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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.
-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 t, (time) Show system
C-a C-t information.
────────────────────────────────────────────────────────
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.
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.
maxwin num
Set the maximum window number screen will create. Doesn't affect
already existing windows. The number can be increased only when
there are no existing windows.
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.
nethack [ on | off ]
Changes the kind of error messages used by screen. When you are
familiar with the game nethack, you may enjoy the nethack-style
messages which will often blur the facts a little, but are much
funnier to read. Anyway, standard messages often tend to be
unclear as well.
This option is only available if screen was compiled with the
NETHACK flag defined. The default setting is then determined by
the presence of the environment variable $NETHACKOPTIONS and the
file ~/.nethackrc - if either one is present, the default is on.
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), but it can be changed by using `maxwin' command. 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
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
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
? 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.
NETHACKOPTIONS Turns on nethack option.
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-4.?.??/etc/screenrc
.../screen-4.?.??/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>
/local/screens/S-<login> 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
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program (see the file COPYING); if not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA
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.
• If a password is set, the command line options -d and -D still
detach a session without asking.
• 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.
• Send bug-reports, fixes, enhancements, t-shirts, money, beer &
pizza to [email protected].
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 2024-06-14. (At
that time, the date of the most recent commit that was found in
the repository was 2024-06-11.) 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 2024 MMM DDD 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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