Detach::.
`pow_detach_msg [MESSAGE]'
Set message displayed on `pow_detach'. *Note Power Detach::.
`prev'
Switch to the previous window. *Note Selecting::.
`printcmd [CMD]'
Set a command for VT100 printer port emulation. *Note Printcmd::.
`process [KEY]'
Treat a register as input to `screen'. *Note Registers::.
`quit'
Kill all windows and exit. *Note Quit::.
`readbuf [-e ENCODING] [FILENAME]'
Read the paste buffer from the screen-exchange file. *Note Screen
Exchange::.
`readreg [-e ENCODING] [REG [FILE]]'
Load a register from paste buffer or file. *Note Registers::.
`redisplay'
Redisplay the current window. *Note Redisplay::.
`register [-e ENCODING] KEY STRING'
Store a string to a register. *Note Registers::.
`remove'
Kill current region. *Note Regions::.
`removebuf'
Delete the screen-exchange file. *Note Screen Exchange::.
`reset'
Reset the terminal settings for the window. *Note Reset::.
`resize [(+/-)lines]'
Grow or shrink a region
`screen [OPTS] [N] [CMD [ARGS]]'
Create a new window. *Note Screen Command::.
`scrollback NUM'
Set size of scrollback buffer. *Note Scrollback::.
`select [N]'
Switch to a specified window. *Note Selecting::.
`sessionname [NAME]'
Name this session. *Note Session Name::.
`setenv [VAR [STRING]]'
Set an environment variable for new windows. *Note Setenv::.
`setsid STATE'
Controll process group creation for windows. *Note Setsid::.
`shell COMMAND'
Set the default program for new windows. *Note Shell::.
`shelltitle TITLE'
Set the default name for new windows. *Note Shell::.
`silence [STATE|SECONDS]'
Monitor a window for inactivity. *Note Silence::.
`silencewait SECONDS'
Default timeout to trigger an inactivity notify. *Note Silence::.
`sleep NUM'
Pause during startup. *Note Startup::.
`slowpaste MSEC'
Slow down pasting in windows. *Note Paste::.
`source FILE'
Run commands from a file. *Note Source::.
`sorendition [ATTR [COLOR]]'
Change text highlighting. *Note Sorendition::.
`split'
Split region into two parts. *Note Regions::.
`startup_message STATE'
Display copyright notice on startup. *Note Startup::.
`stuff STRING'
Stuff a string in the input buffer of a window. *Note Paste::.
`su [USERNAME [PASSWORD [PASSWORD2]]]'
Identify a user. *Note Multiuser Session::.
`suspend'
Put session in background. *Note Suspend::.
`term TERM'
Set `$TERM' for new windows. *Note Term::.
`termcap TERM TERMINAL-TWEAKS [WINDOW-TWEAKS]'
Tweak termcap entries for best performance. *Note Termcap
Syntax::.
`terminfo TERM TERMINAL-TWEAKS [WINDOW-TWEAKS]'
Ditto, for terminfo systems. *Note Termcap Syntax::.
`termcapinfo TERM TERMINAL-TWEAKS [WINDOW-TWEAKS]'
Ditto, for both systems. *Note Termcap Syntax::.
`time [STRING]'
Display time and load average. *Note Time::.
`title [WINDOWTITLE]'
Set the name of the current window. *Note Title Command::.
`umask [USERS]+/-BITS ...'
Synonym to `aclumask'. *Note Umask::.
`unsetenv VAR'
Unset environment variable for new windows. *Note Setenv::.
`utf8 [STATE [DSTATE]]'
Select character encoding of the current window. *Note Character
Processing::.
`vbell [STATE]'
Use visual bell. *Note Bell::.
`vbell_msg [MESSAGE]'
Set vbell message. *Note Bell::.
`vbellwait SEC'
Set delay for vbell message. *Note Bell::.
`version'
Display `screen' version. *Note Version::.
`wall MESSAGE'
Write a message to all displays. *Note Multiuser Session::.
`width [COLS [LINES]]'
Set the width of the window. *Note Window Size::.
`windowlist [-b] | string [STRING] | title [TITLE]'
Present a list of all windows for selection. *Note Windowlist::.
`windows'
List active windows. *Note Windows::.
`wrap [STATE]'
Control line-wrap behavior. *Note Wrap::.
`writebuf [-e ENCODING] [FILENAME]'
Write paste buffer to screen-exchange file. *Note Screen
Exchange::.
`writelock ON|OFF|AUTO'
Grant exclusive write permission. *Note Multiuser Session::.
`xoff'
Send an XOFF character. *Note XON/XOFF::.
`xon'
Send an XON character. *Note XON/XOFF::.
`zmodem [off|auto|catch|pass]'
Define how screen treats zmodem requests. *Note Zmodem::.
`zombie [KEYS]'
Keep dead windows. *Note Zombie::.
File: screen.info, Node: New Window, Next: Selecting, Prev: Commands, Up: Top
New Window
**********
This section describes the commands for creating a new window for
running programs. When a new window is created, the first available
number from the range 0...9 is assigned to it. The number of windows
is limited at compile-time by the MAXWIN configuration parameter.
* Menu:
* Chdir:: Change the working directory for new windows.
* Screen Command:: Create a new window.
* Setenv:: Set environment variables for new windows.
* Shell:: Parameters for shell windows.
* Term:: Set the terminal type for new windows.
* Window Types:: Creating different types of windows.
File: screen.info, Node: Chdir, Next: Screen Command, Up: New Window
Chdir
=====
- Command: chdir [directory]
(none)
Change the current directory of `screen' to the specified directory
or, if called without an argument, to your home directory (the
value of the environment variable `$HOME'). All windows that are
created by means of the `screen' command from within `.screenrc'
or by means of `C-a : screen ...' or `C-a c' use this as their
default directory. Without a `chdir' command, this would be the
directory from which `screen' was invoked. Hardcopy and log files
are always written to the _window's_ default directory, _not_ the
current directory of the process running in the window. You can
use this command multiple times in your `.screenrc' to start
various windows in different default directories, but the last
`chdir' value will affect all the windows you create interactively.
File: screen.info, Node: Screen Command, Next: Setenv, Prev: Chdir, Up: New Window
Screen Command
==============
- Command: screen [opts] [n] [cmd [args]]
(`C-a c', `C-a C-c')
Establish a new window. The flow-control options (`-f', `-fn' and
`-fa'), title option (`-t'), login options (`-l' and `-ln') ,
terminal type option (`-T TERM'), the all-capability-flag (`-a')
and scrollback option (`-h NUM') may be specified with each
command. The option (`-M') turns monitoring on for this window.
The option (`-L') turns output logging on for this window. If an
optional number N in the range 0...9 is given, the window number N
is assigned to the newly created window (or, if this number is
already in-use, the next available number). If a command is
specified after `screen', this command (with the given arguments)
is started in the window; otherwise, a shell is created.
Screen has built in some functionality of `cu' and `telnet'.
*Note Window Types::.
Thus, if your `.screenrc' contains the lines
# example for .screenrc:
screen 1
screen -fn -t foobar 2 -L telnet foobar
`screen' creates a shell window (in window #1) and a window with a
TELNET connection to the machine foobar (with no flow-control using the
title `foobar' in window #2) and will write a logfile `screenlog.2' of
the telnet session. If you do not include any `screen' commands in
your `.screenrc' file, then `screen' defaults to creating a single
shell window, number zero. When the initialization is completed,
`screen' switches to the last window specified in your .screenrc file
or, if none, it opens default window #0.
File: screen.info, Node: Setenv, Next: Shell, Prev: Screen Command, Up: New Window
Setenv
======
- Command: setenv var string
(none)
Set the environment variable VAR to value STRING. If only VAR is
specified, the user will be prompted to enter a value. If no
parameters are specified, the user will be prompted for both
variable and value. The environment is inherited by all
subsequently forked shells.
- Command: unsetenv var
(none)
Unset an environment variable.
File: screen.info, Node: Shell, Next: Term, Prev: Setenv, Up: New Window
Shell
=====
- Command: shell command
- Command: defshell command
(none)
Set the command to be used to create a new shell. This overrides
the value of the environment variable `$SHELL'. This is useful if
you'd like to run a tty-enhancer which is expecting to execute the
program specified in `$SHELL'. If the command begins with a `-'
character, the shell will be started as a login-shell.
`defshell' is currently a synonym to the `shell' command.
- Command: shelltitle title
(none)
Set the title for all shells created during startup or by the C-a
C-c command. *Note Naming Windows::, for details about what
titles are.
File: screen.info, Node: Term, Next: Window Types, Prev: Shell, Up: New Window
Term
====
- Command: term term
(none)
In each window `screen' opens, it sets the `$TERM' variable to
`screen' by default, unless no description for `screen' is
installed in the local termcap or terminfo data base. In that
case it pretends that the terminal emulator is `vt100'. This
won't do much harm, as `screen' is VT100/ANSI compatible. The use
of the `term' command is discouraged for non-default purpose.
That is, one may want to specify special `$TERM' settings (e.g.
vt100) for the next `screen rlogin othermachine' command. Use the
command `screen -T vt100 rlogin othermachine' rather than setting
and resetting the default.
File: screen.info, Node: Window Types, Prev: Term, Up: New Window
Window Types
============
Screen provides three different window types. New windows are created
with `screen''s `screen' command (*note Screen Command::). The first
parameter to the `screen' command defines which type of window is
created. The different window types are all special cases of the normal
type. They have been added in order to allow `screen' to be used
efficiently as a console with 100 or more windows.
* The normal window contains a shell (default, if no parameter is
given) or any other system command that could be executed from a
shell. (e.g. `slogin', etc...).
* If a tty (character special device) name (e.g. `/dev/ttya') is
specified as the first parameter, then the window is directly
connected to this device. This window type is similar to `screen
cu -l /dev/ttya'. Read and write access is required on the device
node, an exclusive open is attempted on the node to mark the
connection line as busy. An optional parameter is allowed
consisting of a comma separated list of flags in the notation used
by `stty(1)':
`<baud_rate>'
Usually 300, 1200, 9600 or 19200. This affects transmission
as well as receive speed.
`cs8 or cs7'
Specify the transmission of eight (or seven) bits per byte.
`ixon or -ixon'
Enables (or disables) software flow-control (CTRL-S/CTRL-Q)
for sending data.
`ixoff or -ixoff'
Enables (or disables) software flow-control for receiving
data.
`istrip or -istrip'
Clear (or keep) the eight bit in each received byte.
You may want to specify as many of these options as applicable.
Unspecified options cause the terminal driver to make up the
parameter values of the connection. These values are system
dependant and may be in defaults or values saved from a previous
connection.
For tty windows, the `info' command shows some of the modem
control lines in the status line. These may include `RTS', `CTS',
`DTR', `CD' and more. This depends rather on on the available
`ioctl()''s and system header files than on the physical
capabilities of the serial board. The name of a logical low
(inactive) signal is preceded by an exclamation mark (`!'),
otherwise the signal is logical high (active). Unsupported but
shown signals are usually shown low. When the `CLOCAL' status bit
is true, the whole set of modem signals is placed inside curly
braces (`{' and `}'). When the `CRTSCTS' or `TIOCSOFTCAR' bit is
true, the signals `CTS' or `CD' are shown in parenthesis,
respectively.
For tty windows, the command `break' causes the Data transmission
line (TxD) to go low for a specified period of time. This is
expected to be interpreted as break signal on the other side. No
data is sent and no modem control line is changed when a `break'
is issued.
* If the first parameter is `//telnet', the second parameter is
expected to be a host name, and an optional third parameter may
specify a TCP port number (default decimal 23). Screen will
connect to a server listening on the remote host and use the
telnet protocol to communicate with that server.
For telnet windows, the command `info' shows details about the
connection in square brackets (`[' and `]') at the end of the
status line.
`b'
BINARY. The connection is in binary mode.
`e'
ECHO. Local echo is disabled.
`c'
SGA. The connection is in `character mode' (default: `line
mode').
`t'
TTYPE. The terminal type has been requested by the remote
host. Screen sends the name `screen' unless instructed
otherwise (see also the command `term').
`w'
NAWS. The remote site is notified about window size changes.
`f'
LFLOW. The remote host will send flow control information.
(Ignored at the moment.)
Additional flags for debugging are `x', `t' and `n' (XDISPLOC,
TSPEED and NEWENV).
For telnet windows, the command `break' sends the telnet code `IAC
BREAK' (decimal 243) to the remote host.
File: screen.info, Node: Selecting, Next: Session Management, Prev: New Window, Up: Top
Selecting a Window
******************
This section describes the commands for switching between windows in
an `screen' session. The windows are numbered from 0 to 9, and are
created in that order by default (*note New Window::).
* Menu:
* Next and Previous:: Forward or back one window.
* Other Window:: Switch back and forth between two windows.
* Select:: Switch to a window (and to one after `kill').
* Windowlist:: Present a list of all windows for selection.
File: screen.info, Node: Next and Previous, Next: Other Window, Up: Selecting
Moving Back and Forth
=====================
- Command: next
(`C-a <SPC>', `C-a n', `C-a C-n')
Switch to the next window. This command can be used repeatedly to
cycle through the list of windows. (On some terminals, C-<SPC>
generates a NUL character, so you must release the control key
before pressing space.)
- Command: prev
(`C-a p', `C-a C-p')
Switch to the previous window (the opposite of `C-a n').
File: screen.info, Node: Other Window, Next: Select, Prev: Next and Previous, Up: Selecting
Other Window
============
- Command: other
(`C-a C-a')
Switch to the last window displayed. Note that this command
defaults to the command character typed twice, unless overridden.
For instance, if you use the option `-e]x', this command becomes
`]]' (*note Command Character::).
File: screen.info, Node: Select, Next: Windowlist, Prev: Other Window, Up: Selecting
Select
======
- Command: select [n]
(`C-a N', `C-a '')
Switch to the window with the number N. If no window number is
specified, you get prompted for an identifier. This can be a
window name (title) or a number. When a new window is
established, the lowest available number is assigned to this
window. Thus, the first window can be activated by `select 0';
there can be no more than 10 windows present simultaneously
(unless screen is compiled with a higher MAXWIN setting). There
are two special arguments, `select -' switches to the internal
blank window and `select .' switches to the current window. The
latter is useful if used with screen's `-X' option.
File: screen.info, Node: Windowlist, Prev: Select, Up: Selecting
Windowlist
==========
- Command: windowlist [-b] [-m]
- Command: windowlist string [STRING]
- Command: windowlist title [TITLE]
(`C-a "')
Display all windows in a table for visual window selection. The
desired window can be selected via the standard movement keys
(*note Movement::) and activated via the return key. If the `-b'
option is given, screen will switch to the blank window before
presenting the list, so that the current window is also selectable.
The `-m' option changes the order of the windows, instead of
sorting by window numbers screen uses its internal
most-recently-used list.
The table format can be changed with the string and title option,
the title is displayed as table heading, while the lines are made
by using the string setting. The default setting is `Num
Name%=Flags' for the title and `%3n %t%=%f' for the lines. See the
string escapes chapter (*note String Escapes::) for more codes
(e.g. color settings).
File: screen.info, Node: Session Management, Next: Regions, Prev: Selecting, Up: Top
Session Management Commands
***************************
Perhaps the most useful feature of `screen' is the way it allows the
user to move a session between terminals, by detaching and reattaching.
This also makes life easier for modem users who have to deal with
unexpected loss of carrier.
* Menu:
* Detach:: Disconnect `screen' from your terminal.
* Power Detach:: Detach and log out.
* Lock:: Lock your terminal temporarily.
* Multiuser Session:: Changing number of allowed users.
* Session Name:: Rename your session for later reattachment.
* Suspend:: Suspend your session.
* Quit:: Terminate your session.
File: screen.info, Node: Detach, Next: Power Detach, Up: Session Management
Detach
======
- Command: autodetach state
(none)
Sets whether `screen' will automatically detach upon hangup, which
saves all your running programs until they are resumed with a
`screen -r' command. When turned off, a hangup signal will
terminate `screen' and all the processes it contains. Autodetach is
on by default.
- Command: detach
(`C-a d', `C-a C-d')
Detach the `screen' session (disconnect it from the terminal and
put it into the background). A detached `screen' can be resumed by
invoking `screen' with the `-r' option (*note Invoking Screen::).
The `-h' option tells screen to immediately close the connection
to the terminal (`hangup').
- Command: password [crypted_pw]
(none)
Present a crypted password in your `.screenrc' file and screen will
ask for it, whenever someone attempts to resume a detached
session. This is useful, if you have privileged programs running
under `screen' and you want to protect your session from reattach
attempts by users that managed to assume your uid. (I.e. any
superuser.) If no crypted password is specified, screen prompts
twice a password and places its encryption in the paste buffer.
Default is `none', which disables password checking.
File: screen.info, Node: Power Detach, Next: Lock, Prev: Detach, Up: Session Management
Power Detach
============
- Command: pow_detach
(`C-a D D')
Mainly the same as `detach', but also sends a HANGUP signal to the
parent process of `screen'.
_Caution_: This will result in a logout if `screen' was started
from your login shell.
- Command: pow_detach_msg [message]
(none)
The MESSAGE specified here is output whenever a power detach is
performed. It may be used as a replacement for a logout message or
to reset baud rate, etc. Without parameter, the current message
is shown.
File: screen.info, Node: Lock, Next: Multiuser Session, Prev: Power Detach, Up: Session Management
Lock
====
- Command: lockscreen
(`C-a x', `C-a C-x')
Call a screenlock program (`/local/bin/lck' or `/usr/bin/lock' or
a builtin, if no other is available). Screen does not accept any
command keys until this program terminates. Meanwhile processes in
the windows may continue, as the windows are in the detached state.
The screenlock program may be changed through the environment
variable `$LOCKPRG' (which must be set in the shell from which
`screen' is started) and is executed with the user's uid and gid.
Warning: When you leave other shells unlocked and have no password
set on `screen', the lock is void: One could easily re-attach from
an unlocked shell. This feature should rather be called
`lockterminal'.
File: screen.info, Node: Multiuser Session, Next: Session Name, Prev: Lock, Up: Session Management
Multiuser Session
=================
These commands allow other users to gain access to one single
`screen' session. When attaching to a multiuser `screen' the
sessionname is specified as `username/sessionname' to the `-S' command
line option. `Screen' must be compiled with multiuser support to
enable features described here.
* Menu:
* Multiuser:: Enable / Disable multiuser mode.
* Acladd:: Enable a specific user.
* Aclchg:: Change a users permissions.
* Acldel:: Disable a specific user.
* Aclgrp:: Grant a user permissions to other users.
* Displays:: List all active users at their displays.
* Umask:: Predefine access to new windows.
* Wall:: Write a message to all users.
* Writelock:: Grant exclusive window access.
* Su:: Substitute user.
File: screen.info, Node: Multiuser, Next: Acladd, Up: Multiuser Session
Multiuser
---------
- Command: multiuser STATE
(none)
Switch between single-user and multi-user mode. Standard screen
operation is single-user. In multi-user mode the commands
`acladd', `aclchg' and `acldel' can be used to enable (and
disable) other users accessing this `screen'.
File: screen.info, Node: Acladd, Next: Aclchg, Prev: Multiuser, Up: Multiuser Session
Acladd
------
- Command: acladd USERNAMES
- Command: addacl USERNAMES
(none)
Enable users to fully access this screen session. USERNAMES can be
one user or a comma separated list of users. This command enables
to attach to the `screen' session and performs the equivalent of
`aclchg USERNAMES +rwx "#?"'. To add a user with restricted access,
use the `aclchg' command below. `Addacl' is a synonym to `acladd'.
Multi-user mode only.
File: screen.info, Node: Aclchg, Next: Acldel, Prev: Acladd, Up: Multiuser Session
Aclchg
------
- Command: aclchg USERNAMES PERMBITS LIST
- Command: chacl USERNAMES PERMBITS LIST
(none)
Change permissions for a comma separated list of users.
Permission bits are represented as `r', `w' and `x'. Prefixing
`+' grants the permission, `-' removes it. The third parameter is
a comma separated list of commands or windows (specified either by
number or title). The special list `#' refers to all windows, `?'
to all commands. If USERNAMES consists of a single `*', all known
users are affected. A command can be executed when the user has
the `x' bit for it. The user can type input to a window when he
has its `w' bit set and no other user obtains a writelock for this
window. Other bits are currently ignored. To withdraw the
writelock from another user in e.g. window 2: `aclchg USERNAME
-w+w 2'. To allow read-only access to the session: `aclchg
USERNAME -w "#"'. As soon as a user's name is known to screen, he
can attach to the session and (per default) has full permissions
for all command and windows. Execution permission for the acl
commands, `at' and others should also be removed or the user may
be able to regain write permission. `Chacl' is a synonym to
`aclchg'. Multi-user mode only.
File: screen.info, Node: Acldel, Next: Aclgrp, Prev: Aclchg, Up: Multiuser Session
Acldel
------
- Command: acldel USERNAME
(none)
Remove a user from screen's access control list. If currently
attached, all the user's displays are detached from the session.
He cannot attach again. Multi-user mode only.
File: screen.info, Node: Aclgrp, Next: Displays, Prev: Acldel, Up: Multiuser Session
Aclgrp
------
- Command: aclgrp USERNAME [GROUPNAME]
(none)
Creates groups of users that share common access rights. The name
of the group is the username of the group leader. Each member of
the group inherits the permissions that are granted to the
group leader. That means, if a user fails an access check, another
check is made for the group leader. A user is removed from all
groups the special value `none' is used for GROUPNAME. If the
second parameter is omitted all groups the user is in are listed.
File: screen.info, Node: Displays, Next: Umask, Prev: Aclgrp, Up: Multiuser Session
Displays
--------
- Command: displays
(`C-a *')
Shows a tabular listing of all currently connected user
front-ends (displays). This is most useful for multiuser
sessions.
File: screen.info, Node: Umask, Next: Wall, Prev: Displays, Up: Multiuser Session
aclumask
--------
- Command: aclumask [USERS]+/-BITS ...
- Command: umask [USERS]+/-BITS ...
(none)
This specifies the access other users have to windows that will
be created by the caller of the command. USERS may be no, one
or a comma separated list of known usernames. If no users are
specified, a list of all currently known users is assumed. BITS
is any combination of access control bits allowed defined
with the `aclchg' command. The special username `?' predefines the
access that not yet known users will be granted to any
window initially. The special username `??' predefines the access
that not yet known users are granted to any command. Rights of
the special username nobody cannot be changed (see the `su'
command). `Umask' is a synonym to `aclumask'.
File: screen.info, Node: Wall, Next: Writelock, Prev: Umask, Up: Multiuser Session
Wall
----
- Command: wall MESSAGE
(none)
Write a message to all displays. The message will appear in the
terminal's status line.
File: screen.info, Node: Writelock, Next: Su, Prev: Wall, Up: Multiuser Session
Writelock
---------
- Command: writelock ON|OFF|AUTO
(none)
In addition to access control lists, not all users may be able to
write to the same window at once. Per default, writelock is in
`auto' mode and grants exclusive input permission to the user who
is the first to switch to the particular window. When he leaves
the window, other users may obtain the writelock (automatically).
The writelock of the current window is disabled by the command
`writelock off'. If the user issues the command `writelock on' he
keeps the exclusive write permission while switching to other
windows.
- Command: defwritelock ON|OFF|AUTO
(none)
Sets the default writelock behavior for new windows. Initially all
windows will be created with no writelocks.
File: screen.info, Node: Su, Prev: Writelock, Up: Multiuser Session
Su
--
- Command: su [USERNAME [PASSWORD [PASSWORD2]]]
(none)
Substitute the user of a display. The command prompts for all
parameters that are omitted. If passwords are specified as
parameters, they have to be specified un-crypted. The first
password is matched against the systems passwd database, the
second password is matched against the `screen' password as
set with the commands `acladd' or `password'. `Su' may be useful
for the `screen' administrator to test multiuser setups. When
the identification fails, the user has access to the commands
available for user `nobody'. These are `detach', `license',
`version', `help' and `displays'.
File: screen.info, Node: Session Name, Next: Suspend, Prev: Multiuser Session, Up: Session Management
Session Name
============
- Command: sessionname [NAME]
(none)
Rename the current session. Note that for `screen -list' the name
shows up with the process-id prepended. If the argument NAME is
omitted, the name of this session is displayed.
_Caution_: The `$STY' environment variable still reflects the old
name. This may result in confusion. The default is constructed
from the tty and host names.
File: screen.info, Node: Suspend, Next: Quit, Prev: Session Name, Up: Session Management
Suspend
=======
- Command: suspend
(`C-a z', `C-a C-z')
Suspend `screen'. The windows are in the detached state while
`screen' is suspended. This feature relies on the parent shell
being able to do job control.
File: screen.info, Node: Quit, Prev: Suspend, Up: Session Management
Quit
====
- Command: quit
(`C-a C-\')
Kill all windows and terminate `screen'. Note that on VT100-style
terminals the keys `C-4' and `C-\' are identical. So be careful
not to type `C-a C-4' when selecting window no. 4. Use the empty
bind command (as in `bind "^\"') to remove a key binding (*note
Key Binding::).
File: screen.info, Node: Regions, Next: Window Settings, Prev: Session Management, Up: Top
Regions
*******
Screen has the ability to display more than one window on the user's
display. This is done by splitting the screen in regions, which can
contain different windows.
* Menu:
* Split:: Split a region into two
* Focus:: Change to the next region
* Only:: Delete all other regions
* Remove:: Delete the current region
* Resize:: Grow or shrink a region
* Caption:: Control the window's caption
* Fit:: Resize a window to fit the region
File: screen.info, Node: Split, Next: Focus, Up: Regions
Split
=====
- Command: split
(`C-a S')
Split the current region into two new ones. All regions on the
display are resized to make room for the new region. The blank
window is displayed on the new region.
File: screen.info, Node: Focus, Next: Only, Prev: Split, Up: Regions
Focus
=====
- Command: focus
(`C-a <Tab>')
Move the input focus to the next region. This is done in a cyclic
way so that the top region is selected after the bottom one. If no
subcommand is given it defaults to `down'. `up' cycles in the
opposite order, `top' and `bottom' go to the top and bottom region
respectively. Useful bindings are (j and k as in vi)
bind j focus down
bind k focus up
bind t focus top
bind b focus bottom
File: screen.info, Node: Only, Next: Remove, Prev: Focus, Up: Regions
Only
====
- Command: only
(`C-a Q')
Kill all regions but the current one.
File: screen.info, Node: Remove, Next: Resize, Prev: Only, Up: Regions
Remove
======
- Command: remove
(`C-a X')
Kill the current region. This is a no-op if there is only one
region.
File: screen.info, Node: Resize, Next: Caption, Prev: Remove, Up: Regions
Resize
======
- Command: resize [(+/-)LINES]
(none)
Resize the current region. The space will be removed from or added
to the region below or if there's not enough space from the region
above.
resize +N increase current region height by N
resize -N decrease current region height by N
resize N set current region height to N
resize = make all windows equally high
resize max maximize current region height
resize min minimize current region height
File: screen.info, Node: Caption, Next: Fit, Prev: Resize, Up: Regions
Caption
=======
- Command: caption `always'|`splitonly' [string]
- Command: caption `string' [string]
(none)
This command controls the display of the window captions. Normally
a caption is only used if more than one window is shown on the
display (split screen mode). But if the type is set to `always',
`screen' shows a caption even if only one window is displayed. The
default is `splitonly'.
The second form changes the text used for the caption. You can use
all string escapes (*note String Escapes::). `Screen' uses a
default of `%3n %t'.
You can mix both forms by providing the string as an additional
argument.
File: screen.info, Node: Fit, Prev: Caption, Up: Regions
Fit
===
- Command: fit
(`C-a F')
Change the window size to the size of the current region. This
command is needed because screen doesn't adapt the window size
automatically if the window is displayed more than once.
File: screen.info, Node: Window Settings, Next: Virtual Terminal, Prev: Regions, Up: Top
Window Settings
***************
These commands control the way `screen' treats individual windows in
a session. *Note Virtual Terminal::, for commands to control the
terminal emulation itself.
* Menu:
* Naming Windows:: Control the name of the window
* Console:: See the host's console messages
* Kill:: Destroy an unwanted window
* Login:: Control `/etc/utmp' logging
* Mode:: Control the file mode of the pty
* Monitor:: Watch for activity in a window
* Windows:: List the active windows
* Hardstatus:: Set a window's hardstatus line
File: screen.info, Node: Naming Windows, Next: Console, Up: Window Settings
Naming Windows (Titles)
=======================
You can customize each window's name in the window display (viewed
with the `windows' command (*note Windows::) by setting it with one of
the title commands. Normally the name displayed is the actual command
name of the program created in the window. However, it is sometimes
useful to distinguish various programs of the same name or to change
the name on-the-fly to reflect the current state of the window.
The default name for all shell windows can be set with the
`shelltitle' command (*note Shell::). You can specify the name you
want for a window with the `-t' option to the `screen' command when the
window is created (*note Screen Command::). To change the name after
the window has been created you can use the title-string escape-sequence
(`<ESC> k NAME <ESC> \') and the `title' command (C-a A). The former
can be output from an application to control the window's name under
software control, and the latter will prompt for a name when typed.
You can also bind predefined names to keys with the `title' command to
set things quickly without prompting.
* Menu:
* Title Command:: The `title' command.
* Dynamic Titles:: Make shell windows change titles dynamically.
* Title Prompts:: Set up your shell prompt for dynamic Titles.
* Title Screenrc:: Set up Titles in your `.screenrc'.
File: screen.info, Node: Title Command, Next: Dynamic Titles, Up: Naming Windows
Title Command
-------------
- Command: title [windowtitle]
(`C-a A')
Set the name of the current window to WINDOWTITLE. If no name is
specified, screen prompts for one.
File: screen.info, Node: Dynamic Titles, Next: Title Prompts, Prev: Title Command, Up: Naming Windows
Dynamic Titles
--------------
`screen' has a shell-specific heuristic that is enabled by setting
the window's name to SEARCH|NAME and arranging to have a null title
escape-sequence output as a part of your prompt. The SEARCH portion
specifies an end-of-prompt search string, while the NAME portion
specifies the default shell name for the window. If the NAME ends in a
`:' `screen' will add what it believes to be the current command
running in the window to the end of the specified name (e.g. NAME:CMD).
Otherwise the current command name supersedes the shell name while it
is running.
Here's how it works: you must modify your shell prompt to output a
null title-escape-sequence (<ESC> k <ESC> \) as a part of your prompt.
The last part of your prompt must be the same as the string you
specified for the SEARCH portion of the title. Once this is set up,
`screen' will use the title-escape-sequence to clear the previous
command name and get ready for the next command. Then, when a newline
is received from the shell, a search is made for the end of the prompt.
If found, it will grab the first word after the matched string and use
it as the command name. If the command name begins with `!', `%', or
`^', `screen' will use the first word on the following line (if found)
in preference to the just-found name. This helps csh users get more
accurate titles when using job control or history recall commands.
File: screen.info, Node: Title Prompts, Next: Title Screenrc, Prev: Dynamic Titles, Up: Naming Windows
Setting up your prompt for shell titles
---------------------------------------
One thing to keep in mind when adding a null title-escape-sequence
to your prompt is that some shells (like the csh) count all the
non-control characters as part of the prompt's length. If these
invisible characters aren't a multiple of 8 then backspacing over a tab
will result in an incorrect display. One way to get around this is to
use a prompt like this:
set prompt='[0000mk\% '
The escape-sequence `[0000m' not only normalizes the character
attributes, but all the zeros round the length of the invisible
characters up to 8.
Tcsh handles escape codes in the prompt more intelligently, so you
can specify your prompt like this:
set prompt="%{\ek\e\\%}\% "
Bash users will probably want to echo the escape sequence in the
PROMPT_COMMAND:
PROMPT_COMMAND='echo -n -e "\033k\033\134"'
(I used `\134' to output a `\' because of a bug in v1.04).
File: screen.info, Node: Title Screenrc, Prev: Title Prompts, Up: Naming Windows
Setting up shell titles in your `.screenrc'
-------------------------------------------
Here are some .screenrc examples:
screen -t top 2 nice top
Adding this line to your .screenrc would start a niced version of the
`top' command in window 2 named `top' rather than `nice'.
shelltitle '> |csh'
screen 1
This file would start a shell using the given shelltitle. The title
specified is an auto-title that would expect the prompt and the typed
command to look something like the following:
/usr/joe/src/dir> trn
(it looks after the '> ' for the command name). The window status
would show the name `trn' while the command was running, and revert to
`csh' upon completion.
bind R screen -t '% |root:' su
Having this command in your .screenrc would bind the key sequence
`C-a R' to the `su' command and give it an auto-title name of `root:'.
For this auto-title to work, the screen could look something like this:
% !em
emacs file.c
Here the user typed the csh history command `!em' which ran the
previously entered `emacs' command. The window status would show
`root:emacs' during the execution of the command, and revert to simply
`root:' at its completion.
bind o title
bind E title ""
bind u title (unknown)
The first binding doesn't have any arguments, so it would prompt you
for a title when you type `C-a o'. The second binding would clear an
auto-titles current setting (C-a E). The third binding would set the
current window's title to `(unknown)' (C-a u).
File: screen.info, Node: Console, Next: Kill, Prev: Naming Windows, Up: Window Settings
Console
=======
- Command: console [STATE]
(none)
Grabs or un-grabs the machines console output to a window. When
the argument is omitted the current state is displayed. _Note_:
Only the owner of `/dev/console' can grab the console output. This
command is only available if the host supports the ioctl
`TIOCCONS'.
File: screen.info, Node: Kill, Next: Login, Prev: Console, Up: Window Settings
Kill
====
- Command: kill
(`C-a k', `C-a C-k')
Kill the current window.
If there is an `exec' command running (*note Exec::) then it is
killed. Otherwise the process (e.g. shell) running in the window
receives a `HANGUP' condition, the window structure is removed and
screen (your display) switches to another window. When the last
window is destroyed, `screen' exits. After a kill screen switches
to the previously displayed window.
_Caution_: `emacs' users may find themselves killing their `emacs'
session when trying to delete the current line. For this reason,
it is probably wise to use a different command character (*note
Command Character::) or rebind `kill' to another key sequence,
such as `C-a K' (*note Key Binding::).
File: screen.info, Node: Login, Next: Mode, Prev: Kill, Up: Window Settings
Login
=====
- Command: deflogin state
(none)
Same as the `login' command except that the default setting for new
windows is changed. This defaults to `on' unless otherwise
specified at compile time (*note Installation::). Both commands
are only present when `screen' has been compiled with utmp support.
- Command: login [state]
(`C-a L')
Adds or removes the entry in `/etc/utmp' for the current window.
This controls whether or not the window is "logged in". In
addition to this toggle, it is convenient to have "log in" and
"log out" keys. For instance, `bind I login on' and `bind O login
off' will map these keys to be `C-a I' and `C-a O' (*note Key
Binding::).
File: screen.info, Node: Mode, Next: Monitor, Prev: Login, Up: Window Settings
Mode
====
- Command: defmode mode
(none)
The mode of each newly allocated pseudo-tty is set to MODE. MODE
is an octal number as used by chmod(1). Defaults to 0622 for
windows which are logged in, 0600 for others (e.g. when `-ln' was
specified for creation, *note Screen Command::).
File: screen.info, Node: Monitor, Next: Windows, Prev: Mode, Up: Window Settings
Monitoring
==========
- Command: activity message
(none)
When any activity occurs in a background window that is being
monitored, `screen' displays a notification in the message line.
The notification message can be redefined by means of the
`activity' command. Each occurrence of `%' in MESSAGE is replaced
by the number of the window in which activity has occurred, and
each occurrence of `^G' is replaced by the definition for bell in
your termcap (usually an audible bell). The default message is
'Activity in window %n'
Note that monitoring is off for all windows by default, but can be
altered by use of the `monitor' command (`C-a M').
- Command: defmonitor state
(none)
Same as the `monitor' command except that the default setting for
new windows is changed. Initial setting is `off'.
- Command: monitor [state]
(`C-a M')
Toggles monitoring of the current window. When monitoring is
turned on and the affected window is switched into the background,
the activity notification message will be displayed in the status
line at the first sign of output, and the window will also be
marked with an `@' in the window-status display (*note Windows::).
Monitoring defaults to `off' for all windows.
File: screen.info, Node: Windows, Next: Hardstatus, Prev: Monitor, Up: Window Settings
Windows
=======
- Command: windows
(`C-a w', `C-a C-w')
Uses the message line to display a list of all the windows. Each
window is listed by number with the name of the program running in
the window (or its title).
The current window is marked with a `*'; the previous window is
marked with a `-'; all the windows that are logged in are marked
with a `$' (*note Login::); a background window that has received
a bell is marked with a `!'; a background window that is being
monitored and has had activity occur is marked with an `@' (*note
Monitor::); a window which has output logging turned on is marked
with `(L)'; windows occupied by other users are marked with `&' or
`&&' if the window is shared by other users; windows in the zombie
state are marked with `Z'.
If this list is too long to fit on the terminal's status line only
the portion around the current window is displayed.
File: screen.info, Node: Hardstatus, Prev: Windows, Up: Window Settings
Hardstatus
==========
`Screen' maintains a hardstatus line for every window. If a window
gets selected, the display's hardstatus will be updated to match the
window's hardstatus line. The hardstatus line can be changed with the
ANSI Application Program Command (APC): `ESC_<string>ESC\'. As a
convenience for xterm users the sequence `ESC]0..2;<string>^G' is also
accepted.
- Command: defhstatus [status]
(none)
The hardstatus line that all new windows will get is set to STATUS.
This command is useful to make the hardstatus of every window
display the window number or title or the like. STATUS may
contain the same directives as in the window messages, but the
directive escape character is `^E' (octal 005) instead of `%'.
This was done to make a misinterpretation of program generated
hardstatus lines impossible. If the parameter STATUS is omitted,
the current default string is displayed. Per default the
hardstatus line of new windows is empty.
- Command: hstatus status
(none)
Changes the current window's hardstatus line to STATUS.
File: screen.info, Node: Virtual Terminal, Next: Copy and Paste, Prev: Window Settings, Up: Top
Virtual Terminal
****************
Each window in a `screen' session emulates a VT100 terminal, with
some extra functions added. The VT100 emulator is hard-coded, no other
terminal types can be emulated. The commands described here modify the
terminal emulation.
* Menu:
* Control Sequences:: Details of the internal VT100 emulation.
* Input Translation:: How keystrokes are remapped.
* Digraph:: Entering digraph sequences.
* Bell:: Getting your attention.
* Clear:: Clear the window display.
* Info:: Terminal emulation statistics.
* Redisplay:: When the display gets confusing.
* Wrap:: Automatic margins.
* Reset:: Recovering from ill-behaved applications.
* Window Size:: Changing the size of your terminal.
* Character Processing:: Change the effect of special characters.
File: screen.info, Node: Control Sequences, Next: Input Translation, Up: Virtual Terminal
Control Sequences
=================
The following is a list of control sequences recognized by `screen'.
`(V)' and `(A)' indicate VT100-specific and ANSI- or ISO-specific
functions, respectively.
ESC E Next Line
ESC D Index
ESC M Reverse Index
ESC H Horizontal Tab Set
ESC Z Send VT100 Identification String
ESC 7 (V) Save Cursor and Attributes
ESC 8 (V) Restore Cursor and Attributes
ESC [s (A) Save Cursor and Attributes
ESC [u (A) Restore Cursor and Attributes
ESC c Reset to Initial State
ESC g Visual Bell
ESC Pn p Cursor Visibility (97801)
Pn = 6 Invisible
7 Visible
ESC = (V) Application Keypad Mode
ESC > (V) Numeric Keypad Mode
ESC # 8 (V) Fill Screen with E's
ESC \ (A) String Terminator
ESC ^ (A) Privacy Message String (Message Line)
ESC ! Global Message String (Message Line)
ESC k Title Definition String
ESC P (A) Device Control String
Outputs a string directly to the host
terminal without interpretation.
ESC _ (A) Application Program Command (Hardstatus)
ESC ] 0 ; string ^G (A) Operating System Command (Hardstatus, xterm
title hack)
ESC ] 83 ; cmd ^G (A) Execute screen command. This only works if
multi-user support is compiled into screen.
The pseudo-user ":window:" is used to check
the access control list. Use "addacl :window:
-rwx #?" to create a user with no rights and
allow only the needed commands.
Control-N (A) Lock Shift G1 (SO)
Control-O (A) Lock Shift G0 (SI)
ESC n (A) Lock Shift G2
ESC o (A) Lock Shift G3
ESC N (A) Single Shift G2
ESC O (A) Single Shift G3
ESC ( Pcs (A) Designate character set as G0
ESC ) Pcs (A) Designate character set as G1
ESC * Pcs (A) Designate character set as G2
ESC + Pcs (A) Designate character set as G3
ESC [ Pn ; Pn H Direct Cursor Addressing
ESC [ Pn ; Pn f same as above
ESC [ Pn J Erase in Display
Pn = None or 0 From Cursor to End of Screen
1 From Beginning of Screen to Cursor
2 Entire Screen
ESC [ Pn K Erase in Line
Pn = None or 0 From Cursor to End of Line
1 From Beginning of Line to Cursor
2 Entire Line
ESC [ Pn X Erase character
ESC [ Pn A Cursor Up
ESC [ Pn B Cursor Down
ESC [ Pn C Cursor Right
ESC [ Pn D Cursor Left
ESC [ Pn E Cursor next line
ESC [ Pn F Cursor previous line
ESC [ Pn G Cursor horizontal position
ESC [ Pn ` same as above
ESC [ Pn d Cursor vertical position
ESC [ Ps ;...; Ps m Select Graphic Rendition
Ps = None or 0 Default Rendition
1 Bold
2 (A) Faint
3 (A) Standout Mode (ANSI: Italicized)
4 Underlined
5 Blinking
7 Negative Image
22 (A) Normal Intensity
23 (A) Standout Mode off (ANSI: Italicized off)
24 (A) Not Underlined
25 (A) Not Blinking
27 (A) Positive Image
30 (A) Foreground Black
31 (A) Foreground Red
32 (A) Foreground Green
33 (A) Foreground Yellow
34 (A) Foreground Blue
35 (A) Foreground Magenta
36 (A) Foreground Cyan
37 (A) Foreground White
39 (A) Foreground Default
40 (A) Background Black
... ...
49 (A) Background Default
ESC [ Pn g Tab Clear
Pn = None or 0 Clear Tab at Current Position
3 Clear All Tabs
ESC [ Pn ; Pn r (V) Set Scrolling Region
ESC [ Pn I (A) Horizontal Tab
ESC [ Pn Z (A) Backward Tab
ESC [ Pn L (A) Insert Line
ESC [ Pn M (A) Delete Line
ESC [ Pn @ (A) Insert Character
ESC [ Pn P (A) Delete Character
ESC [ Pn S Scroll Scrolling Region Up
ESC [ Pn T Scroll Scrolling Region Down
ESC [ Pn ^ same as above
ESC [ Ps ;...; Ps h Set Mode
ESC [ Ps ;...; Ps l Reset Mode
Ps = 4 (A) Insert Mode
20 (A) `Automatic Linefeed' Mode.
34 Normal Cursor Visibility
?1 (V) Application Cursor Keys
?3 (V) Change Terminal Width to 132 columns
?5 (V) Reverse Video
?6 (V) `Origin' Mode
?7 (V) `Wrap' Mode
?9 X10 mouse tracking
?25 (V) Visible Cursor
?47 Alternate Screen (old xterm code)
?1000 (V) VT200 mouse tracking
?1047 Alternate Screen (new xterm code)
?1049 Alternate Screen (new xterm code)
ESC [ 5 i (A) Start relay to printer (ANSI Media Copy)
ESC [ 4 i (A) Stop relay to printer (ANSI Media Copy)
ESC [ 8 ; Ph ; Pw t Resize the window to `Ph' lines and
`Pw' columns (SunView special)
ESC [ c Send VT100 Identification String
ESC [ x (V) Send Terminal Parameter Report
ESC [ > c Send Secondary Device Attributes String
ESC [ 6 n Send Cursor Position Report
File: screen.info, Node: Input Translation, Next: Digraph, Prev: Control Sequences, Up: Virtual Terminal
Input Translation
=================
In order to do a full VT100 emulation `screen' has to detect that a
sequence of characters in the input stream was generated by a keypress
on the user's keyboard and insert the VT100 style escape sequence.
`Screen' has a very flexible way of doing this by making it possible to
map arbitrary commands on arbitrary sequences of characters. For
standard VT100 emulation the command will always insert a string in the
input buffer of the window (see also command `stuff', *note Paste::).
Because the sequences generated by a keypress can change after a
reattach from a different terminal type, it is possible to bind
commands to the termcap name of the keys. `Screen' will insert the
correct binding after each reattach. See *Note Bindkey:: for further
details on the syntax and examples.
Here is the table of the default key bindings. (A) means that the
command is executed if the keyboard is switched into application mode.
Key name Termcap name Command
-----------------------------------------------------
Cursor up ku stuff \033[A
stuff \033OA (A)
Cursor down kd stuff \033[B
stuff \033OB (A)
Cursor right kr stuff \033[C
stuff \033OC (A)
Cursor left kl stuff \033[D
stuff \033OD (A)
Function key 0 k0 stuff \033[10~
Function key 1 k1 stuff \033OP
Function key 2 k2 stuff \033OQ
Function key 3 k3 stuff \033OR
Function key 4 k4 stuff \033OS
Function key 5 k5 stuff \033[15~
Function key 6 k6 stuff \033[17~
Function key 7 k7 stuff \033[18~
Function key 8 k8 stuff \033[19~
Function key 9 k9 stuff \033[20~
Function key 10 k; stuff \033[21~
Function key 11 F1 stuff \033[23~
Function key 12 F2 stuff \033[24~
Home kh stuff \033[1~
End kH stuff \033[4~
Insert kI stuff \033[2~
Delete kD stuff \033[3~
Page up kP stuff \033[5~
Page down kN stuff \033[6~
Keypad 0 f0 stuff 0
stuff \033Op (A)
Keypad 1 f1 stuff 1
stuff \033Oq (A)
Keypad 2 f2 stuff 2
stuff \033Or (A)
Keypad 3 f3 stuff 3
stuff \033Os (A)
Keypad 4 f4 stuff 4
stuff \033Ot (A)
Keypad 5 f5 stuff 5
stuff \033Ou (A)
Keypad 6 f6 stuff 6
stuff \033Ov (A)
Keypad 7 f7 stuff 7
stuff \033Ow (A)
Keypad 8 f8 stuff 8
stuff \033Ox (A)
Keypad 9 f9 stuff 9
stuff \033Oy (A)
Keypad + f+ stuff +
stuff \033Ok (A)
Keypad - f- stuff -
stuff \033Om (A)
Keypad * f* stuff *
stuff \033Oj (A)
Keypad / f/ stuff /
stuff \033Oo (A)
Keypad = fq stuff =
stuff \033OX (A)
Keypad . f. stuff .
stuff \033On (A)
Keypad , f, stuff ,
stuff \033Ol (A)
Keypad enter fe stuff \015
stuff \033OM (A)
File: screen.info, Node: Digraph, Next: Bell, Prev: Input Translation, Up: Virtual Terminal
Digraph
=======
- Command: digraph [preset]
(none)
This command prompts the user for a digraph sequence. The next two
characters typed are looked up in a builtin table and the
resulting character is inserted in the input stream. For example,
if the user enters `a"', an a-umlaut will be inserted. If the
first character entered is a 0 (zero), `screen' will treat the
following characters (up to three) as an octal number instead.
The optional argument PRESET is treated as user input, thus one
can create an "umlaut" key. For example the command `bindkey ^K
digraph '"'' enables the user to generate an a-umlaut by typing
`CTRL-K a'.
File: screen.info, Node: Bell, Next: Clear, Prev: Digraph, Up: Virtual Terminal
Bell
====
- Command: bell_msg [message]
(none)
When a bell character is sent to a background window, `screen'
displays a notification in the message line. The notification
message can be re-defined by this command. Each occurrence of `%'
in MESSAGE is replaced by the number of the window to which a bell
has been sent, and each occurrence of `^G' is replaced by the
definition for bell in your termcap (usually an audible bell).
The default message is
'Bell in window %n'
An empty message can be supplied to the `bell_msg' command to
suppress output of a message line (`bell_msg ""'). Without
parameter, the current message is shown.
- Command: vbell [state]
(`C-a C-g')
Sets or toggles the visual bell setting for the current window. If
`vbell' is switched to `on', but your terminal does not support a
visual bell, the visual bell message is displayed in the status
line when the bell character is received. Visual bell support of
a terminal is defined by the termcap variable `vb'. *Note Visual
Bell: (termcap)Bell, for more information on visual bells. The
equivalent terminfo capability is `flash'.
Per default, `vbell' is `off', thus the audible bell is used.
- Command: vbell_msg [message]
(none)
Sets the visual bell message. MESSAGE is printed to the status
line if the window receives a bell character (^G), `vbell' is set
to `on' and the terminal does not support a visual bell. The
default message is `Wuff, Wuff!!'. Without parameter, the current
message is shown.
- Command: vbellwait sec
(none)
Define a delay in seconds after each display of `screen' 's visual
bell message. The default is 1 second.
File: screen.info, Node: Clear, Next: Info, Prev: Bell, Up: Virtual Terminal
Clear
=====
- Command: clear
(`C-a C')
Clears the screen and saves its contents to the scrollback buffer.
File: screen.info, Node: Info, Next: Redisplay, Prev: Clear, Up: Virtual Terminal
Info
====
- Command: info
(`C-a i', `C-a C-i')
Uses the message line to display some information about the current
window: the cursor position in the form `(COLUMN,ROW)' starting
with `(1,1)', the terminal width and height plus the size of the
scrollback buffer in lines, like in `(80,24)+50', the current
state of window XON/XOFF flow control is shown like this (*note
Flow Control::):
+flow automatic flow control, currently on.
-flow automatic flow control, currently off.
+(+)flow flow control enabled. Agrees with automatic control.
-(+)flow flow control disabled. Disagrees with automatic control.
+(-)flow flow control enabled. Disagrees with automatic control.
-(-)flow flow control disabled. Agrees with automatic control.
The current line wrap setting (`+wrap' indicates enabled, `-wrap'
not) is also shown. The flags `ins', `org', `app', `log', `mon'
and `nored' are displayed when the window is in insert mode,
origin mode, application-keypad mode, has output logging, activity
monitoring or partial redraw enabled.
The currently active character set (`G0', `G1', `G2', or `G3'),
and in square brackets the terminal character sets that are
currently designated as `G0' through `G3'. If the window is in
UTF-8 mode, the string `UTF-8' is shown instead. Additional modes
depending on the type of the window are displayed at the end of
the status line (*note Window Types::).
If the state machine of the terminal emulator is in a non-default
state, the info line is started with a string identifying the
current state.
For system information use `time'.
- Command: dinfo
(none)
Show what screen thinks about your terminal. Useful if you want to
know why features like color or the alternate charset don't work.
File: screen.info, Node: Redisplay, Next: Wrap, Prev: Info, Up: Virtual Terminal
Redisplay
=========
- Command: allpartial state
(none)
If set to on, only the current cursor line is refreshed on window
change. This affects all windows and is useful for slow terminal
lines. The previous setting of full/partial refresh for each
window is restored with `allpartial off'. This is a global flag
that immediately takes effect on all windows overriding the
`partial' settings. It does not change the default redraw behavior
of newly created windows.
- Command: altscreen state
(none)
If set to on, "alternate screen" support is enabled in virtual
terminals, just like in xterm. Initial setting is `off'.
- Command: partial state
(none)
Defines whether the display should be refreshed (as with
`redisplay') after switching to the current window. This command
only affects the current window. To immediately affect all
windows use the `allpartial' command. Default is `off', of
course. This default is fixed, as there is currently no
`defpartial' command.
- Command: redisplay
(`C-a l', `C-a C-l')
Redisplay the current window. Needed to get a full redisplay in
partial redraw mode.
File: screen.info, Node: Wrap, Next: Reset, Prev: Redisplay, Up: Virtual Terminal
Wrap
====
- Command: wrap state
(`C-a r', `C-a C-r')
Sets the line-wrap setting for the current window. When line-wrap
is on, the second consecutive printable character output at the
last column of a line will wrap to the start of the following
line. As an added feature, backspace (^H) will also wrap through
the left margin to the previous line. Default is `on'.
- Command: defwrap state
(none)
Same as the `wrap' command except that the default setting for new
windows is changed. Initially line-wrap is on and can be toggled
with the `wrap' command (`C-a r') or by means of "C-a : wrap
on|off".
File: screen.info, Node: Reset, Next: Window Size, Prev: Wrap, Up: Virtual Terminal
Reset
=====
- Command: reset
(`C-a Z')
Reset the virtual terminal to its "power-on" values. Useful when
strange settings (like scroll regions or graphics character set)
are left over from an application.
File: screen.info, Node: Window Size, Next: Character Processing, Prev: Reset, Up: Virtual Terminal
Window Size
===========
- Command: width [`-w'|`-d'] [cols [lines]]
(`C-a W')
Toggle the window width between 80 and 132 columns, or set it to
COLS columns if an argument is specified. This requires a capable
terminal and the termcap entries `Z0' and `Z1'. See the `termcap'
command (*note Termcap::), for more information. You can also
specify a height if you want to change both values. The `-w'
option tells screen to leave the display size unchanged and just
set the window size, `-d' vice versa.
- Command: height [`-w'|`-d'] [lines [cols]]
(none)
Set the display height to a specified number of lines. When no
argument is given it toggles between 24 and 42 lines display.
File: screen.info, Node: Character Processing, Prev: Window Size, Up: Virtual Terminal
Character Processing
====================
- Command: c1 [state]
(none)
Change c1 code processing. `c1 on' tells screen to treat the input
characters between 128 and 159 as control functions. Such an
8-bit code is normally the same as ESC followed by the
corresponding 7-bit code. The default setting is to process c1
codes and can be changed with the `defc1' command. Users with
fonts that have usable characters in the c1 positions may want to
turn this off.
- Command: gr [state]
(none)
Turn GR charset switching on/off. Whenever screen sees an input
char with an 8th bit set, it will use the charset stored in the GR
slot and print the character with the 8th bit stripped. The
default (see also `defgr') is not to process GR switching because
otherwise the ISO88591 charset would not work.
- Command: bce [state]
(none)
Change background-color-erase setting. If `bce' is set to on, all
characters cleared by an erase/insert/scroll/clear operation will
be displayed in the current background color. Otherwise the
default background color is used.
- Command: encoding enc [denc]
(none)
Tell screen how to interpret the input/output. The first argument
sets the encoding of the current window. Each window can emulate
a different encoding. The optional second parameter overwrites the
encoding of the connected terminal. It should never be needed as
screen uses the locale setting to detect the encoding. There is
also a way to select a terminal encoding depending on the terminal
type by using the `KJ' termcap entry. *Note Special Capabilities::.
Supported encodings are `eucJP', `SJIS', `eucKR', `eucCN', `Big5',
`GBK', `KOI8-R', `CP1251', `UTF-8', `ISO8859-2', `ISO8859-3',
`ISO8859-4', `ISO8859-5', `ISO8859-6', `ISO8859-7', `ISO8859-8',
`ISO8859-9', `ISO8859-10', `ISO8859-15', `jis'.
See also `defencoding', which changes the default setting of a new
window.
- Command: charset set
(none)
Change the current character set slot designation and charset
mapping. The first four character of SET are treated as charset
designators while the fifth and sixth character must be in range
`0' to `3' and set the GL/GR charset mapping. On every position a
`.' may be used to indicate that the corresponding charset/mapping
should not be changed (SET is padded to six characters internally
by appending `.' chars). New windows have `BBBB02' as default
charset, unless a `encoding' command is active.
The current setting can be viewed with the *Note Info:: command.
- Command: utf8 [state [dstate]]
(none)
Change the encoding used in the current window. If utf8 is
enabled, the strings sent to the window will be UTF-8 encoded and
vice versa. Omitting the parameter toggles the setting. If a
second parameter is given, the display's encoding is also changed
(this should rather be done with screen's `-U' option). See also
`defutf8', which changes the default setting of a new window.
- Command: defc1 state
(none)
Same as the `c1' command except that the default setting for new
windows is changed. Initial setting is `on'.
- Command: defgr state
(none)
Same as the `gr' command except that the default setting for new
windows is changed. Initial setting is `off'.
- Command: defbce state
(none)
Same as the `bce' command except that the default setting for new
windows is changed. Initial setting is `off'.
- Command: defencoding enc
(none)
Same as the `encoding' command except that the default setting for
new windows is changed. Initial setting is the encoding taken from
the terminal.
- Command: defcharset [set]
Like the `charset' command except that the default setting for new
windows is changed. Shows current default if called without
argument.
- Command: defutf8 state
(none)
Same as the `utf8' command except that the default setting for new
windows is changed. Initial setting is `on' if screen was started
with `-U', otherwise `off'.
File: screen.info, Node: Copy and Paste, Next: Subprocess Execution, Prev: Virtual Terminal, Up: Top
Copy and Paste
**************
For those confined to a hardware terminal, these commands provide a
cut and paste facility more powerful than those provided by most
windowing systems.
* Menu:
* Copy:: Copy from scrollback to buffer
* Paste:: Paste from buffer into window
* Registers:: Longer-term storage
* Screen Exchange:: Sharing data between screen users
* History:: Recalling previous input
File: screen.info, Node: Copy, Next: Paste, Up: Copy and Paste
Copying
=======
- Command: copy
(`C-a [', `C-a C-[', `C-a <ESC>')
Enter copy/scrollback mode. This allows you to copy text from the
current window and its history into the paste buffer. In this mode
a `vi'-like full screen editor is active, with controls as
outlined below.
* Menu:
* Line Termination:: End copied lines with CR/LF
* Scrollback:: Set the size of the scrollback buffer
* Copy Mode Keys:: Remap keys in copy mode
* Movement:: Move around in the scrollback buffer
* Marking:: Select the text you want
* Repeat count:: Repeat a command
* Searching:: Find the text you want
* Specials:: Other random keys
File: screen.info, Node: Line Termination, Next: Scrollback, Up: Copy
CR/LF
-----
- Command: crlf [state]
(none)
This affects the copying of text regions with the `C-a [' command.
If it is set to `on', lines will be separated by the two character
sequence `CR'/`LF'. Otherwise only `LF' is used. `crlf' is off
by default. When no parameter is given, the state is toggled.
File: screen.info, Node: Scrollback, Next: Copy Mode Keys, Prev: Line Termination, Up: Copy
Scrollback
----------
- Command: defscrollback num
(none)
Same as the `scrollback' command except that the default setting
for new windows is changed. Defaults to 100.
- Command: scrollback num
(none)
Set the size of the scrollback buffer for the current window to
NUM lines. The default scrollback is 100 lines. Use `C-a i' to
view the current setting.
- Command: compacthist [state]
(none)
This tells screen whether to suppress trailing blank lines when
scrolling up text into the history buffer. Turn compacting `on' to
hold more useful lines in your scrollback buffer.
File: screen.info, Node: Copy Mode Keys, Next: Movement, Prev: Scrollback, Up: Copy
markkeys
--------
- Command: markkeys string
(none)
This is a method of changing the keymap used for copy/history
mode. The string is made up of OLDCHAR=NEWCHAR pairs which are
separated by `:'. Example: The command `markkeys h=^B:l=^F:$=^E'
would set some keys to be more familiar to `emacs' users. If your
terminal sends characters, that cause you to abort copy mode, then
this command may help by binding these characters to do nothing.
The no-op character is `a'nd is used like this: `markkeys @=L=H'
if you do not want to use the `H' or `L' commands any longer. As
shown in this example, multiple keys can be assigned to one
function in a single statement.
File: screen.info, Node: Movement, Next: Marking, Prev: Copy Mode Keys, Up: Copy
Movement Keys
-------------
`h', `j', `k', `l' move the cursor line by line or column by column.
`0', `^' and `$' move to the leftmost column or to the first or last
non-whitespace character on the line.
`H', `M' and `L' move the cursor to the leftmost column of the top,
center or bottom line of the window.
`+' and `-' move the cursor to the leftmost column of the next or
previous line.
`G' moves to the specified absolute line (default: end of buffer).
`|' moves to the specified absolute column.
`w', `b', `e' move the cursor word by word.
`B', `E' move the cursor WORD by WORD (as in vi).
`C-u' and `C-d' scroll the display up/down by the specified amount of
lines while preserving the cursor position. (Default: half screenfull).
`C-b' and `C-f' move the cursor up/down a full screen.
`g' moves to the beginning of the buffer.
`%' jumps to the specified percentage of the buffer.
Note that Emacs-style movement keys can be specified by a .screenrc
command. (`markkeys "h=^B:l=^F:$=^E"') There is no simple method for a
full emacs-style keymap, however, as this involves multi-character
codes.
File: screen.info, Node: Marking, Next: Repeat count, Prev: Movement, Up: Copy
Marking
-------
The copy range is specified by setting two marks. The text between
these marks will be highlighted. Press `space' to set the first or
second mark respectively.
`Y' and `y' can be used to mark one whole line or to mark from start of
line.
`W' marks exactly one word.
File: screen.info, Node: Repeat count, Next: Searching, Prev: Marking, Up: Copy
Repeat Count
------------
Any command in copy mode can be prefixed with a number (by pressing
digits `0...9') which is taken as a repeat count. Example: `C-a C-[ H
10 j 5 Y' will copy lines 11 to 15 into the paste buffer.
File: screen.info, Node: Searching, Next: Specials, Prev: Repeat count, Up: Copy
Searching
---------
`/' `vi'-like search forward.
`?' `vi'-like search backward.
`C-a s' `emacs' style incremental search forward.
`C-r' `emacs' style reverse i-search.
- Command: ignorecase [state]
(none)
Tell screen to ignore the case of characters in searches. Default
is `off'.
File: screen.info, Node: Specials, Prev: Searching, Up: Copy
Specials
--------
There are, however, some keys that act differently here from in
`vi'. `Vi' does not allow to yank rectangular blocks of text, but
`screen' does. Press
`c' or `C' to set the left or right margin respectively. If no repeat
count is given, both default to the current cursor position.
Example: Try this on a rather full text screen: `C-a [ M 20 l SPACE c
10 l 5 j C SPACE'.
This moves one to the middle line of the screen, moves in 20 columns
left, marks the beginning of the paste buffer, sets the left column,
moves 5 columns down, sets the right column, and then marks the end of
the paste buffer. Now try:
`C-a [ M 20 l SPACE 10 l 5 j SPACE'
and notice the difference in the amount of text copied.
`J' joins lines. It toggles between 4 modes: lines separated by a
newline character (012), lines glued seamless, lines separated by a
single space or comma separated lines. Note that you can prepend the
newline character with a carriage return character, by issuing a `set
crlf on'.
`v' is for all the `vi' users who use `:set numbers' - it toggles the
left margin between column 9 and 1.
`a' before the final space key turns on append mode. Thus the contents
of the paste buffer will not be overwritten, but appended to.
`A' turns on append mode and sets a (second) mark.
`>' sets the (second) mark and writes the contents of the paste buffer
to the screen-exchange file (`/tmp/screen-exchange' per default) once
copy-mode is finished. *Note Screen Exchange::.
This example demonstrates how to dump the whole scrollback buffer to
that file:
`C-a [ g SPACE G $ >'.
`C-g' gives information about the current line and column.
`x' exchanges the first mark and the current cursor position. You can
use this to adjust an already placed mark.
`@' does nothing. Absolutely nothing. Does not even exit copy mode.
All keys not described here exit copy mode.
File: screen.info, Node: Paste, Next: Registers, Prev: Copy, Up: Copy and Paste
Paste
=====
- Command: paste [registers [destination]]
(`C-a ]', `C-a C-]')
Write the (concatenated) contents of the specified registers to
the stdin stream of the current window. The register `.' is
treated as the paste buffer. If no parameter is specified the user
is prompted to enter a single register. The paste buffer can be
filled with the `copy', `history' and `readbuf' commands. Other
registers can be filled with the `register', `readreg' and `paste'
commands. If `paste' is called with a second argument, the
contents of the specified registers is pasted into the named
destination register rather than the window. If `.' is used as the
second argument, the display's paste buffer is the destination.
Note, that `paste' uses a wide variety of resources: Usually both,
a current window and a current display are required. But whenever
a second argument is specified no current window is needed. When
the source specification only contains registers (not the paste
buffer) then there need not be a current display (terminal
attached), as the registers are a global resource. The paste
buffer exists once for every user.
- Command: stuff string
(none)
Stuff the string STRING in the input buffer of the current window.
This is like the `paste' command, but with much less overhead.
You cannot paste large buffers with the `stuff' command. It is most
useful for key bindings. *Note Bindkey::.
- Command: pastefont [state]
Tell screen to include font information in the paste buffer. The
default is not to do so. This command is especially useful for
multi character fonts like kanji.
- Command: slowpaste msec
- Command: defslowpaste msec
(none)
Define the speed text is inserted in the current window by the
`paste' command. If the slowpaste value is nonzero text is written
character by character. `screen' will pause for MSEC milliseconds
after each write to allow the application to process the input.
only use `slowpaste' if your underlying system exposes flow
control problems while pasting large amounts of text.
`defslowpaste' specifies the default for new windows.
- Command: readreg [-e encoding] [register [filename]]
(none)
Does one of two things, dependent on number of arguments: with
zero or one arguments it it duplicates the paste buffer contents
into the register specified or entered at the prompt. With two
arguments it reads the contents of the named file into the
register, just as `readbuf' reads the screen-exchange file into
the paste buffer. You can tell screen the encoding of the file
via the `-e' option. The following example will paste the
system's password file into the screen window (using register p,
where a copy remains):
C-a : readreg p /etc/passwd
C-a : paste p
File: screen.info, Node: Registers, Next: Screen Exchange, Prev: Paste, Up: Copy and Paste
Registers
=========
- Command: copy_reg [key]
(none)
Removed. Use `readreg' instead.
- Command: ins_reg [key]
(none)
Removed. Use `paste' instead.
- Command: process [key]
(none)
Stuff the contents of the specified register into the `screen'
input queue. If no argument is given you are prompted for a
register name. The text is parsed as if it had been typed in from
the user's keyboard. This command can be used to bind multiple
actions to a single key.
- Command: register [-e encoding] key string
(none)
Save the specified STRING to the register KEY. The encoding of
the string can be specified via the `-e' option.
File: screen.info, Node: Screen Exchange, Next: History, Prev: Registers, Up: Copy and Paste
Screen Exchange
===============
- Command: bufferfile [EXCHANGE-FILE]
(none)
Change the filename used for reading and writing with the paste
buffer. If the EXCHANGE-FILE parameter is omitted, `screen'
reverts to the default of `/tmp/screen-exchange'. The following
example will paste the system's password file into the screen
window (using the paste buffer, where a copy remains):
C-a : bufferfile /etc/passwd
C-a < C-a ]
C-a : bufferfile
- Command: readbuf [-e ENCODING] [FILENAME]
(`C-a <')
Reads the contents of the specified file into the paste buffer.
You can tell screen the encoding of the file via the `-e' option.
If no file is specified, the screen-exchange filename is used.
- Command: removebuf
(`C-a =')
Unlinks the screen-exchange file.
- Command: writebuf [-e ENCODING] [FILENAME]
(`C-a >')
Writes the contents of the paste buffer to the specified file, or
the public accessible screen-exchange file if no filename is given.
This is thought of as a primitive means of communication between
`screen' users on the same host. If an encoding is specified the
paste buffer is recoded on the fly to match the encoding. See also
`C-a <ESC>' (*note Copy::).
File: screen.info, Node: History, Prev: Screen Exchange, Up: Copy and Paste
History
=======
- Command: history
(`C-a {')
Usually users work with a shell that allows easy access to previous
commands. For example, `csh' has the command `!!' to repeat the
last command executed. `screen' provides a primitive way of
recalling "the command that started ...": You just type the first
letter of that command, then hit `C-a {' and `screen' tries to
find a previous line that matches with the prompt character to the
left of the cursor. This line is pasted into this window's input
queue. Thus you have a crude command history (made up by the
visible window and its scrollback buffer).
File: screen.info, Node: Subprocess Execution, Next: Key Binding, Prev: Copy and Paste, Up: Top
Subprocess Execution
********************
Control Input or Output of a window by another filter process. Use
with care!
* Menu:
* Exec:: The `exec' command syntax.
* Using Exec:: Weird things that filters can do.
File: screen.info, Node: Exec, Next: Using Exec, Up: Subprocess Execution
Exec
====
- Command: exec [[FDPAT] NEWCOMMAND [ARGS ... ]]
(none)
Run a unix subprocess (specified by an executable path NEWCOMMAND
and its optional arguments) in the current window. The flow of
data between newcommands stdin/stdout/stderr, the process
originally started (let us call it "application-process") and
screen itself (window) is controlled by the filedescriptor pattern
FDPAT. This pattern is basically a three character sequence
representing stdin, stdout and stderr of newcommand. A dot (`.')
connects the file descriptor to screen. An exclamation mark (`!')
causes the file descriptor to be connected to the
application-process. A colon (`:') combines both.
User input will go to newcommand unless newcommand receives the
application-process' output (FDPATs first character is `!' or `:')
or a pipe symbol (`|') is added to the end of FDPAT.
Invoking `exec' without arguments shows name and arguments of the
currently running subprocess in this window. Only one subprocess
can be running per window.
When a subprocess is running the `kill' command will affect it
instead of the windows process. Only one subprocess a time can be
running in each window.
Refer to the postscript file `doc/fdpat.ps' for a confusing
illustration of all 21 possible combinations. Each drawing shows
the digits 2, 1, 0 representing the three file descriptors of
newcommand. The box marked `W' is usual pty that has the
application-process on its slave side. The box marked `P' is the
secondary pty that now has screen at its master side.
File: screen.info, Node: Using Exec, Prev: Exec, Up: Subprocess Execution
Using Exec
==========
Abbreviations:
* Whitespace between the word `exec' and FDPAT and the command name
can be omitted.
* Trailing dots and a FDPAT consisting only of dots can be omitted.
* A simple `|' is synonymous for the `!..|' pattern.
* The word `exec' can be omitted when the `|' abbreviation is used.
* The word `exec' can always be replaced by leading `!'.
Examples:
`!/bin/sh'
`exec /bin/sh'
`exec ... /bin/sh'
All of the above are equivalent. Creates another shell in the
same window, while the original shell is still running. Output of
both shells is displayed and user input is sent to the new
`/bin/sh'.
`!!stty 19200'
`exec!stty 19200'
`exec !.. stty 19200'
All of the above are equivalent. Set the speed of the window's
tty. If your stty command operates on stdout, then add another
`!'. This is a useful command, when a screen window is directly
connected to a serial line that needs to be configured.
`|less'
`exec !..| less'
Both are equivalent. This adds a pager to the window output. The
special character `|' is needed to give the user control over the
pager although it gets its input from the window's process. This
works, because `less' listens on stderr (a behavior that `screen'
would not expect without the `|') when its stdin is not a tty.
`Less' versions newer than 177 fail miserably here; good old `pg'
still works.
`!:sed -n s/.*Error.*/\007/p'
Sends window output to both, the user and the sed command. The sed
inserts an additional bell character (oct. 007) to the window
output seen by screen. This will cause 'Bell in window x'
messages, whenever the string `Error' appears in the window.
File: screen.info, Node: Key Binding, Next: Flow Control, Prev: Subprocess Execution, Up: Top
Key Binding
***********
You may disagree with some of the default bindings (I know I do).
The `bind' command allows you to redefine them to suit your preferences.
* Menu:
* Bind:: `bind' syntax.
* Bind Examples:: Using `bind'.
* Command Character:: The character used to start keyboard commands.
* Help:: Show current key bindings.
* Bindkey:: `bindkey' syntax.
* Bindkey Examples:: Some easy examples.
* Bindkey Control:: How to control the bindkey mechanism.
File: screen.info, Node: Bind, Next: Bind Examples, Up: Key Binding
The `bind' command
==================
- Command: bind [-c class] key [command [args]]
(none)
Bind a command to a key. The KEY argument is either a single
character, a two-character sequence of the form `^x' (meaning
`C-x'), a backslash followed by an octal number (specifying the
ASCII code of the character), or a backslash followed by a second
character, such as `\^' or `\\'. The argument can also be quoted,
if you like. If no further argument is given, any previously
established binding for this key is removed. The COMMAND argument
can be any command (*note Command Index::).
If a command class is specified via the `-c' option, the key is
bound for the specified class. Use the `command' command to
activate a class. Command classes can be used to create multiple
command keys or multi-character bindings.
By default, most suitable commands are bound to one or more keys
(*note Default Key Bindings::; for instance, the command to create
a new window is bound to `C-c' and `c'. The `bind' command can be
used to redefine the key bindings and to define new bindings.
File: screen.info, Node: Bind Examples, Next: Command Character, Prev: Bind, Up: Key Binding
Examples of the `bind' command
==============================
Some examples:
bind ' ' windows
bind ^f screen telnet foobar
bind \033 screen -ln -t root -h 1000 9 su
would bind the space key to the command that displays a list of windows
(so that the command usually invoked by `C-a C-w' would also be
available as `C-a space'), bind `C-f' to the command "create a window
with a TELNET connection to foobar", and bind <ESC> to the command that
creates an non-login window with title `root' in slot #9, with a
superuser shell and a scrollback buffer of 1000 lines.
bind -c demo1 0 select 10
bind -c demo1 1 select 11
bind -c demo1 2 select 12
bindkey "^B" command -c demo1
makes `C-b 0' select window 10, `C-b 1' window 11, etc.
bind -c demo2 0 select 10
bind -c demo2 1 select 11
bind -c demo2 2 select 12
bind - command -c demo2
makes `C-a - 0' select window 10, `C-a - 1' window 11, etc.
File: screen.info, Node: Command Character, Next: Help, Prev: Bind Examples, Up: Key Binding
Command Character
=================
- Command: escape xy
(none)
Set the command character to X and the character generating a
literal command character (by triggering the `meta' command) to Y
(similar to the `-e' option). Each argument is either a single
character, a two-character sequence of the form `^x' (meaning
`C-x'), a backslash followed by an octal number (specifying the
ASCII code of the character), or a backslash followed by a second
character, such as `\^' or `\\'. The default is `^Aa', but ```'
is recommended by one of the authors.
- Command: defescape xy
(none)
Set the default command characters. This is equivalent to the
command `escape' except that it is useful for multiuser sessions
only. In a multiuser session `escape' changes the command
character of the calling user, where `defescape' changes the
def