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SCREEN(1) General Commands Manual SCREEN(1)
screen - screen manager with VT100/ANSI terminal emulation
screen [ -options ] [ cmd [ args ] ]
screen -r [[pid.]tty[.host]]
screen -r sessionowner/[[pid.]tty[.host]]
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 a 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 moving 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 existing windows, view a
list of windows, turn output logging on and off, copy-and-paste
text between windows, view the scrollback history, switch between
windows in whatever manner you wish, 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 previous 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 and all the key bindings 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 terminated. 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 also C-a L.
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 test
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 ?.
Typing these two characters will display a list of the available
screen commands and their bindings. Each keystroke is discussed in
the section DEFAULT KEY BINDINGS. The manual section CUSTOMIZATION
deals with the contents of your .screenrc.
If your terminal is a true auto-margin terminal (it doesn't allow
the last position on the screen to be updated without scrolling
the screen) consider using a version of your terminal's termcap
that has automatic margins turned off. This will ensure an
accurate and optimal update of the screen in all circumstances.
Most terminals nowadays have magic margins (automatic margins plus
usable last column). This is the VT100 style type and perfectly
suited for screen. If all you've got is a true auto-margin
terminal screen will be content to use it, but updating a
character put into the last position on the screen may not be
possible until the screen scrolls or the character is moved into a
safe position in some other way. This delay can be shortened by
using a terminal with insert-character capability.
Screen has the following command-line options:
-a include all capabilities (with some minor exceptions) in each
window's termcap, even if screen must redraw parts of the
display in order to implement a function.
-A Adapt the sizes of all windows to the size of the current
terminal. By default, screen tries to restore its old window
sizes when attaching to resizable terminals (those with WS in
its description, e.g. suncmd or some xterm).
-c file
override the default configuration file from $HOME/.screenrc
to file.
-d|-D [pid.tty.host]
does not start screen, but detaches the elsewhere running
screen session. It has the same effect as typing C-a d from
screen's controlling terminal. -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 always a good idea to check the status of your
sessions by means of screen -list.
-e xy
specifies the command character to be x and the character
generating a literal command character to y (when typed after
the command character). The default is 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 changes only the command character of
the attaching user. This option is equivalent to either the
commands defescape or escape respectively.
-f, -fn, and -fa
turns flow-control on, off, or automatic switching mode.
This can also be defined through the defflow .screenrc
command.
-h num
Specifies the history scrollback buffer to be num lines high.
-i will cause the interrupt key (usually C-c) to interrupt the
display immediately when flow-control is on. See the defflow
.screenrc command for details. The use of this option is
discouraged.
-l and -ln
turns login mode on or off (for /etc/utmp updating). This
can also be defined through the deflogin .screenrc command.
-ls [match]
-list [match]
does not start screen, but prints a list of pid.tty.host
strings identifying your screen sessions. Sessions marked
`detached' can be resumed with screen -r. Those marked
`attached' are running and have a controlling terminal. If
the session runs in multiuser mode, it is marked `multi'.
Sessions marked as `unreachable' either live on a different
host or are `dead'. An unreachable session is considered
dead, when its name matches either the name of the local
host, or the specified parameter, if any. See the -r flag
for a description how to construct matches. Sessions marked
as `dead' should be thoroughly checked and removed. Ask your
system administrator if you are not sure. Remove sessions
with the -wipe option.
-L tells screen to turn on automatic output logging for the
windows.
-Logfile file
By default logfile name is screenlog.0. You can set new
logfile name with the -Logfile option.
-m causes screen to ignore the $STY environment variable. With
screen -m creation of a new session is enforced, regardless
whether screen is 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.
-O selects an 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 a termcap command.
-p number_or_name|-|=|+
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 a new window. The command will not be executed if the
specified window could not be found.
-P 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.
-q Suppress printing of error messages. In combination with -ls
the exit value is 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.
-Q 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
-r [pid.tty.host]
-r sessionowner/[pid.tty.host]
resumes a detached screen session. No other options (except
combinations with -d/-D) may be specified, though an optional
prefix of [pid.]tty.host may be needed to distinguish between
multiple detached screen sessions. The second form is used
to connect to another user's screen session which runs in
multiuser mode. This indicates that screen should look for
sessions in another user's directory. This requires setuid-
root.
-R resumes screen only when it's unambiguous which one to
attach, usually when only one screen is detached. Otherwise
lists available sessions. -RR attempts to resume the first
detached screen session it finds. If successful, all other
command-line options are ignored. If no detached session
exists, starts a new session using the specified options,
just as if -R had not been specified. The option is set by
default if screen is run as a login-shell (actually screen
uses -xRR in that case). For combinations with the -d/-D
option see there.
-s program
sets the default shell to the program specified, instead of
the value in the environment variable $SHELL (or /bin/sh if
not defined). This can also be defined through the shell
.screenrc command. See also there.
-S sessionname
When creating a new session, this option can be used to
specify a meaningful name for the session. This name
identifies the session for screen -list and screen -r
actions. It substitutes the default [tty.host] suffix. This
name should not be longer then 80 symbols.
-t name
sets the title (a.k.a.) for the default shell or specified
program. See also the shelltitle .screenrc command.
-T term
Set the $TERM environment variable using the specified term
as opposed to the default setting of screen.
-U Run screen in UTF-8 mode. This option tells screen that your
terminal sends and understands UTF-8 encoded characters. It
also sets the default encoding for new windows to `utf8'.
-v Print version number.
-wipe [match]
does the same as screen -ls, but removes destroyed sessions
instead of marking them as `dead'. An unreachable session is
considered dead, when its name matches either the name of the
local host, or the explicitly given parameter, if any. See
the -r flag for a description how to construct matches.
-x Attach to a not detached screen session. (Multi display
mode). Screen refuses to attach from within itself. But
when cascading multiple screens, loops are not detected; take
care.
-X Send the specified command to a running screen session. You
may use the -S option to specify the screen session if you
have several screen sessions 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.
-4 Resolve hostnames only to IPv4 addresses.
-6 Resolve hostnames only to IPv6 addresses.
As mentioned, each screen 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, C-a c as well as C-a C-c can be used to create a window. See
section CUSTOMIZATION for a description of the command.
The following table shows the default key bindings. The trailing
commas in boxes with multiple keystroke entries are separators,
not part of the bindings.
────────────────────────────────────────────────────────
C-a ' (select) Prompt for a
window name or
number to switch
to.
────────────────────────────────────────────────────────
C-a " (windowlist -b) Present a list of
all windows for
selection.
────────────────────────────────────────────────────────
C-a digit (select 0-9) Switch to window
number 0 - 9
────────────────────────────────────────────────────────
C-a - (select -) Switch to window
number 0 - 9, or
to the blank
window.
────────────────────────────────────────────────────────
C-a tab (focus) Switch the input
focus to the next
region. See also
split, remove,
only.
────────────────────────────────────────────────────────
C-a C-a (other) Toggle to the
window displayed
previously. Note
that this binding
defaults to the
command character
typed twice,
unless overridden.
For instance, if
you use the option
-e]x, this command
becomes ]].
────────────────────────────────────────────────────────
C-a a (meta) Send the command
character (C-a) to
window. See escape
command.
────────────────────────────────────────────────────────
C-a A (title) Allow the user to
enter a name for
the current
window.
────────────────────────────────────────────────────────
C-a b, (break) Send a break to
C-a C-b window.
────────────────────────────────────────────────────────
C-a B (pow_break) Reopen the
terminal line and
send a break.
────────────────────────────────────────────────────────
C-a c, (screen) Create a new
C-a C-c window with a
shell and switch
to that window.
────────────────────────────────────────────────────────
C-a C (clear) Clear the screen.
────────────────────────────────────────────────────────
C-a d, (detach) Detach screen from
C-a C-d this terminal.
────────────────────────────────────────────────────────
C-a D D (pow_detach) Detach and logout.
────────────────────────────────────────────────────────
C-a f, (flow) Toggle flow on,
C-a C-f off or auto.
────────────────────────────────────────────────────────
C-a F (fit) Resize the window
to the current
region size.
────────────────────────────────────────────────────────
C-a C-g (vbell) Toggles screen's
visual bell mode.
────────────────────────────────────────────────────────
C-a h (hardcopy) Write a hardcopy
of the current
window to the file
hardcopy.n.
────────────────────────────────────────────────────────
C-a H (log) Begins/ends
logging of the
current window to
the file
screenlog.n.
────────────────────────────────────────────────────────
C-a i, (info) Show info about
C-a C-i this window.
────────────────────────────────────────────────────────
C-a k, (kill) Destroy current
C-a C-k window.
────────────────────────────────────────────────────────
C-a l, (redisplay) Fully refresh
C-a C-l current window.
────────────────────────────────────────────────────────
C-a L (login) Toggle this
windows login
slot. Available
only if screen is
configured to
update the utmp
database.
────────────────────────────────────────────────────────
C-a m, (lastmsg) Repeat the last
C-a C-m message displayed
in the message
line.
────────────────────────────────────────────────────────
C-a M (monitor) Toggles monitoring
of the current
window.
────────────────────────────────────────────────────────
C-a space, (next) Switch to the next
C-a n, window.
C-a C-n
────────────────────────────────────────────────────────
C-a N (number) Show the number
(and title) of the
current window.
────────────────────────────────────────────────────────
C-a backspace, (prev) Switch to the
C-a C-h, previous window
C-a p, (opposite of C-a
C-a C-p n).
────────────────────────────────────────────────────────
C-a q, (xon) Send a control-q
C-a C-q to the current
window.
────────────────────────────────────────────────────────
C-a Q (only) Delete all regions
but the current
one. See also
split, remove,
focus.
────────────────────────────────────────────────────────
C-a r, (wrap) Toggle the current
C-a C-r window's line-wrap
setting (turn the
current window's
automatic margins
on and off).
────────────────────────────────────────────────────────
C-a s, (xoff) Send a control-s
C-a C-s; to the current
window.
────────────────────────────────────────────────────────
C-a S (split) Split the current
region
horizontally into
two new ones. See
also only, remove,
focus.
────────────────────────────────────────────────────────
C-a v (version) Display the
version and
compilation date.
────────────────────────────────────────────────────────
C-a C-v (digraph) Enter digraph.
────────────────────────────────────────────────────────
C-a w, (windows) Show a list of
C-a C-w window.
────────────────────────────────────────────────────────
C-a W (width) Toggle 80/132
columns.
────────────────────────────────────────────────────────
C-a x or C-a C-x (lockscreen) Lock this
terminal.
────────────────────────────────────────────────────────
C-a X (remove) Kill the current
region. See also
split, only,
focus.
────────────────────────────────────────────────────────
C-a z, (suspend) Suspend screen.
C-a C-z Your system must
support BSD-style
job-control.
────────────────────────────────────────────────────────
C-a Z (reset) Reset the virtual
terminal to its
power-on values.
────────────────────────────────────────────────────────
C-a . (dumptermcap) Write out a
.termcap file.
────────────────────────────────────────────────────────
C-a ? (help) Show key bindings.
────────────────────────────────────────────────────────
C-a \ (quit) Kill all windows
and terminate
screen.
────────────────────────────────────────────────────────
C-a : (colon) Enter command line
mode.
────────────────────────────────────────────────────────
C-a [, (copy) Enter
C-a C-[, copy/scrollback
C-a esc mode.
────────────────────────────────────────────────────────
C-a C-], (paste .) Write the contents
C-a ] of the paste
buffer to the
stdin queue of the
current window.
────────────────────────────────────────────────────────
C-a {, (history) Copy and paste a
C-a } previous (command)
line.
────────────────────────────────────────────────────────
C-a > (writebuf) Write paste buffer
to a file.
────────────────────────────────────────────────────────
C-a < (readbuf) Reads the screen-
exchange file into
the paste buffer.
────────────────────────────────────────────────────────
C-a = (removebuf) Removes the file
used by C-a < and
C-a >.
────────────────────────────────────────────────────────
C-a , (license) Shows where screen
comes from, where
it went to and why
you can use it.
────────────────────────────────────────────────────────
C-a _ (silence) Start/stop
monitoring the
current window for
inactivity.
────────────────────────────────────────────────────────
C-a | (split -v) Split the current
region vertically
into two new ones.
────────────────────────────────────────────────────────
C-a * (displays) Show a listing of
all currently
attached displays.
────────────────────────────────────────────────────────
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) socket directory. If screen is not running setuid-root,
the user can specify any mode 700 directory in the environment
variable $SCREENDIR.
When screen is invoked, it executes initialization commands from
the files /usr/local/etc/screenrc and defaults that can be
overridden in the following ways: for the global screenrc file
screen searches for the environment variable $SYSSCREENRC (this
override feature may be disabled at compile-time). The user
specific screenrc file is searched in $SCREENRC, then
$HOME/.screenrc. The command line option -c takes precedence over
the above user screenrc files.
Commands in these files are used to set options, bind functions to
keys, and to automatically establish one or more windows at the
beginning of your screen session. Commands are listed one per
line, with empty lines being ignored. A command's arguments are
separated by tabs or spaces, and may be surrounded by single or
double quotes. A `#' turns the rest of the line into a comment,
except in quotes. Unintelligible lines are warned about and
ignored. Commands may contain references to environment
variables. The syntax is the shell-like "$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 shall be performed. 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.
Customization can also be done 'on-line'. To enter the command
mode type `C-a :'. Note that commands starting with def change
default values, while others change current settings.
The following commands are available:
acladd usernames [crypted-pw]
addacl usernames
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 "#?"'. executed. To add a user with
restricted access, use the `aclchg' command below. If an optional
second parameter is supplied, it should be a crypted password for
the named user(s). `Addacl' is a synonym to `acladd'. Multi user
mode only.
aclchg usernames permbits list
chacl usernames permbits list
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 and/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 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. Rights of the special username nobody cannot be
changed (see the su command). `Chacl' is a synonym to `aclchg'.
Multi user mode only.
acldel username
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.
aclgrp username [groupname]
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.
aclumask [[ users ] +bits | [ users ] -bits... ]
umask [[ users ] +bits | [ users ] -bits... ]
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'.
activity message
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 re-defined 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).
allpartial [ on | off ]
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.
altscreen [ on | off ]
If set to on, "alternate screen" support is enabled in virtual
terminals, just like in xterm. Initial setting is `off'.
at [identifier][#|*|%] command [args ... ]
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. Permission is checked for initiator of the at command,
not for the owners of the affected display(s). Note that the '#'
character works as a comment introducer when it is preceded by
whitespace. This can be escaped by prefixing 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. process) require that a display is associated with the
target windows. These commands may not work correctly under at
looping over windows.
attrcolor attrib [attribute/color-modifier]
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 STRING ESCAPES
chapter 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.
auth [ on | off ]
This command enables/disables password protection for the screen
session. It is off by default (authentication is disabled).
autodetach [ on | off ]
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.
autonuke [ on | off ]
Sets whether a clear screen sequence should nuke all the output
that has not been written to the terminal. See also obuflimit.
backtick id lifespan autorefresh cmd args...
backtick id
Program the backtick command with the numerical id id. The output
of such a command is used for substitution of the %` string
escape. 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.
bce [ on | off ]
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.
bell_msg [message]
When a bell character is sent to a background window, screen
displays a notification in the message line. The notification
message can be re-defined by this command. Each occurrence of `%'
in message is replaced by the number of the window to which a bell
has been sent, and each occurrence of `^G' is replaced by the
definition for bell in your termcap (usually an audible bell).
The default message is
'Bell in window %n'
An empty message can be supplied to the bell_msg command to
suppress output of a message line (bell_msg ""). Without
parameter, the current message is shown.
bind [class] key [command [args]]
Bind a command to a key. By default, most of the commands
provided by screen are bound to one or more keys as indicated in
the DEFAULT KEY BINDINGS section, e.g. 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. 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 listed in this section.
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.
Some examples:
bind ' ' windows
bind ^k
bind k
bind K kill
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). The next three lines remove the
default kill binding from C-a C-k and C-a k. C-a K is then bound
to the kill command. Then it binds C-f to the command create a
window with a TELNET connection to foobar, and bind escape to the
command that creates an non-login window with a.k.a. 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.
bindkey [-d] [-m] [-a] [[-k|-t] string [cmd-args]]
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 section 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.
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 ^T an escape character for key-bindings. If
you did the above stuff barfoo binding, you can enter the word foo
by typing ^Tfoo. If you want to insert a ^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
^A).
break [duration]
Send a break signal for duration*0.25 seconds to this window. For
non-Posix systems the time interval may be rounded up to full
seconds. Most useful if a character device is attached to the
window rather than a shell process (See also chapter WINDOW
TYPES). The maximum duration of a break signal is limited to 15
seconds.
blanker
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.
blankerprg [program-args]
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.
breaktype [tcsendbreak|TIOCSBRK|TCSBRK]
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 method for the current window.
bufferfile [exchange-file]
Change the filename used for reading and writing with the paste
buffer. If the optional argument to the bufferfile command is
omitted, the default setting (/tmp/screen-exchange) is
reactivated. 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
bumpleft
Swaps window with previous one on window list.
bumpright
Swaps window with next one on window list.
c1 [ on | off ]
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.
caption [ top | bottom ] always|splitonly[string]
caption string [string]
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 escapes from the STRING ESCAPES chapter. Screen uses a default
of `%3n %t'.
You can mix both forms by providing a string as an additional
argument.
You can have the caption displayed either at the top or bottom of
the window. The default is bottom.
charset set
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.
chdir [directory]
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.
cjkwidth [ on | off ]
Treat ambiguous width characters as full/half width.
clear
Clears the current window and saves its image to the scrollback
buffer.
collapse
Reorders window on window list, removing number gaps between them.
colon [prefix]
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!
Usually commands affect the current window rather than default
settings for future windows. Change defaults with commands
starting with 'def...'.
If you consider this as the `Ex command mode' of screen, you may
regard C-a esc (copy mode) as its `Vi command mode'.
command [ -c class"]"
This command has the same effect as typing the screen escape
character (^A). It is probably only useful for key bindings. If
the -c option is given, select the specified command class. See
also bind and bindkey.
compacthist [ on | off ]
This tells screen whether to suppress trailing blank lines when
scrolling up text into the history buffer.
console [ on | off ]
Grabs or un-grabs the machines console output to a window. Note:
Only the owner of /dev/console can grab the console output. This
command is only available if the machine supports the ioctl
TIOCCONS.
copy
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:
The editor's movement keys are:
────────────────────────────────────────────────────────────────
h, C-h, move the cursor left.
left arrow
────────────────────────────────────────────────────────────────
j, C-n, move the cursor down.
down arrow
────────────────────────────────────────────────────────────────
k, C-p, move the cursor up.
up arrow
────────────────────────────────────────────────────────────────
l ('el'), move the cursor right.
right arrow
────────────────────────────────────────────────────────────────
0 (zero) C-a move to the leftmost column.
────────────────────────────────────────────────────────────────
+ and - positions one line up and down.
────────────────────────────────────────────────────────────────
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 leftmost column, 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
occurrence 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 screen-full).
────────────────────────────────────────────────────────────────
C-b and C-f scroll the display up/down a full screen.
────────────────────────────────────────────────────────────────
Note: Emacs style movement keys can be customized by a .screenrc
command. (E.g. markkeys "h=^B:l=^F:$=^E") There is no simple
method for a full emacs-style keymap, as this involves multi-
character codes.
Some keys are defined to do mark and replace operations.
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 used to mark one whole line or to mark from start
of line.
W marks exactly one word.
Any of these commands can be prefixed with a repeat count 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.
The following search keys are defined:
/ Vi-like search forward.
? Vi-like search backward.
C-a s Emacs style incremental search forward.
C-r Emacs style reverse i-search.
n Find next search pattern.
N Find previous search pattern.
There are however some keys that act differently than in vi. Vi
does not allow one 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 whitespace and comma separated lines. Note that you can
prepend the newline character with a carriage return character, by
issuing a crlf on.
v or V is for all the vi users with :set numbers - it toggles the
left margin between column 9 and 1. Press
a before the final space key to toggle in append mode. Thus the
contents of the paste buffer will not be overwritten, but is
appended to.
A toggles in 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.
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 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. Does not even exit copy mode.
All keys not described here exit copy mode.
copy_reg [key]
No longer exists, use readreg instead.
crlf [ on | off ]
This affects the copying of text regions with the `C-a [' command.
If it is set to `on', lines will be separated by the two character
sequence `CR' - `LF'. Otherwise (default) only `LF' is used.
When no parameter is given, the state is toggled.
defc1 [ on | off ]
Same as the c1 command except that the default setting for new
windows is changed. Initial setting is `on'.
defautonuke [ on | off ]
Same as the autonuke command except that the default setting for
new displays is changed. Initial setting is `off'. Note that you
can use the special `AN' terminal capability if you want to have a
dependency on the terminal type.
defbce [ on | off ]
Same as the bce command except that the default setting for new
windows is changed. Initial setting is `off'.
defbreaktype [tcsendbreak|TIOCSBRK|TCSBRK]
Choose one of the available methods of generating a break signal
for terminal devices. 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.
defcharset [set]
Like the charset command except that the default setting for new
windows is changed. Shows current default if called without
argument.
defdynamictitle [ on | off ]
Set default behaviour for new windows regarding if screen should
change window title when seeing proper escape sequence. See also
"TITLES (naming windows)" section.
defescape xy
Set the default command characters. This is equivalent to the
escape except that it is useful 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.
defflow [ on | off | auto [ interrupt ]]
Same as the flow command except that the default setting for new
windows is changed. Initial setting is `auto'. Specifying defflow
auto interrupt is the same as the command-line options -fa and -i.
defgr [ on | off ]
Same as the gr command except that the default setting for new
windows is changed. Initial setting is `off'.
defhstatus [status]
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.
defencoding enc
Same as the encoding command except that the default setting for
new windows is changed. Initial setting is the encoding taken from
the terminal.
deflog [ on | off ]
Same as the log command except that the default setting for new
windows is changed. Initial setting is `off'.
deflogin [ on | off ]
Same as the login command except that the default setting for new
windows is changed. This is initialized with `on' as distributed
(see config.h.in).
defmode mode
The mode of each newly allocated pseudo-tty is set to mode. Mode
is an octal number. When no defmode command is given, mode 0622
is used.
defmonitor [ on | off]
Same as the monitor command except that the default setting for
new windows is changed. Initial setting is `off'.
defmousetrack [ on | off ]
Same as the mousetrack command except that the default setting for
new windows is changed. Initial setting is `off'.
defnonblock [ on | off | numsecs]
Same as the nonblock command except that the default setting for
displays is changed. Initial setting is `off'.
defobuflimit limit
Same as the obuflimit command except that the default setting for
new displays is changed. Initial setting is 256 bytes. Note that
you can use the special 'OL' terminal capability if you want to
have a dependency on the terminal type.
defscrollback num
Same as the scrollback command except that the default setting for
new windows is changed. Initial setting is 100.
defshell command
Synonym to the shell .screenrc command. See there.
defsilence [ on | off ]
Same as the silence command except that the default setting for
new windows is changed. Initial setting is `off'.
defslowpaste msec
Same as the slowpaste command except that the default setting for
new windows is changed. Initial setting is 0 milliseconds, meaning
`off'.
defutf8 [ on | off ]
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'.
defwrap [ on | off ]
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".
defwritelock [ on | off | auto ]
Same as the writelock command except that the default setting for
new windows is changed. Initially writelocks will off.
detach [-h]
Detach the screen session (disconnect it from the terminal and put
it into the background). This returns you to the shell where you
invoked screen. A detached screen can be resumed by invoking
screen with the -r option (see also section COMMAND-LINE OPTIONS).
The -h option tells screen to immediately close the connection to
the terminal (hangup).
dinfo
Show what screen thinks about your terminal. Useful if you want to
know why features like color or the alternate charset don't work.
displays
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 that display
───────────────────────────────────────────────────────
D Power detach that 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.
┌─────────────────────────────────────────────────────────┐
│ Window permissions indicators │
├──────────────────┬──────────────────┬───────────────────┤
│ 1st character │ 2nd character │ 3rd character │
├─────┬────────────┼─────┬────────────┼─────┬─────────────┤
│ - │no read │ - │no write │ - │no execute │
├─────┼────────────┼─────┼────────────┼─────┼─────────────┤
│ r │read │ w │write │ x │execute │
├─────┼────────────┼─────┼────────────┼─────┼─────────────┤
│ │ │ W │own wlock │ │ │
├─────┴────────────┴─────┴────────────┴─────┴─────────────┤
│ Indicators of permissions suppressed by a foreign wlock │
├─────┬────────────┬─────┬────────────┬─────┬─────────────┤
│ R │read only │ . │no write │ │ │
└─────┴────────────┴─────┴────────────┴─────┴─────────────┘
displays needs a region size of at least 10 characters wide
and 5 characters high in order to display.
digraph [preset[unicode-value]]
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.
dumptermcap
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 the FILES section below). 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.
dynamictitle [ on | off ]
Change behaviour for windows regarding if screen should change
window title when seeing proper escape sequence. See also "TITLES
(naming windows)" section.
echo [-n] message
The echo command may be used to annoy screen users with a 'message
of the day'. Typically installed in a global /local/etc/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.
encoding enc [enc]
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.
Supported encodings are eucJP, SJIS, eucKR, eucCN, Big5, GBK,
KOI8-R, KOI8-U, 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.
escape xy
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.
eval command1[command2 ...]
Parses and executes each argument as separate command.
exec [[fdpat]newcommand [args ...]]
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 in the window (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 (as a fourth character) to the end of fdpat.
Invoking `exec' without arguments shows name and arguments of the
currently running subprocess in this window. Only one subprocess a
time can be running in each window.
When a subprocess is running the `kill' command will affect it
instead of the windows process.
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 the 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.
Abbreviations: Whitespace between the word `exec' and fdpat and
the command can be omitted. Trailing dots and a fdpat consisting
only of dots can be omitted. A simple `|' is synonymous for the
pattern `!..|'; the word exec can be omitted here and can always
be replaced by `!'.
Examples:
exec ... /bin/sh
exec /bin/sh
!/bin/sh
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.
exec !.. stty 19200
exec ! stty 19200
!!stty 19200
Set the speed of the window's tty. If your stty
command operates on stdout, then add another `!'.
exec !..| less
|less
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.
fit
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.
flow [ on | off | auto]
Sets the flow-control mode for this window. Without parameters it
cycles the current window's flow-control setting from "automatic"
to "on" to "off". See the discussion on FLOW-CONTROL later on in
this document for full details and note, that this is subject to
change in future releases. Default is set by `defflow'.
focus [ next | prev | up | down | left | right | top | bottom ]
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.
focusminsize [ ( width|max|_ ) ( height|max|_ ) ]
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.
gr [ on | off ]
Turn GR charset switching on/off. Whenever screen sees an input
character with the 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.
group [grouptitle]
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.
hardcopy [-h] [file]
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. See below. If the option -h
is specified, dump also the contents of the scrollback buffer.
hardcopy_append [ on | off ]
If set to "on", screen will append to the "hardcopy.n" files
created by the command C-a h, otherwise these files are
overwritten each time. Default is `off'.
hardcopydir directory
Defines a directory where hardcopy files will be placed. If unset,
hardcopys are dumped in screen's current working directory.
hardstatus [ on | off ]
hardstatus [ always ] firstline | lastline | message | ignore [
string ]
hardstatus string [ string ]
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). When 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.
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;<string>^G or ESC_<string>ESC\)
is displayed. You can customize this to any string you like
including the escapes from the STRING ESCAPES chapter. 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.
height [-w|-d] [lines [cols]]
Set the display height to a specified number of lines. When no
argument is given it toggles between 24 and 42 lines display. You
can also specify a width 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.
help[class]
Not really a online help, but displays a help screen showing you
all the key bindings. The first pages list all the internal
commands followed by their current 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
also DEFAULT KEY BINDINGS section.
history
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 allows you to have a primitive
way of re-calling 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).
hstatus status
Change the window's hardstatus line to the string status.
idle [timeout[cmd-args]]
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 (or the special timeout off) disables the timer.
If no arguments are given, the current settings are displayed.
ignorecase [ on | off ]
Tell screen to ignore the case of characters in searches. Default
is `off'. Without any options, the state of ignorecase is toggled.
info
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 also
section 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' or
`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 is shown. 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 also chapter 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 the time command.
ins_reg [key]
No longer exists, use paste instead.
kill
Kill current window.
If there is an `exec' command running then it is killed. Otherwise
the process (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.
Note: Emacs users should keep this command in mind, when killing a
line. It is recommended not to use C-a as the screen escape key
or to rebind kill to C-a K.
lastmsg
Redisplay the last contents of the message/status line. Useful if
you're typing when a message appears, because the message goes
away when you press a key (unless your terminal has a hardware
status line). Refer to the commands msgwait and msgminwait for
fine tuning.
layout new [title]
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.
layout remove [n|title]
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.
layout next
Switch to the next layout available
layout prev
Switch to the previous layout available
layout select [n|title]
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.
layout show
List on the message line the number(s) and title(s) of the
available layout(s). The current layout is flagged.
layout title [title]
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.
layout number [n]
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.
layout attach [title|:last]
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.
layout save [n|title]
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 situation.
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.
layout autosave [ on | off]
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 off, the current status is displayed on
the message line.
layout dump [filename]
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:
C-a : layout dump /home/user/.screenrc
will save or append the layout to the user's .screenrc file.
license
Display the disclaimer page. This is done whenever screen is
started without options, which should be often enough. See also
the startup_message command.
lockscreen
Lock this display. Call a screenlock program. 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 you 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'.
log [ on | off ]
Start/stop writing output of the current window to a 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 state of
logging 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'.
logfile filename
logfile flush secs
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.
login [ on | off ]
Adds or removes the entry in the utmp database file for the
current window. This controls if the window is `logged in'. When
no parameter is given, the login state of the window is toggled.
Additionally to that toggle, it is convenient having a `log in'
and a `log out' key. E.g. `bind I login on' and `bind O login off'
will map these keys to be C-a I and C-a O. The default setting
(in config.h.in) should be on for a screen that runs under suid-
root. Use the deflogin command to change the default login state
for new windows. Both commands are only present when screen has
been compiled with utmp support.
logtstamp [on|off]
logtstamp after [secs]
logtstamp string
[string]
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).
mapdefault
Tell screen that the next input character should only be looked up
in the default bindkey table. See also bindkey.
mapnotnext
Like mapdefault, but don't even look in the default bindkey table.
maptimeout [timeout]
Set the inter-character timer for input sequence detection to a
timeout of timeout ms. The default timeout is 300ms. Maptimeout
with no arguments shows the current setting. See also bindkey.
markkeys string
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 string B=^B:F=^F will change the
keys `C-b' and `C-f' to the vi style binding (scroll up/down fill
page). This happens to be the default binding for `B' and `F'.
The command markkeys h=^B:l=^F:$=^E would set the mode for an
emacs-style binding. 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.
meta
Insert the command character (C-a) in the current window's input
stream.
monitor [ on | off ]
Toggles activity monitoring of windows. When monitoring is turned
on and an affected window is switched into the background, you
will receive the activity notification message in the status line
at the first sign of output and the window will also be marked
with an `@' in the window-status display. Monitoring is initially
off for all windows.
mousetrack [ on | off ]
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.
msgminwait sec
Defines the time screen delays a new message when one message is
currently displayed. The default is 1 second.
msgwait sec
Defines the time a message is displayed if screen is not disturbed
by other activity. The default is 5 seconds.
multiuser [ on | off ]
Switch between singleuser and multiuser mode. Standard screen
operation is singleuser. In multiuser mode the commands `acladd',
`aclchg', `aclgrp' and `acldel' can be used to enable (and
disable) other users accessing this screen session.
next
Switch to the next window. This command can be used repeatedly to
cycle through the list of windows.
nonblock [ on | off | numsecs ]
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.
number [[+|-]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 `+' or `-' will change the window's
number by the relative amount specified.
obuflimit [limit]
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.
only
Kill all regions but the current one.
other
Switch to the window displayed previously. If this window does no
longer exist, other has the same effect as next.
partial [ on | off ]
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.
password [crypted_pw]
Present a crypted password in your .screenrc file and screen will
ask for it, whenever someone attempts to resume a detached. This
is useful if you have privileged programs running under screen and
you want to protect your session from reattach attempts by another
user masquerading as your uid (i.e. any superuser.) If no crypted
password is specified, screen prompts twice for typing a password
and places its encryption in the paste buffer. Default is `none',
this disables password checking.
paste [registers [dest_reg]]
Write the (concatenated) contents of the specified registers to
the stdin queue of the current window. The register '.' is treated
as the paste buffer. If no parameter is given the user is prompted
for a single register to paste. 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
displays paste buffer is the destination. Note, that paste uses a
wide variety of resources: 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.
pastefont [ on | off ]
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.
pow_break
Reopen the window's terminal line and send a break condition. See
`break'.
pow_detach
Power detach. Mainly the same as detach, but also sends a HANGUP
signal to the parent process of screen. CAUTION: This will result
in a logout, when screen was started from your login-shell.
pow_detach_msg [message]
The message specified here is output whenever a `Power detach' was
performed. It may be used as a replacement for a logout message or
to reset baud rate, etc. Without parameter, the current message
is shown.
prev
Switch to the window with the next lower number. This command can
be used repeatedly to cycle through the list of windows.
printcmd [cmd]
If cmd is not an empty string, screen will not use the terminal
capabilities po/pf 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 printcmd without a command displays the current
setting. The ansi sequence ESC [ 4 i 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.
process [key]
Stuff the contents of the specified register into screen's 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.
quit
Kill all windows and terminate screen. Note that on VT100-style
terminals the keys C-4 and C-\ are identical. This makes the
default bindings dangerous: Be careful not to type C-a C-4 when
selecting window no. 4. Use the empty bind command (as in bind
'^\') to remove a key binding.
readbuf [encoding] [filename]
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.
See also bufferfile command.
readreg [encoding] [register [filename]]
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
redisplay
Redisplay the current window. Needed to get a full redisplay when
in partial redraw mode.
register [-eencoding]key-string
Save the specified string to the register key. The encoding of
the string can be specified via the -e option. See also the paste
command.
remove
Kill the current region. This is a no-op if there is only one
region.
removebuf
Unlinks the screen-exchange file used by the commands writebuf and
readbuf.
rendition [ bell | monitor | silence | so ] attr [ color ]
Change the way screen renders the titles of windows that have
monitor or bell flags set in caption or hardstatus or windowlist.
See the STRING ESCAPES chapter 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 =u for
silence.
reset
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.
resize [-h|-v|-b|-l|-p] [[+|-] n[%] |=|max|min|_|0]
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 minimum size a region
can have.
screen [-opts] [n] [cmd [args]|//group]
Establish a new window. The flow-control options (-f, -fn and
-fa), title (a.k.a.) 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.
Thus, if your .screenrc contains the lines
# example for .screenrc:
screen 1
screen -fn -t foobar -L 2 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. Note, that unlike previous
versions of screen no additional default window is created when
screen commands are included in your .screenrc file. When the
initialization is completed, screen switches to the last window
specified in your .screenrc file or, if none, opens a default
window #0.
Screen has built in some functionality of cu and telnet. See also
chapter WINDOW TYPES.
scrollback num
Set the size of the scrollback buffer for the current windows to
num lines. The default scrollback is 100 lines. See also the
defscrollback command and use info to view the current setting. To
access and use the contents in the scrollback buffer, use the copy
command.
select [WindowID]
Switch to the window identified by WindowID. This can be a prefix
of a window title (alphanumeric window name) or a window number.
The parameter is optional and if omitted, you get prompted for an
identifier. When a new window is established, the first available
number is assigned to this window. Thus, the first window can be
activated by select 0. The number of windows is set by the MAXWIN
configuration parameter (which defaults to 100). There are two
special WindowIDs, - selects the internal blank window and .
selects the current window. The latter is useful if used with
screen's -X option.
sessionname [name]
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 variables 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.
setenv [var [string]]
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.
setsid [ on | off ]
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.
shell command
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 ~/.bash_profile unless it is
a login-shell.
shelltitle title
Set the title for all shells created during startup or by the C-A
C-c command. For details about what a title is, see the
discussion entitled TITLES (naming windows).
silence [ on | off | sec ]
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.
silencewait sec
Define the time that all windows monitored for silence should wait
before displaying a message. Default 30 seconds.
sleep num
This command will pause the execution of a .screenrc file for num
seconds. Keyboard activity will end the sleep. It may be used to
give users a chance to read the messages output by echo.
slowpaste msec
Define the speed at which text is inserted into the current window
by the paste ("C-a ]") command. If the slowpaste value is nonzero
text is written character by character. screen will make a pause
of msec milliseconds after each single character write to allow
the application to process its input. Only use slowpaste if your
underlying system exposes flow control problems while pasting
large amounts of text.
sort
Sort the windows in alphabetical order of the window tiles.
source file
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.
sorendition [attr[color]]
This command is deprecated. See "rendition so" instead.
split[-v]
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.
startup_message [ on | off ]
Select whether you want to see the copyright notice during
startup. Default is `on', as you probably noticed.
status [ top | up | down | bottom ] [ left | right ]
The status window by default is in bottom-left corner. This
command can move status messages to any corner of the screen. top
is the same as up, down is the same as bottom.
stuff [string]
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 also bindkey.
su [username [password [password2]]]
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.
suspend
Suspend screen. The windows are in the `detached' state, while
screen is suspended. This feature relies on the shell being able
to do job control.
term term
In each window's environment screen opens, the $TERM variable is
set to screen by default. But when no description for screen is
installed in the local termcap or terminfo data base, you set
$TERM to - say - 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.
termcap term terminal-tweaks[window-tweaks]
terminfo term terminal-tweaks[window-tweaks]
termcapinfo term terminal-tweaks[window-tweaks]
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 termcap
names of the capabilities have to 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 the
VIRTUAL TERMINAL section).
Some examples:
termcap xterm* LP: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 (LP), but they don't really have a status line (no 'hs' -
append `@' to turn entries off). Note that we assume `LP' for all
terminal names that start with vt, but only if you don't specify a
termcap command for that terminal.
termcap vt* LP
termcap vt102|vt220 Z0=\E[?3h:Z1=\E[?3l
Specifies the firm-margined `LP' 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 the discussion on the VIRTUAL TERMINAL in this
manual, and the termcap(5) man page for more information on
termcap definitions.
title [windowtitle]
Set the name of the current window to windowtitle. If no name is
specified, screen prompts for one. This command was known as `aka'
in previous releases.
truecolor [on|off]
Enables truecolor support. Currently autodetection of truecolor
support cannot be done reliably, as such it's left to user to
enable. Default is off. Known terminals that may support it are:
iTerm2, Konsole, st. Xterm includes support for truecolor escapes
but converts them back to indexed 256 color space.
unbindall
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'.
unsetenv var
Unset an environment variable.
utf8 [ on | off [ on | off ]]
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.
vbell [ on | off ]
Sets the visual bell setting for this window. Omitting the
parameter toggles the setting. If vbell is switched on, but your
terminal does not support a visual bell, a `vbell-message' is
displayed in the status line when the bell character (^G) is
received. Visual bell support of a terminal is defined by the
termcap variable `vb' (terminfo: 'flash').
Per default, vbell is off, thus the audible bell is used. See
also `bell_msg'.
vbell_msg [message]
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, but the terminal does not support a visual bell. The default
message is Wuff, Wuff!!. Without a parameter, the current message
is shown.
vbellwait sec
Define a delay in seconds after each display of screen's visual
bell message. The default is 1 second.
verbose [ on | off ]
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.
version
Print the current version and the compile date in the status line.
wall message
Write a message to all displays. The message will appear in the
terminal's status line.
width [-w|-d] [cols [lines]]
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 for more information. You can also specify a new 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.
windowlist [ -b ] [ -m ] [ -g ]
windowlist string [string]
windowlist title [title]
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 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.
windows [ string ]
Uses the message line to display a list of all the windows. Each
window is listed by number with the name of process that has been
started 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 `$'; 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 `@'; a window which has output logging turned on is
marked with `(L)'; windows occupied by other users are marked with
`&'; 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. The optional
string parameter follows the STRING ESCAPES format. If string
parameter is passed, the output size is unlimited. The default
command without any parameter is limited to a size of 1024 bytes.
wrap [ on | off ]
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.
writebuf [-e encoding] [filename]
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. The
filename can be set with the bufferfile command and defaults to
/tmp/screen-exchange.
writelock [ on | off | auto]
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.
xoff
xon
Insert a CTRL-s / CTRL-q character to the stdin queue of the
current window.
zmodem [ off | auto | catch | pass ]
zmodem sendcmd [string]
zmodem recvcmd [string]
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.
zombie [keys[onerror]]
Per default screen 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 such a
window. Pressing the first key in the dead window has the same
effect. When pressing the second key, 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 their process exits.
As the zombie-setting is manipulated 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.
zombie_timeout[seconds]
Per default screen windows are removed from the window list as
soon as the windows process (e.g. shell) exits. If zombie keys are
defined (compare with above zombie command), it is possible to
also set a timeout when screen tries to automatically reconnect a
dead screen window.
Screen displays informational messages and other diagnostics in a
message line. While this line is distributed to appear at the
bottom of the screen, it can be defined to appear at the top of
the screen during compilation. If your terminal has a status line
defined in its termcap, screen will use this for displaying its
messages, otherwise a line of the current 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.
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 '<esc>^Hello world from window '$WINDOW'<esc>\\'
where '<esc>' is an escape, '^' is a literal up-arrow, and '\\'
turns into a single backslash.
Screen provides three different window types. New windows are
created with screen's screen command (see also the entry in
chapter CUSTOMIZATION). 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
multiplexer with 100 or more windows.
• The normal window contains a shell (default, if no parameter is
given) or any other system command that could be executed from
a shell (e.g. slogin, etc...)
• If a tty (character special device) name (e.g. /dev/ttya) is
specified as the first parameter, then the window is directly
connected to this device. This window type is similar to
screen cu -l /dev/ttya. Read and write access is required on
the device node, an exclusive open is attempted on the node to
mark the connection line as busy. An optional parameter is
allowed consisting of a comma separated list of flags in the
notation used by stty(1):
<baud_rate>
Usually 300, 1200, 9600 or 19200. This affects
transmission as well as receive speed.
cs8 or cs7
Specify the transmission of eight (or seven) bits per
byte.
cstopb or -cstopb
Specify two stop bits per character (one with '-')
parenb or -parenb
Generate parity bit in output and expect parity bit in
input
parodd or -parodd
Set odd parity (or even parity with '-')
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', `DSR', `CD' and more. This depends on the
available ioctl()'s and system header files as well as the on
the physical capabilities of the serial board. Signals that
are logical low (inactive) have their name preceded by an
exclamation mark (!), otherwise the signal is logical high
(active). Signals not supported by the hardware but available
to the ioctl() interface 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 set, the signals `CTS' or `CD'
are shown in parenthesis, respectively.
For tty windows, the command break causes the Data transmission
line (TxD) to go low for a specified period of time. This is
expected to be interpreted as break signal on the other side.
No data is sent and no modem control line is changed when a
break is issued.
• If the first parameter is //telnet, the second parameter is
expected to be a host name, and an optional third parameter may
specify a TCP port number (default decimal 23). Screen will
connect to a server listening on the remote host and use the
telnet protocol to communicate with that server.
For telnet windows, the command info shows details about the
connection in square brackets ([ and ]) at the end of the status
line.
b BINARY. The connection is in binary mode.
e ECHO. Local echo is disabled.
c SGA. The connection is in `character mode' (default:
`line mode').
t TTYPE. The terminal type has been requested by the
remote host. Screen sends the name screen unless
instructed otherwise (see also the command `term').
w NAWS. The remote site is notified about window size
changes.
f LFLOW. The remote host will send flow control
information. (Ignored at the moment.)
Additional flags for debugging are x, t and n (XDISPLOC,
TSPEED and NEWENV).
For telnet windows, the command break sends the telnet code
IAC BREAK (decimal 243) to the remote host.
This window type is only available if screen was compiled
with the ENABLE_TELNET option defined.
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 AM or PM. 'AM' stands for the Latin 'ante meridiem',
translating to "before midday". This is the time before
noon. 'PM' stands for post meridiem or 'after midday' – the
time after noon.
a the same as 'A', but written in small letters: 'am' or
'pm'.
C 12 hours time format like 1:48
c the same like 'C', but uses 24 hours time format (for
example, 13:48)
D day of the week (for example, Mon, Wed, Fri)
d day of the month (number).
E sets %? to true if the escape character has been pressed.
e encoding
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 The count of screen windows. Prefix with '-' to limit to
current window group.
M name of the month (for example, Aug, Dec)
m month of the year (number)
n window number
P sets %? to true if the current region is in copy/paste mode
S session name
s window size
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
x the executed command including arguments running in this
windows
X the executed command without arguments running in this
windows
Y year (four numbers like '2024')
y last two digits of the year (for example, '24')
? 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.
The 'c' and 'C' escape may be qualified with a '0' to make screen
use zero instead of space as fill character. The '0' qualifier
also makes the '=' escape use absolute positions. 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:
i2 set color to bright green
+b r use bold red
#F00;FFA
write in bright red color on a pale yellow background.
%-Lw%{#AAA;#006}%50>%n%f* %t%{-}%+Lw%<
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.
%?%F%{;2}%?%3n %t%? [%h]%?
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.
Each 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 .screenrc command. Per 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 find out 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 it is possible to interrupt
the output of the virtual terminal to your physical terminal when
flow-control is enabled. If this happens, 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.
You can customize each window's name in the window display (viewed
with the windows command (C-a w)) 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 in the .screenrc file, while all other windows
are created with a screen command and thus can have their name set
with the -t option. Interactively, there is the title-string
escape-sequence (<esc>kname<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 pre-defined names to
keys with the title command to set things quickly without
prompting. Changing title by this escape sequence can be
controlled by defdynamictitle and dynamictitle commands.
Finally, 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 window's
shell 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 either '!', '%', 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 better command
names when using job control or history recall commands.
Here's some .screenrc examples:
screen -t top 2 nice top
Adding this line to your .screenrc would start a nice-d version of
the top command in window 2 named top rather than nice.
shelltitle '> |csh'
screen 1
These commands would start a shell with 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-title's current setting (C-a E). The third binding
would set the current window's title to (unknown) (C-a u).
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='^[[0000m^[k^[\% '
The escape-sequence <esc>[0000m not only normalizes the character
attributes, but all the zeros round the length of the invisible
characters up to 8. 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 bash v1.04).
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.
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. Notice that, however, on machines using the
terminfo database this variable has no effect. 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 .screenrc command, or by defining the variable
$SCREENCAP prior to startup. When the latter is 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 .screenrc command if the
system uses the terminfo database rather than termcap.
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 `PRIN' while the printer is active.
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. If the display has no hardstatus the
line will be displayed as a standard screen message. 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.
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.
The "alternate screen" capability is not enabled by default. Set
the altscreen .screenrc command to enable it.
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
Pn = 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 A.k.a. 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
Pn = 1 From Beginning of Screen to Cursor
Pn = 2 Entire Screen
ESC [ Pn K
Erase in Line
Pn = None or 0
From Cursor to End of Line
Pn = 1 From Beginning of Line to Cursor
Pn = 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
Ps = 1 Bold
Ps = 2 (A)
Faint
Ps = 3 (A)
Standout Mode (ANSI: Italicized)
Ps = 4 Underlined
Ps = 5 Blinking
Ps = 7 Negative Image
Ps = 22 (A)
Normal Intensity
Ps = 23 (A)
Standout Mode off (ANSI: Italicized off)
Ps = 24 (A)
Not Underlined
Ps = 25 (A)
Not Blinking
Ps = 27 (A)
Positive Image
Ps = 30 (A)
Foreground Black
Ps = 31 (A)
Foreground Red
Ps = 32 (A)
Foreground Green
Ps = 33 (A)
Foreground Yellow
Ps = 34 (A)
Foreground Blue
Ps = 35 (A)
Foreground Magenta
Ps = 36 (A)
Foreground Cyan
Ps = 37 (A)
Foreground White
Ps = 39 (A)
Foreground Default
Ps = 40 (A)
Background Black
Ps = ...
Ps = 49 (A)
Background Default
ESC [ Pn g
Tab Clear
Pn = None or 0
Clear Tab at Current Position
Pn = 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
Ps = 20 (A)
Automatic Linefeed Mode
Ps = 34
Normal Cursor Visibility
Ps = ?1 (V)
Application Cursor Keys
Ps = ?3 (V)
Change Terminal Width to 132 columns
Ps = ?5 (V)
Reverse Video
Ps = ?6 (V)
Origin Mode
Ps = ?7 (V)
Wrap Mode
Ps = ?9
X10 mouse tracking
Ps = ?25 (V)
Visible Cursor
Ps = ?47
Alternate Screen (old xterm code)
Ps = ?1000 (V)
VT200 mouse tracking
Ps = ?1047
Alternate Screen (new xterm code)
Ps = ?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
Send Terminal Parameter Report
ESC [ > c
Send VT220 Secondary Device Attributes String
ESC [ 6 n
Send Cursor Position Report
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 in the command table). 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 the bindkey command for further details
on the syntax and examples.
Here is the table of the default key bindings. The fourth is what
command is executed if the keyboard is switched into application
mode.
┌─────────────────┬──────────────┬──────────┬──────────┐
│ Key name │ Termcap name │ Command │ App mode │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Cursor up │ ku │ \033[A │ \033OA │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Cursor down │ kd │ \033[B │ \033OB │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Cursor right │ kr │ \033[C │ \033OC │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Cursor left │ kl │ \033[D │ \033OD │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 0 │ k0 │ \033[10~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 1 │ k1 │ \033OP │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 2 │ k2 │ \033OQ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 3 │ k3 │ \033OR │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 4 │ k4 │ \033OS │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 5 │ k5 │ \033[15~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 6 │ k6 │ \033[17~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 7 │ k7 │ \033[18~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 8 │ k8 │ \033[19~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 9 │ k9 │ \033[20~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 10 │ k; │ \033[21~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 11 │ F1 │ \033[23~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Function key 12 │ F2 │ \033[24~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Home │ kh │ \033[1~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ End │ kH │ \033[4~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Insert │ kI │ \033[2~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Delete │ kD │ \033[3~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Page up │ kP │ \033[5~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Page down │ kN │ \033[6~ │ │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 0 │ f0 │ 0 │ \033Op │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 1 │ f1 │ 1 │ \033Oq │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 2 │ f2 │ 2 │ \033Or │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 3 │ f3 │ 3 │ \033Os │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 4 │ f4 │ 4 │ \033Ot │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 5 │ f5 │ 5 │ \033Ou │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 6 │ f6 │ 6 │ \033Ov │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 7 │ f7 │ 7 │ \033Ow │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 8 │ f8 │ 8 │ \033Ox │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad 9 │ f9 │ 9 │ \033Oy │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad + │ f+ │ + │ \033Ok │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad - │ f- │ - │ \033Om │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad * │ f* │ * │ \033Oj │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad / │ f/ │ / │ \033Oo │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad = │ fq │ = │ \033OX │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad . │ f. │ . │ \033On │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad , │ f, │ , │ \033Ol │
├─────────────────┼──────────────┼──────────┼──────────┤
│ Keypad enter │ fe │ \015 │ \033OM │
└─────────────────┴──────────────┴──────────┴──────────┘
The following table describes all terminal capabilities that are
recognized by screen and are not in the termcap(5) manual. 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.
LP (bool)
Terminal has VT100 style margins (`magic margins'). Note
that this capability is obsolete because screen uses the
standard 'xn' instead.
Z0 (str)
Change width to 132 columns.
Z1 (str)
Change width to 80 columns.
WS (str)
Resize display. This capability has the desired width and
height as arguments. SunView(tm) example: '\E[8;%d;%dt'.
NF (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'.
G0 (bool)
Terminal can deal with ISO 2022 font selection sequences.
S0 (str)
Switch charset 'G0' to the specified charset. Default is
'\E(%.'.
E0 (str)
Switch charset 'G0' back to standard charset. Default is
'\E(B'.
C0 (str)
Use the string as a conversion table for font '0'. See the
'ac' capability for more details.
CS (str)
Switch cursor-keys to application mode.
CE (str)
Switch cursor-keys back to normal mode.
AN (bool)
Turn on autonuke. See the 'autonuke' command for more
details.
OL (num)
Set the output buffer limit. See the 'obuflimit' command
for more details.
KJ (str)
Set the encoding of the terminal. See the 'encoding'
command for valid encodings.
AF (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).
AB (str)
Same as 'AF', but change background color.
AX (bool)
Does understand ANSI set default fg/bg color (\E[39m /
\E[49m).
XC (str)
Describe a translation of characters to strings depending
on the current font. More details follow in the next
section.
XT (bool)
Terminal understands special xterm sequences (OSC, mouse
tracking).
C8 (bool)
Terminal needs bold to display high-intensity colors (e.g.
Eterm).
TF (bool)
Add missing capabilities to the termcap/info entry. (Set by
default).
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'.
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.
SYSSCREENRC Alternate system screenrc file.
TERM Terminal name.
TERMCAP Terminal description.
WINDOW Window number of a window (at creation time).
.../screen-5.0.0/etc/screenrc
.../screen-5.0.0/etc/etcscreenrc Examples in the screen
distribution package for private
and global initialization files.
$SYSSCREENRC
/usr/local/etc/screenrc screen initialization commands
$SCREENRC
$HOME/.screenrc Read in after
/usr/local/etc/screenrc
$SCREENDIR/S-<login>
$HOME/.screen Socket directories (default)
/usr/tmp/screens/S-<login> Alternate socket directories.
<socket directory>/.termcap Written by the "termcap" output
function
/usr/tmp/screens/screen-exchange or
/tmp/screen-exchange screen `interprocess
communication buffer'
hardcopy.[0-9] Screen images created by the
hardcopy function
screenlog.[0-9] Output log files created by the
log function
/usr/lib/terminfo/?/* or
/etc/termcap Terminal capability databases
/etc/utmp Login records
$LOCKPRG Program that locks a terminal.
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 <[email protected]> and Alexander Naumov
<[email protected]>.
Copyright (c) 2018-2024
Alexander Naumov <[email protected]>
Amadeusz Slawinski <[email protected]>
Copyright (c) 2015-2017
Juergen Weigert <[email protected]>
Alexander Naumov <[email protected]>
Amadeusz Slawinski <[email protected]>
Copyright (c) 2010-2015
Juergen Weigert <[email protected]>
Sadrul Habib Chowdhury <[email protected]>
Copyright (c) 2008, 2009
Juergen Weigert <[email protected]>
Michael Schroeder <[email protected]>
Micah Cowan <[email protected]>
Sadrul Habib Chowdhury <[email protected]>
Copyright (C) 1993-2003
Juergen Weigert <[email protected]>
Michael Schroeder <[email protected]>
Copyright (C) 1987 Oliver Laumann
Elizaveta Sytsevich <[email protected]>,
Julian Kolesnikov <[email protected]>,
Vincent Lefevre <[email protected]>,
Carl Drougge <[email protected]>,
Maarten ter Huurne <[email protected]>,
Jussi Kukkonen <[email protected]>,
Eric S. Raymond <[email protected]>,
Thomas Renninger <[email protected]>,
Axel Beckert <[email protected]>,
Ken Beal <[email protected]>,
Rudolf Koenig <[email protected]>,
Toerless Eckert <[email protected]>,
Wayne Davison <[email protected]>,
Patrick Wolfe <[email protected], kailand!pat>,
Bart Schaefer <[email protected]>,
Nathan Glasser <[email protected]>,
Larry W. Virden <[email protected]>,
Howard Chu <[email protected]>,
Tim MacKenzie <[email protected]>,
Markku Jarvinen <mta@{cc,cs,ee}.tut.fi>,
Marc Boucher <[email protected]>,
Doug Siebert <[email protected]>,
Ken Stillson <[email protected]>,
Ian Frechett <[email protected]>,
Brian Koehmstedt <[email protected]>,
Don Smith <[email protected]>,
Frank van der Linden <[email protected]>,
Martin Schweikert <[email protected]>,
David Vrona <[email protected]>,
E. Tye McQueen <tye%[email protected]>,
Matthew Green <[email protected]>,
Christopher Williams <[email protected]>,
Matt Mosley <[email protected]>,
Gregory Neil Shapiro <[email protected]>,
Johannes Zellner <[email protected]>,
Pablo Averbuj <[email protected]>.
The latest official release of screen available via anonymous ftp
from ftp.gnu.org/gnu/screen/ or any other GNU distribution site.
The home page of screen is
https://savannah.gnu.org/projects/screen/ and the git repo is
https://git.savannah.gnu.org/cgit/screen.git. If you want to
help, send a note to [email protected].
• `dm' (delete mode) and `xs' are not handled correctly (they are
ignored). `xn' is treated as a magic-margin indicator.
• Screen has no clue about double-high or double-wide characters.
But this is the only area where vttest is allowed to fail.
• It is not possible to change the environment variable $TERMCAP
when reattaching under a different terminal type.
• The support of terminfo based systems is very limited. Adding
extra capabilities to $TERMCAP may not have any effects.
• Screen does not make use of hardware tabs.
• Screen must be installed as set-uid with owner 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.
• Entries in /etc/utmp are not removed when 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.
• When the modem line was hung up, screen may not automatically
detach (or quit) unless the device driver is configured to send
a HANGUP signal. To detach a screen session use the -D or -d
command line option.
• Both 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.
• When attaching to a multiuser session, the user's .screenrc
file is not sourced. Each user's personal settings have to be
included in the .screenrc file from which the session is
booted, or have to be changed manually.
• A weird imagination is most useful to gain full advantage of
all the features.
termcap(5), utmp(5), vi(1), captoinfo(1), tic(1), tty(4), pty(7)
This page is part of the screen (screen manager) project.
Information about the project can be found at
⟨http://www.gnu.org/software/screen/⟩. If you have a bug report
for this manual page, see
⟨https://savannah.gnu.org/bugs/?func=additem&group=screen⟩. This
page was obtained from the project's upstream Git repository
⟨https://git.savannah.gnu.org/git/screen.git⟩ on 2025-08-11. (At
that time, the date of the most recent commit that was found in
the repository was 2024-08-28.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
GNU Screen 5.0.0 Aug 2024 SCREEN(1)
Pages that refer to this page: curs_termcap(3x), logind.conf(5), tmpfiles.d(5), user_caps(5), pty(7)
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