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!!!SCREEN

----
!!NAME


screen - screen manager with VT100/ANSI terminal emulation
!!SYNOPSIS


 __screen__ [[ __-__''options'' ] [[ ''cmd'' [[''args'' ] ]
 __screen -r__ [[[[''pid''.]''tty''[[__.__''host'']]
 __screen -r__ ''sessionowner''/[[[[''pid''.]''tty''[[.''host'']]

!!DESCRIPTION

''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.


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. Please use the caret notation ("^A" instead of
"C-a") as arguments to e.g. the "escape" command or
the "-e" option. ''Screen'' will also print out
control characters in caret notation.


The standard way to create a new window is to type "C-a
c". This creates a new window running a shell and switches
to that window immediately, regardless of the state of the
process running in the current window. Similarly, you can
create a new window with a custom command in it by first
binding the command to a keystroke (in your .screenrc file
or at the "C-a :" command line) and then using it just
like the "C-a c" command. In addition, new windows can be
created by running a command like:

;:screen emacs prog.c


from a shell prompt within a previously created window. This
will not run another copy of ''screen'', but will instead
supply the command name and its arguments to the window
manager (specified in the $STY environment variable) who
will use it to create the new window. The above example
would start the emacs editor (editing prog.c) and switch to
its window.


If "/var/run/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".
!!GETTING STARTED


Before you begin to use ''screen'' you'll need to make
sure you have correctly selected your terminal type, just as
you would for any other termcap/terminfo program. (You can
do this by using ''tset'' 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 to use 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.


!!COMMAND-LINE OPTIONS


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 /var/run/utmp updating). This can also be defined through the ``deflogin'' .screenrc command.

;__-ls__ and __-list__: 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'' your auto-margin terminal has a writable last-position on the screen. This can also be set in your .screenrc by specifying `LP' in a ``termcap'' command.

;__-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 a more optimal output mode for your terminal rather than true VT100 emulation (only affects auto-margin terminals without `LP'). This can also be set in your .screenrc by specifying `OP' in a "termcap" command.

;__-q__: Suppress printing of error messages. In combination with ``-ls'' the exit value is as follows: 9 indicates a directory without sessions. 10 indicates a directory with running but not attachable sessions. 11 (or more) indicates 1 (or more) usable sessions. In combination with ``-r'' the exit value is as follows: 10 indicates that there is no session to resume. 12 (or more) indicates that there are 2 (or more) sessions to resume and you should specify which one to choose. In all other cases "-q" has no effect.

;__-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__: 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__: 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.

;__-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.

;__-t__ ''name'': sets the title (a.k.a.) for the default shell or specified program. See also the "shelltitle" .screenrc command.

;__-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).

;__-X__: Send the specified command to a running screen session. You can use the __-d__ or __-r__ option to tell screen to look only for attached or detached screen sessions. Note that this command doesn't work if the session is password protected.

!!DEFAULT KEY BINDINGS


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:


__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 0__ (select 0)


__...__ ...


__C-a 9__ (select 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.


__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__


__C-a C-b__ (break)


Send a break to window.


__C-a B__ (pow_break)


Reopen the terminal line and send a break.


__C-a c__


__C-a C-c__ (screen)


Create a new window with a shell and switch to that
window.


__C-a C__ (clear)


Clear the screen.


__C-a d__


__C-a C-d__ (detach)


Detach ''screen'' from this terminal.


__C-a D D__ (pow_detach)


Detach and logout.


__C-a f__


__C-a C-f__ (flow) Toggle flow ''on'', ''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__


__C-a C-i__ (info) Show info about this
window.


__C-a k__


__C-a C-k__ (kill) Destroy current window.


__C-a l__


__C-a C-l__ (redisplay)


Fully refresh 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__


__C-a C-m__ (lastmsg)


Repeat the last message displayed in the message
line.


__C-a M__ (monitor)


Toggles monitoring of the current window.


__C-a space__


__C-a n__


__C-a C-n__ (next) Switch to the next
window.


__C-a N__ (number)


Show the number (and title) of the current
window.


__C-a backspace__


__C-a h__


__C-a p__


__C-a C-p__ (prev) Switch to the previous window
(opposite of __C-a n__).


__C-a q__


__C-a C-q__ (xon) Send a control-q to the current
window.


__C-a Q__ (only) Delete all regions but the current
one.


__C-a r__


__C-a C-r__ (wrap) Toggle the current window's line-wrap
setting (turn the current window's automatic margins on and
off).


__C-a s__


__C-a C-s__ (xoff) Send a control-s to the current
window.


__C-a S__ (split)


Split the current region into two new ones.


__C-a t__


__C-a C-t__ (time) Show system information.


__C-a v__ (version)


Display the version and compilation date.


__C-a C-v__ (digraph)


Enter digraph.


__C-a w__


__C-a C-w__ (windows)


Show a list of window.


__C-a W__ (width)


Toggle 80/132 columns.


__C-a x__


__C-a C-x__ (lockscreen)


Lock this terminal.


__C-a X__ (remove)


Kill the current region.


__C-a z__


__C-a C-z__ (suspend)


Suspend ''screen''. 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 C-\__ (quit) Kill all windows and terminate
''screen''.


__C-a :__ (colon)


Enter command line mode.


__C-a [[__


__C-a C-[[__


__C-a esc__ (copy) Enter copy/scrollback
mode.


__C-a ]__ (paste .)


Write the contents of the paste buffer to the stdin queue of
the current window.


__C-a {__


__C-a }__ (history)


Copy and paste 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 *__ (displays)


Show a listing of all currently attached
displays.
!!CUSTOMIZATION


The ``socket directory'' defaults either to $HOME/.screen or
simply to /tmp/screens or preferably to /var/run/screen
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 ``/etc/screenrc'' and ``.screenrc''
in the user's home directory. These are the ``programmer's
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
''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
''


__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
''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.


__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. ``stuff'',
``process'' or ``paste'') 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


Change the color to bright red if bold text is to be
printed.


attrcolor u


Use blue text instead of underline.


attrcolor b


Use bright colors for bold text. Most terminal emulators do
this already.


attrcolor i


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''.


__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


__bind__ [[__-c__ ''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
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


        bindkey -t foo stuff barfoo
Make


        bindkey
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.


__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
__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 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.


__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
''
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.


__clear__


Clears the current window and saves its image to the
scrollback buffer.


__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 weather 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:''
Movement keys'':


__h__, __j__, __k__, __l__ move the cursor line
by line or column by column.


__0__, __^__ and __$__ move to the leftmost column,
to the first or last non-whitespace character on the
line.


__H__, __M__ and __L__ move the cursor to the
leftmost column of the top, center or bottom line of the
window.


__+__ and __-__ positions one line up and
down.


__G__ moves to the specified absolute line (default: end
of buffer).


__|__ moves to the specified absolute
column.


__w__, __b__, __e__ move the cursor word by
word.


__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.


__g__ moves to the beginning of the buffer.


__%__ jumps to the specified percentage of the
buffer.


''Note'':


Emacs style movement keys can be customized by a .screenrc
command. (E.g. markkeys


''Marking'':


The copy range is specified by setting two marks. The text
between these marks will be highlighted. Press


__space__ to set the first or second mark
respectively.


__Y__ and __y__ used to mark one whole line or to mark
from start of line.


__W__ marks exactly one word.


''Repeat count'':


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.


''Searching'':


__/__ ''Vi''-like search forward. __?__
''Vi''-like search backward. __C-a s__ ''Emacs''
style incremental search forward. __C-r__ ''Emacs''
style reverse i-search.


''Specials'':


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__ 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__ exchanges the first mark and the current cursor
position. You can use this to adjust an already placed
mark.__
@__ 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.


__debug on__|__off__


Turns runtime debugging on or off. If ''screen'' has been
compiled with option -DDEBUG debugging available and is
turned on per default. Note that this command only affects
debugging output from the main ``SCREEN'' process correctly.
Debug output from attacher processes can only be turned off
once and forever.


__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 dependant, 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.


__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'.


__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__ 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 __


__defwritelock on__|__off__|__auto__


Same as the __writelock__ command except that the default
setting for new windows is changed. Initially writelocks
will off.


__defzombie__ [[''keys'']


Synonym to the __zombie__ command. Both currently change
the default. See there.


__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.


__digraph__ [[''preset'']


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
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
''


__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''.


__echo__ [[__-n__] ''message''


The echo command may be used to annoy ''screen'' users
with a 'message of the day'. Typically installed in a global
/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.


__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 seperate
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
''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
''


__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


__focus__
[[__up__|__down__|__top__|__bottom__]


Move the input focus to the next region. This is done in a
cyclic way so that the top region is selected after the
bottom one. If no subcommand is given it defaults to `down'.
`up' cycles in the opposite order, `top' and `bottom' go to
the top and bottom region respectively. Useful bindings are
(j and k as in vi)


    bind j focus down
bind k focus up
bind t focus top
bind b focus bottom
__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.


__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 screen'' will append to the
''


__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__]__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
''screen'' will
reserve the 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,
''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'', 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__ [[__-c__ ''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''.


__ignorecase__ [[__on__|__off__]


Tell screen to ignore the case of caracters in searches.
Default is `off'.


__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, insert mode, origin mode, application-keypad mode, 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.


__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,
KOI8-R, CP1251, UTF-8, ISO8859-2, ISO8859-3, ISO8859-4,
ISO8859-5, ISO8859-6, ISO8859-7, ISO8859-8, ISO8859-9,
ISO8859-10, ISO8859-15, jis.


See also ``defencoding'', which changes the default setting
of a new window.


__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.


__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 (/local/bin/lck
or /usr/bin/lock or a builtin if no other is available).
Screen does not accept any command keys until this program
terminates. Meanwhile processes in the windows may continue,
as the windows are in the `detached' state. The screenlock
program may be changed through the environment variable
$LOCKPRG (which must be set in the shell from which
''screen'' is started) and is executed with the user's
uid and gid.
Warning: When you leave other shells unlocked and 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 logfiles 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__ [[''timo'']


Set the inter-character timer for input sequence detection
to a timeout of ''timo'' ms. The default timeout is
300ms. Maptimeout with no arguments shows the current
setting. See also ``bindkey''.


__markkeys__ ''string''


This is a method of changing the keymap used for
copy/history mode. The string is made up of
''oldchar''=''newchar'' pairs which are separated by
`:'. Example: The string ``B=^B:F=^F'' will change the keys
`C-b' and `C-f' to the vi style binding (scroll up/down fill
page). This happens to be the default binding for `B' and
`F'. The command ``markkeys h=^B:l=^F:$=^E'' would set the
mode for an emacs-style binding. If your terminal sends
characters, that cause you to abort copy mode, then this
command may help by binding these characters to do nothing.
The no-op character is `@' and is used like this: ``markkeys
@=L=H'' if you do not want to use the `H' or `L' commands
any longer. As shown in this example, multiple keys can be
assigned to one function in a single statement.


__meta__


Insert the command character (C-a) in the current window's
input stream.


__monitor__ [[__on__|__off__]


Toggles activity monitoring of windows. When monitoring is
turned on and an affected window is switched into the
background, you will receive the activity notification
message in the status line at the first sign of output and
the window will also be marked with an `@' in the
window-status display. Monitoring is initially off for all
windows.


__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.


__next__


Switch to the next window. This command can be used
repeatedly to cycle through the list of
windows.


__nonblock__ [[__on__|__off__]


Enable or disable flow control for the current user
interface (display). It is used to prevent a slow display
from slowing down the processing of data output by a window.
This command may be helpful when multiple displays show the
same window. Nonblock is initially off for all
displays.


__number__ [[''n'']


Change the current windows 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.


__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 ``'cat ''printcmd__
without a command displays the current setting. The ansi
sequence __ESC \__ ends printing and closes the pipe.
Warning: Be careful with this command! If other user have
write access to your terminal, they will be able to fire off
print commands.


__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__ [[__-e__ ''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__ [[__-e__ ''encoding''] [[''register''
[[''filename'']]


Does one of two things, dependent on number of arguments:
with zero or one arguments it it duplicates the paste buffer
contents into the register specified or entered at the
prompt. With two arguments it reads the contents of the
named file into the register, just as ''readbuf'' reads
the screen-exchange file into the paste buffer. You can tell
screen the encoding of the file via the __-e__ option.
The following example will paste the system's password file
into the ''screen'' window (using register p, where a
copy remains):


            C-a : readreg p /etc/passwd
C-a : paste p
__redisplay__


Redisplay the current window. Needed to get a full redisplay
when in partial redraw mode.


__register__ [[__-e__ ''encoding''] ''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''.


__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__


Resize the current region. The space will be removed from or
added to the region below or if there's not enough space
from the region above.


resize +N increase current region height by N


resize -N decrease current region height by N


resize N set current region height to N


resize = make all windows equally high


resize max maximize current region height


resize min minimize current region height


__screen__ [[''-opts''] [[''n''] [[''cmd''
[[''args'']]


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__
__-a__) and scrollback option
(__-h__
__-M__) turns monitoring on for this window.
The option (__-L__) turns output logging on for this
window. If an optional number ''n'' in the range 0..9 is
given, the window number ''n'' is assigned to the newly
created window (or, if this number is already in-use, the
next available number). If a command is specified after
``screen'', this command (with the given arguments) is
started in the window; otherwise, a shell is created. 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 ``C-a
i'' to view the current setting.


__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 limited at compile-time by the
MAXWIN configuration parameter.


__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 still
reflects the old name. This may result in confusion. 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.


__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 (
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.


__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 already processes
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'']]


Change the way ''screen'' does highlighting for text
marking and printing messages. See the ``STRING ESCAPES''
chapter for the syntax of the modifiers. The default is
currently ``=s dd'' (standout, default colors).


__split__


Split the current region into two new ones. All regions on
the display are resized to make room for the new region. The
blank window is displayed on the new region.


__startup_message on__|__off__


Select whether you want to see the copyright notice during
startup. Default is `on', as you probably
noticed.


__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. 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 works 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


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.


__time__ [[''string'']


Uses the message line to display the time of day, the host
name, and the load averages over 1, 5, and 15 minutes (if
this is available on your system). For window specific
information use ``info''.


If a string is specified, it changes the format of the time
report like it is described in the ``STRING ESCAPES''
chapter. Screen uses a default of


__title__ [[''windowalias'']


Set the name of the current window to ''windowalias''. If
no name is specified, ''screen'' prompts for one. This
command was known as `aka' in previous
releases.


__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 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 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__] | __string__
[[''string''] | __title__ [[''title'']


Display all windows in a table for visual window selection.
The desired window can be selected via the standard movement
keys (see the ``copy'' command) and activated via the return
key. If the __-b__ option is given, screen will switch to
the blank window before presenting the list, so that the
current window is also selectable.


The 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).


__windows__


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
`


__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'.


__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.


__zombie__ [[''keys'']__
defzombie__ [[''keys'']


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 only be called
__defzombie__. Until we need this as a per window
setting, the commands __zombie__ and __defzombie__ are
synonymous.
!!THE MESSAGE LINE


''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 '


where 'escape'', '^' is a literal
up-arrow, and '\' turns into a single
backslash.
!!WINDOW TYPES


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):




Usually 300, 1200, 9600 or 19200. This affects transmission
as well as receive speed.


cs8 or cs7


Specify the transmission of eight (or seven) bits per
byte.


ixon or -ixon


Enables (or disables) software flow-control (CTRL-S/CTRL-Q)
for sending data.


ixoff or -ixon


Enables (or disables) software flow-control for receiving
data.


istrip or -istrip


Clear (or keep) the eight bit in each received
byte.


You may want to specify as many of these options as
applicable. Unspecified options cause the terminal driver to
make up the parameter values of the connection. These values
are system dependant and may be in defaults or values saved
from a previous connection.


For tty windows, the __info__ command shows some of the
modem control lines in the status line. These may include
`RTS', `CTS', 'DTR', `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 BUILTIN_TELNET option
defined.
!!STRING ESCAPES


Screen provides an escape mechanism to insert information
like the current time into messages or file names. The
escape character is '%' with one exception: inside of a
window's hardstatus '^%' ('^E') is used
instead.


Here is the full list of supported escapes:


%


the escape character itself


a


either 'am' or 'pm'


A


either 'AM' or 'PM'


c


current time HH:MM in 24h format


C


current time HH:MM in 12h format


d


day number


D


weekday name


f


flags of the window


F


sets %? to true if the window has the focus


h


hardstatus of the window


H


hostname of the system


l


current load of the system


m


month number


M


month name


n


window number


s


seconds


t


window title


u


all other users on this window


w


all window numbers and names. With '-' quailifier: up to the
current window; with '+' qualifier: starting with the window
after the current one.


W


all window numbers and names except the current
one


y


last two digits of the year number


Y


full year number


?


the part to the next '%?' is displayed only if an escape
expands to an nonempty 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
``}''


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 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 desciption. 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:


u


underline


b


bold


r


reverse


s


standout


B


blinking


Colors are coded either as a hexadecimal number or two
letters specifying the desired background and foreground
color (in that order). The following colors are
known:


k


black


r


red


g


green


y


yellow


b


blue


m


magenta


c


cyan


w


white


d


default color


.


leave color unchanged


The capitalized versions of the letter specify bright
colors. You can also use the pseudo-color 'i' to set just
the brightness and leave the color unchanged.
A one digit/letter color description is treated as
foreground or background color dependant on the current
attributes: if reverse mode is set, the background color is
changed instead of the foreground color. If you don't like
this, prefix the color with a ``.''. If you want the same
behaviour for two-letter color descriptions, also prefix
them with a ``.''.
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:


``G''


set color to bright green


``+b r''


use bold red


``= yd''


clear all attributes, write in default color on yellow
background.


%-Lw%{= BW}%50


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%{.R.}%?%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''.
!!FLOW-CONTROL


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
__


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.
!!TITLES (naming windows)


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
(__name''
''


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
(
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 '
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


(it looks after the '


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
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 ``


PROMPT_COMMAND='echo -n -e


(I used ``134'' to output a `' because of a bug in bash
v1.04).
!!THE VIRTUAL TERMINAL


Each window in a ''screen'' session emulates a VT100
terminal, with some extra functions added. The VT100
emulator is hard-coded, no other terminal types can be
emulated.
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.
''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.
''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 is latter defined, its value will be copied verbatim
into each window's $TERMCAP variable. This can either be the
full terminal definition, or a filename where the terminal
``screen'' (and/or ``screen-w'') is defined.


Note that ''screen'' honors the ``terminfo'' .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_
''


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 following is a list of control sequences recognized by
''screen''. ``(V)'' and ``(A)'' indicate VT100-specific
and ANSI- or ISO-specific functions,
respectively.


__ESC E__ Next Line


__ESC D__ Index


__ESC M__ Reverse Index


__ESC H__ Horizontal Tab Set


__ESC Z__ Send VT100 Identification String


__ESC 7__ (V)


Save Cursor and Attributes


__ESC 8__ (V)


Restore Cursor and Attributes


__ESC [[s__ (A)


Save Cursor and Attributes


__ESC [[u__ (A)


Restore Cursor and Attributes


__ESC c__ Reset to Initial State


__ESC g__ Visual Bell


__ESC__ Pn __p__ Cursor Visibility
(97801)


Pn = __6__ Invisible


__7__ Visible


__ESC =__ (V)


Application Keypad Mode


__ESC __ (V)


Numeric Keypad Mode


__ESC # 8__ (V)


Fill Screen with E's


__ESC \__ (A)


String Terminator


__ESC ^__ (A)


Privacy Message String (Message Line)


__ESC !__ Global Message String (Message
Line)


__ESC k__ 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


__1__ From Beginning of Screen to Cursor


__2__ Entire Screen


__ESC [[__ Pn __K__ Erase in Line


Pn = None or __0__


From Cursor to End of Line


__1__ From Beginning of Line to Cursor


__2__ Entire Line


__ESC [[__ Pn __X__ Erase character


__ESC [[__ Pn __A__ Cursor Up


__ESC [[__ Pn __B__ Cursor Down


__ESC [[__ Pn __C__ Cursor Right


__ESC [[__ Pn __D__ Cursor Left


__ESC [[__ Pn __E__ Cursor next line


__ESC [[__ Pn __F__ Cursor previous line


__ESC [[__ Pn __G__ Cursor horizontal
position


__ESC [[__ Pn __`__ same as above


__ESC [[__ Pn __d__ Cursor vertical
position


__ESC [[__ Ps __;__...__;__ Ps __m__ Select
Graphic Rendition


Ps = None or __0__


Default Rendition


__1__ Bold


__2__ (A)


Faint


__3__ (A)


''Standout'' Mode (ANSI: Italicized)


__4__ Underlined


__5__ Blinking


__7__ Negative Image


__22__ (A)


Normal Intensity


__23__ (A)


''Standout'' Mode off (ANSI: Italicized off)


__24__ (A)


Not Underlined


__25__ (A)


Not Blinking


__27__ (A)


Positive Image


__30__ (A)


Foreground Black


__31__ (A)


Foreground Red


__32__ (A)


Foreground Green


__33__ (A)


Foreground Yellow


__34__ (A)


Foreground Blue


__35__ (A)


Foreground Magenta


__36__ (A)


Foreground Cyan


__37__ (A)


Foreground White


__39__ (A)


Foreground Default


__40__ (A)


Background Black


__...__


__49__ (A)


Background Default


__ESC [[__ Pn __g__ Tab Clear


Pn = None or __0__


Clear Tab at Current Position


__3__ Clear All Tabs


__ESC [[__ Pn __;__ Pn __r__ (V)


Set Scrolling Region


__ESC [[__ Pn __I__ (A)


Horizontal Tab


__ESC [[__ Pn __Z__ (A)


Backward Tab


__ESC [[__ Pn __L__ (A)


Insert Line


__ESC [[__ Pn __M__ (A)


Delete Line


__ESC [[__ Pn __@__ (A)


Insert Character


__ESC [[__ Pn __P__ (A)


Delete Character


__ESC [[__ Pn __S__ Scroll Scrolling Region
Up


__ESC [[__ Pn __T__ Scroll Scrolling Region
Down


__ESC [[__ Pn __^__ same as above


__ESC [[__ Ps __;__...__;__ Ps __h__ Set
Mode


__ESC [[__ Ps __;__...__;__ Ps __l__ Reset
Mode


Ps = __4__ (A)


Insert Mode


__20__ (A)


''Automatic Linefeed'' Mode


__34__ Normal Cursor Visibility


__?1__ (V)


Application Cursor Keys


__?3__ (V)


Change Terminal Width to 132 columns


__?5__ (V)


Reverse Video


__?6__ (V)


''Origin'' Mode


__?7__ (V)


''Wrap'' Mode


__?9__ X10 mouse tracking


__?25__ (V)


Visible Cursor


__?1000__ (V)


VT200 mouse tracking


__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 [[ __ Send VT220 Secondary Device Attributes
String


__ESC [[ 6 n__ Send Cursor Position Report
!!INPUT TRANSLATION


In order to do a full VT100 emulation ''screen'' has to
detect that a sequence of characters in the input stream was
generated by a keypress on the user's keyboard and insert
the VT100 style escape sequence. ''Screen'' has a very
flexible way of doing this by making it possible to map
arbitrary commands on arbitrary sequences of characters. For
standard VT100 emulation the command will always insert a
string in the input buffer of the window (see also command
__stuff__ 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. (A) means
that the command is executed if the keyboard is switched
into application mode.


Key name          Termcap name    Command
______________________________________________________
Cursor up             ku          stuff 033[[A
stuff 033OA    (A)
Cursor down           kd          stuff 033[[B
stuff 033OB    (A)
Cursor right          kr          stuff 033[[C
stuff 033OC    (A)
Cursor left           kl          stuff 033[[D
stuff 033OD    (A)
Function key 0        k0          stuff 033[[10~
Function key 1        k1          stuff 033OP
Function key 2        k2          stuff 033OQ
Function key 3        k3          stuff 033OR
Function key 4        k4          stuff 033OS
Function key 5        k5          stuff 033[[15~
Function key 6        k6          stuff 033[[17~
Function key 7        k7          stuff 033[[18~
Function key 8        k8          stuff 033[[19~
Function key 9        k9          stuff 033[[20~
Function key 10       k;          stuff 033[[21~
Function key 11       F1          stuff 033[[23~
Function key 12       F2          stuff 033[[24~
Home                  kh          stuff 033[[1~
End                   kH          stuff 033[[4~
Insert                kI          stuff 033[[2~
Delete                kD          stuff 033[[3~
Page up               kP          stuff 033[[5~
Page down             kN          stuff 033[[6~
Keypad 0              f0          stuff 0
stuff 033Op    (A)
Keypad 1              f1          stuff 1
stuff 033Oq    (A)
Keypad 2              f2          stuff 2
stuff 033Or    (A)
Keypad 3              f3          stuff 3
stuff 033Os    (A)
Keypad 4              f4          stuff 4
stuff 033Ot    (A)
Keypad 5              f5          stuff 5
stuff 033Ou    (A)
Keypad 6              f6          stuff 6
stuff 033Ov    (A)
Keypad 7              f7          stuff 7
stuff 033Ow    (A)
Keypad 8              f8          stuff 8
stuff 033Ox    (A)
Keypad 9              f9          stuff 9
stuff 033Oy    (A)
Keypad +              f+          stuff +
stuff 033Ok    (A)
Keypad -              f-          stuff -
stuff 033Om    (A)
Keypad *              f*          stuff *
stuff 033Oj    (A)
Keypad /              f/          stuff /
stuff 033Oo    (A)
Keypad =              fq          stuff =
stuff 033OX    (A)
Keypad .              f.          stuff .
stuff 033On    (A)
Keypad ,              f,          stuff ,
stuff 033Ol    (A)
Keypad enter          fe          stuff 015
stuff 033OM    (A)
!!SPECIAL TERMINAL CAPABILITIES


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).
!!CHARACTER TRANSLATION


''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=__''''{__,,__''''}
''    '' := ''''{__,__''''}
''    '' := ''
''The things in braces may be repeated any number of times.


A '''' tells ''screen'' how to
map characters in font '''' ('B':
Ascii, 'A': UK, 'K': german, etc.) to strings. Every
'''' 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 '''' gets
substituted with the '''' specified
together with the character. If your strings are not similar
at all, then use '%' as a template and place the full string
in ''''. 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=BE(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 ''''. 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'.
!!ENVIRONMENT


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'').


STY Alternate socket name.


SYSSCREENRC


Alternate system screenrc file.


TERM Terminal name.


TERMCAP Terminal description.


WINDOW Window number of a window (at creation
time).
!!FILES


.../screen-3.?.??/etc/screenrc


.../screen-3.?.??/etc/etcscreenrc


Examples in the ''screen'' distribution package for
private and global initialization files.


$SYSSCREENRC


/etc/screenrc ''screen'' initialization
commands


$SCREENRC


$HOME/.screenrc Read in after /etc/screenrc


$SCREENDIR/S-


/var/run/screen/S-


/usr/tmp/screens/S-




Written by the


/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


/var/run/utmp Login records


$LOCKPRG Program that locks a terminal.
!!SEE ALSO


termcap(5), utmp(5), vi(1), captoinfo(1),
tic(1)
!!AUTHORS


Originally created by Oliver Laumann, this latest version
was produced by Wayne Davison, Juergen Weigert and Michael
Schroeder.
!!COPYLEFT


Copyright (C) 1993-2002
Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
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 2, 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
!!CONTRIBUTORS


Ken Beal (kbeal@amber.ssd.csd.harris.com),
Rudolf Koenig (rfkoenig@immd4.informatik.uni-erlangen.de),
Toerless Eckert (eckert@immd4.informatik.uni-erlangen.de),
Wayne Davison (davison@borland.com),
Patrick Wolfe (pat@kai.com, kailand!pat),
Bart Schaefer (schaefer@cse.ogi.edu),
Nathan Glasser (nathan@brokaw.lcs.mit.edu),
Larry W. Virden (lvirden@cas.org),
Howard Chu (hyc@hanauma.jpl.nasa.gov),
Tim !MacKenzie (tym@dibbler.cs.monash.edu.au),
Markku Jarvinen (mta@{cc,cs,ee}.tut.fi),
Marc Boucher (marc@CAM.ORG),
Doug Siebert (dsiebert@isca.uiowa.edu),
Ken Stillson (stillson@tsfsrv.mitre.org),
Ian Frechett (frechett@spot.Colorado.EDU),
Brian Koehmstedt (bpk@gnu.ai.mit.edu),
Don Smith (djs6015@ultb.isc.rit.edu),
Frank van der Linden (vdlinden@fwi.uva.nl),
Martin Schweikert (schweik@cpp.ob.open.de),
David Vrona (dave@sashimi.lcu.com),
E. Tye !McQueen (tye%spillman.UUCP@uunet.uu.net),
Matthew Green (mrg@mame.mu.oz.au),
Christopher Williams (cgw@unt.edu),
Matt Mosley (mattm@access.digex.net),
Gregory Neil Shapiro (gshapiro@wpi.WPI.EDU),
Johannes Zellner (johannes@zellner.org),
Pablo Averbuj (pablo@averbuj.com).
!!VERSION


This is version 3.9.9. Its roots are a merge of a custom
version 2.3PR7 by Wayne Davison and several enhancements to
Oliver Laumann's version 2.0. Note that all versions
numbered 2.x are copyright by Oliver Laumann.
!!AVAILABILITY


The latest official release of ''screen'' available via
anonymous ftp from gnudist.gnu.org, nic.funet.fi or any
other ''GNU'' distribution site. The home site of
''screen'' is ftp.uni-erlangen.de, in the directory
pub/utilities/screen. The subdirectory `private' contains
the latest beta testing release. If you want to help, send a
note to screen@uni-erlangen.de.
!!BUGS


`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
``/var/run/utmp''.


Entries in ``/var/run/utmp'' are not removed when
''screen'' is killed with SIGKILL. This will cause some
programs (like
''


''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
screen@uni-erlangen.de__.
----
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Last edited on Friday, July 7, 2006 9:46:43 am by AristotlePagaltzis
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