This is Info file screen.info, produced by Makeinfo-1.55 from the input
file ./screen.texinfo.

   This file documents the `Screen' virtual terminal manager.

   Copyright (c) 1993-1995 Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that
the entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Foundation.


File: screen.info,  Node: Detach,  Next: Power Detach,  Up: Session Management

Detach
======

 - Command: autodetach STATE
     (none)
     Sets whether `screen' will automatically detach upon hangup, which
     saves all your running programs until they are resumed with a
     `screen -r' command.  When turned off, a hangup signal will
     terminate `screen' and all the processes it contains. Autodetach is
     on by default.

 - Command: detach
     (`C-a d', `C-a C-d')
     Detach the `screen' session (disconnect it from the terminal and
     put it into the background).  A detached `screen' can be resumed by
     invoking `screen' with the `-r' option. (*note Invoking Screen::.)

 - Command: password [CRYPTED_PW]
     (none)
     Present a crypted password in your `.screenrc' file and screen will
     ask for it, whenever someone attempts to resume a detached
     session. This is useful, if you have privileged programs running
     under `screen' and you want to protect your session from reattach
     attempts by users that managed to assume your uid. (I.e. any
     superuser.)  If no crypted password is specified, screen prompts
     twice a password and places its encryption in the paste buffer.
     Default is `none', which disables password checking.


File: screen.info,  Node: Power Detach,  Next: Lock,  Prev: Detach,  Up: Session Management

Power Detach
============

 - Command: pow_detach
     (`C-a D')
     Mainly the same as `detach', but also sends a HANGUP signal to the
     parent process of `screen'.
     *Caution*: This will result in a logout if `screen' was started
     from your login shell.

 - Command: pow_detach_msg [MESSAGE]
     (none)
     The MESSAGE specified here is output whenever a power detach is
     performed. It may be used as a replacement for a logout message or
     to reset baud rate, etc.  Without parameter, the current message
     is shown.


File: screen.info,  Node: Lock,  Next: Multiuser Session,  Prev: Power Detach,  Up: Session Management

Lock
====

 - Command: lockscreen
     (`C-a x', `C-a C-x')
     Call a screenlock program (`/local/bin/lck' or `/usr/bin/lock' or
     a builtin, if no other is available). Screen does not accept any
     command keys until this program terminates. Meanwhile processes in
     the windows may continue, as the windows are in the detached state.
     The screenlock program may be changed through the environment
     variable `$LOCKPRG' (which must be set in the shell from which
     `screen' is started) and is executed with the user's uid and gid.

     Warning: When you leave other shells unlocked and have no password
     set on `screen', the lock is void: One could easily re-attach from
     an unlocked shell. This feature should rather be called
     `lockterminal'.


File: screen.info,  Node: Multiuser Session,  Next: Session Name,  Prev: Lock,  Up: Session Management

Multiuser Session
=================

   These commands allow other users to gain access to one single
`screen' session. When attaching to a multiuser `screen' the
sessionname is specified as `username/sessionname' to the `-S' command
line option.  `Screen' must be compiled with multiuser support to
enable features described here.

* Menu:

* Multiuser::			Enable / Disable multiuser mode.
* Acladd::			Enable a specific user.
* Aclchg::                      Change a users permissions.
* Acldel::			Disable a specific user.
* Aclgrp::			Grant a user permissions to other users.
* Displays::			List all active users at their displays.
* Umask::			Predefine access to new windows.
* Wall::                        Write a message to all users.
* Writelock::                   Grant exclusive window access.
* Su::                          Substitute user.


File: screen.info,  Node: Multiuser,  Next: Acladd,  Up: Multiuser Session

Multiuser
---------

 - Command: multiuser STATE
     (none)
     Switch between single-user and multi-user mode. Standard screen
     operation is single-user. In multi-user mode the commands
     `acladd', `aclchg' and `acldel' can be used to enable (and
     disable) other users accessing this `screen'.


File: screen.info,  Node: Acladd,  Next: Aclchg,  Prev: Multiuser,  Up: Multiuser Session

Acladd
------

 - Command: acladd USERNAMES
 - Command: addacl USERNAMES
     (none)
     Enable users to fully access this screen session. USERNAMES can be
     one user or a comma separated list of users. This command enables
     to attach to the `screen' session and performs the equivalent of
     `aclchg USERNAMES +rwx "#?"'. To add a user with restricted access,
     use the `aclchg' command below.  `Addacl' is a synonym to `acladd'.
     Multi-user mode only.


File: screen.info,  Node: Aclchg,  Next: Acldel,  Prev: Acladd,  Up: Multiuser Session

Aclchg
------

 - Command: aclchg USERNAMES PERMBITS LIST
 - Command: chacl USERNAMES PERMBITS LIST
     (none)
     Change permissions for a comma separated list of users.
     Permission bits are represented as `r', `w' and `x'.  Prefixing
     `+' grants the permission, `-' removes it. The third parameter is
     a comma separated list of commands or windows (specified either by
     number or title). The special list `#' refers to all windows, `?'
     to all commands. If USERNAMES consists of a single `*', all known
     users is affected.  A command can be executed when the user has
     the `x' bit for it. The user can type input to a window when he
     has its `w' bit set and no other user obtains a writelock for this
     window. Other bits are currently ignored.  To withdraw the
     writelock from another user in e.g. window 2: `aclchg USERNAME
     -w+w 2'. To allow read-only access to the session: `aclchg
     USERNAME -w "#"'. As soon as a user's name is known to screen, he
     can attach to the session and (per default) has full permissions
     for all command and windows. Execution permission for the acl
     commands, `at' and others should also be removed or the user may
     be able to regain write permission.  `Chacl' is a synonym to
     `aclchg'.  Multi-user mode only.


File: screen.info,  Node: Acldel,  Next: Aclgrp,  Prev: Aclchg,  Up: Multiuser Session

Acldel
------

 - Command: acldel USERNAME
     (none)
     Remove a user from screen's access control list. If currently
     attached, all the user's displays are detached from the session.
     He cannot attach again.  Multi-user mode only.


File: screen.info,  Node: Aclgrp,  Next: Displays,  Prev: Acldel,  Up: Multiuser Session

Aclgrp
------

 - Command: aclgrp USERNAME [GROUPNAME]
     (none)
     Creates groups of users that share common access rights. The name
     of the group is the username of the group leader. Each member of
     the  group  inherits  the  permissions  that  are granted  to the
     group leader. That means, if a user fails an access check, another
     check is made for the group leader.  A user is removed from all
     groups the special value `none' is used for GROUPNAME. If the
     second parameter is omitted all groups the user is in are listed.


File: screen.info,  Node: Displays,  Next: Umask,  Prev: Aclgrp,  Up: Multiuser Session

Displays
--------

 - Command: displays
     (`C-a *')
     Shows a tabular listing  of  all  currently  connected  user
     front-ends  (displays).   This  is most useful for multiuser
     sessions.


File: screen.info,  Node: Umask,  Next: Wall,  Prev: Displays,  Up: Multiuser Session

aclumask
--------

 - Command: aclumask [[USERS]+BITS |[USERS]-BITS .... ]
 - Command: umask [[USERS]+BITS |[USERS]-BITS .... ]
     (none)
     This specifies the access other users have to  windows  that will
     be  created  by  the caller of the command. USERS may be no, one
     or a comma separated list of known usernames.  If  no  users  are
     specified,  a  list of all currently known users is assumed.  BITS
     is any  combination  of  access  control  bits  allowed defined
     with the `aclchg' command. The special username `?' predefines the
     access that  not  yet  known  users  will  be granted  to any
     window initially.  The special username `??' predefines the access
     that not yet known users  are  granted to any command. Rights of
     the special username nobody cannot be changed (see the `su'
     command).  `Umask' is a synonym to `aclumask'.


File: screen.info,  Node: Wall,  Next: Writelock,  Prev: Umask,  Up: Multiuser Session

Wall
----

 - Command: wall MESSAGE
     (none)
     Write a message to all displays. The message will appear in the
     terminal's status line.


File: screen.info,  Node: Writelock,  Next: Su,  Prev: Wall,  Up: Multiuser Session

Writelock
---------

 - Command: writelock ON|OFF|AUTO
     (none)
     In addition to access control lists, not all users may be able to
     write to the same window at once. Per default, writelock is in
     `auto' mode and grants exclusive input permission to the user who
     is the first to switch to the particular window. When he leaves
     the window, other users may obtain the writelock (automatically).
     The writelock of the current window is disabled by the command
     `writelock off'. If the user issues the command `writelock on' he
     keeps the exclusive write permission while switching to other
     windows.

 - Command: defwritelock ON|OFF|AUTO
     (none)
     Sets the default writelock behavior for new windows. Initially all
     windows will be created with no writelocks.


File: screen.info,  Node: Su,  Prev: Writelock,  Up: Multiuser Session

Su
--

 - Command: su [USERNAME [PASSWORD [PASSWORD2]]]
     (none)
     Substitute the user of a display. The  command  prompts  for all
     parameters that are omitted. If passwords are specified as
     parameters, they have  to  be  specified  un-crypted.  The first
     password  is matched against the systems passwd database, the
     second password  is  matched  against  the `screen' password  as
     set  with the commands `acladd' or `password'.  `Su' may be useful
     for the `screen' administrator to test multiuser  setups.  When
     the  identification  fails,  the  user has access to the commands
     available for user `nobody'. These are `detach', `license',
     `version', `help' and `displays'.


File: screen.info,  Node: Session Name,  Next: Suspend,  Prev: Multiuser Session,  Up: Session Management

Session Name
============

 - Command: sessionname [NAME]
     (none)
     Rename the current session. Note that for `screen -list' the name
     shows up with the process-id prepended. If the argument NAME is
     omitted, the name of this session is displayed.
     *Caution*: The `$STY' environment variable still reflects the old
     name. This may result in confusion.  The default is constructed
     from the tty and host names.


File: screen.info,  Node: Suspend,  Next: Quit,  Prev: Session Name,  Up: Session Management

Suspend
=======

 - Command: suspend
     (`C-a z', `C-a C-z')
     Suspend `screen'.  The windows are in the detached state while
     `screen' is suspended.  This feature relies on the parent shell
     being able to do job control.


File: screen.info,  Node: Quit,  Prev: Suspend,  Up: Session Management

Quit
====

 - Command: quit
     (`C-a C-\')
     Kill all windows and terminate `screen'.  Note that on VT100-style
     terminals the keys `C-4' and `C-\' are identical.  So be careful
     not to type `C-a C-4' when selecting window no. 4.  Use the empty
     bind command (as in `bind "^\"') to remove a key binding (*note
     Key Binding::.).


File: screen.info,  Node: Regions,  Next: Window Settings,  Prev: Session Management,  Up: Top

Regions
*******

   Screen has the ability to display more than one window on the user's
display. This is done by splitting the screen in regions, which can
contain different windows.

* Menu:

* Split::			Split a region into two
* Focus::			Change to the next region
* Only::			Delete all other regions
* Remove::			Delete the current region
* Resize::			Grow or shrink a region
* Caption::			Control the window's caption
* Fit::				Resize a window to fit the region


File: screen.info,  Node: Split,  Next: Focus,  Up: Regions

Split
=====

 - Command: split
     (`C-a S')
     Split the current region into two new ones. All regions on the
     display are resized to make room for the new region. The blank
     window is displayed on the new region.


File: screen.info,  Node: Focus,  Next: Only,  Prev: Split,  Up: Regions

Focus
=====

 - Command: focus
     (`C-a Tab')
     Move the input focus to the next region. This is done in a cyclic
     way so that the top region is selected after the bottom one. If no
     subcommand is given it defaults to `down'. `up' cycles in the
     opposite order, `top' and `bottom' go to the top and bottom region
     respectively. Useful bindings are (j and k as in vi)
          bind j focus down
          bind k focus up
          bind t focus top
          bind b focus bottom


File: screen.info,  Node: Only,  Next: Remove,  Prev: Focus,  Up: Regions

Only
====

 - Command: only
     (`C-a Q')
     Kill all regions but the current one.


File: screen.info,  Node: Remove,  Next: Resize,  Prev: Only,  Up: Regions

Remove
======

 - Command: remove
     (`C-a X')
     Kill the current region. This is a no-op if there is only one
     region.


File: screen.info,  Node: Resize,  Next: Caption,  Prev: Remove,  Up: Regions

Resize
======

 - Command: resize [(+/-)LINES]
     (none)
     Resize the current region. The space will be removed from or added
     to the region below or if there's not enough space from the region
     above.
          resize +N       increase current region height by N
          resize -N       decrease current region height by N
          resize  N       set current region height to N
          resize  =       make all windows equally high
          resize  max     maximize current region height
          resize  min     minimize current region height


File: screen.info,  Node: Caption,  Next: Fit,  Prev: Resize,  Up: Regions

Caption
=======

 - Command: caption `always'|`splitonly' [STRING]
 - Command: caption `string' [STRING]
     (none)
     This command controls the display of the window captions. Normally
     a caption is only used if more than one window is shown on the
     display (split screen mode). But if the type is set to `always',
     `screen' shows a caption even if only one window is displayed. The
     default is `splitonly'.

     The second form changes the text used for the caption. You can use
     all string escapes (*Note String Escapes::). `Screen' uses a
     default of `%3n %t'.

     You can mix both forms by providing the string as an additional
     argument.


File: screen.info,  Node: Fit,  Prev: Caption,  Up: Regions

Fit
===

 - Command: fit
     (`C-a F')
     Change the window size to the size of the current region. This
     command is needed because screen doesn't adapt the window size
     automatically if the window is displayed more than once.


File: screen.info,  Node: Window Settings,  Next: Virtual Terminal,  Prev: Regions,  Up: Top

Window Settings
***************

   These commands control the way `screen' treats individual windows in
a session.  *Note Virtual Terminal::, for commands to control the
terminal emulation itself.

* Menu:

* Naming Windows::		Control the name of the window
* Console::			See the host's console messages
* Kill::                        Destroy an unwanted window
* Login::                       Control `/etc/utmp' logging
* Mode::                        Control the file mode of the pty
* Monitor::                     Watch for activity in a window
* Windows::			List the active windows
* Hardstatus::			Set a window's hardstatus line


File: screen.info,  Node: Naming Windows,  Next: Console,  Up: Window Settings

Naming Windows (Titles)
=======================

   You can customize each window's name in the window display (viewed
with the `windows' command (*note Windows::.) by setting it with one of
the title commands.  Normally the name displayed is the actual command
name of the program created in the window.  However, it is sometimes
useful to distinguish various programs of the same name or to change
the name on-the-fly to reflect the current state of the window.

   The default name for all shell windows can be set with the
`shelltitle' command (*note Shell::.).  You can specify the name you
want for a window with the `-t' option to the `screen' command when the
window is created (*note Screen Command::.).  To change the name after
the window has been created you can use the title-string escape-sequence
(`ESC k NAME ESC \') and the `title' command (C-a A).  The former can
be output from an application to control the window's name under
software control, and the latter will prompt for a name when typed.
You can also bind predefined names to keys with the `title' command to
set things quickly without prompting.

* Menu:

* Title Command::                 The `title' command.
* Dynamic Titles::                Make shell windows change titles dynamically.
* Title Prompts::                 Set up your shell prompt for dynamic Titles.
* Title Screenrc::                Set up Titles in your `.screenrc'.


File: screen.info,  Node: Title Command,  Next: Dynamic Titles,  Up: Naming Windows

Title Command
-------------

 - Command: title [WINDOWTITLE]
     (`C-a A')
     Set the name of the current window to WINDOWALIAS. If no name is
     specified, screen prompts for one.


File: screen.info,  Node: Dynamic Titles,  Next: Title Prompts,  Prev: Title Command,  Up: Naming Windows

Dynamic Titles
--------------

   `screen' has a shell-specific heuristic that is enabled by setting
the window's name to SEARCH|NAME and arranging to have a null title
escape-sequence output as a part of your prompt.  The SEARCH portion
specifies an end-of-prompt search string, while the NAME portion
specifies the default shell name for the window.  If the NAME ends in a
`:' `screen' will add what it believes to be the current command
running in the window to the end of the specified name (e.g. NAME:CMD).
Otherwise the current command name supersedes the shell name while it
is running.

   Here's how it works: you must modify your shell prompt to output a
null title-escape-sequence (ESC k ESC \) as a part of your prompt.  The
last part of your prompt must be the same as the string you specified
for the SEARCH portion of the title.  Once this is set up, `screen'
will use the title-escape-sequence to clear the previous command name
and get ready for the next command.  Then, when a newline is received
from the shell, a search is made for the end of the prompt.  If found,
it will grab the first word after the matched string and use it as the
command name.  If the command name begins with `!', `%', or `^',
`screen' will use the first word on the following line (if found) in
preference to the just-found name.  This helps csh users get more
accurate titles when using job control or history recall commands.


File: screen.info,  Node: Title Prompts,  Next: Title Screenrc,  Prev: Dynamic Titles,  Up: Naming Windows

Setting up your prompt for shell titles
---------------------------------------

   One thing to keep in mind when adding a null title-escape-sequence
to your prompt is that some shells (like the csh) count all the
non-control characters as part of the prompt's length.  If these
invisible characters aren't a multiple of 8 then backspacing over a tab
will result in an incorrect display.  One way to get around this is to
use a prompt like this:

     set prompt='[0000mk\% '

   The escape-sequence `[0000m' not only normalizes the character
attributes, but all the zeros round the length of the invisible
characters up to 8.

   Tcsh handles escape codes in the prompt more intelligently, so you
can specify your prompt like this:

     set prompt="%{\ek\e\\%}\% "

   Bash users will probably want to echo the escape sequence in the
PROMPT_COMMAND:

     PROMPT_COMMAND='echo -n -e "\033k\033\134"'

   (I used `\134' to output a `\' because of a bug in v1.04).


File: screen.info,  Node: Title Screenrc,  Prev: Title Prompts,  Up: Naming Windows

Setting up shell titles in your `.screenrc'
-------------------------------------------

   Here are some .screenrc examples:

     screen -t top 2 nice top

   Adding this line to your .screenrc would start a niced version of the
`top' command in window 2 named `top' rather than `nice'.

     shelltitle '> |csh'
     screen 1

   This file would start a shell using the given shelltitle.  The title
specified is an auto-title that would expect the prompt and the typed
command to look something like the following:

     /usr/joe/src/dir> trn

   (it looks after the '> ' for the command name).  The window status
would show the name `trn' while the command was running, and revert to
`csh' upon completion.

     bind R screen -t '% |root:' su

   Having this command in your .screenrc would bind the key sequence
`C-a R' to the `su' command and give it an auto-title name of `root:'.
For this auto-title to work, the screen could look something like this:

     % !em
     emacs file.c

   Here the user typed the csh history command `!em' which ran the
previously entered `emacs' command.  The window status would show
`root:emacs' during the execution of the command, and revert to simply
`root:' at its completion.

     bind o title
     bind E title ""
     bind u title (unknown)

   The first binding doesn't have any arguments, so it would prompt you
for a title when you type `C-a o'.  The second binding would clear an
auto-titles current setting (C-a E).  The third binding would set the
current window's title to `(unknown)' (C-a u).


File: screen.info,  Node: Console,  Next: Kill,  Prev: Naming Windows,  Up: Window Settings

Console
=======

 - Command: console [STATE]
     (none)
     Grabs or un-grabs the machines console output to a window. When
     the argument is omitted the current state is displayed.  *Note*:
     Only the owner of `/dev/console' can grab the console output. This
     command is only available if the host supports the ioctl
     `TIOCCONS'.


File: screen.info,  Node: Kill,  Next: Login,  Prev: Console,  Up: Window Settings

Kill
====

 - Command: kill
     (`C-a k', `C-a C-k')
     Kill the current window.
     If there is an `exec' command running (*note Exec::.) then it is
     killed.  Otherwise the process (e.g. shell) running in the window
     receives a `HANGUP' condition, the window structure is removed and
     screen (your display) switches to another window. When the last
     window is destroyed, `screen' exits.  After a kill screen switches
     to the previously displayed window.
     *Caution*: `emacs' users may find themselves killing their `emacs'
     session when trying to delete the current line.  For this reason,
     it is probably wise to use a different command character (*note
     Command Character::.) or rebind `kill' to another key sequence,
     such as `C-a K' (*note Key Binding::.).


File: screen.info,  Node: Login,  Next: Mode,  Prev: Kill,  Up: Window Settings

Login
=====

 - Command: deflogin STATE
     (none)
     Same as the `login' command except that the default setting for new
     windows is changed.  This defaults to `on' unless otherwise
     specified at compile time (*note Installation::.). Both commands
     are only present when `screen' has been compiled with utmp support.

 - Command: login [STATE]
     (`C-a L')
     Adds or removes the entry in `/etc/utmp' for the current window.
     This controls whether or not the window is "logged in".  In
     addition to this toggle, it is convenient to have "log in" and
     "log out" keys.  For instance, `bind I login on' and `bind O login
     off' will map these keys to be `C-a I' and `C-a O' (*note Key
     Binding::.).


File: screen.info,  Node: Mode,  Next: Monitor,  Prev: Login,  Up: Window Settings

Mode
====

 - Command: defmode MODE
     (none)
     The mode of each newly allocated pseudo-tty is set to MODE.  MODE
     is an octal number as used by chmod(1).  Defaults to 0622 for
     windows which are logged in, 0600 for others (e.g. when `-ln' was
     specified for creation. *note Screen Command::.).


File: screen.info,  Node: Monitor,  Next: Windows,  Prev: Mode,  Up: Window Settings

Monitoring
==========

 - Command: activity MESSAGE
     (none)
     When any activity occurs in a background window that is being
     monitored, `screen' displays a notification in the message line.
     The notification message can be redefined by means of the
     `activity' command.  Each occurrence of `%' in MESSAGE is replaced
     by the number of the window in which activity has occurred, and
     each occurrence of `^G' is replaced by the definition for bell in
     your termcap (usually an audible bell).  The default message is

          'Activity in window %n'

     Note that monitoring is off for all windows by default, but can be
     altered by use of the `monitor' command (`C-a M').

 - Command: defmonitor STATE
     (none)
     Same as the `monitor' command except that the default setting for
     new windows is changed.  Initial setting is `off'.

 - Command: monitor [STATE]
     (`C-a M')
     Toggles monitoring of the current window.  When monitoring is
     turned on and the affected window is switched into the background,
     the activity notification message will be displayed in the status
     line at the first sign of output, and the window will also be
     marked with an `@' in the window-status display (*note
     Windows::.).  Monitoring defaults to `off' for all windows.


File: screen.info,  Node: Windows,  Next: Hardstatus,  Prev: Monitor,  Up: Window Settings

Windows
=======

 - Command: windows
     (`C-a w', `C-a C-w')
     Uses the message line to display a list of all the windows.  Each
     window is listed by number with the name of the program running in
     the window (or its title).

     The current window is marked with a `*'; the previous window is
     marked with a `-'; all the windows that are logged in are marked
     with a `$' (*note Login::.); a background window that has received
     a bell is marked with a `!'; a background window that is being
     monitored and has had activity occur is marked with an `@' (*note
     Monitor::.); a window which has output logging turned on is marked
     with `(L)'; windows occupied by other users are marked with `&' or
     `&&' if the window is shared by other users; windows in the zombie
     state are marked with `Z'.

     If this list is too long to fit on the terminal's status line only
     the portion around the current window is displayed.


File: screen.info,  Node: Hardstatus,  Prev: Windows,  Up: Window Settings

Hardstatus
==========

   `Screen' maintains a hardstatus line for every window. If a window
gets selected, the display's hardstatus will be updated to match the
window's hardstatus line.  The hardstatus line can be changed with the
ANSI Application Program Command (APC): `ESC_<string>ESC\'. As a
convenience for xterm users the sequence `ESC]0..2;<string>^G' is also
accepted.

 - Command: defhstatus [STATUS]
     (none)
     The hardstatus line that all new windows will get is set to STATUS.
     This command is useful to make the hardstatus of every window
     display the window number or title or the like.  STATUS may
     contain the same directives as in the window messages, but the
     directive escape character is `^E' (octal 005) instead of `%'.
     This was done to make a misinterpretation of program generated
     hardstatus lines impossible.  If the parameter STATUS is omitted,
     the current default string is displayed.  Per default the
     hardstatus line of new windows is empty.

 - Command: hstatus STATUS
     (none)
     Changes the current window's hardstatus line to STATUS.


File: screen.info,  Node: Virtual Terminal,  Next: Copy and Paste,  Prev: Window Settings,  Up: Top

Virtual Terminal
****************

   Each window in a `screen' session emulates a VT100 terminal, with
some extra functions added. The VT100 emulator is hard-coded, no other
terminal types can be emulated.  The commands described here modify the
terminal emulation.

* Menu:

* Control Sequences::           Details of the internal VT100 emulation.
* Input Translation::           How keystrokes are remapped.
* Digraph::			Entering digraph sequences.
* Bell::                        Getting your attention.
* Clear::                       Clear the window display.
* Info::                        Terminal emulation statistics.
* Redisplay::                   When the display gets confusing.
* Wrap::                        Automatic margins.
* Reset::                       Recovering from ill-behaved applications.
* Window Size::                 Changing the size of your terminal.
* Character Processing::	Change the effect of special characters.


File: screen.info,  Node: Control Sequences,  Next: Input Translation,  Up: Virtual Terminal

Control Sequences
=================

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

     ESC E                           Next Line
     ESC D                           Index
     ESC M                           Reverse Index
     ESC H                           Horizontal Tab Set
     ESC Z                           Send VT100 Identification String
     ESC 7                   (V)     Save Cursor and Attributes
     ESC 8                   (V)     Restore Cursor and Attributes
     ESC [s                  (A)     Save Cursor and Attributes
     ESC [u                  (A)     Restore Cursor and Attributes
     ESC c                           Reset to Initial State
     ESC g                           Visual Bell
     ESC Pn p                        Cursor Visibility (97801)
         Pn = 6                      Invisible
              7                      Visible
     ESC =                   (V)     Application Keypad Mode
     ESC >                   (V)     Numeric Keypad Mode
     ESC # 8                 (V)     Fill Screen with E's
     ESC \                   (A)     String Terminator
     ESC ^                   (A)     Privacy Message String (Message Line)
     ESC !                           Global Message String (Message Line)
     ESC k                           Title Definition String
     ESC P                   (A)     Device Control String
                                     Outputs a string directly to the host
                                     terminal without interpretation.
     ESC _                   (A)     Application Program Command (Hardstatus)
     ESC ]                   (A)     Operating System Command (Hardstatus, xterm
                                     title hack)
     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 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                 (V)     Send Terminal Parameter Report
     ESC [ > c                       Send Secondary Device Attributes String
     ESC [ 6 n                       Send Cursor Position Report


File: screen.info,  Node: Input Translation,  Next: Digraph,  Prev: Control Sequences,  Up: Virtual Terminal

Input Translation
=================

   In order to do a full VT100 emulation `screen' has to detect that a
sequence of characters in the input stream was generated by a keypress
on the user's keyboard and insert the VT100 style escape sequence.
`Screen' has a very flexible way of doing this by making it possible to
map arbitrary commands on arbitrary sequences of characters. For
standard VT100 emulation the command will always insert a string in the
input buffer of the window (see also command `stuff', *note Paste::.).
Because the sequences generated by a keypress can change after a
reattach from a different terminal type, it is possible to bind
commands to the termcap name of the keys.  `Screen' will insert the
correct binding after each reattach. *Note Bindkey:: for further
details on the syntax and examples.

   Here is the table of the default key bindings. (A) means that the
command is executed if the keyboard is switched into application mode.

     Key name        Termcap name    Command
     -----------------------------------------------------
     Cursor up            ku         stuff \033[A
                                     stuff \033OA      (A)
     Cursor down          kd         stuff \033[B
                                     stuff \033OB      (A)
     Cursor right         kr         stuff \033[C
                                     stuff \033OC      (A)
     Cursor left          kl         stuff \033[D
                                     stuff \033OD      (A)
     Function key 0       k0         stuff \033[10~
     Function key 1       k1         stuff \033OP
     Function key 2       k2         stuff \033OQ
     Function key 3       k3         stuff \033OR
     Function key 4       k4         stuff \033OS
     Function key 5       k5         stuff \033[15~
     Function key 6       k6         stuff \033[17~
     Function key 7       k7         stuff \033[18~
     Function key 8       k8         stuff \033[19~
     Function key 9       k9         stuff \033[20~
     Function key 10      k;         stuff \033[21~
     Function key 11      F1         stuff \033[22~
     Function key 12      F2         stuff \033[23~
     Backspace            kb         stuff \010
     Home                 kh         stuff \033[1~
     End                  kH         stuff \033[4~
     Insert               kI         stuff \033[2~
     Delete               kD         stuff \033[3~
     Page up              kP         stuff \033[5~
     Page down            kN         stuff \033[6~
     Keypad 0             f0         stuff 0
                                     stuff \033Op      (A)
     Keypad 1             f1         stuff 1
                                     stuff \033Oq      (A)
     Keypad 2             f2         stuff 2
                                     stuff \033Or      (A)
     Keypad 3             f3         stuff 3
                                     stuff \033Os      (A)
     Keypad 4             f4         stuff 4
                                     stuff \033Ot      (A)
     Keypad 5             f5         stuff 5
                                     stuff \033Ou      (A)
     Keypad 6             f6         stuff 6
                                     stuff \033Ov      (A)
     Keypad 7             f7         stuff 7
                                     stuff \033Ow      (A)
     Keypad 8             f8         stuff 8
                                     stuff \033Ox      (A)
     Keypad 9             f9         stuff 9
                                     stuff \033Oy      (A)
     Keypad +             f+         stuff +
                                     stuff \033Ok      (A)
     Keypad -             f-         stuff -
                                     stuff \033Om      (A)
     Keypad *             f*         stuff *
                                     stuff \033Oj      (A)
     Keypad /             f/         stuff /
                                     stuff \033Oo      (A)
     Keypad =             fq         stuff =
                                     stuff \033OX      (A)
     Keypad .             f.         stuff .
                                     stuff \033On      (A)
     Keypad ,             f,         stuff ,
                                     stuff \033Ol      (A)
     Keypad enter         fe         stuff \015
                                     stuff \033OM      (A)


File: screen.info,  Node: Digraph,  Next: Bell,  Prev: Input Translation,  Up: Virtual Terminal

Digraph
=======

 - Command: digraph [PRESET]
     (none)
     This command prompts the user for a digraph sequence. The next two
     characters typed are looked up in a builtin table and the
     resulting character is inserted in the input stream. For example,
     if the user enters `a"', an a-umlaut will be inserted. If the
     first character entered is a 0 (zero), `screen' will treat the
     following characters (up to three) as an octal number instead.
     The optional argument PRESET is treated as user input, thus one
     can create an "umlaut" key.  For example the command `bindkey ^K
     digraph '"'' enables the user to generate an a-umlaut by typing
     `CTRL-K a'.


File: screen.info,  Node: Bell,  Next: Clear,  Prev: Digraph,  Up: Virtual Terminal

Bell
====

 - Command: bell_msg [MESSAGE]
     (none)
     When a bell character is sent to a background window, `screen'
     displays a notification in the message line.  The notification
     message can be re-defined by this command.  Each occurrence of `%'
     in MESSAGE is replaced by the number of the window to which a bell
     has been sent, and each occurrence of `^G' is replaced by the
     definition for bell in your termcap (usually an audible bell).
     The default message is

          'Bell in window %n'

     An empty message can be supplied to the `bell_msg' command to
     suppress output of a message line (`bell_msg ""').  Without
     parameter, the current message is shown.

 - Command: vbell [STATE]
     (`C-a C-g')
     Sets or toggles the visual bell setting for the current window. If
     `vbell' is switched to `on', but your terminal does not support a
     visual bell, the visual bell message is displayed in the status
     line when the bell character is received.  Visual bell support of
     a terminal is defined by the termcap variable `vb'. *Note Visual
     Bell: (termcap)Bell, for more information on visual bells.  The
     equivalent terminfo capability is `flash'.

     Per  default, `vbell' is `off', thus the audible bell is used.

 - Command: vbell_msg [MESSAGE]
     (none)
     Sets the visual bell message. MESSAGE is printed to the status
     line if the window receives a bell character (^G), `vbell' is set
     to `on' and the terminal does not support a visual bell.  The
     default message is `Wuff, Wuff!!'.  Without parameter, the current
     message is shown.

 - Command: vbellwait SEC
     (none)
     Define a delay in seconds after each display of `screen' 's visual
     bell message. The default is 1 second.


File: screen.info,  Node: Clear,  Next: Info,  Prev: Bell,  Up: Virtual Terminal

Clear
=====

 - Command: clear
     (`C-a C')
     Clears the screen and saves its contents to the scrollback buffer.


File: screen.info,  Node: Info,  Next: Redisplay,  Prev: Clear,  Up: Virtual Terminal

Info
====

 - Command: info
     (`C-a i', `C-a C-i')
     Uses the message line to display some information about the current
     window: the cursor position in the form `(COLUMN,ROW)' starting
     with `(1,1)', the terminal width and height plus the size of the
     scrollback buffer in lines, like in `(80,24)+50', the current
     state of window XON/XOFF flow control is shown like this (see also
     *Note Flow Control::):
            +flow     automatic flow control, currently on.
            -flow     automatic flow control, currently off.
            +(+)flow  flow control enabled. Agrees with automatic control.
            -(+)flow  flow control disabled. Disagrees with automatic control.
            +(-)flow  flow control enabled. Disagrees with automatic control.
            -(-)flow  flow control disabled. Agrees with automatic control.

     The current line wrap setting (`+wrap' indicates enabled, `-wrap'
     not) is also shown. The flags `ins', `org', `app', `log', `mon'
     and `nored' are displayed when the window is in insert mode,
     origin mode, application-keypad mode, has output logging, 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'.  Additional modes
     depending on the type of the window are displayed at the end of
     the status line (*note Window Types::.).

     If the state machine of the terminal emulator is in a non-default
     state, the info line is started with a string identifying the
     current state.

     For system information use `time'.


File: screen.info,  Node: Redisplay,  Next: Wrap,  Prev: Info,  Up: Virtual Terminal

Redisplay
=========

 - Command: allpartial STATE
     (none)
     If set to on, only the current cursor line is refreshed on window
     change.  This affects all windows and is useful for slow terminal
     lines. The previous setting of full/partial refresh for each
     window is restored with `allpartial off'. This is a global flag
     that immediately takes effect on all windows overriding the
     `partial' settings. It does not change the default redraw behavior
     of newly created windows.

 - Command: partial STATE
     (none)
     Defines whether the display should be refreshed (as with
     `redisplay') after switching to the current window. This command
     only affects the current window.  To immediately affect all
     windows use the `allpartial' command.  Default is `off', of
     course.  This default is fixed, as there is currently no
     `defpartial' command.

 - Command: redisplay
     (`C-a l', `C-a C-l')
     Redisplay the current window.  Needed to get a full redisplay in
     partial redraw mode.


File: screen.info,  Node: Wrap,  Next: Reset,  Prev: Redisplay,  Up: Virtual Terminal

Wrap
====

 - Command: wrap STATE
     (`C-a r', `C-a C-r')
     Sets the line-wrap setting for the current window.  When line-wrap
     is on, the second consecutive printable character output at the
     last column of a line will wrap to the start of the following
     line.  As an added feature, backspace (^H) will also wrap through
     the left margin to the previous line.  Default is `on'.

 - Command: defwrap STATE
     (none)
     Same as the `wrap' command except that the default setting for new
     windows is changed. Initially line-wrap is on and can be toggled
     with the `wrap' command (`C-a r') or by means of "C-a : wrap
     on|off".


File: screen.info,  Node: Reset,  Next: Window Size,  Prev: Wrap,  Up: Virtual Terminal

Reset
=====

 - Command: reset
     (`C-a Z')
     Reset the virtual terminal to its "power-on" values. Useful when
     strange settings (like scroll regions or graphics character set)
     are left over from an application.


File: screen.info,  Node: Window Size,  Next: Character Processing,  Prev: Reset,  Up: Virtual Terminal

Window Size
===========

 - Command: width [NUM]
     (`C-a W')
     Toggle the window width between 80 and 132 columns, or set it to
     NUM columns if an argument is specified.  This requires a capable
     terminal and the termcap entries `Z0' and `Z1'.  See the `termcap'
     command (*note Termcap::.), for more information.

 - Command: height [LINES]
     (none)
     Set the display height to a specified number of lines. When no
     argument is given it toggles between 24 and 42 lines display.

