Next: Getting Started, Previous: Top, Up: Top [Contents][Index]
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. Shells usually distinguish between running as login-shell or sub-shell.
Screen runs them as sub-shells, unless told otherwise (See shell
.screenrc command).
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 (see Command Character) and all the key bindings (see 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, although
this notation is used in this manual for readability.
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.
- Note that you cannot transport environment variables from
the invoking shell to the application (emacs in this case), because it is
forked from the parent screen process, not from the invoking shell.
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. See Login.
Next: Invoking Screen
, Previous: Overview, Up: Top [Contents][Index]
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 ? (see 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 (see Default Key Bindings).
Another section (see Customizing Screen
) 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.
See Special Terminal Capabilities, for more information about telling
screen
what kind of terminal you have.
Next: Customizing Screen
, Previous: Getting Started, Up: Top [Contents][Index]
Screen
Screen has the following command-line options:
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.
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
).
Use file as the user’s configuration file instead of the default of $HOME/.screenrc.
Do not start screen
, but instead detach a screen
session
running elsewhere (see 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.
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. (see Command Character).
Set flow-control to on, off, or automatic switching mode, respectively.
This option is equivalent to the defflow
command (see Flow Control).
Set the history scrollback buffer to be num lines high.
Equivalent to the defscrollback
command (see Copying).
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 (see Flow Control). Its use is discouraged.
Turn login mode on or off (for /etc/utmp updating). This option
is equivalent to the deflogin
command (see Login).
Do not start screen
, but instead print a list of session
identification strings (usually of the form pid.tty.host;
see 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.
Tell screen
to turn on automatic output logging for the
windows.
By default logfile name is "screenlog.0". You can set new logfile name
with the -Logfile
option.
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.
Select a more optimal output mode for your terminal rather than true VT100
emulation (only affects auto-margin terminals without ‘LP’). This
can also be set in your .screenrc by specifying ‘OP’ in the
termcap
command.
Preselect a window. This is useful when you want to reattach to a specific window or you want to send a command via the ‘-X’ option to a specific window. As with screen’s select command, ‘-’ selects the blank window. As a special case for reattach, ‘=’ brings up the windowlist on the blank window, while a ‘+’ will create new window. The command will not be executed if the specified window could not be found.
Turns authentication on. By default screen
allows to attach without
enter the user’s password. This option changes this behavior, i.e.
enables authentication.
The same effect can be done by using "auth on" command.
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.
Some commands now can be queried from a remote session using this flag, e.g. ’screen -Q windows’. The commands will send the response to the stdout of the querying process. If there was an error in the command, then the querying process will exit with a non-zero status.
The commands that can be queried now are:
echo
info
lastmsg
number
select
time
title
windows
Resume a detached screen
session. No other options (except
combinations with ‘-d’ or ‘-D’) may be specified, though
the session name
(see 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.
resumes screen only when it’s unambiguous which one to attach, usually
when only one screen
is detached. Otherwise lists available sessions.
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.
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 (see Shell). See also there.
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 (see Session Name).
Set the title (name) for the default shell or specified program.
This option is equivalent to the shelltitle
command
(see Shell).
Set the $TERM enviroment variable using the specified term as
opposed to the default setting of screen
.
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’.
Print the version number.
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.
Attach to a session which is already attached elsewhere (multi-display
mode).
Screen
refuses to attach from within itself.
But when cascading multiple screens, loops are not detected; take care.
Send the specified command to a running screen session. You may use
the -S
option to specify the screen session if you have several
running. 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.
Next: Commands, Previous: Invoking Screen
, Up: Top [Contents][Index]
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.
Next: Source, Up: Customizing Screen
[Contents][Index]
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 $SYSTEM_SCREENRC
(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 (see 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.
Next: Colon, Previous: The .screenrc file, Up: Customizing Screen
[Contents][Index]
(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.
Previous: Source, Up: Customizing Screen
[Contents][Index]
Customization can also be done online, with this command:
(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
(see Copy and Paste).
Next: New Window, Previous: Customizing Screen
, Up: Top [Contents][Index]
A command in screen
can either be bound to a key, invoked from a
screenrc file, or called from the colon
prompt
(see Customizing Screen
). 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:
(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.
Next: Command Summary, Up: Commands [Contents][Index]
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:
(select)
Prompt for a window identifier and switch.
See Selecting a Window.
(windowlist -b)
Present a list of all windows for selection.
See Selecting a Window.
(select 0…select 9, select -)
Switch to window number 0…9, or the blank window.
See Selecting a Window.
(focus)
Switch the input focus to the next region. See Regions.
(other)
Toggle to the window displayed previously. If this window does no
longer exist, other
has the same effect as next
.
See Selecting a Window.
(meta)
Send the command character (C-a) to window. See escape
command.
See Command Character.
(title)
Allow the user to enter a title for the current window.
See Naming Windows (Titles).
(break)
Send a break to the tty.
See Break.
(pow_break)
Close and reopen the tty-line.
See Break.
(screen)
Create a new window with a shell and switch to that window.
See Screen Command.
(clear)
Clear the screen. See Clear.
(detach)
Detach screen
from this terminal. See Detach.
(pow_detach)
Detach and logout. See Power Detach.
(flow)
Cycle flow among ‘on’, ‘off’ or ‘auto’. See Flow.
(fit)
Resize the window to the current region size. See Fit.
(vbell)
Toggle visual bell mode. See Bell.
(hardcopy)
Write a hardcopy of the current window to the file “hardcopy.n”.
See hardcopy.
(log)
Toggle logging of the current window to the file “screenlog.n”.
See log.
(info)
Show info about the current window. See Info.
(kill)
Destroy the current window. See Kill.
(redisplay)
Fully refresh the current window. See Redisplay.
(login)
Toggle the current window’s login state. See Login.
(lastmsg)
Repeat the last message displayed in the message line.
See Display Last Message.
(monitor) Toggle monitoring of the current window. See Monitoring.
(next)
Switch to the next window. See Selecting a Window.
(number)
Show the number (and title) of the current window. See Number.
(prev)
Switch to the previous window (opposite of C-a n).
See Selecting a Window.
(xon)
Send a ^Q (ASCII XON) to the current window. See XON and XOFF.
(only)
Delete all regions but the current one. See Regions.
(wrap)
Toggle the current window’s line-wrap setting (turn the current window’s
automatic margins on or off). See Wrap.
(xoff)
Send a ^S (ASCII XOFF) to the current window. See XON and XOFF.
(split)
Split the current region horizontally into two new ones. See Regions.
(parent)
Switch to the parent window.
See Selecting a Window.
(version)
Display the version and compilation date. See Version.
(digraph)
Enter digraph. See Digraph.
(windows)
Show a list of active windows. See Windows.
(width)
Toggle between 80 and 132 columns. See Window Size.
(lockscreen)
Lock your terminal. See Lock.
(remove)
Kill the current region. See Regions.
(suspend)
Suspend screen
. See Suspend.
(reset)
Reset the virtual terminal to its “power-on” values.
See Reset.
(dumptermcap)
Write out a .termcap file. See Write out the window’s termcap entry.
(help)
Show key bindings. See Help.
(quit)
Kill all windows and terminate screen
. See Quit.
(colon)
Enter a command line. See Colon.
(copy)
Enter copy/scrollback mode. See Copying.
(paste .)
Write the contents of the paste buffer to the stdin queue of the
current window. See Paste.
(history)
Copy and paste a previous (command) line. See History.
(writebuf)
Write the paste buffer out to the screen-exchange file.
See Screen Exchange.
(readbuf)
Read the screen-exchange file into the paste buffer.
See Screen Exchange.
(removebuf)
Delete the screen-exchange file. See Screen Exchange.
(silence)
Start/stop monitoring the current window for inactivity. See Monitoring.
(split -v)
Split the current region vertically into two new ones. See Regions.
(license)
Show the copyright page. See License.
(displays)
Show the listing of attached displays. See Displays.
Previous: Default Key Bindings, Up: Commands [Contents][Index]
acladd usernames
Allow other users in this session. See Multiuser Session.
aclchg usernames permbits list
Change a user’s permissions. See Multiuser Session.
acldel username
Disallow other user in this session. See Multiuser Session.
aclgrp usrname [groupname]
Inherit permissions granted to a group leader. See Multiuser Session.
aclumask [users]+/-bits ...
Predefine access to new windows. See aclumask.
activity message
Set the activity notification message. See Monitoring.
addacl usernames
Synonym to acladd
. See Multiuser Session.
allpartial state
Set all windows to partial refresh. See Redisplay.
altscreen state
Enables support for the "alternate screen" terminal capability. See Redisplay.
at [ident][#|*|%] command [args]
Execute a command at other displays or windows. See At.
attrcolor attrib [attribute/color-modifier]
Map attributes to colors. See Attrcolor.
auth state
This command enables/disables password protection for the screen session. It is off by default (authentication is disabled).
autodetach state
Automatically detach the session on SIGHUP. See Detach.
autonuke state
Enable a clear screen to discard unwritten output. See Autonuke.
backtick id lifespan autorefresh command [args]
Define a command for the backtick string escape. See Backtick.
bce [state]
Change background color erase. See Character Processing.
bell_msg [message]
Set the bell notification message. See Bell.
bind [-c class] key [command [args]]
Bind a command to a key. See The bind
command.
bindkey [opts] [string [cmd args]]
Bind a string to a series of keystrokes. See Bindkey.
blanker
Blank the screen. See Screen Saver.
blankerprg
Define a blanker program. See Screen Saver.
break [duration]
Send a break signal to the current window. See Break.
breaktype [tcsendbreak | TCSBRK | TIOCSBRK]
Specify how to generate breaks. See Break.
bufferfile [exchange-file]
Select a file for screen-exchange. See Screen Exchange.
bumpleft
Swaps window with previous one on window list. See Bumpleft.
bumpright
Swaps window with previous one on window list. See Bumpright.
c1 [state]
Change c1 code processing. See Character Processing.
caption mode [string]
Change caption mode and string. See Regions.
chacl usernames permbits list
Synonym to aclchg
. See Multiuser Session.
charset set
Change character set slot designation. See Character Processing.
chdir [directory]
Change the current directory for future windows. See Chdir.
cjkwidth
Treat ambiguous width characters as full/half width. See Character Processing.
clear
Clear the window screen. See Clear.
colon
Enter a screen
command. See Colon.
collapse
Reorders window on window list, removing number gaps between them. See Collapse.
command [-c class]
Simulate the screen escape key. See Command Character.
compacthist [state]
Selects compaction of trailing empty lines. See Scrollback.
console [state]
Grab or ungrab console output. See Console.
copy
Enter copy mode. See Copying.
copy_reg [key]
Removed. Use paste
instead. See Registers.
crlf state
Select line break behavior for copying. See CR/LF.
defautonuke state
Select default autonuke behavior. See Autonuke.
defbce state
Select background color erase. See Character Processing.
defbreaktype [tcsendbreak | TCSBRK | TIOCSBRK]
Specify the default for generating breaks. See Break.
defc1 state
Select default c1 processing behavior. See Character Processing.
defcharset [set]
Change defaul character set slot designation. See Character Processing.
defencoding enc
Select default window encoding. See Character Processing.
defescape xy
Set the default command and meta
characters. See Command Character.
defflow fstate
Select default flow control behavior. See Flow.
defgr state
Select default GR processing behavior. See Character Processing.
defhstatus [status]
Select default window hardstatus line. See Hardstatus.
deflog state
Select default window logging behavior. See log.
deflogin state
Select default utmp logging behavior. See Login.
defmode mode
Select default file mode for ptys. See Mode.
defmonitor state
Select default activity monitoring behavior. See Monitoring.
defmousetrack on|off
Select the default mouse tracking behavior. See Mousetrack.
defnonblock state|numsecs
Select default nonblock mode. See Nonblock.
defobuflimit limit
Select default output buffer limit. See Obuflimit.
defscrollback num
Set default lines of scrollback. See Scrollback.
defshell command
Set the default program for new windows. See Shell.
defsilence state
Select default idle monitoring behavior. See Monitoring.
defslowpaste msec
Select the default inter-character timeout when pasting. See Paste.
defutf8 state
Select default character encoding. See Character Processing.
defwrap state
Set default line-wrapping behavior. See Wrap.
defwritelock on|off|auto
Set default writelock behavior. See Multiuser Session.
zombie_timeout [seconds]
Try to reconnect dead windows after timeout. See Zombie.
detach [-h]
Disconnect screen
from the terminal. See Detach.
digraph [preset [unicode-value]]
Enter a digraph sequence. See Digraph.
dinfo
Display terminal information. See Info.
displays
List currently active user interfaces. See Displays.
dumptermcap
Write the window’s termcap entry to a file. See Write out the window’s termcap entry.
echo [-n] message
Display a message on startup. See Startup.
encoding enc [denc]
Set the encoding of a window. See Character Processing.
escape xy
Set the command and meta
characters. See Command Character.
eval command1 [command2 ...]
Parse and execute each argument. See Eval.
exec [[fdpat] command [args ...]]
Run a subprocess (filter). See Exec.
fit
Change window size to current display size. See Window Size.
flow [fstate]
Set flow control behavior. See Flow.
focus [next
|prev
|up
|down
|left
|right
|top
|bottom
]
Move focus to next region. See Regions.
focusminsize
Force the current region to a certain size. See Focusminsize.
gr [state]
Change GR charset processing. See Character Processing.
group [grouptitle]
Change or show the group the current window belongs to. See Window Groups.
hardcopy [-h] [file]
Write out the contents of the current window. See hardcopy.
hardcopy_append state
Append to hardcopy files. See hardcopy.
hardcopydir directory
Place, where to dump hardcopy files. See hardcopy.
hardstatus [state]
Use the hardware status line. See Hardware Status Line.
height [lines [cols]]
Set display height. See Window Size.
help [-c class]
Display current key bindings. See Help.
history
Find previous command beginning …. See History.
hstatus status
Change the window’s hardstatus line. See Hardstatus.
idle [timeout [cmd args]]
Define a screen saver command. See Screen Saver.
ignorecase [on|off]
Ignore character case in searches. See Searching.
info
Display window settings. See Info.
ins_reg [key]
Removed, use paste
instead. See Registers.
kill
Destroy the current window. See Kill.
lastmsg
Redisplay the last message. See Display Last Message.
layout new [title]
Create a layout. See Layout.
layout remove [n|title]
Delete a layout. See Layout.
layout next
Select the next layout. See Layout.
layout prev
Select the previous layout. See Layout.
layout select [n|title]
Jump to a layout. See Layout.
layout show
List the available layouts. See Layout.
layout title [title]
Show or set the title of a layout. See Layout.
layout number [n]
Show or set the number of a layout. See Layout.
layout attach [title|:last]
Show or set which layout to reattach to. See Layout.
layout save [n|title]
Remember the organization of a layout. See Layout.
layout autosave [on|off]
Show or set the status of layout saving. See Layout.
layout dump [filename]
Save the layout arrangement to a file. See Layout.
license
Display licensing information. See Startup.
lockscreen
Lock the controlling terminal. See Lock.
log [state]
Log all output in the current window. See log.
logfile filename
Place where to collect logfiles. See log.
login [state]
Log the window in /etc/utmp. See Login.
logtstamp [state]
Configure logfile time-stamps. See log.
mapdefault
Use only the default mapping table for the next keystroke. See Bindkey Control.
mapnotnext
Don’t try to do keymapping on the next keystroke. See Bindkey Control.
maptimeout n
Set the inter-character timeout used for keymapping. See Bindkey Control.
markkeys string
Rebind keys in copy mode. See Markkeys.
meta
Insert the command character. See Command Character.
monitor [state]
Monitor activity in window. See Monitoring.
mousetrack [on|off]
Enable selecting split regions with mouse clicks. See Mousetrack.
msgminwait sec
Set minimum message wait. See Message Wait.
msgwait sec
Set default message wait. See Message Wait.
multiuser state
Go into single or multi user mode. See Multiuser Session.
next
Switch to the next window. See Selecting a Window.
nonblock [state|numsecs]
Disable flow control to the current display. See Nonblock.|numsecs]
number [n]
Change/display the current window’s number. See Number.
obuflimit [limit]
Select output buffer limit. See Obuflimit.
only
Kill all other regions. See Regions.
other
Switch to the window you were in last. See Selecting a Window.
parent
Switch to the parent window. See Selecting a Window.
partial state
Set window to partial refresh. See Redisplay.
paste [src_regs [dest_reg]]
Paste contents of paste buffer or registers somewhere. See Paste.
pastefont [state]
Include font information in the paste buffer. See Paste.
pow_break
Close and Reopen the window’s terminal. See Break.
pow_detach
Detach and hang up. See Power Detach.
pow_detach_msg [message]
Set message displayed on pow_detach
. See Power Detach.
prev
Switch to the previous window. See Selecting a Window.
printcmd [cmd]
Set a command for VT100 printer port emulation. See Printcmd.
process [key]
Treat a register as input to screen
. See Registers.
quit
Kill all windows and exit. See Quit.
readbuf [-e encoding] [filename]
Read the paste buffer from the screen-exchange file. See Screen Exchange.
readreg [-e encoding] [reg [file]]
Load a register from paste buffer or file. See Registers.
redisplay
Redisplay the current window. See Redisplay.
register [-e encoding] key string
Store a string to a register. See Registers.
remove
Kill current region. See Regions.
removebuf
Delete the screen-exchange file. See Screen Exchange.
rendition bell | monitor | silence | so attr [color]
Change text attributes in caption for flagged windows. See Rendition.
reset
Reset the terminal settings for the window. See Reset.
resize [(+/-)lines]
Grow or shrink a region. See Resize.
screen [opts] [n] [cmd [args] | //group]
Create a new window. See Screen Command.
scrollback num
Set size of scrollback buffer. See Scrollback.
select [n|-|.]
Switch to a specified window. See Selecting a Window.
sessionname [name]
Name this session. See Session Name.
setenv [var [string]]
Set an environment variable for new windows. See Setenv.
setsid state
Controll process group creation for windows. See Setsid.
shell command
Set the default program for new windows. See Shell.
shelltitle title
Set the default name for new windows. See Shell.
silence [state|seconds]
Monitor a window for inactivity. See Monitoring.
silencewait seconds
Default timeout to trigger an inactivity notify. See Monitoring.
sleep num
Pause during startup. See Startup.
slowpaste msec
Slow down pasting in windows. See Paste.
source file
Run commands from a file. See Source.
sorendition [attr [color]]
Deprecated. Use rendition so
instead. See Rendition.
split
Split region into two parts. See Regions.
startup_message state
Display copyright notice on startup. See Startup.
stuff [string]
Stuff a string in the input buffer of a window. See Paste.
su [username [password [password2]]]
Identify a user. See Multiuser Session.
suspend
Put session in background. See Suspend.
term term
Set $TERM
for new windows. See Term.
termcap term terminal-tweaks [window-tweaks]
Tweak termcap entries for best performance. See The termcap
command.
terminfo term terminal-tweaks [window-tweaks]
Ditto, for terminfo systems. See The termcap
command.
termcapinfo term terminal-tweaks [window-tweaks]
Ditto, for both systems. See The termcap
command.
title [windowtitle]
Set the name of the current window. See Title Command.
umask [users]+/-bits ...
Synonym to aclumask
. See aclumask.
unbindall
Unset all keybindings. See The bind
command.
unsetenv var
Unset environment variable for new windows. See Setenv.
utf8 [state [dstate]]
Select character encoding of the current window. See Character Processing.
vbell [state]
Use visual bell. See Bell.
vbell_msg [message]
Set vbell message. See Bell.
vbellwait sec
Set delay for vbell message. See Bell.
version
Display screen
version. See Version.
wall message
Write a message to all displays. See Multiuser Session.
width [cols [lines]]
Set the width of the window. See Window Size.
windowlist [[-b] [-m] [-g]] | string [string] | title [title]
Present a list of all windows for selection. See Windowlist.
windows
List active windows. See Windows.
wrap [ on | off ]
Control line-wrap behavior. See Wrap.
writebuf [-e encoding] [filename]
Write paste buffer to screen-exchange file. See Screen Exchange.
writelock on|off|auto
Grant exclusive write permission. See Multiuser Session.
xoff
Send an XOFF character. See XON and XOFF.
xon
Send an XON character. See XON and XOFF.
zmodem [off|auto|catch|pass]
Define how screen treats zmodem requests. See Zmodem.
zombie [keys [onerror] ]
Keep dead windows. See Zombie.
Next: Selecting a Window, Previous: Commands, Up: Top [Contents][Index]
This section describes the commands for creating a new window for running programs. When a new window is created, the first available number is assigned to it. The number of windows is limited at compile-time by the MAXWIN configuration parameter (which defaults to 40).
Next: Screen Command, Up: New Window [Contents][Index]
(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.
Next: Setenv, Previous: Chdir, Up: New Window [Contents][Index]
(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…MAXWIN-1 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.
If ‘//group’ is supplied, a container-type window is created in
which other windows may be created inside it. See Window Groups.
Screen has built in some functionality of ‘cu’ and ‘telnet’. See 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.
Next: Shell, Previous: Screen Command, Up: New Window [Contents][Index]
(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.
(none)
Unset an environment variable.
Next: Term, Previous: Setenv, Up: New Window [Contents][Index]
(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. Typical shells do only minimal initialization when not started as a login-shell.
E.g. Bash will not read your ~/.bashrc unless it is a login-shell.
defshell
is currently a synonym to the shell
.screenrc command.
(none)
Set the title for all shells created during startup or by the C-a C-c
command. See Naming Windows (Titles), for details about what titles are.
Next: Window Types, Previous: Shell, Up: New Window [Contents][Index]
(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.
Next: Window Groups, Previous: Term, Up: New Window [Contents][Index]
Screen provides three different window types. New windows are created
with screen
’s ‘screen’ command (see 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.
<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-dependent 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.
//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.
Previous: Window Types, Up: New Window [Contents][Index]
Screen provides a method for grouping windows together. Windows can be
organized in a hierarchical fashion, resembling a tree structure. New
screens are created using the screen
command while new groups
are created using screen //group
. See Screen Command.
Once a new group is created, it will act as a container for windows
and even other groups. When a group is selected, you will see the
output of the windowlist
command, allowing you to select a
window inside. If there are no windows inside a group, use the
screen
command to create one. Once inside a group, using the
commands next
and prev
will switch between windows only
in that group. Using the windowlist
command will give you the
opportunity to leave the group you are in. See Windowlist.
(none)
Change or show the group the current window belongs to. Windows can
be moved around between different groups by specifying the name of
the destination group. Without specifying a group, the title of the
current group is displayed.
Using groups in combination with layouts will help create a multi-desktop experience. One group can be assigned for each layout made. Windows can be made, split, and organized within each group as desired. Afterwhich, switching between groups can be as easy as switching layouts.
Next: Session Management Commands, Previous: New Window, Up: Top [Contents][Index]
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 (see New Window).
Next: Other Window, Up: Selecting a Window [Contents][Index]
(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.)
(C-a p, C-a C-p, C-a C-h, C-a Backspace)
Switch to the previous window (the opposite of C-a n).
(C-a u, C-a C-u)
Switch to the parent window.
Next: Select, Previous: Moving Back and Forth, Up: Selecting a Window [Contents][Index]
(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 ]] (see Command Character).
Next: Windowlist, Previous: Other Window, Up: Selecting a Window [Contents][Index]
(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.
Previous: Select, Up: Selecting a Window [Contents][Index]
(C-a ")
Display all windows in a table for visual window selection.
If screen was in a window group, screen will
back out of the group and then display the windows in that
group. 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 -g
option will show the windows inside any groups
in that level and downwards.
The following keys are used to navigate in windowlist
:
k, C-p, or up Move up one line.
j, C-n, or down Move down one line.
C-g or escape Exit windowlist.
C-a or home Move to the first line.
C-e or end Move to the last line.
C-u or C-d Move one half page up or down.
C-b or C-f Move one full page up or down.
0..9 Using the number keys, move to the selected line.
mouseclick Move to the selected line. Available when
mousetrack
is set to on
.
/ Search.
n Repeat search in the forward direction.
N Repeat search in the backward direction.
m Toggle MRU.
g Toggle group nesting.
a All window view.
C-h or backspace Back out the group.
, Switch numbers with the previous window.
. Switch numbers with the next window.
K Kill that window.
space or enter Select that window.
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 (see String Escapes) for more codes (e.g. color settings).
Windowlist
needs a region size of at least 10 characters
wide and 6 characters high in order to display.
Next: Regions, Previous: Selecting a Window, Up: Top [Contents][Index]
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.
Next: Power Detach, Up: Session Management Commands [Contents][Index]
(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.
(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 (see Invoking Screen
).
The -h
option tells screen to immediately close the connection
to the terminal (‘hangup’).
(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.
Next: Lock, Previous: Detach, Up: Session Management Commands [Contents][Index]
(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.
(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 a parameter, the current message is shown.
Next: Multiuser Session, Previous: Power Detach, Up: Session Management Commands [Contents][Index]
(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
.
Next: Session Name, Previous: Lock, Up: Session Management Commands [Contents][Index]
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.
Next: Acladd, Up: Multiuser Session [Contents][Index]
(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
.
Next: Aclchg, Previous: Multiuser, Up: Multiuser Session [Contents][Index]
(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.
Next: Acldel, Previous: Acladd, Up: Multiuser Session [Contents][Index]
(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.
Next: Aclgrp, Previous: Aclchg, Up: Multiuser Session [Contents][Index]
(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.
Next: Displays, Previous: Acldel, Up: Multiuser Session [Contents][Index]
(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.
Next: aclumask, Previous: Aclgrp, Up: Multiuser Session [Contents][Index]
(C-a *)
Shows a tabular listing of all currently connected user
front-ends (displays). This is most useful for multiuser
sessions.
The following keys can be used in displays
list:
k, C-p, or up Move up one line.
j, C-n, or down Move down one line.
C-a or home Move to the first line.
C-e or end Move to the last line.
C-u or C-d Move one half page up or down.
C-b or C-f Move one full page up or down.
mouseclick Move to the selected line. Available when
mousetrack
is set to on
.
space Refresh the list.
d Detach the selected display.
D Power detach the selected display.
C-g, enter, or escape Exit the list.
The following is an example of what displays
could
look like:
xterm 80x42 jnweiger@/dev/ttyp4 0(m11) &rWx facit 80x24 mlschroe@/dev/ttyhf nb 11(tcsh) rwx xterm 80x42 jnhollma@/dev/ttyp5 0(m11) &R.x (A) (B) (C) (D) (E) (F)(G) (H)(I)
The legend is as follows:
(A) The terminal type known by screen
for this display.
(B) Displays geometry as width x height.
(C) Username who is logged in at the display.
(D) Device name of the display or the attached device
(E) Display is in blocking or nonblocking mode. The available
modes are "nb", "NB", "Z<", "Z>", and "BL".
(F) Number of the window
(G) Name/title of window
(H) Whether the window is shared
(I) Window permissions. Made up of three characters:
(1st character) ‘-’ : no read ‘r’ : read ‘R’ : read only due to foreign wlock (2nd character) ‘-’ : no write ‘.’ : write suppressed by foreign wlock ‘w’ : write ‘W’ : own wlock (3rd character) ‘-’ : no execute ‘x’ : execute
Displays
needs a region size of at least 10 characters
wide and 5 characters high in order to display.
Next: Wall, Previous: Displays, Up: Multiuser Session [Contents][Index]
(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
.
Next: Writelock, Previous: aclumask, Up: Multiuser Session [Contents][Index]
(none)
Write a message to all displays. The message will appear in the terminal’s
status line.
Next: Su, Previous: Wall, Up: Multiuser Session [Contents][Index]
(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.
(none)
Sets the default writelock behavior for new windows. Initially all windows
will be created with no writelocks.
Previous: Writelock, Up: Multiuser Session [Contents][Index]
(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
.
Next: Suspend, Previous: Multiuser Session, Up: Session Management Commands [Contents][Index]
(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 will still reflect the old name in pre-existing
shells. This may result in
confusion. Use of this command is generally
discouraged. Use the -S
command-line option if you want to
name a new session.The default is constructed from the tty and host names.
Next: Quit, Previous: Session Name, Up: Session Management Commands [Contents][Index]
(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.
Previous: Suspend, Up: Session Management Commands [Contents][Index]
(C-a \)
Kill all windows and terminate screen
.
(see Key Binding).
Next: Window Settings, Previous: Session Management Commands, Up: Top [Contents][Index]
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.
(C-a S, C-a |)
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 in the new region. The default is to create
a horizontal split, putting the new regions on the top and
bottom of each other. Using ‘-v’ will create a vertical split,
causing the new regions to appear side by side of each other.
Use the remove
or the only
command to delete regions.
Use focus
to toggle between regions.
When a region is split opposite of how it was previously split
(that is, vertical then horizontal or horizontal then vertical),
a new layer is created. The layer is used to group together the
regions that are split the same. Normally, as a user, you should
not see nor have to worry about layers, but they will affect how
some commands (focus
and resize
) behave.
With this current implementation of screen
, scrolling data
will appear much slower in a vertically split region than one
that is not. This should be taken into consideration if you need
to use system commands such as cat
or tail -f
.
next|prev|up|down|left|right|top|bottom
] ¶(C-a Tab)
Move the input focus to the next region. This is done in a cyclic
way so that the top left region is selected after the bottom right
one. If no option is given it defaults to next
. The next
region to be selected is determined by how the regions are layered.
Normally, the next region in the same layer would be selected.
However, if that next region contains one or more layers, the first
region in the highest layer is selected first. If you are at the
last region of the current layer, next
will move the focus
to the next region in the lower layer (if there is a lower layer).
Prev
cycles in the opposite order. See Split for more
information about layers.
The rest of the options (up
, down
, left
,
right
, top
, and bottom
) are more indifferent
to layers. The option up
will move the focus upward to the
region that is touching the upper left corner of the current region.
Down
will move downward to the region that is touching the
lower left corner of the current region. The option left
will move the focus leftward to the region that is touching the
upper left corner of the current region, while right
will
move rightward to the region that is touching the upper right corner
of the current region. Moving left from a left most region or moving
right from a right most region will result in no action.
The option top
will move the focus to the very first region
in the upper list corner of the screen, and bottom
will move
to the region in the bottom right corner of the screen. Moving up from
a top most region or moving down from a bottom most region will result
in no action.
Useful bindings are (h, j, k, and l as in vi):
bind h focus left bind j focus down bind k focus up bind l focus right bind t focus top bind b focus bottom
Note that ‘k’ is traditionally bound to the kill
command.
(C-a X)
Kill the current region. This is a no-op if there is only one region.
-h|-v|-b|-l|-p
] [ [+|-]n[%
] | =
| max
| min
| _
| 0
] ¶(none)
Resize the current region. The space will be removed from or added to
the surrounding regions depending on the order of the splits.
The available options for resizing are ‘-h’(horizontal),
‘-v’(vertical), ‘-b’(both), ‘-l’(local to layer),
and ‘-p’(perpendicular). Horizontal resizes will add or remove width
to a region, vertical will add or remove height, and both will add or
remove size from both dimensions. Local and perpendicular are similar to
horizontal and vertical, but they take in account of how a region was split.
If a region’s last split was horizontal, a local resize will work like a
vertical resize. If a region’s last split was vertical, a local resize will
work like a horizontal resize. Perpendicular resizes work in opposite of
local resizes. If no option is specified, local is the default.
The amount of lines to add or remove can be expressed a couple of different
ways. By specifying a number n by itself will resize the region by
that absolute amount. You can specify a relative amount by prefixing a
plus ‘+’ or minus ‘-’ to the amount, such as adding +n
lines
or removing -n
lines. Resizing can also be expressed as an absolute
or relative percentage by postfixing a percent sign ‘%’. Using zero
‘0’ is a synonym for min
and using an underscore ‘_’ is a
synonym for max
.
Some examples are:
resize +N increase current region by N resize -N decrease current region by N resize N set current region to N resize 20% set current region to 20% of original size resize +20% increase current region by 20% resize -b = make all windows equally resize max maximize current region resize min minimize current region
Without any arguments, screen
will prompt for how you would
like to resize the current region.
See focusminsize
if you want to restrict the minimun size a region can have.
(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 (see String Escapes). Screen
uses
a default of ‘%3n %t’.
You can mix both forms by providing the string as an additional argument.
Next: Focusminsize, Previous: Caption, Up: Regions [Contents][Index]
(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.
max
|_
) (height|max
|_
) ] ¶(none)
This forces any currently selected region to be automatically
resized at least a certain width and height. All
other surrounding regions will be resized in order to accommodate.
This constraint follows every time the focus
command is
used. The resize
command can be used to increase either
dimension of a region, but never below what is set with
focusminsize
. The underscore ‘_’ is a synonym for
max
. Setting a width and height of 0 0
(zero zero) will undo any constraints and allow for manual resizing.
Without any parameters, the minimum width and height is shown.
Previous: Focusminsize, Up: Regions [Contents][Index]
Using regions, and perhaps a large enough terminal, you can give
screen
more of a desktop feel. By being able to split
regions horizontally or vertically, you can take advantage of the
lesser used spaces of your terminal. The catch to these splits has
been that they’re not kept between screen detachments and reattachments.
Layouts will help organize your regions. You can create one layout of four horizontal regions and then create a separate layout of regions in a two by two array. The regions could contain the same windows, but they don’t have to. You can easily switch between layouts and keep them between detachments and reattachments.
Note that there are several subcommands to layout
.
new
[title] ¶(none)
Create a new layout. The screen will change to one whole region
and be switched to the blank window. From here, you build the
regions and the windows they show as you desire. The new layout
will be numbered with the smallest available integer, starting
with zero. You can optionally give a title to your new layout.
Otherwise, it will have a default title of layout
. You
can always change the title later by using the command
layout title
.
remove
[n|title] ¶(none)
Remove, or in other words, delete the specified layout. Either
the number or the title can be specified. Without either
specification, screen
will remove the current layout.
Removing a layout does not affect your set windows or regions.
next
¶(none)
Switch to the next layout available
prev
¶(none)
Switch to the previous layout available
select
[n|title] ¶(none)
Select the desired layout. Either the number or the title can
be specified. Without either specification, screen
will
prompt and ask which screen is desired. To see which layouts are
available, use the layout show
command.
show
¶(none)
List on the message line the number(s) and title(s) of the available
layout(s). The current layout is flagged.
title
[title] ¶(none)
Change or display the title of the current layout. A string given
will be used to name the layout. Without any options, the current
title and number is displayed on the message line.
number
[n] ¶(none)
Change or display the number of the current layout. An integer given
will be used to number the layout. Without any options, the current
number and title is displayed on the message line.
attach
[title|:last
] ¶(none)
Change or display which layout to reattach back to. The default is
:last
, which tells screen
to reattach back to the last
used layout just before detachment. By supplying a title, You can
instruct screen
to reattach to a particular layout regardless
which one was used at the time of detachment. Without any options,
the layout to reattach to will be shown in the message line.
save
[n|title] ¶(none)
Remember the current arrangement of regions. When used, screen
will remember the arrangement of vertically and horizontally split
regions. This arrangement is restored when a screen
session
is reattached or switched back from a different layout. If the
session ends or the screen
process dies, the layout
arrangements are lost. The layout dump
command should help
in this siutation. If a number
or title is supplied, screen
will remember the arrangement of
that particular layout. Without any options, screen
will
remember the current layout.
Saving your regions can be done automatically by using the
layout autosave
command.
autosave
[on
|off
] ¶(none)
Change or display the status of automatically saving layouts. The
default is on
, meaning when screen
is detached or
changed to a different layout, the arrangement of regions and windows
will be remembered at the time of change and restored upon return.
If autosave is set to off
, that arrangement will only be
restored to either to the last manual save, using layout save
,
or to when the layout was first created, to a single region with
a single window. Without either an on
or an off
, the
current status is displayed on the message line.
dump
[filename] ¶(none)
Write to a file the order of splits made in the current layout. This
is useful to recreate the order of your regions used in your current
layout. Only the current layout is recorded. While the order of the
regions are recorded, the sizes of those regions and which windows
correspond to which regions are not. If no filename is specified,
the default is layout-dump, saved in the directory that the
screen
process was started in. If the file already exists,
layout dump
will append to that file. As an example:
layout dump /home/user/.screenrc
will save or append the layout to the user’s .screenrc file.
Next: Virtual Terminal, Previous: Regions, Up: Top [Contents][Index]
These commands control the way screen
treats individual windows
in a session. See Virtual Terminal, for commands to control the
terminal emulation itself.
Next: Console, Up: Window Settings [Contents][Index]
You can customize each window’s name in the window display (viewed with
the windows
command (see 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 (see Shell). You can specify the name you
want for a window with the ‘-t’ option to the screen
command
when the window is created (see 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.
Next: Dynamic Titles, Up: Naming Windows (Titles) [Contents][Index]
(C-a A)
Set the name of the current window to windowtitle. If no name is
specified, screen prompts for one.
Next: Setting up your prompt for shell titles, Previous: Title Command, Up: Naming Windows (Titles) [Contents][Index]
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.
Next: Setting up shell titles in your .screenrc, Previous: Dynamic Titles, Up: Naming Windows (Titles) [Contents][Index]
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='{No value for `esc'}[0000m{No value for `esc'}k{No value for `esc'}\% '
The escape-sequence ‘{No value for `esc'}[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='printf "\033k\033\134"'
(I used ‘\134’ to output a ‘\’ because of a bug in v1.04).
Previous: Setting up your prompt for shell titles, Up: Naming Windows (Titles) [Contents][Index]
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).
Next: Kill, Previous: Naming Windows (Titles), Up: Window Settings [Contents][Index]
(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
.
Next: Login, Previous: Console, Up: Window Settings [Contents][Index]
(C-a k, C-a C-k)
Kill the current window.
If there is an exec
command running (see 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
(see Command Character) or rebind kill
to another key
sequence, such as C-a K (see Key Binding).
Next: Mode, Previous: Kill, Up: Window Settings [Contents][Index]
(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 (see Installation). Both commands are only present when
screen
has been compiled with utmp support.
(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
(see Key Binding).
Next: Monitoring, Previous: Login, Up: Window Settings [Contents][Index]
(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, see Screen Command).
Next: Windows, Previous: Mode, Up: Window Settings [Contents][Index]
(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).
(none)
Same as the monitor
command except that the default setting for
new windows is changed. Initial setting is ‘off’.
(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 (see Windows). Monitoring defaults to
‘off’ for all windows.
(C-a _)
Toggles silence monitoring of windows. When silence is turned on and an
affected window is switched into the background, you will receive the
silence notification message in the status line after a specified period
of inactivity (silence). The default timeout can be changed with the
silencewait
command or by specifying a number of seconds instead of
on
or off
. Silence is initially off for all windows.
(none)
Same as the silence
command except that the default setting for
new windows is changed. Initial setting is ‘off’.
(none)
Define the time that all windows monitored for silence should wait
before displaying a message. Default is 30 seconds.
Next: Hardstatus, Previous: Monitoring, Up: Window Settings [Contents][Index]
(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 ‘$’ (see 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 ‘@’ (see Monitoring); 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.
You can customize the output format to any string you like including string escapes (see String Escapes). In this case, if the string parameter is passed, the maximum output size is unlimited (instead of 1024 bytes if no parameter is passed).
Next: Mousetrack, Previous: Windows, Up: Window Settings [Contents][Index]
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.
(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.
(none)
Changes the current window’s hardstatus line to status.
Previous: Hardstatus, Up: Window Settings [Contents][Index]
on|off
] ¶(none)
This command determines whether screen
will watch for
mouse clicks. When this command is enabled, regions that have
been split in various ways can be selected by pointing to them
with a mouse and left-clicking them. Without specifying on
or off, the current state is displayed. The default state
is determined by the defmousetrack
command.
on|off
¶(none)
This command determines the default state of the mousetrack
command, currently defaulting of off.
Next: Copy and Paste, Previous: Window Settings, Up: Top [Contents][Index]
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.
Next: Input Translation, Up: Virtual Terminal [Contents][Index]
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
Next: Digraph, Previous: Control Sequences, Up: Virtual Terminal [Contents][Index]
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
, see 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 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)
Next: Bell, Previous: Input Translation, Up: Virtual Terminal [Contents][Index]
(C-a C-v)
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’. When a non-zero
unicode-value is specified, a new digraph is created with the
specified preset. The digraph is unset if a zero value is provided
for the unicode-value.
The following table is the builtin sequences.
Sequence Octal Digraph Unicode Equivalent ----------------------------------------------- ' ', ' ' 160 (space) U+00A0 'N', 'S' 160 (space) U+00A0 '~', '!' 161 ¡ U+00A1 '!', '!' 161 ¡ U+00A1 '!', 'I' 161 ¡ U+00A1 'c', '|' 162 ¢ U+00A2 'c', 't' 162 ¢ U+00A2 '$', '$' 163 £ U+00A3 'P', 'd' 163 £ U+00A3 'o', 'x' 164 ¤ U+00A4 'C', 'u' 164 ¤ U+00A4 'C', 'u' 164 ¤ U+00A4 'E', 'u' 164 ¤ U+00A4 'Y', '-' 165 ¥ U+00A5 'Y', 'e' 165 ¥ U+00A5 '|', '|' 166 ¦ U+00A6 'B', 'B' 166 ¦ U+00A6 'p', 'a' 167 § U+00A7 'S', 'E' 167 § U+00A7 '"', '"' 168 ¨ U+00A8 ''', ':' 168 ¨ U+00A8 'c', 'O' 169 © U+00A9 'C', 'o' 169 © U+00A9 'a', '-' 170 ª U+00AA '<', '<' 171 « U+00AB '-', ',' 172 ¬ U+00AC 'N', 'O' 172 ¬ U+00AC '-', '-' 173 U+00AD 'r', 'O' 174 ® U+00AE 'R', 'g' 174 ® U+00AE '-', '=' 175 ¯ U+00AF ''', 'm' 175 ¯ U+00AF '~', 'o' 176 ° U+00B0 'D', 'G' 176 ° U+00B0 '+', '-' 177 ± U+00B1 '2', '2' 178 ² U+00B2 '2', 'S' 178 ² U+00B2 '3', '3' 179 ³ U+00B3 '3', 'S' 179 ³ U+00B3 ''', ''' 180 ´ U+00B4 'j', 'u' 181 µ U+00B5 'M', 'y' 181 µ U+00B5 'p', 'p' 182 ¶ U+00B6 'P', 'I' 182 ¶ U+00B6 '~', '.' 183 · U+00B7 '.', 'M' 183 · U+00B7 ',', ',' 184 ¸ U+00B8 ''', ',' 184 ¸ U+00B8 '1', '1' 185 ¹ U+00B9 '1', 'S' 185 ¹ U+00B9 'o', '-' 186 º U+00BA '>', '>' 187 » U+00BB '1', '4' 188 ¼ U+00BC '1', '2' 189 ½ U+00BD '3', '4' 190 ¾ U+00BE '~', '?' 191 ¿ U+00BF '?', '?' 191 ¿ U+00BF '?', 'I' 191 ¿ U+00BF 'A', '`' 192 À U+00C0 'A', '!' 192 À U+00C0 'A', ''' 193 Á U+00C1 'A', '^' 194 Â U+00C2 'A', '>' 194 Â U+00C2 'A', '~' 195 Ã U+00C3 'A', '?' 195 Ã U+00C3 'A', '"' 196 Ä U+00C4 'A', ':' 196 Ä U+00C4 'A', '@' 197 Å U+00C5 'A', 'A' 197 Å U+00C5 'A', 'E' 198 Æ U+00C6 'C', ',' 199 Ç U+00C7 'E', '`' 200 È U+00C8 'E', '!' 200 È U+00C8 'E', ''' 201 É U+00C9 'E', '^' 202 Ê U+00CA 'E', '>' 202 Ê U+00CA 'E', '"' 203 Ë U+00CB 'E', ':' 203 Ë U+00CB 'I', '`' 204 Ì U+00CC 'I', '!' 204 Ì U+00CC 'I', ''' 205 Í U+00CD 'I', '^' 206 Î U+00CE 'I', '>' 206 Î U+00CE 'I', '"' 207 Ï U+00CF 'I', ':' 207 Ï U+00CF 'D', '-' 208 Ð U+00D0 'N', '~' 209 Ñ U+00D1 'N', '?' 209 Ñ U+00D1 'O', '`' 210 Ò U+00D2 'O', '!' 210 Ò U+00D2 'O', ''' 211 Ó U+00D3 'O', '^' 212 Ô U+00D4 'O', '>' 212 Ô U+00D4 'O', '~' 213 Õ U+00D5 'O', '?' 213 Õ U+00D5 'O', '"' 214 Ö U+00D6 'O', ':' 214 Ö U+00D6 '/', '\' 215 × U+00D7 '*', 'x' 215 × U+00D7 'O', '/' 216 Ø U+00D8 'U', '`' 217 Ù U+00D9 'U', '!' 217 Ù U+00D9 'U', ''' 218 Ú U+00DA 'U', '^' 219 Û U+00DB 'U', '>' 219 Û U+00DB 'U', '"' 220 Ü U+00DC 'U', ':' 220 Ü U+00DC 'Y', ''' 221 Ý U+00DD 'I', 'p' 222 Þ U+00DE 'T', 'H' 222 Þ U+00DE 's', 's' 223 ß U+00DF 's', '"' 223 ß U+00DF 'a', '`' 224 à U+00E0 'a', '!' 224 à U+00E0 'a', ''' 225 á U+00E1 'a', '^' 226 â U+00E2 'a', '>' 226 â U+00E2 'a', '~' 227 ã U+00E3 'a', '?' 227 ã U+00E3 'a', '"' 228 ä U+00E4 'a', ':' 228 ä U+00E4 'a', 'a' 229 å U+00E5 'a', 'e' 230 æ U+00E6 'c', ',' 231 ç U+00E7 'e', '`' 232 è U+00E8 'e', '!' 232 è U+00E8 'e', ''' 233 é U+00E9 'e', '^' 234 ê U+00EA 'e', '>' 234 ê U+00EA 'e', '"' 235 ë U+00EB 'e', ':' 235 ë U+00EB 'i', '`' 236 ì U+00EC 'i', '!' 236 ì U+00EC 'i', ''' 237 í U+00ED 'i', '^' 238 î U+00EE 'i', '>' 238 î U+00EE 'i', '"' 239 ï U+00EF 'i', ':' 239 ï U+00EF 'd', '-' 240 ð U+00F0 'n', '~' 241 ñ U+00F1 'n', '?' 241 ñ U+00F1 'o', '`' 242 ò U+00F2 'o', '!' 242 ò U+00F2 'o', ''' 243 ó U+00F3 'o', '^' 244 ô U+00F4 'o', '>' 244 ô U+00F4 'o', '~' 245 õ U+00F5 'o', '?' 245 õ U+00F5 'o', '"' 246 ö U+00F6 'o', ':' 246 ö U+00F6 ':', '-' 247 ÷ U+00F7 'o', '/' 248 ø U+00F8 'u', '`' 249 ù U+00F9 'u', '!' 249 ù U+00F9 'u', ''' 250 ú U+00FA 'u', '^' 251 û U+00FB 'u', '>' 251 û U+00FB 'u', '"' 252 ü U+00FC 'u', ':' 252 ü U+00FC 'y', ''' 253 ý U+00FD 'i', 'p' 254 þ U+00FE 't', 'h' 254 þ U+00FE 'y', '"' 255 ÿ U+00FF 'y', ':' 255 ÿ U+00FF '"', '[' 196 Ä U+00C4 '"', '\' 214 Ö U+00D6 '"', ']' 220 Ü U+00DC '"', '{' 228 ä U+00E4 '"', '|' 246 ö U+00F6 '"', '}' 252 ü U+00FC '"', '~' 223 ß U+00DF
Next: Clear, Previous: Digraph, Up: Virtual Terminal [Contents][Index]
(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 a parameter, the current message is shown.
(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
. See Bell,
for more information on visual bells.
The equivalent terminfo capability is flash
.
Per default, vbell
is ‘off’, thus the audible bell is used.
(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 a parameter, the current message is shown.
(none)
Define a delay in seconds after each display of screen
’s visual
bell message. The default is 1 second.
Next: Info, Previous: Bell, Up: Virtual Terminal [Contents][Index]
(C-a C)
Clears the screen and saves its contents to the scrollback buffer.
Next: Redisplay, Previous: Clear, Up: Virtual Terminal [Contents][Index]
(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
(see 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 (see 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
.
(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.
Next: Wrap, Previous: Info, Up: Virtual Terminal [Contents][Index]
(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.
(none)
If set to on, "alternate screen" support is enabled in virtual terminals,
just like in xterm. Initial setting is ‘off’.
(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.
(C-a l, C-a C-l)
Redisplay the current window. Needed to get a full redisplay in
partial redraw mode.
Next: Reset, Previous: Redisplay, Up: Virtual Terminal [Contents][Index]
(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’. Without any options, the state of
wrap
is toggled.
(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".
Next: Window Size, Previous: Wrap, Up: Virtual Terminal [Contents][Index]
(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.
Next: Character Processing, Previous: Reset, Up: Virtual Terminal [Contents][Index]
-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 (see 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.
-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.
Previous: Window Size, Up: Virtual Terminal [Contents][Index]
(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.
(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.
(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.
(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. See Special Terminal 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.
(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 Info command.
(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.
(none)
Same as the ‘c1’ command except that the default setting for
new windows is changed. Initial setting is ‘on’.
(none)
Same as the ‘gr’ command except that the default setting for
new windows is changed. Initial setting is ‘off’.
(none)
Same as the ‘bce’ command except that the default setting for
new windows is changed. Initial setting is ‘off’.
(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.
(none)
Like the ‘charset’ command except that the default setting for
new windows is changed. Shows current default if called without
argument.
(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
.
(none)
Toggle how ambiguoous characters are treated. If cjkwidth is on screen
interprets them as double (full) width characters. If off then they are seen
as one cell (half) width characters.
Next: Subprocess Execution, Previous: Virtual Terminal, Up: Top [Contents][Index]
For those confined to a hardware terminal, these commands provide a cut and paste facility more powerful than those provided by most windowing systems.
Next: Paste, Up: Copy and Paste [Contents][Index]
(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.
Next: Scrollback, Up: Copying [Contents][Index]
(none)
This affects the copying of text regions with the copy
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.
To access and use the contents in the scrollback buffer, use the copy
command. See Copying.
(none)
Same as the scrollback
command except that the default setting
for new windows is changed. Defaults to 100.
(none)
Set the size of the scrollback buffer for the current window to
num lines. The default scrollback is 100 lines. Use info
to view the current setting.
(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.
Next: Movement Keys, Previous: Scrollback, Up: Copying [Contents][Index]
(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 ‘@’ and 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.
h, C-h, or left arrow move the cursor left.
j, C-n, or down arrow move the cursor down.
k, C-p, or up arrow move the cursor up.
l (’el’), or right arrow move the cursor right.
0 (zero) or C-a move to the leftmost column.
+ and - move the cursor to the leftmost column of the next or previous line.
H, M and L move the cursor to the leftmost column of the top, center or bottom line of the window.
| moves to the specified absolute column.
g or home moves to the beginning of the buffer.
G or end moves to the specified absolute line (default: end of buffer).
% jumps to the specified percentage of the buffer.
^ or $ move to the first or last non-whitespace character on the line.
w, b, and e move the cursor word by word.
B, E move the cursor WORD by WORD (as in vi).
f/F, t/T move the cursor forward/backward to the next occurence of the target. (eg, ’3fy’ will move the cursor to the 3rd ’y’ to the right.)
; and , Repeat the last f/F/t/T command in the same/opposite direction.
C-e and C-y scroll the display up/down by one line while preserving the cursor position.
C-u and C-d scroll the display up/down by the specified amount of lines while preserving the cursor position. (Default: half screenful).
C-b and C-f move the cursor up/down a full screen.
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.
Next: Repeat Count, Previous: Movement Keys, Up: Copying [Contents][Index]
The copy range is specified by setting two marks. The text between these marks will be highlighted. Press:
space or enter to set the first or second mark respectively.
If mousetrack
is set to on
, marks can also be set using
left mouse click.
Y and y can be used to mark one whole line or to mark from start of line.
W marks exactly one word.
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.
Next: Specials, Previous: Repeat Count, Up: Copying [Contents][Index]
/ vi
-like search forward.
? vi
-like search backward.
C-a s emacs
style incremental search forward.
C-r emacs
style reverse i-search.
(none)
Tell screen to ignore the case of characters in searches. Default is
off
. Without any options, the state of ignorecase
is toggled.
n Repeat search in forward direction.
N Repeat search in backward direction.
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 or 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. See 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 or o (’oh’) exchanges the first mark and the current cursor position. You can use this to adjust an already placed mark.
C-l (’el’) will redraw the screen.
@ does nothing. Absolutely nothing. Does not even exit copy mode.
All keys not described here exit copy mode.
Next: Registers, Previous: Copying, Up: Copy and Paste [Contents][Index]
(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.
(none)
Stuff the string string in the input buffer of the current window.
This is like the paste
command, but with much less overhead.
Without a parameter, screen
will prompt for a string to stuff.
You cannot paste large buffers with the stuff
command. It is most
useful for key bindings. See Bindkey.
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.
(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.
(none)
Does one of two things, dependent on number of arguments: with zero or one
arguments 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
Next: Screen Exchange, Previous: Paste, Up: Copy and Paste [Contents][Index]
(none)
Removed. Use readreg
instead.
(none)
Removed. Use paste
instead.
(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.
(none)
Save the specified string to the register key.
The encoding of the string can be specified via the -e
option.
Next: History, Previous: Registers, Up: Copy and Paste [Contents][Index]
(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
(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.
(C-a =)
Unlinks the screen-exchange file.
(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 (see Copying).
Previous: Screen Exchange, Up: Copy and Paste [Contents][Index]
(C-a {, 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).
Next: Key Binding, Previous: Copy and Paste, Up: Top [Contents][Index]
Control Input or Output of a window by another filter process. Use with care!
Next: Using Exec, Up: Subprocess Execution [Contents][Index]
(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 file descriptor 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.
Previous: Exec, Up: Subprocess Execution [Contents][Index]
Abbreviations:
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.
Next: Flow Control, Previous: Subprocess Execution, Up: Top [Contents][Index]
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.
bind
commandbind
command
Next: Examples of the bind
command, Up: Key Binding [Contents][Index]
bind
command(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 (see 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
(see 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.
(none)
Unbind all the bindings. This can be useful when
screen is used solely for its detaching abilities, such as when
letting a console application run as a daemon. If, for some reason,
it is necessary to bind commands after this, use ’screen -X’.
Next: Command Character, Previous: The bind
command, Up: Key Binding [Contents][Index]
bind
commandSome 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.
Next: Help, Previous: Examples of the bind
command, Up: Key Binding [Contents][Index]
(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.
(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 default command characters for users that
will be added later.
(C-a a)
Send the command character (C-a) to the process in the current
window. The keystroke for this command is the second parameter to the
‘-e’ command line switch (see Invoking Screen
), or the
escape
.screenrc directive.
(none)
This command has the same effect as typing the screen escape character
(C-a). It is probably only useful for key bindings.
If the ‘-c’ option is given, select the specified command class.
See The bind
command, See Bindkey.
Next: Bindkey, Previous: Command Character, Up: Key Binding [Contents][Index]
(C-a ?)
Displays a help screen showing you all the key bindings. The first
pages list all the internal commands followed by their bindings.
Subsequent pages will display the custom commands, one command per key.
Press space when you’re done reading each page, or return to exit early.
All other characters are ignored.
If the ‘-c’ option is given, display all bound commands for the
specified command class.
See Default Key Bindings.
Next: Bindkey Examples, Previous: Help, Up: Key Binding [Contents][Index]
(none)
This command manages screen’s input translation tables. Every
entry in one of the tables tells screen how to react if a certain
sequence of characters is encountered. There are three tables:
one that should contain actions programmed by the user, one for
the default actions used for terminal emulation and one for
screen’s copy mode to do cursor movement. See Input Translation
for a list of default key bindings.
If the ‘-d’ option is given, bindkey modifies the default table, ‘-m’ changes the copy mode table and with neither option the user table is selected. The argument ‘string’ is the sequence of characters to which an action is bound. This can either be a fixed string or a termcap keyboard capability name (selectable with the ‘-k’ option).
Some keys on a VT100 terminal can send a different string if application mode is turned on (e.g. the cursor keys). Such keys have two entries in the translation table. You can select the application mode entry by specifying the ‘-a’ option.
The ‘-t’ option tells screen not to do inter-character timing. One cannot turn off the timing if a termcap capability is used.
‘cmd’ can be any of screen’s commands with an arbitrary number of ‘args’. If ‘cmd’ is omitted the key-binding is removed from the table.
Next: Bindkey Control, Previous: Bindkey, Up: Key Binding [Contents][Index]
Here are some examples of keyboard bindings:
bindkey -d
Show all of the default key bindings. The application mode entries are marked with [A].
bindkey -k k1 select 1
Make the "F1" key switch to window one.
bindkey -t foo stuff barfoo
Make ‘foo’ an abbreviation of the word ‘barfoo’. Timeout is disabled so that users can type slowly.
bindkey "\024" mapdefault
This key-binding makes ‘C-t’ an escape character for key-bindings. If you did the above ‘stuff barfoo’ binding, you can enter the word ‘foo’ by typing ‘C-t foo’. If you want to insert a ‘C-t’ you have to press the key twice (i.e., escape the escape binding).
bindkey -k F1 command
Make the F11 (not F1!) key an alternative screen escape (besides ‘C-a’).
Previous: Bindkey Examples, Up: Key Binding [Contents][Index]
(none)
Tell screen that the next input character should only be looked up
in the default bindkey table.
(none)
Like mapdefault, but don’t even look in the default bindkey table.
(none)
Set the inter-character timer for input sequence detection to a timeout
of n ms. The default timeout is 300ms. Maptimeout with no
arguments shows the current setting.
Next: Termcap, Previous: Key Binding, Up: Top [Contents][Index]
screen
can trap flow control characters or pass them to the
program, as you see fit. This is useful when your terminal wants to use
XON/XOFF flow control and you are running a program which wants to use
^S/^Q for other purposes (i.e. emacs
).
Next: Flow, Up: Flow Control [Contents][Index]
screen
flow control settingsEach window has a flow-control setting that determines how screen deals
with the XON and XOFF characters (and perhaps the interrupt character).
When flow-control is turned off, screen ignores the XON and XOFF
characters, which allows the user to send them to the current program by
simply typing them (useful for the emacs
editor, for instance).
The trade-off is that it will take longer for output from a
“normal” program to pause in response to an XOFF. With
flow-control turned on, XON and XOFF characters are used to immediately
pause the output of the current window. You can still send these
characters to the current program, but you must use the appropriate
two-character screen commands (typically C-a q (xon) and C-a
s (xoff)). The xon/xoff commands are also useful for typing C-s and
C-q past a terminal that intercepts these characters.
Each window has an initial flow-control value set with either the
‘-f’ option or the defflow
command. By default the
windows are set to automatic flow-switching. It can then be toggled
between the three states ’fixed on’, ’fixed off’ and ’automatic’
interactively with the flow
command bound to C-a f.
The automatic flow-switching mode deals with flow control using the
TIOCPKT mode (like rlogin
does). If the tty driver does not
support TIOCPKT, screen tries to determine the right mode based on the
current setting of the application keypad — when it is enabled,
flow-control is turned off and visa versa. Of course, you can still
manipulate flow-control manually when needed.
If you’re running with flow-control enabled and find that pressing the
interrupt key (usually C-c) does not interrupt the display until another
6-8 lines have scrolled by, try running screen with the ‘interrupt’
option (add the ‘interrupt’ flag to the flow
command in your
.screenrc, or use the ‘-i’ command-line option). This causes the
output that screen
has accumulated from the interrupted program
to be flushed. One disadvantage is that the virtual terminal’s memory
contains the non-flushed version of the output, which in rare cases can
cause minor inaccuracies in the output. For example, if you switch
screens and return, or update the screen with C-a l you would see
the version of the output you would have gotten without ‘interrupt’
being on. Also, you might need to turn off flow-control (or use
auto-flow mode to turn it off automatically) when running a program that
expects you to type the interrupt character as input, as the
‘interrupt’ parameter only takes effect when flow-control is
enabled. If your program’s output is interrupted by mistake, a simple
refresh of the screen with C-a l will restore it. Give each mode
a try, and use whichever mode you find more comfortable.
Next: XON and XOFF, Previous: About screen
flow control settings, Up: Flow Control [Contents][Index]
(none)
Same as the flow
command except that the default setting for new
windows is changed. Initial setting is ‘auto’.
Specifying flow auto interrupt
has the same effect as the
command-line options ‘-fa’ and ‘-i’.
Note that if ‘interrupt’ is enabled, all existing displays are
changed immediately to forward interrupt signals.
(C-a f, C-a C-f)
Sets the flow-control mode for this window to fstate, which can be
‘on’, ‘off’ or ‘auto’.
Without parameters it cycles the current window’s
flow-control setting. Default is set by ‘defflow’.
Previous: Flow, Up: Flow Control [Contents][Index]
(C-a q, C-a C-q)
Send a ^Q (ASCII XON) to the program in the current window. Redundant
if flow control is set to ‘off’ or ‘auto’.
(C-a s, C-a C-s)
Send a ^S (ASCII XOFF) to the program in the current window.
Next: The Message Line, Previous: Flow Control, Up: Top [Contents][Index]
Screen
demands the most out of your terminal so that it can
perform its VT100 emulation most efficiently. These functions provide
means for tweaking the termcap entries for both your physical terminal
and the one simulated by screen
.
termcap
commandNext: Write out the window’s termcap entry, Up: Termcap [Contents][Index]
Usually screen
tries to emulate as much of the VT100/ANSI
standard as possible. But if your terminal lacks certain capabilities
the emulation may not be complete. In these cases screen
has to
tell the applications that some of the features are missing. This is no
problem on machines using termcap, because screen
can use the
$TERMCAP
variable to customize the standard screen termcap.
But if you do a rlogin on another machine or your machine supports only
terminfo this method fails. Because of this screen
offers a way
to deal with these cases. Here is how it works:
When screen
tries to figure out a terminal name for itself, it
first looks for an entry named screen.term
, where
term is the contents of your $TERM
variable. If no such entry
exists, screen
tries ‘screen’ (or ‘screen-w’, if the
terminal is wide (132 cols or more)). If even this entry cannot be
found, ‘vt100’ is used as a substitute.
The idea is that if you have a terminal which doesn’t support an
important feature (e.g. delete char or clear to EOS) you can build a new
termcap/terminfo entry for screen
(named
‘screen.dumbterm’) in which this capability has been
disabled. If this entry is installed on your machines you are able to
do a rlogin and still keep the correct termcap/terminfo entry. The
terminal name is put in the $TERM
variable of all new windows.
screen
also sets the $TERMCAP
variable reflecting the
capabilities of the virtual terminal emulated.
Furthermore, the variable $WINDOW
is set to the window number of each
window.
The actual set of capabilities supported by the virtual terminal depends
on the capabilities supported by the physical terminal. If, for
instance, the physical terminal does not support underscore mode,
screen
does not put the ‘us’ and ‘ue’ capabilities into
the window’s $TERMCAP
variable, accordingly. However, a minimum number
of capabilities must be supported by a terminal in order to run
screen
; namely scrolling, clear screen, and direct cursor
addressing (in addition, screen
does not run on hardcopy
terminals or on terminals that over-strike).
Also, you can customize the $TERMCAP
value used by screen
by
using the termcap
command, or by defining the variable
$SCREENCAP
prior to startup. When the latter defined, its value will be
copied verbatim into each window’s $TERMCAP
variable. This can either
be the full terminal definition, or a filename where the terminal
‘screen’ (and/or ‘screen-w’) is defined.
Note that screen
honors the terminfo
command if the system
uses the terminfo database rather than termcap. On such machines the
$TERMCAP
variable has no effect and you must use the
dumptermcap
command (see Write out the window’s termcap entry) and the tic
program to generate terminfo entries for screen
windows.
When the boolean ‘G0’ capability is present in the termcap entry
for the terminal on which screen
has been called, the terminal
emulation of screen
supports multiple character sets. This
allows an application to make use of, for instance, the VT100 graphics
character set or national character sets. The following control
functions from ISO 2022 are supported: ‘lock shift G0’ (‘SI’),
‘lock shift G1’ (‘SO’), ‘lock shift G2’, ‘lock shift
G3’, ‘single shift G2’, and ‘single shift G3’. When a virtual
terminal is created or reset, the ASCII character set is designated as
‘G0’ through ‘G3’. When the ‘G0’ capability is present,
screen evaluates the capabilities ‘S0’, ‘E0’, and ‘C0’ if
present. ‘S0’ is the sequence the terminal uses to enable and start
the graphics character set rather than ‘SI’. ‘E0’ is the
corresponding replacement for ‘SO’. ‘C0’ gives a character by
character translation string that is used during semi-graphics mode.
This string is built like the ‘acsc’ terminfo capability.
When the ‘po’ and ‘pf’ capabilities are present in the
terminal’s termcap entry, applications running in a screen
window
can send output to the printer port of the terminal. This allows a user
to have an application in one window sending output to a printer
connected to the terminal, while all other windows are still active (the
printer port is enabled and disabled again for each chunk of output).
As a side-effect, programs running in different windows can send output
to the printer simultaneously. Data sent to the printer is not
displayed in the window. The info
command displays a line starting
with ‘PRIN’ while the printer is active.
Some capabilities are only put into the $TERMCAP
variable of the virtual
terminal if they can be efficiently implemented by the physical
terminal. For instance, ‘dl’ (delete line) is only put into the
$TERMCAP
variable if the terminal supports either delete line itself or
scrolling regions. Note that this may provoke confusion, when the
session is reattached on a different terminal, as the value of $TERMCAP
cannot be modified by parent processes. You can force screen
to
include all capabilities in $TERMCAP
with the ‘-a’
command-line option (see Invoking Screen
).
The "alternate screen" capability is not enabled by default.
Set the altscreen
.screenrc command to enable it.
Next: The termcap
command, Previous: Choosing the termcap entry for a window, Up: Termcap [Contents][Index]
(C-a .)
Write the termcap entry for the virtual terminal optimized for the
currently active window to the file .termcap in the user’s
$HOME/.screen directory (or wherever screen
stores its
sockets. see Files Referenced). This termcap entry is identical to
the value of the environment variable $TERMCAP
that is set up by
screen
for each window. For terminfo based systems you will need
to run a converter like captoinfo
and then compile the entry with
tic
.
Next: Termcap Examples, Previous: Write out the window’s termcap entry, Up: Termcap [Contents][Index]
termcap
command(none)
Use this command to modify your terminal’s termcap entry without going
through all the hassles involved in creating a custom termcap entry.
Plus, you can optionally customize the termcap generated for the
windows.
You have to place these commands in one of the screenrc startup files, as they
are meaningless once the terminal emulator is booted.
If your system uses the terminfo database rather than termcap,
screen
will understand the terminfo
command, which has the
same effects as the termcap
command. Two separate commands are
provided, as there are subtle syntactic differences, e.g. when parameter
interpolation (using ‘%’) is required. Note that the termcap names of
the capabilities should also be used with the terminfo
command.
In many cases, where the arguments are valid in both terminfo and termcap
syntax, you can use the command termcapinfo
, which is just a
shorthand for a pair of termcap
and terminfo
commands with
identical arguments.
The first argument specifies which terminal(s) should be affected by this definition. You can specify multiple terminal names by separating them with ‘|’s. Use ‘*’ to match all terminals and ‘vt*’ to match all terminals that begin with ‘vt’.
Each tweak argument contains one or more termcap defines (separated by ‘:’s) to be inserted at the start of the appropriate termcap entry, enhancing it or overriding existing values. The first tweak modifies your terminal’s termcap, and contains definitions that your terminal uses to perform certain functions. Specify a null string to leave this unchanged (e.g. ""). The second (optional) tweak modifies all the window termcaps, and should contain definitions that screen understands (see Virtual Terminal).
Next: Special Terminal Capabilities, Previous: The termcap
command, Up: Termcap [Contents][Index]
Some examples:
termcap xterm* xn:hs@
Informs screen
that all terminals that begin with ‘xterm’
have firm auto-margins that allow the last position on the screen to be
updated (xn), but they don’t really have a status line (no ’hs’ –
append ‘@’ to turn entries off). Note that we assume ‘xn’ for
all terminal names that start with ‘vt’, but only if you don’t
specify a termcap command for that terminal.
termcap vt* xn termcap vt102|vt220 Z0=\E[?3h:Z1=\E[?3l
Specifies the firm-margined ‘xn’ capability for all terminals that begin with ‘vt’, and the second line will also add the escape-sequences to switch into (Z0) and back out of (Z1) 132-character-per-line mode if this is a VT102 or VT220. (You must specify Z0 and Z1 in your termcap to use the width-changing commands.)
termcap vt100 "" l0=PF1:l1=PF2:l2=PF3:l3=PF4
This leaves your vt100 termcap alone and adds the function key labels to each window’s termcap entry.
termcap h19|z19 am@:im=\E@:ei=\EO dc=\E[P
Takes a h19 or z19 termcap and turns off auto-margins (am@) and enables the insert mode (im) and end-insert (ei) capabilities (the ‘@’ in the ‘im’ string is after the ‘=’, so it is part of the string). Having the ‘im’ and ‘ei’ definitions put into your terminal’s termcap will cause screen to automatically advertise the character-insert capability in each window’s termcap. Each window will also get the delete-character capability (dc) added to its termcap, which screen will translate into a line-update for the terminal (we’re pretending it doesn’t support character deletion).
If you would like to fully specify each window’s termcap entry, you
should instead set the $SCREENCAP
variable prior to running
screen
. See Virtual Terminal, for the details of the
screen
terminal emulation. See Termcap,
for more information on termcap definitions.
Next: Autonuke, Previous: Termcap Examples, Up: Termcap [Contents][Index]
The following table describes all terminal capabilities that are
recognized by screen
and are not in the termcap manual
(see Termcap).
You can place these capabilities in your termcap entries (in
/etc/termcap) or use them with the commands termcap
,
terminfo
and termcapinfo
in your screenrc
files. It is
often not possible to place these capabilities in the terminfo database.
(bool)
Terminal has VT100 style margins (‘magic margins’). Note that
this capability is obsolete — screen
now uses the standard
‘xn’ instead.
(str)
Change width to 132 columns.
(str)
Change width to 80 columns.
(str)
Resize display. This capability has the desired width and height as
arguments. SunView(tm) example: ‘\E[8;%d;%dt’.
(bool)
Terminal doesn’t need flow control. Send ^S and ^Q direct to
the application. Same as flow off
. The opposite of this
capability is ‘nx’.
(bool)
Terminal can deal with ISO 2022 font selection sequences.
(str)
Switch charset ‘G0’ to the specified charset. Default
is ‘\E(%.’.
(str)
Switch charset ‘G0’ back to standard charset. Default
is ‘\E(B’.
(str)
Use the string as a conversion table for font 0. See
the ‘ac’ capability for more details.
(str)
Switch cursor-keys to application mode.
(str)
Switch cursor-keys to cursor mode.
(bool)
Enable autonuke for displays of this terminal type.
(see Autonuke).
(num)
Set the output buffer limit. See the ‘obuflimit’ command
(see Obuflimit) for more details.
(str)
Set the encoding of the terminal. See the ‘encoding’ command
(see Character Processing) for valid encodings.
(str)
Change character foreground color in an ANSI conform way. This
capability will almost always be set to ‘\E[3%dm’
(‘\E[3%p1%dm’ on terminfo machines).
(str)
Same as ‘AF’, but change background color.
(bool)
Does understand ANSI set default fg/bg color (‘\E[39m / \E[49m’).
(str)
Describe a translation of characters to strings depending on the
current font. (see Character Translation).
(bool)
Terminal understands special xterm sequences (OSC, mouse tracking).
(bool)
Terminal needs bold to display high-intensity colors (e.g. Eterm).
(bool)
Add missing capabilities to the termcap/info entry. (Set by default).
Next: Obuflimit, Previous: Special Terminal Capabilities, Up: Termcap [Contents][Index]
(none)
Sets whether a clear screen sequence should nuke all the output
that has not been written to the terminal. See Obuflimit.
This property is set per display, not per window.
(none)
Same as the autonuke
command except that the default setting for
new displays is also changed. Initial setting is off
.
Note that you can use the special AN
terminal capability if you
want to have a terminal type dependent setting.
Next: Character Translation, Previous: Autonuke, Up: Termcap [Contents][Index]
(none)
If the output buffer contains more bytes than the specified limit, no
more data will be read from the windows. The default value is 256. If
you have a fast display (like xterm
), you can set it to some
higher value. If no argument is specified, the current setting is displayed.
This property is set per display, not per window.
(none)
Same as the obuflimit
command except that the default setting for new
displays is also changed. Initial setting is 256 bytes. Note that you can use
the special OL
terminal capability if you want to have a terminal
type dependent limit.
Screen
has a powerful mechanism to translate characters to
arbitrary strings depending on the current font and terminal type.
Use this feature if you want to work with a common standard character
set (say ISO8851-latin1) even on terminals that scatter the more
unusual characters over several national language font pages.
Syntax:
XC=<charset-mapping>{,,<charset-mapping>} <charset-mapping> := <designator><template>{,<mapping>} <mapping> := <char-to-be-mapped><template-arg>
The things in braces may be repeated any number of times.
A <charset-mapping> tells screen how to map characters in font <designator> (‘B’: Ascii, ‘A’: UK, ‘K’: german, etc.) to strings. Every <mapping> describes to what string a single character will be translated. A template mechanism is used, as most of the time the codes have a lot in common (for example strings to switch to and from another charset). Each occurrence of ‘%’ in <template> gets substituted with the template-arg specified together with the character. If your strings are not similar at all, then use ‘%’ as a template and place the full string in <template-arg>. A quoting mechanism was added to make it possible to use a real ‘%’. The ‘\’ character quotes the special characters ‘\’, ‘%’, and ‘,’.
Here is an example:
termcap hp700 'XC=B\E(K%\E(B,\304[,\326\\\\,\334]'
This tells screen
, how to translate ISOlatin1 (charset ‘B’)
upper case umlaut characters on a hp700
terminal that has a
German charset. ‘\304’ gets translated to
‘\E(K[\E(B’ and so on.
Note that this line gets parsed *three* times before the internal
lookup table is built, therefore a lot of quoting is needed to
create a single ‘\’.
Another extension was added to allow more emulation: If a mapping translates the unquoted ‘%’ char, it will be sent to the terminal whenever screen switches to the corresponding <designator>. In this special case the template is assumed to be just ‘%’ because the charset switch sequence and the character mappings normally haven’t much in common.
This example shows one use of the extension:
termcap xterm 'XC=K%,%\E(B,[\304,\\\\\326,]\334'
Here, a part of the German (‘K’) charset is emulated on an xterm. If screen has to change to the ‘K’ charset, ‘\E(B’ will be sent to the terminal, i.e. the ASCII charset is used instead. The template is just ‘%’, so the mapping is straightforward: ‘[’ to ‘\304’, ‘\’ to ‘\326’, and ‘]’ to ‘\334’.
Screen
displays informational messages and other diagnostics in a
message line at the bottom of the screen. If your terminal has a
status line defined in its termcap, screen will use this for displaying
its messages, otherwise the last line of the screen will be temporarily
overwritten and output will be momentarily interrupted. The message
line is automatically removed after a few seconds delay, but it can also
be removed early (on terminals without a status line) by beginning to
type.
Next: Hardware Status Line, Up: The Message Line [Contents][Index]
The message line facility can be used by an application running in the current window by means of the ANSI Privacy message control sequence. For instance, from within the shell, try something like:
echo "{No value for `esc'}^Hello world from window $WINDOW{No value for `esc'}\"
where ‘{No value for `esc'}’ is ASCII ESC and the ‘^’ that follows it is a literal caret or up-arrow.
Next: Display Last Message, Previous: Using the message line from your program, Up: The Message Line [Contents][Index]
always
]firstline
|lastline
|message
|ignore
[string] ¶string
[string] ¶(none)
This command configures the use and emulation of the terminal’s
hardstatus line. The first form toggles whether screen
will use the hardware status line to display messages. If the
flag is set to ‘off’, these messages
are overlaid in reverse video mode at the display line. The default
setting is ‘on’.
The second form tells screen what to do if the terminal doesn’t
have a hardstatus line (i.e. the termcap/terminfo capabilities
"hs", "ts", "fs" and "ds" are not set). If the type
firstline
/lastline
is used, screen will reserve the first/last
line of the display for the hardstatus. message
uses
screen
’s message mechanism and
ignore
tells screen
never to display the hardstatus.
If you prepend the word always
to the type (e.g., alwayslastline
), screen
will use
the type even if the terminal supports a hardstatus line.
The third form specifies the contents of the hardstatus line.
%h
is used as default string, i.e., the stored hardstatus of the
current window (settable via ‘ESC]0;^G’ or ‘ESC_\\’) is
displayed.
You can customize this to any string you like including
string escapes (see String Escapes).
If you leave
out the argument string, the current string is displayed.
You can mix the second and third form by providing the string as additional argument.
Next: Message Wait, Previous: Hardware Status Line, Up: The Message Line [Contents][Index]
(C-a m, C-a C-m)
Repeat the last message displayed in the message line. Useful if you’re
typing when a message appears, because (unless your terminal has a
hardware status line) the message goes away when you press a key.
Previous: Display Last Message, Up: The Message Line [Contents][Index]
(none)
Defines the time screen
delays a new message when another is
currently displayed. Defaults to 1 second.
(none)
Defines the time a message is displayed, if screen
is not
disturbed by other activity. Defaults to 5 seconds.
Next: Startup, Previous: The Message Line, Up: Top [Contents][Index]
This section describes the commands for keeping a record of your session.
(C-a h)
Writes out the currently displayed image to the file file, or,
if no filename is specified, to hardcopy.n
in the default directory, where n is the number of the
current window. This either appends or overwrites the file if it
exists, as determined by the hardcopy_append
command.
If the option -h
is specified, dump also the
contents of the scrollback buffer.
(none)
If set to ‘on’, screen
will append to the
hardcopy.n files created by the command hardcopy
;
otherwise, these files are overwritten each time.
(none)
Defines a directory where hardcopy files will be placed.
If unset, hardcopys are dumped in screen’s current working
directory.
(none)
Same as the log
command except that the default setting for new
windows is changed. Initial setting is ‘off’.
(C-a H)
Begins/ends logging of the current window to the file
screenlog.n in the window’s default directory, where
n is the number of the current window.
This filename can be changed with the ‘logfile’ command.
If no parameter is given,
the logging state is toggled. The session log is
appended to the previous contents of the file if it already exists. The
current contents and the contents of the scrollback history are not
included in the session log. Default is ‘off’.
(none)
Defines the name the log files will get. The default is ‘screenlog.%n’.
The second form changes the number of seconds screen
will wait before flushing the logfile buffer to the file-system. The
default value is 10 seconds.
after
secs ¶string
string ¶(none)
This command controls logfile time-stamp mechanism of screen. If
time-stamps are turned ‘on’, screen adds a string containing
the current time to the logfile after two minutes of inactivity.
When output continues and more than another two minutes have passed,
a second time-stamp is added to document the restart of the
output. You can change this timeout with the second form
of the command. The third form is used for customizing the time-stamp
string (‘-- %n:%t -- time-stamp -- %M/%d/%y %c:%s --\n’ by
default).
Next: Miscellaneous commands, Previous: Logging, Up: Top [Contents][Index]
This section describes commands which are only useful in the .screenrc file, for use at startup.
(none)
The echo command may be used to annoy screen
users with a
’message of the day’. Typically installed in a global screenrc.
The option ‘-n’ may be used to suppress the line feed.
See also sleep
.
Echo is also useful for online checking of environment variables.
Next: String Escapes, Previous: Startup, Up: Top [Contents][Index]
The commands described here do not fit well under any of the other categories.
Next: Break, Up: Miscellaneous commands [Contents][Index]
(none)
Execute a command at other displays or windows as if it had been entered there.
At
changes the context (the ‘current window’ or ‘current display’
setting) of the command. If the first parameter describes a non-unique context,
the command will be executed multiple times. If the first parameter is of the
form ‘identifier*’ then identifier is matched against user names.
The command is executed once for each display of the selected user(s).
If the first parameter is of the form ‘identifier%’ identifier is
matched against displays. Displays are named after the ttys they attach. The
prefix ‘/dev/’ or ‘/dev/tty’ may be omitted from the identifier.
If identifier has a #
or nothing appended it is matched against
window numbers and titles. Omitting an identifier in front of the #
,
*
or %
character selects all users, displays or windows because
a prefix-match is performed. Note that on the affected display(s) a short
message will describe what happened.
Note that the #
character works as a comment introducer when it is
preceded by whitespace. This can be escaped by prefixing #
with a
\
.
Permission is checked for the initiator of the at
command, not for the
owners of the affected display(s).
Caveat:
When matching against windows, the command is executed at least
once per window. Commands that change the internal arrangement of windows
(like other
) may be called again. In shared windows the command will
be repeated for each attached display. Beware, when issuing toggle commands
like login
!
Some commands (e.g. \*Qprocess
) require
that a display is associated with the target windows. These commands may not
work correctly under at
looping over windows.
Next: Bumpleft, Previous: At, Up: Miscellaneous commands [Contents][Index]
(C-a b, C-a C-b)
Send a break signal for duration*0.25 seconds to this window.
For non-Posix systems the time interval is rounded up to full seconds.
Most useful if a character device is attached to the window rather than
a shell process (see Window Types). The maximum duration of
a break signal is limited to 15 seconds.
(C-a B)
Reopen the window’s terminal line and send a break condition.
(none)
Choose one of the available methods of generating a break signal for
terminal devices. This command should affect the current window only.
But it still behaves identical to defbreaktype
. This will be changed in
the future.
Calling breaktype
with no parameter displays the break setting for the
current window.
(none)
Choose one of the available methods of generating a break signal for
terminal devices opened afterwards. The preferred methods are
tcsendbreak
and
TIOCSBRK
. The third, TCSBRK
, blocks the complete screen
session for the duration of the break, but it may be the only way to
generate long breaks. tcsendbreak
and TIOCSBRK
may or may not
produce long breaks with spikes (e.g. 4 per second). This is not only system
dependent, this also differs between serial board drivers.
Calling defbreaktype
with no parameter displays the current setting.
Next: Bumpright, Previous: Break, Up: Miscellaneous commands [Contents][Index]
(none)
Exchanges windows positions on window list, with window having lower number
(left to current one).
Next: Collapse, Previous: Bumpleft, Up: Miscellaneous commands [Contents][Index]
(none)
Exchanges windows positions on window list, with window having bigger number
(right to current one).
Next: License, Previous: Bumpright, Up: Miscellaneous commands [Contents][Index]
(none)
Changes windows numbers, so there is no gaps between them.
Next: Collapse, Previous: Miscellaneous commands [Contents][Index]
(C-a ,)
Display the disclaimer page. This is done whenever screen
is
started without options, which should be often enough.
Next: Number, Previous: Miscellaneous commands [Contents][Index]
Tell screen how to deal with user interfaces (displays) that cease to
accept output. This can happen if a user presses ^S or a TCP/modem
connection gets cut but no hangup is received. If nonblock is
off
(this is the default) screen waits until the display
restarts to accept the output. If nonblock is on
, screen
waits until the timeout is reached (on
is treated as 1s). If the
display still doesn’t receive characters, screen will consider
it “blocked” and stop sending characters to it. If at
some time it restarts to accept characters, screen will unblock
the display and redisplay the updated window contents.
Same as the nonblock
command except that the default setting for
displays is changed. Initial setting is off
.
Next: Nonblock, Previous: Miscellaneous commands [Contents][Index]
(C-a N)
Change the current window’s number. If the given number n is already
used by another window, both windows exchange their numbers. If no argument is
specified, the current window number (and title) is shown. Using either a
plus (‘+’) or minus (‘-’) will change the window’s number by the relative
amount specified.
Next: Version, Previous: Miscellaneous commands [Contents][Index]
If verbose is switched on, the command name is echoed, whenever a window is created (or resurrected from zombie state). Default is off. Without a parameter, the current setting is shown.
Next: Zombie, Previous: Verbose, Up: Miscellaneous commands [Contents][Index]
(C-a v)
Display the version and modification date in the message line.
Next: Printcmd, Previous: Version, Up: Miscellaneous commands [Contents][Index]
(none)
Per default windows are removed from the window list as soon as the
windows process (e.g. shell) exits. When a string of two keys is
specified to the zombie command, ‘dead’ windows will remain in the list.
The kill
command may be used to remove the window. Pressing the first key
in the dead window has the same effect. Pressing the second key, however,
screen will attempt to resurrect the window. The process that was initially
running in the window will be launched again. Calling zombie
without
parameters will clear the zombie setting, thus making windows disappear when
the process terminates.
As the zombie setting is affected globally for all windows, this command
should probably be called defzombie
, but it isn’t.
Optionally you can put the word onerror
after the keys. This will
cause screen to monitor exit status of the process running in the window.
If it exits normally (’0’), the window disappears. Any other exit value
causes the window to become a zombie.
Additionally the zombie_timeout
command exists.
If a window is declared “dead”, screen will automatically try to
resurrect the window after the timeout.
It only works if zombie keys are defined via zombie
command.
Next: Rendition, Previous: Zombie, Up: Miscellaneous commands [Contents][Index]
(none)
If cmd is not an empty string, screen will not use the terminal
capabilities po/pf
for printing if it detects an ansi print
sequence ESC [ 5 i
, but pipe the output into cmd.
This should normally be a command like ‘lpr’ or
‘cat > /tmp/scrprint’.
Printcmd
without an argument displays the current setting.
The ansi sequence ESC \
ends printing and closes the pipe.
Warning: Be careful with this command! If other user have write access to your terminal, they will be able to fire off print commands.
Next: Sorendition, Previous: Printcmd, Up: Miscellaneous commands [Contents][Index]
(none)
Change the way screen renders the titles of windows that have monitor
or bell flags set in caption or hardstatus or windowlist.
See the chapter
about string escapes (see String Escapes) for the syntax of
the modifiers. The default for monitor is currently ‘=b’ (bold,
active colors), for bell ‘=ub’ (underline, bold and active colors), and
for silence ‘=u’.
Next: Attrcolor, Previous: Rendition, Up: Miscellaneous commands [Contents][Index]
(none)
This command has been deprecated. Use rendition so
instead.
Next: Setsid, Previous: Sorendition, Up: Miscellaneous commands [Contents][Index]
(none)
This command can be used to highlight attributes by changing the color of
the text. If the attribute
attrib
is in use, the specified attribute/color modifier is also applied. If no
modifier is given, the current one is deleted. See the chapter
about string escapes (see String Escapes) for the syntax of
the modifier. Screen
understands two pseudo-attributes, i
stands for high-intensity foreground color and I
for
high-intensity background color.
Examples:
attrcolor b "R"
Change the color to bright red if bold text is to be printed.
attrcolor u "-u b"
Use blue text instead of underline.
attrcolor b ".I"
Use bright colors for bold text. Most terminal emulators do this already.
attrcolor i "+b"
Make bright colored text also bold.
Next: Eval, Previous: Attrcolor, Up: Miscellaneous commands [Contents][Index]
(none)
Normally screen
uses different sessions and process groups for
the windows. If setsid is turned off
, this is not done
anymore and all windows will be in the same process group as the
screen backend process. This also breaks job-control, so be careful.
The default is on
, of course. This command is probably useful
only in rare circumstances.
Previous: Setsid, Up: Miscellaneous commands [Contents][Index]
(none)
Parses and executes each argument as separate command.
Next: Screen Saver, Up: Miscellaneous commands [Contents][Index]
(none)
Program the backtick command with the numerical id id.
The output of such a command is used for substitution of the
%`
string escape (see String Escapes).
The specified lifespan is the number
of seconds the output is considered valid. After this time, the
command is run again if a corresponding string escape is encountered.
The autorefresh parameter triggers an
automatic refresh for caption and hardstatus strings after the
specified number of seconds. Only the last line of output is used
for substitution.
If both the lifespan and the autorefresh parameters are zero, the backtick program is expected to stay in the background and generate output once in a while. In this case, the command is executed right away and screen stores the last line of output. If a new line gets printed screen will automatically refresh the hardstatus or the captions.
The second form of the command deletes the backtick command with the numerical id id.
Next: Zmodem, Previous: Backtick, Up: Miscellaneous commands [Contents][Index]
(none)
Sets a command that is run after the specified number of
seconds inactivity is reached. This command will normally
be the blanker
command to create a screen blanker, but
it can be any screen command. If no command is specified,
only the timeout is set. A timeout of zero (ot the special
timeout off
) disables the timer. If no arguments are
given, the current settings are displayed.
(none)
Activate the screen blanker. First the screen is cleared.
If no blanker program is defined, the cursor is turned
off, otherwise, the program is started and it’s output is
written to the screen. The screen blanker is killed with
the first keypress, the read key is discarded.
This command is normally used together with the idle
command.
Defines a blanker program. Disables the blanker program if an empty argument is given. Shows the currently set blanker program if no arguments are given.
Previous: Screen Saver, Up: Miscellaneous commands [Contents][Index]
(none)
Define zmodem support for screen
. Screen
understands two
different modes when it detects a zmodem request: pass
and catch
. If the mode is set to pass
, screen will
relay all data to the attacher until the end of the
transmission is reached. In catch
mode screen acts as a
zmodem endpoint and starts the corresponding rz/sz commands.
If the mode is set to auto
, screen will use catch
if
the window is a tty (e.g. a serial line), otherwise it
will use pass
.
You can define the templates screen uses in catch
mode
via the second and the third form.
Note also that this is an experimental feature.
Next: Environment Variables, Previous: Miscellaneous commands, Up: Top [Contents][Index]
Screen provides an escape mechanism to insert information like the
current time into messages or file names. The escape character
is %
with one exception: inside of a window’s hardstatus
^%
(^E
) is used instead.
Here is the full list of supported escapes:
%
the escape character itself
a
either am
or pm
A
either AM
or PM
c
current time HH:MM
in 24h format
C
current time HH:MM
in 12h format
d
day number
D
weekday name
E
sets %? to true if the escape character has been pressed.
f
flags of the window. See Windows, for meanings of the various flags.
F
sets %? to true if the window has the focus
h
hardstatus of the window
H
hostname of the system
O
count of screen windows. Prefix with '-'
to limit to current window group.
l
current load of the system
m
month number
M
month name
n
window number
P
sets %? to true if the current region is in copy/paste mode
S
session name
t
window title
u
all other users on this window
w
all window numbers and names. With -
qualifier: up to the current
window; with +
qualifier: starting with the window after the current
one.
W
all window numbers and names except the current one
y
last two digits of the year number
Y
full year number
?
the part to the next %?
is displayed only if a %
escape
inside the part expands to a non-empty string
:
else part of %?
=
pad the string to the display’s width (like TeX’s hfill). If a
number is specified, pad to the percentage of the window’s width.
A 0
qualifier tells screen to treat the number as absolute position.
You can specify to pad relative to the last absolute pad position
by adding a +
qualifier or to pad relative to the right margin
by using -
. The padding truncates the string if the specified
position lies before the current position. Add the L
qualifier
to change this.
<
same as %=
but just do truncation, do not fill with spaces
>
mark the current text position for the next truncation. When
screen needs to do truncation, it tries to do it in a way that
the marked position gets moved to the specified percentage of
the output area. (The area starts from the last absolute pad
position and ends with the position specified by the truncation
operator.) The L
qualifier tells screen to mark the truncated
parts with ‘...’.
{
attribute/color modifier string terminated by the next }
`
Substitute with the output of a ‘backtick’ command. The length qualifier is misused to identify one of the commands. See Backtick.
The c
and C
escape may be qualified with a 0
to
make screen use
zero instead of space as fill character.
The n
and
=
escapes understand
a length qualifier (e.g. %3n
), D
and M
can be
prefixed with L
to generate long names, w
and
W
also show the window flags if L
is given.
An attribute/color modifier is used to change the attributes or the color settings. Its format is ‘[attribute modifier] [color description]’. The attribute modifier must be prefixed by a change type indicator if it can be confused with a color description. The following change types are known:
+
add the specified set to the current attributes
-
remove the set from the current attributes
!
invert the set in the current attributes
=
change the current attributes to the specified set
The attribute set can either be specified as a hexadecimal number or a combination of the following letters:
d
dim
u
underline
b
bold
r
reverse
s
standout
B
blinking
The old format of specifying colors by letters (k,r,g,y,b,m,c,w) is
now deprecated. Colors are coded as 0-7 for basic ANSI, 0-255 for 256
color mode, or for truecolor, either a hexadecimal code starting with
x, or HTML notation as either 3 or 6 hexadecimal digits.
Foreground and background are specified by putting a semicolon between
them.
Ex: #FFF;#000
or i7;0
is white on a black background.
The following numbers are for basic ANSI:
0
black
1
red
2
green
3
yellow
4
blue
5
magenta
6
cyan
7
white
You can also use the pseudo-color ’i’ to set just the brightness and leave the color unchanged. As a special case, ‘%{-}’ restores the attributes and colors that were set before the last change was made (i.e. pops one level of the color-change stack).
Examples:
set color to bright green
use bold red
write in bright red color on a pale yellow background
The available windows centered at the current window and truncated to the available width. The current window is displayed white on blue. This can be used with ‘hardstatus alwayslastline’.
The window number and title and the window’s hardstatus, if one is set. Also use a red background if this is the active focus. Useful for ‘caption string’.
Next: Files Referenced, Previous: String Escapes, Up: Top [Contents][Index]
COLUMNS
Number of columns on the terminal (overrides termcap entry).
HOME
Directory in which to look for .screenrc.
LINES
Number of lines on the terminal (overrides termcap entry).
LOCKPRG
Screen lock program.
PATH
Used for locating programs to run.
SCREENCAP
For customizing a terminal’s TERMCAP
value.
SCREENDIR
Alternate socket directory.
SCREENRC
Alternate user screenrc file.
SHELL
Default shell program for opening windows (default /bin/sh).
See also shell
.screenrc command.
STY
Alternate socket name. If screen
is invoked, and the environment variable
STY
is set, then it creates only a window in the running screen
session rather than starting a new session.
SYSTEM_SCREENRC
Alternate system screenrc file.
TERM
Terminal name.
TERMCAP
Terminal description.
WINDOW
Window number of a window (at creation time).
Next: Credits, Previous: Environment Variables, Up: Top [Contents][Index]
Examples in the screen
distribution package for private and
global initialization files.
$SYSTEM_SCREENRC
screen
initialization commands
$SCREENRC
$HOME
/.iscreenrc$HOME
/.screenrcRead in after /local/etc/screenrc
$SCREENDIR
/S-loginSocket directories (default)
Alternate socket directories.
Written by the dumptermcap
command
screen
interprocess communication buffer
Screen images created by the hardcopy command
Output log files created by the log command
Terminal capability databases
Login records
$LOCKPRG
Program for locking the terminal.
Next: Bugs, Previous: Files Referenced, Up: Top [Contents][Index]
Authors
=======
Originally created by Oliver Laumann. For a long time maintained and developed by Juergen Weigert, Michael Schroeder, Micah Cowan and Sadrul Habib Chowdhury. Since 2015 maintained and developed by Amadeusz Slawinski <amade@asmblr.net> and Alexander Naumov <alexander_naumov@opensuse.org>.
Contributors
============
Eric S. Raymond <esr@thyrsus.com>, Thomas Renninger <treen@suse.com>, Axel Beckert <abe@deuxchevaux.org>, Ken Beal <kbeal@@amber.ssd.csd.harris.com>, Rudolf Koenig <rfkoenig@@informatik.uni-erlangen.de>, Toerless Eckert <eckert@@informatik.uni-erlangen.de>, Wayne Davison <davison@@borland.com>, Patrick Wolfe <pat@@kai.com, kailand!pat>, Bart Schaefer <schaefer@@cse.ogi.edu>, Nathan Glasser <nathan@@brokaw.lcs.mit.edu>, Larry W. Virden <lvirden@@cas.org>, Howard Chu <hyc@@hanauma.jpl.nasa.gov>, Tim MacKenzie <tym@@dibbler.cs.monash.edu.au>, Markku Jarvinen <mta@@@{cc,cs,ee@}.tut.fi>, Marc Boucher <marc@@CAM.ORG>, Doug Siebert <dsiebert@@isca.uiowa.edu>, Ken Stillson <stillson@@tsfsrv.mitre.org>, Ian Frechett <frechett@@spot.Colorado.EDU>, Brian Koehmstedt <bpk@@gnu.ai.mit.edu>, Don Smith <djs6015@@ultb.isc.rit.edu>, Frank van der Linden <vdlinden@@fwi.uva.nl>, Martin Schweikert <schweik@@cpp.ob.open.de>, David Vrona <dave@@sashimi.lcu.com>, E. Tye McQueen <tye%spillman.UUCP@@uunet.uu.net>, Matthew Green <mrg@@eterna.com.au>, Christopher Williams <cgw@@pobox.com>, Matt Mosley <mattm@@access.digex.net>, Gregory Neil Shapiro <gshapiro@@wpi.WPI.EDU>, Jason Merrill <jason@@jarthur.Claremont.EDU>, Johannes Zellner <johannes@@zellner.org>, Pablo Averbuj <pablo@@averbuj.com>.
Version
=======
This manual describes version 5.0.0 of the screen
program. Its roots are a merge of a custom version 2.3PR7 by Wayne
Davison and several enhancements to Oliver Laumann’s version 2.0.
Note that all versions numbered 2.x are copyright by Oliver Laumann.
See also See Availability.
Next: Installation, Previous: Credits, Up: Top [Contents][Index]
Just like any other significant piece of software, screen
has a
few bugs and missing features. Please send in a bug report if you have
found a bug not mentioned here.
Next: Reporting Bugs, Up: Bugs [Contents][Index]
screen
has no clue about double-high or double-wide characters.
But this is the only area where vttest
is allowed to fail.
$TERMCAP
when reattaching under a different terminal type.
$TERMCAP
may not have any effects.
screen
does not make use of hardware tabs.
screen
must be installed setuid root on most systems
in order to be able to
correctly change the owner of the tty device file for each window.
Special permission may also be required to write the file
/etc/utmp.
screen
is killed
with SIGKILL. This will cause some programs (like "w" or "rwho") to
advertise that a user is logged on who really isn’t.
screen
may give a strange warning when your tty has no utmp
entry.
screen
may not automatically detach
(or quit) unless the device driver sends a HANGUP signal. To detach such a
screen
session use the -D or -d command line option.
breaktype
and defbreaktype
change the break generating
method used by all terminal devices. The first should change a window
specific setting, where the latter should change only the default for new
windows.
Next: Availability, Previous: Known Bugs, Up: Bugs [Contents][Index]
If you find a bug in Screen
, please send electronic mail to
‘screen-devel@gnu.org’. Include the version number
of Screen
which you are using. Also include in your message the
hardware and operating system, the compiler used to compile, a
description of the bug behavior, and the conditions that triggered the
bug.
Previous: Reporting Bugs, Up: Bugs [Contents][Index]
Screen
is available under the GNU
copyleft.
The latest official release of screen
available via anonymous
ftp from ‘prep.ai.mit.edu’, ‘nic.funet.fi’ or any other
GNU
distribution site. The home site of
screen
is ‘ftp.uni-erlangen.de
(131.188.3.71)’, in the directory pub/utilities/screen.
The subdirectory ‘private’ contains the latest beta testing release.
If you want to help, send a note to screen-devel@gnu.org.
Next: Concept Index, Previous: Bugs, Up: Top [Contents][Index]
Since screen
uses pseudo-ttys, the select system call, and
UNIX-domain sockets/named pipes, it will not run under a system that
does not include these features of 4.2 and 4.3 BSD UNIX.
The socket directory defaults either to $HOME/.screen or simply to
/tmp/screens or preferably to /usr/local/screens chosen at
compile-time. If screen
is installed
setuid root, then the administrator should compile screen with an
adequate (not NFS mounted) SOCKDIR
. If screen
is not
running setuid-root, the user can specify any mode 700 directory in the
environment variable $SCREENDIR
.
Previous: Socket Directory, Up: Installation [Contents][Index]
To compile and install screen:
The screen
package comes with a GNU Autoconf
configuration
script. Before you compile the package run
sh ./configure
This will create a config.h and Makefile for your machine.
If configure
fails for some reason, then look at the examples and
comments found in the Makefile.in and config.h.in templates.
Rename config.status to config.status.machine when
you want to keep configuration data for multiple architectures. Running
sh ./config.status.machine
recreates your configuration
significantly faster than rerunning configure
.
Read through the "User Configuration" section of config.h, and verify
that it suits your needs.
A comment near the top of this section explains why it’s best to
install screen setuid to root.
Check for the place for the global screenrc-file and for the socket
directory.
Check the compiler used in Makefile, the prefix path where to install
screen
. Then run
make
If make
fails to produce one of the files term.h, comm.h
or tty.c, then use filename.x.dist
instead.
For additional information about installation of screen
refer to the
file INSTALLATION, coming with this package.
Next: Command Index, Previous: Installation, Up: Top [Contents][Index]
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Next: Keystroke Index, Previous: Concept Index, Up: Top [Contents][Index]
This is a list of all the commands supported by screen
.
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Previous: Command Index, Up: Top [Contents][Index]
This is a list of the default key bindings.
The leading escape character (see Command Character) has been omitted from the key sequences, since it is the same for all bindings.
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