screen

SCREEN(1) General Commands Manual SCREEN(1)

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 mech
   anism 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 win
   dows, view a list of windows, turn output logging on and off, copy-and-paste text between windows, view the scrollback history,  switch  between  windows  in
   whatever  manner  you wish, etc. All windows run their programs completely independent of each other. Programs continue to run when their window is currently
   not visible and even when the whole screen session is detached from the user's terminal.  When a program terminates, screen (per default)  kills  the  window
   that contained it.  If this window was in the foreground, the display switches to the previous window; if none are left, screen exits. Shells usually distin‐
   guish between running as login-shell or sub-shell.  Screen runs them as sub-shells, unless told otherwise (See shell .screenrc command).

   Everything you type is sent to the program running in the current window.  The only exception to this is the one keystroke that is used to initiate a command
   to  the window manager.  By default, each command begins with a control-a (abbreviated C-a from now on), and is followed by one other keystroke.  The command
   character and all the key bindings can be fully customized to be anything you like, though they are always two characters in length.

   Screen does not understand the prefix C- to mean control, although this notation is used in this manual for readability.  Please use the caret  notation  (^A
   instead of C-a) as arguments to e.g. the escape command or the -e option.  Screen will also print out control characters in caret notation.

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

          screen emacs prog.c

   from a shell prompt within a previously created window.  This will not run another copy of screen, but will instead supply the command name and its arguments
   to  the window manager (specified in the $STY environment variable) who will use it to create the new window.  The above example would start the emacs editor
   (editing prog.c) and switch to its window. - Note that you cannot transport environment variables from the invoking shell to the application (emacs  in  this
   case), because it is forked from the parent screen process, not from the invoking shell.

   If  /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 pro‐
   gram.  (You can do this by using test for example.)

   If you're impatient and want to get started without doing a lot more reading, you should remember this one command:  C-a ?.  Typing these two characters will
   display  a list of the available screen commands and their bindings. Each keystroke is discussed in the section DEFAULT KEY BINDINGS. The manual section CUS
   TOMIZATION deals with the contents of your .screenrc.

   If your terminal is a true auto-margin terminal (it doesn't allow the last position on the screen to be updated without scrolling the screen) consider  using
   a  version  of  your  terminal's  termcap that has automatic margins turned off. This will ensure an accurate and optimal update of the screen in all circum
   stances. 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  termi
   nal 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  resiz‐
        able 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 run
           ning 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 de‐
        fault  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  com
        mand 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 /run/utmp updating).  This can also be defined through the deflogin .screenrc command.

   -ls [match]
   -list [match]
        does not start screen, but prints a list of pid.tty.host strings and creation timestamps identifying your screen sessions.  Sessions  marked  `detached'
        can  be resumed with screen -r. Those marked `attached' are running and have a controlling terminal. If the session runs in multiuser mode, it is marked
        `multi'. Sessions marked as `unreachable' either live on a different host or are `dead'.  An unreachable session  is  considered  dead,  when  its  name
        matches  either  the  name of the local host, or the specified parameter, if any.  See the -r flag for a description how to construct matches.  Sessions
        marked as `dead' should be thoroughly checked and removed.  Ask your system administrator if you are not sure. Remove sessions with the -wipe option.

   -L   tells screen to turn on automatic output logging for the windows.

   -Logfile file
        By default logfile name is screenlog.0. You can set new logfile name with the -Logfile option.

   -m   causes screen to ignore the $STY environment variable. With screen -m creation of a new session is enforced, regardless whether screen  is  called  from
        within another screen session or not. This flag has a special meaning in connection with the `-d' option:

   -d -m   Start screen in detached mode. This creates a new session but doesn't attach to it. This is useful for system startup scripts.

   -D -m   This also starts screen in detached mode, but doesn't fork a new process. The command exits if the session terminates.

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

   -p number_or_name|-|=|+
        Preselect a window. This is useful when you want to reattach to a specific window or you want to send a command via the -X option to a specific  window.
        As  with  screen's select command, - selects the blank window. As a special case for reattach, = brings up the windowlist on the blank window, while a +
        will create a new window. The command will not be executed if the specified window could not be found.

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

   -Q   Some commands now can be queried from a remote session using this flag, e.g. screen -Q windows. The commands will send the response to the stdout of the
        querying process. If there was an error in the command, then the querying process will exit with a non-zero status.

        The commands that can be queried now are:
         echo
         info
         lastmsg
         number
         select
         time
         title
         windows

   -r [pid.tty.host]
   -r sessionowner/[pid.tty.host]
        resumes a detached screen session.  No other options (except combinations with -d/-D) may be specified, though an optional prefix of [pid.]tty.host  may
        be  needed  to distinguish between multiple detached screen sessions.  The second form is used to connect to another user's screen session which runs in
        multiuser mode. This indicates that screen should look for sessions in another user's directory. This requires setuid-root.

   -R   resumes screen only when it's unambiguous which one to attach, usually when only one screen is detached. Otherwise lists available  sessions.   -RR  at‐
        tempts  to resume the youngest (in terms of creation time) 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.  Note: Time-based session
        selection is a Debian addition.

   -s program
        sets the default shell to the program specified, instead of the value in the environment variable $SHELL (or /bin/sh if not defined).  This can also  be
        defined through the shell .screenrc command.  See also there.

   -S sessionname
        When creating a new session, this option can be used to specify a meaningful name for the session. This name identifies the session for screen -list and
        screen -r actions. It substitutes the default [tty.host] suffix. This name should not be longer then 80 symbols.

   -t name
        sets the title (a.k.a.) for the default shell or specified program.  See also the shelltitle .screenrc command.

   -T term
        Set the $TERM environment variable using the specified term as opposed to the default setting of screen.

   -U   Run screen in UTF-8 mode. This option tells screen that your terminal sends and understands UTF-8 encoded characters. It also sets the default  encoding
        for new windows to `utf8'.

   -v   Print version number.

   -wipe [match]
        does the same as screen -ls, but removes destroyed sessions instead of marking them as `dead'.  An unreachable session is considered dead, when its name
        matches either the name of the local host, or the explicitly given parameter, if any.  See the -r flag for a description how to construct matches.

   -x   Attach to a not detached screen session. (Multi display mode).  Screen refuses to attach from within itself.  But when cascading multiple screens, loops
        are not detected; take care.

   -X   Send the specified command to a running screen session. You may use the -S option to specify the screen session if you have several screen sessions run‐
        ning. You can use the -d or -r option to tell screen to look only for attached or detached screen sessions. Note that this command doesn't work  if  the
        session is password protected.

   -4   Resolve hostnames only to IPv4 addresses.

   -6   Resolve hostnames only to IPv6 addresses.

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  win
   dow. See section CUSTOMIZATION for a description of the command.

   The following table shows the default key bindings. The trailing commas in boxes with multiple keystroke entries are separators, not part of the bindings.

   
   C-a '              (select)          Prompt  for  a  window  name or number to
                                        switch to.
   ───────────────────────────────────────────────────────────────────────────────
   C-a "              (windowlist -b)   Present a list of all windows for  selec‐
                                        tion.
   ───────────────────────────────────────────────────────────────────────────────
   C-a digit          (select 0-9)      Switch to window number 0 - 9
   ───────────────────────────────────────────────────────────────────────────────
   C-a -              (select -)        Switch  to window number 0 - 9, or to the
                                        blank window.
   ───────────────────────────────────────────────────────────────────────────────
   C-a tab            (focus)           Switch the input focus to  the  next  re‐
                                        gion.  See also split, remove, only.
   ───────────────────────────────────────────────────────────────────────────────
   C-a C-a            (other)           Toggle  to  the  window  displayed previ‐
                                        ously.  Note that this  binding  defaults
                                        to the command character typed twice, un‐
                                        less overridden.  For  instance,  if  you
                                        use the option -e]x, this command becomes
                                        ]].
   ───────────────────────────────────────────────────────────────────────────────
   C-a a              (meta)            Send the command character (C-a) to  win‐
                                        dow. See escape command.
   ───────────────────────────────────────────────────────────────────────────────
   C-a A              (title)           Allow  the  user  to enter a name for the
                                        current window.
   ───────────────────────────────────────────────────────────────────────────────
   C-a b,             (break)           Send a break to window.
   C-a C-b
   ───────────────────────────────────────────────────────────────────────────────
   C-a B              (pow_break)       Reopen  the  terminal  line  and  send  a
                                        break.
   ───────────────────────────────────────────────────────────────────────────────
   C-a c,             (screen)          Create  a  new  window  with  a shell and
   C-a C-c                              switch to that window.
   ───────────────────────────────────────────────────────────────────────────────
   C-a C              (clear)           Clear the screen.
   ───────────────────────────────────────────────────────────────────────────────
   C-a d,             (detach)          Detach screen from this terminal.
   C-a C-d
   ───────────────────────────────────────────────────────────────────────────────

   C-a D D            (pow_detach)      Detach and logout.
   ───────────────────────────────────────────────────────────────────────────────
   C-a f,             (flow)            Toggle flow on, off or auto.
   C-a C-f
   ───────────────────────────────────────────────────────────────────────────────
   C-a F              (fit)             Resize the window to the  current  region
                                        size.
   ───────────────────────────────────────────────────────────────────────────────
   C-a C-g            (vbell)           Toggles screen's visual bell mode.
   
   C-a h              (hardcopy)        Write a hardcopy of the current window to
                                        the file hardcopy.n.
   
   C-a H              (log)             Begins/ends logging of the current window
                                        to the file screenlog.n.
   
   C-a i,             (info)            Show info about this window.
   C-a C-i
   
   C-a k,             (kill)            Destroy current window.
   C-a C-k
   
   C-a l,             (redisplay)       Fully refresh current window.
   C-a C-l
   
   C-a L              (login)           Toggle this windows login slot. Available
                                        only if screen is  configured  to  update
                                        the utmp database.
   
   C-a m,             (lastmsg)         Repeat  the last message displayed in the
   C-a C-m                              message line.
   
   C-a M              (monitor)         Toggles monitoring of the current window.
   
   C-a space,         (next)            Switch to the next window.
   C-a n,
   C-a C-n
   
   C-a N              (number)          Show the number (and title) of  the  cur
                                        rent window.
   
   C-a backspace,     (prev)            Switch  to  the previous window (opposite
   C-a C-h,                             of C-a n).
   C-a p,
   C-a C-p
   
   C-a q,             (xon)             Send a control-q to the current window.
   C-a C-q
   
   C-a Q              (only)            Delete all regions but the  current  one.
                                        See also split, remove, focus.
   
   C-a r,             (wrap)            Toggle  the  current  window's  line-wrap
   C-a C-r                              setting (turn the current window's  auto
                                        matic margins on and off).
   
   C-a s,             (xoff)            Send a control-s to the current window.
   C-a C-s;
   
   C-a S              (split)           Split  the  current  region  horizontally
                                        into two new ones.  See  also  only,  re
                                        move, focus.
   
   C-a t,             (time)            Show system information.
   C-a C-t
   

   C-a v              (version)         Display the version and compilation date.
   
   C-a C-v            (digraph)         Enter digraph.
   C-a w,             (windows)         Show a list of window.
   C-a C-w
   
   C-a W              (width)           Toggle 80/132 columns.
   
   C-a x or C-a C-x   (lockscreen)      Lock this terminal.
   
   C-a X              (remove)          Kill the current region.  See also split,
                                        only, focus.
   
   C-a z,             (suspend)         Suspend screen.  Your system must support
   C-a C-z                              BSD-style job-control.
   
   C-a Z              (reset)           Reset  the virtual terminal to its power-
                                        on values.
   
   C-a .              (dumptermcap)     Write out a .termcap file.
   
   C-a ?              (help)            Show key bindings.
   
   C-a \              (quit)            Kill all windows and terminate screen.
   
   C-a :              (colon)           Enter command line mode.
   
   C-a [,             (copy)            Enter copy/scrollback mode.
   C-a C-[,
   C-a esc
   
   C-a C-],           (paste .)         Write the contents of the paste buffer to
   C-a ]                                the stdin queue of the current window.
   
   C-a {,             (history)         Copy and paste a previous (command) line.
   C-a }
   
   C-a >              (writebuf)        Write paste buffer to a file.
   
   C-a <              (readbuf)         Reads  the  screen-exchange file into the
                                        paste buffer.
   
   C-a =              (removebuf)       Removes the file used by C-a < and C-a >.
   
   C-a ,              (license)         Shows where screen comes from,  where  it
                                        went to and why you can use it.
   
   C-a _              (silence)         Start/stop  monitoring the current window
                                        for inactivity.
   
   C-a |              (split -v)        Split the current region vertically  into
                                        two new ones.
   
   C-a *              (displays)        Show  a listing of all currently attached
                                        displays.
   

CUSTOMIZATION

   The socket directory defaults either to $HOME/.screen or simply to /tmp/screens or preferably to /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 defaults that can be overridden in the following ways:  for  the
   global  screenrc  file  screen  searches for the environment variable $SYSSCREENRC (this override feature may be disabled at compile-time). The user specific
   screenrc file is searched in $SCREENRC, then $HOME/.screenrc.  The command line option -c takes precedence over the above user screenrc files.

   Commands in these files are used to set options, bind functions to keys, and to automatically establish one or more windows at the beginning of  your  screen
   session.   Commands are listed one per line, with empty lines being ignored.  A command's arguments are separated by tabs or spaces, and may be surrounded by
   single or double quotes.  A `#' turns the rest of the line into a comment, except in quotes.  Unintelligible lines are warned about  and  ignored.   Commands
   may contain references to environment variables. The syntax is the shell-like "$VAR " or "${VAR}". Note that this causes incompatibility with previous screen
   versions, as now the '$'-character has to be protected with '\' if no variable substitution shall be performed. A string in single-quotes is  also  protected
   from variable substitution.

   Two configuration files are shipped as examples with your screen distribution: etc/screenrc and etc/etcscreenrc. They contain a number of useful examples for
   various commands.

   Customization can also be done 'on-line'. To enter the command mode type `C-a :'. Note that commands starting with def change default  values,  while  others
   change current settings.

   The following commands are available:

   acladd usernames [crypted-pw]

   addacl usernames

   Enable  users to fully access this screen session. Usernames can be one user or a comma separated list of users. This command enables to attach to the screen
   session and performs the equivalent of `aclchg usernames +rwx "#?"'.  executed. To add a user with restricted access, use the `aclchg' command below.  If  an
   optional second parameter is supplied, it should be a crypted password for the named user(s). `Addacl' is a synonym to `acladd'.  Multi user mode only.

   aclchg usernames permbits list

   chacl usernames permbits list

   Change permissions for a comma separated list of users. Permission bits are represented as `r', `w' and `x'. Prefixing `+' grants the permission, `-' removes
   it. The third parameter is a comma separated list of commands and/or windows (specified either by number or title). The special list `#' refers to  all  win
   dows, `?' to all commands. if usernames consists of a single `*', all known users are affected.

   A  command can be executed when the user has the `x' bit for it.  The user can type input to a window when he has its `w' bit set and no other user obtains a
   writelock for this window.  Other bits are currently ignored.  To withdraw the writelock from another user in window 2: `aclchg username -w+w 2'.   To  allow
   read-only  access  to  the  session: `aclchg username -w "#"'. As soon as a user's name is known to screen he can attach to the session and (per default) has
   full permissions for all command and windows. Execution permission for the acl commands, `at' and others should also be removed or the user may  be  able  to
   regain  write  permission.  Rights of the special username nobody cannot be changed (see the su command).  `Chacl' is a synonym to `aclchg'.  Multi user mode
   only.

   acldel username

   Remove a user from screen's access control list. If currently attached, all the user's displays are detached from the session. He cannot attach again.  Multi
   user mode only.

   aclgrp username [groupname]

   Creates  groups  of  users  that share common access rights. The name of the group is the username of the group leader. Each member of the group inherits the
   permissions that are granted to the group leader. That means, if a user fails an access check, another check is made for the group leader.  A user is removed
   from all groups the special value none is used for groupname.  If the second parameter is omitted all groups the user is in are listed.

   aclumask [[ users ] +bits | [ users ] -bits... ]

   umask [[ users ] +bits | [ users ] -bits... ]

   This  specifies  the access other users have to windows that will be created by the caller of the command.  Users may be no, one or a comma separated list of
   known usernames. If no users are specified, a list of all currently known users is assumed.  Bits is any combination of access control bits  allowed  defined
   with the aclchg command. The special username ? predefines the access that not yet known users will be granted to any window initially.  The special username
   ?? predefines the access that not yet known users are granted to any command.  Rights of the special username nobody cannot be changed (see the su  command).
   `Umask' is a synonym to `aclumask'.

   activity message

   When any activity occurs in a background window that is being monitored, screen displays a notification in the message line.  The notification message can be
   re-defined by means of the activity command.  Each occurrence of `%' in message is replaced by the number of the window in which activity has  occurred,  and
   each occurrence of `^G' is replaced by the definition for bell in your termcap (usually an audible bell).  The default message is

                   'Activity in window %n'

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

   allpartial [ on | off ]

   If  set to on, only the current cursor line is refreshed on window change.  This affects all windows and is useful for slow terminal lines. The previous set‐
   ting of full/partial refresh for each window is restored with allpartial off.  This is a global flag that immediately takes effect on all windows  overriding
   the partial settings. It does not change the default redraw behavior of newly created windows.

   altscreen [ on | off ]

   If set to on, "alternate screen" support is enabled in virtual terminals, just like in xterm.  Initial setting is `off'.

   at [identifier][#|*|%] command [args ... ]

   Execute  a  command at other displays or windows as if it had been entered there.  At changes the context (the `current window' or `current display' setting)
   of the command. If the first parameter describes a non-unique context, the command will be executed multiple times. If the first parameter  is  of  the  form
   `identifier*'  then  identifier is matched against user names.  The command is executed once for each display of the selected user(s). If the first parameter
   is of the form `identifier%' identifier is matched against displays. Displays are named after the ttys they attach. The prefix `/dev/' or `/dev/tty'  may  be
   omitted from the identifier.  If identifier has a `#' or nothing appended it is matched against window numbers and titles. Omitting an identifier in front of
   the `#', `*' or `%'-character selects all users, displays or windows because a prefix-match is performed. Note that on the affected display(s) a  short  mes‐
   sage  will  describe  what happened. Permission is checked for initiator of the at command, not for the owners of the affected display(s).  Note that the '#'
   character works as a comment introducer when it is preceded by whitespace. This can be escaped by prefixing a '\'.  Permission is checked for  the  initiator
   of the at command, not for the owners of the affected display(s).

   Caveat:  When  matching  against  windows,  the  command is executed at least once per window. Commands that change the internal arrangement of windows (like
   other) may be called again. In shared windows the command will be repeated for each attached display. Beware, when issuing toggle commands like login!   Some
   commands (e.g. process) require that a display is associated with the target windows.  These commands may not work correctly under at looping over windows.

   attrcolor attrib [attribute/color-modifier]

   This command can be used to highlight attributes by changing the color of the text. If the attribute attrib is in use, the specified attribute/color modifier
   is also applied. If no modifier is given, the current one is deleted. See the STRING ESCAPES chapter for the syntax of the modifier. Screen  understands  two
   pseudo-attributes, i stands for high-intensity foreground color and I for high-intensity background color.

   Examples:

          attrcolor b "R"

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

          attrcolor u "-u b"

   Use blue text instead of underline.

          attrcolor b ".I"

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

          attrcolor i "+b"

   Make bright colored text also bold.

   autodetach [ on | off ]

   Sets  whether  screen  will  automatically  detach  upon hangup, which saves all your running programs until they are resumed with a screen -r command.  When
   turned off, a hangup signal will terminate screen and all the processes it contains. Autodetach is on by default.

   autonuke [ on | off ]

   Sets whether a clear screen sequence should nuke all the output that has not been written to the terminal. See also obuflimit.

   backtick id lifespan autorefresh cmd args...

   backtick id

   Program the backtick command with the numerical id id.  The output of such a command is used for substitution of the %` string escape. The specified lifespan
   is  the number of seconds the output is considered valid. After this time, the command is run again if a corresponding string escape is encountered.  The au‐
   torefresh parameter triggers an automatic refresh for caption and hardstatus strings after the specified number of seconds. Only the last line of  output  is
   used for substitution.

   If both the lifespan and the autorefresh parameters are zero, the backtick program is expected to stay in the background and generate output once in a while.
   In this case, the command is executed right away and screen stores the last line of output. If a new line gets printed screen will automatically refresh  the
   hardstatus or the captions.

   The second form of the command deletes the backtick command with the numerical id id.

   bce [ on | off ]

   Change background-color-erase setting. If bce is set to on, all characters cleared by an erase/insert/scroll/clear operation will be displayed in the current
   background color. Otherwise the default background color is used.

   bell_msg [message]

   When a bell character is sent to a background window, screen displays a notification in the message line.  The notification message can be re-defined by this
   command.  Each occurrence of `%' in message is replaced by the number of the window to which a bell has been sent, and each occurrence of `^G' is replaced by
   the definition for bell in your termcap (usually an audible bell).  The default message is

                   'Bell in window %n'

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

   bind [class] key [command [args]]

   Bind a command to a key.  By default, most of the commands provided by screen are bound to one or more keys as indicated in the DEFAULT KEY BINDINGS section,
   e.g. the command to create a new window is bound to C-c and c.  The bind command can be used to redefine the key bindings and to define  new  bindings.   The
   key  argument  is  either  a single character, a two-character sequence of the form ^x (meaning C-x), a backslash followed by an octal number (specifying the
   ASCII code of the character), or a backslash followed by a second character, such as \^ or \\.  The argument can also be quoted, if you like.  If no  further
   argument is given, any previously established binding for this key is removed.  The command argument can be any command listed in this section.

   If a command class is specified via the -c option, the key is bound for the specified class. Use the command command to activate a class. Command classes can
   be used to create multiple command keys or multi-character bindings.

   Some examples:

                   bind ' ' windows
                   bind ^k
                   bind k
                   bind K kill
                   bind ^f screen telnet foobar
                   bind \033 screen -ln -t root -h 1000 9 su

   would bind the space key to the command that displays a list of windows (so that the command usually invoked by C-a  C-w  would  also  be  available  as  C-a
   space).  The next three lines remove the default kill binding from C-a C-k and C-a k.  C-a K is then bound to the kill command. Then it binds C-f to the com‐
   mand create a window with a TELNET connection to foobar, and bind escape to the command that creates an non-login window with a.k.a. root in slot #9, with  a
   superuser shell and a scrollback buffer of 1000 lines.

                   bind -c demo1 0 select 10
                   bind -c demo1 1 select 11
                   bind -c demo1 2 select 12
                   bindkey "^B" command -c demo1

   makes C-b 0 select window 10, C-b 1 window 11, etc.

                   bind -c demo2 0 select 10
                   bind -c demo2 1 select 11
                   bind -c demo2 2 select 12
                   bind - command -c demo2

   makes C-a - 0 select window 10, C-a - 1 window 11, etc.

   bindkey [-d] [-m] [-a] [[-k|-t] string [cmd-args]]

   This command manages screen's input translation tables. Every entry in one of the tables tells screen how to react if a certain sequence of characters is en
   countered. 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 argu‐
   ment 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 transla‐
   tion table. You can select the application mode entry by specifying the -a option.

   The -t option tells screen not to do inter-character timing. One cannot turn off the timing if a termcap capability is used.

   Cmd can be any of screen's commands with an arbitrary number of args.  If cmd is omitted the key-binding is removed from the table.

   Here are some examples of keyboard bindings:

           bindkey -d

   Show all of the default key bindings. The application mode entries are marked with [A].

           bindkey -k k1 select 1

   Make the "F1" key switch to window one.

           bindkey -t foo stuff barfoo

   Make "foo" an abbreviation of the word "barfoo". Timeout is disabled so that users can type slowly.

           bindkey "\024" mapdefault

   This key-binding makes ^T an escape character for key-bindings. If you did the above stuff barfoo binding, you can enter the word foo by typing ^Tfoo. If you
   want to insert a ^T you have to press the key twice (i.e., escape the escape binding).

           bindkey -k F1 command

   Make the F11 (not F1!) key an alternative screen escape (besides ^A).

   break [duration]

   Send  a  break signal for duration*0.25 seconds to this window.  For non-Posix systems the time interval may be rounded up to full seconds.  Most useful if a
   character device is attached to the window rather than a shell process (See also chapter WINDOW TYPES). The maximum duration of a break signal is limited  to
   15 seconds.

   blanker

   Activate  the  screen blanker. First the screen is cleared. If no blanker program is defined, the cursor is turned off, otherwise, the program is started and
   it's output is written to the screen.  The screen blanker is killed with the first keypress, the read key is discarded.

   This command is normally used together with the idle command.

   blankerprg [program-args]

   Defines a blanker program. Disables the blanker program if an empty argument is given. Shows the currently set blanker program if no arguments are given.

   breaktype [tcsendbreak|TIOCSBRK|TCSBRK]

   Choose one of the available methods of generating a break signal for terminal devices. This command should affect the current window only.  But it still  be‐
   haves identical to defbreaktype. This will be changed in the future.  Calling breaktype with no parameter displays the break method for the current window.

   bufferfile [exchange-file]

   Change  the  filename used for reading and writing with the paste buffer.  If the optional argument to the bufferfile command is omitted, the default setting
   (/tmp/screen-exchange) is reactivated.  The following example will paste the system's password file into the screen window (using the paste buffer,  where  a
   copy remains):

                   C-a : bufferfile /etc/passwd
                   C-a < C-a ]
                   C-a : bufferfile

   bumpleft

   Swaps window with previous one on window list.

   bumpright

   Swaps window with next one on window list.

   c1 [ on | off ]

   Change  c1  code  processing.  C1 on tells screen to treat the input characters between 128 and 159 as control functions.  Such an 8-bit code is normally the
   same as ESC followed by the corresponding 7-bit code. The default setting is to process c1 codes and can be changed with the defc1 command.  Users with fonts
   that have usable characters in the c1 positions may want to turn this off.

   caption [ top | bottom ] always|splitonly[string]

   caption string [string]

   This  command  controls  the  display  of  the window captions. Normally a caption is only used if more than one window is shown on the display (split screen
   mode). But if the type is set to always screen shows a caption even if only one window is displayed. The default is splitonly.

   The second form changes the text used for the caption. You can use all escapes from the STRING ESCAPES chapter. Screen uses a default of `%3n %t'.

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

   You can have the caption displayed either at the top or bottom of the window.  The default is bottom.

   charset set

   Change the current character set slot designation and charset mapping.  The first four character of set are treated as charset designators  while  the  fifth
   and  sixth  character  must  be in range '0' to '3' and set the GL/GR charset mapping. On every position a '.' may be used to indicate that the corresponding
   charset/mapping should not be changed (set is padded to six characters internally by appending '.'  chars). New windows have "BBBB02" as default charset, un‐
   less a encoding command is active.
   The current setting can be viewed with the info command.

   chdir [directory]

   Change  the  current  directory  of screen to the specified directory or, if called without an argument, to your home directory (the value of the environment
   variable $HOME).  All windows that are created by means of the screen command from within .screenrc or by means of C-a : screen ...  or C-a  c  use  this  as
   their default directory.  Without a chdir command, this would be the directory from which screen was invoked.

   Hardcopy  and  log  files  are always written to the window's default directory, not the current directory of the process running in the window.  You can use
   this command multiple times in your .screenrc to start various windows in different default directories, but the last chdir value will affect all the windows
   you create interactively.

   cjkwidth [ on | off ]

   Treat ambiguous width characters as full/half width.

   clear

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

   collapse

   Reorders window on window list, removing number gaps between them.

   colon [prefix]

   Allows  you  to  enter .screenrc command lines. Useful for on-the-fly modification of key bindings, specific window creation and changing settings. Note that
   the set keyword no longer exists! Usually commands affect the current window rather than default settings for future windows. Change defaults  with  commands
   starting with 'def...'.

   If you consider this as the `Ex command mode' of screen, you may regard C-a esc (copy mode) as its `Vi command mode'.

   command [ -c class"]"

   This  command has the same effect as typing the screen escape character (^A). It is probably only useful for key bindings.  If the -c option is given, select
   the specified command class.  See also bind and bindkey.

   compacthist [ on | off ]

   This tells screen whether to suppress trailing blank lines when scrolling up text into the history buffer.

   console [ on | off ]

   Grabs or un-grabs the machines console output to a window.  Note: Only the owner of /dev/console can grab the console output.  This command is only available
   if the machine supports the ioctl TIOCCONS.

   copy

   Enter  copy/scrollback  mode. This allows you to copy text from the current window and its history into the paste buffer. In this mode a vi-like `full screen
   editor' is active:
   The editor's movement keys are:

   
   h, C-h,        move the cursor left.
   left arrow
   
   j, C-n,        move the cursor down.
   down arrow
   
   k, C-p,        move the cursor up.
   up arrow
   
   l ('el'),      move the cursor right.
   right arrow
   
   0 (zero) C-a   move to the leftmost column.
   
   + and -        positions one line up and down.
   
   H, M and L     move the cursor to the leftmost column of the top, cen
                  ter or bottom line of the window.
   
   |              moves to the specified absolute column.
   
   g or home      moves to the beginning of the buffer.
   
   G or end       moves  to  the specified absolute line (default: end of
                  buffer).
   
   %              jumps to the specified percentage of the buffer.
   
   ^ or $         move to the leftmost column, to the first or last  non-
                  whitespace character on the line.
   
   w, b, and e    move the cursor word by word.
   
   B, E           move the cursor WORD by WORD (as in vi).
   
   f/F, t/T       move the cursor forward/backward to the next occurrence
                  of the target. (eg, '3fy' will move the cursor  to  the
                  3rd 'y' to the right.)
   
   ; and ,        Repeat  the  last  f/F/t/T command in the same/opposite
                  direction.
   

   C-e and C-y    scroll the display up/down by one line while preserving
                  the cursor position.
   
   C-u and C-d    scroll  the  display up/down by the specified amount of
                  lines while preserving the cursor  position.  (Default:
                  half screen-full).
   
   C-b and C-f    scroll the display up/down a full screen.
   

   Note:  Emacs style movement keys can be customized by a .screenrc command.  (E.g. markkeys "h=^B:l=^F:$=^E") There is no simple method for a full emacs-style
   keymap, as this involves multi-character codes.

   Some keys are defined to do mark and replace operations.

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

          space or enter to set the first or second mark respectively. If mousetrack is set to `on', marks can also be set using left mouse click.

          Y and y used to mark one whole line or to mark from start of line.

          W marks exactly one word.

   Any of these commands can be prefixed with a repeat count number by pressing digits

          0..9 which is taken as a repeat count.

   Example: C-a C-[ H 10 j 5 Y will copy lines 11 to 15 into the paste buffer.

   The following search keys are defined:

          / Vi-like search forward.

          ? Vi-like search backward.

          C-a s Emacs style incremental search forward.

          C-r Emacs style reverse i-search.

          n Find next search pattern.

          N Find previous search pattern.

   There are however some keys that act differently than in vi.  Vi does not allow one to yank rectangular blocks of text, but screen does. Press: c or C to set
   the left or right margin respectively. If no repeat count is given, both default to the current cursor position.

   Example: Try this on a rather full text screen:

          C-a [ M 20 l SPACE c 10 l 5 j C SPACE.

   This  moves  one  to  the middle line of the screen, moves in 20 columns left, marks the beginning of the paste buffer, sets the left column, moves 5 columns
   down, sets the right column, and then marks the end of the paste buffer. Now try:

          C-a [ M 20 l SPACE 10 l 5 j SPACE

   and notice the difference in the amount of text copied.

   J joins lines. It toggles between 4 modes: lines separated by a newline character (012), lines glued seamless, lines separated by  a  single  whitespace  and
   comma separated lines. Note that you can prepend the newline character with a carriage return character, by issuing a crlf on.

   v or V is for all the vi users with :set numbers - it toggles the left margin between column 9 and 1. Press

   a before the final space key to toggle in append mode. Thus the contents of the paste buffer will not be overwritten, but is appended to.

   A toggles in append mode and sets a (second) mark.

   >  sets  the  (second) mark and writes the contents of the paste buffer to the screen-exchange file (/tmp/screen-exchange per default) once copy-mode is fin‐
   ished.

   This example demonstrates how to dump the whole scrollback buffer to that file: C-A [ g SPACE G $ >.

   C-g gives information about the current line and column.

   x or o exchanges the first mark and the current cursor position. You can use this to adjust an already placed mark.

   C-l ('el') will redraw the screen.

   @ does nothing. Does not even exit copy mode.

   All keys not described here exit copy mode.

   copy_reg [key]

   No longer exists, use readreg instead.

   crlf [ on | off ]

   This affects the copying of text regions with the `C-a [' command. If it is set to `on', lines will be separated by the two character sequence `CR'  -  `LF'.
   Otherwise (default) only `LF' is used.  When no parameter is given, the state is toggled.

   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, TCS
   BRK, blocks the complete screen session for the duration of the break, but it may be the only way to generate long breaks.  Tcsendbreak and TIOCSBRK  may  or
   may not produce long breaks with spikes (e.g. 4 per second). This is not only system-dependent, this also differs between serial board drivers.  Calling def
   breaktype with no parameter displays the current setting.

   defcharset [set]

   Like the charset command except that the default setting for new windows is changed. Shows current default if called without argument.

   defdynamictitle [ on | off ]

   Set default behaviour for new windows regarding if screen should change window title when seeing proper escape sequence. See also "TITLES  (naming  windows)"
   section.

   defescape xy

   Set  the default command characters. This is equivalent to the escape except that it is useful multiuser sessions only. In a multiuser session escape changes
   the command character of the calling user, where defescape changes the default command characters for users that will be added later.

   defflow [ on | off | auto [ interrupt ]]

   Same as the flow command except that the default setting for new windows is changed. Initial setting is `auto'.  Specifying defflow  auto  interrupt  is  the
   same as the command-line options -fa and -i.

   defgr [ on | off ]

   Same as the gr command except that the default setting for new windows is changed. Initial setting is `off'.

   defhstatus [status]

   The  hardstatus line that all new windows will get is set to status.  This command is useful to make the hardstatus of every window display the window number
   or title or the like.  Status may contain the same directives as in the window messages, but the directive escape character is '^E' (octal  005)  instead  of
   '%'.   This  was  done to make a misinterpretation of program generated hardstatus lines impossible.  If the parameter status is omitted, the current default
   string is displayed.  Per default the hardstatus line of new windows is empty.

   defencoding enc

   Same as the encoding command except that the default setting for new windows is changed. Initial setting is the encoding taken from the terminal.

   deflog [ on | off ]

   Same as the log command except that the default setting for new windows is changed. Initial setting is `off'.

   deflogin [ on | off ]

   Same as the login command except that the default setting for new windows is changed. This is initialized with `on' as distributed (see config.h.in).

   defmode mode

   The mode of each newly allocated pseudo-tty is set to mode.  Mode is an octal number.  When no defmode command is given, mode 0622 is used.

   defmonitor [ on | off]

   Same as the monitor command except that the default setting for new windows is changed. Initial setting is `off'.

   defmousetrack [ on | off ]

   Same as the mousetrack command except that the default setting for new windows is changed. Initial setting is `off'.

   defnonblock [ on | off | numsecs]

   Same as the nonblock command except that the default setting for displays is changed. Initial setting is `off'.

   defobuflimit limit

   Same as the obuflimit command except that the default setting for new displays is changed. Initial setting is 256 bytes.  Note that you can use  the  special
   'OL' terminal capability if you want to have a dependency on the terminal type.

   defscrollback num

   Same as the scrollback command except that the default setting for new windows is changed. Initial setting is 100.

   defshell command

   Synonym to the shell .screenrc command. See there.

   defsilence [ on | off ]

   Same as the silence command except that the default setting for new windows is changed. Initial setting is `off'.

   defslowpaste msec

   Same as the slowpaste command except that the default setting for new windows is changed. Initial setting is 0 milliseconds, meaning `off'.

   defutf8 [ on | off ]

   Same as the utf8 command except that the default setting for new windows is changed. Initial setting is `on' if screen was started with -U, otherwise `off'.

   defwrap [ on | off ]

   Same  as the wrap command except that the default setting for new windows is changed. Initially line-wrap is on and can be toggled with the wrap command (C-a
   r) or by means of "C-a : wrap on|off".

   defwritelock [ on | off | auto ]

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

   detach [-h]

   Detach the screen session (disconnect it from the terminal and put it into the background).  This returns you to the shell where you invoked screen.   A  de‐
   tached  screen  can be resumed by invoking screen with the -r option (see also section COMMAND-LINE OPTIONS). The -h option tells screen to immediately close
   the connection to the terminal (hangup).

   dinfo

   Show what screen thinks about your terminal. Useful if you want to know why features like color or the alternate charset don't work.

   displays

   Shows a tabular listing of all currently connected user front-ends (displays).  This is most useful for multiuser sessions.  The following keys can  be  used
   in displays list:

   
   k, C-p, or up           Move up one line.
   
   j, C-n, or down         Move down one line.
   
   C-a or home             Move to the first line.
   
   C-e or end              Move to the last line.
   
   C-u or C-d              Move one half page up or down.
   
   C-b or C-f              Move one full page up or down.
   
   mouseclick              Move to the selected line. Available when mousetrack is
                           set to on.
   
   space                   Refresh the list
   
   d                       Detach that display
   
   D                       Power detach that display
   
   C-g, enter, or escape   Exit the list
   

   The following is an example of what displays could look like:
          xterm 80x42 jnweiger@/dev/ttyp4     0(m11)   &rWx
          facit 80x24 mlschroe@/dev/ttyhf nb 11(tcsh)   rwx
          xterm 80x42 jnhollma@/dev/ttyp5     0(m11)   &R.x
           (A)   (B)     (C)     (D)     (E) (F)(G)   (H)(I)

   The legend is as follows:

          (A) The terminal type known by screen for this display.

          (B) Displays geometry as width x height.

          (C) Username who is logged in at the display.

          (D) Device name of the display or the attached device

          (E) Display is in blocking or nonblocking mode.  The available modes are "nb", "NB", "Z<", "Z>", and "BL".

          (F) Number of the window

          (G) Name/title of window

          (H) Whether the window is shared

          (I) Window permissions. Made up of three characters.

          
                       Window permissions indicators              
          
           1st character     2nd character      3rd character   
          
          -   no read      -   no write     -   no execute   
          
          r   read         w   write        x   execute      
          
                           W   own wlock                     
          
          Indicators of permissions suppressed by a foreign wlock 
          
          R   read only    .   no write                      
          
          displays needs a region size of at least 10 characters wide and 5 characters high in order to display.

   digraph [preset[unicode-value]]

   This command prompts the user for a digraph sequence. The next two characters typed are looked up in a builtin table and the resulting character is  inserted
   in  the input stream. For example, if the user enters 'a"', an a-umlaut will be inserted. If the first character entered is a 0 (zero), screen will treat the
   following characters (up to three) as an octal number instead.  The optional argument preset is treated as user input, thus one can  create  an  umlaut  key.
   For  example the command "bindkey ^K digraph '"'" enables the user to generate an a-umlaut by typing CTRL-K a.  When a non-zero unicode-value is specified, a
   new digraph is created with the specified preset. The digraph is unset if a zero value is provided for the unicode-value.

   dumptermcap

   Write the termcap entry for the virtual terminal optimized for the currently active window to the file .termcap in the  user's  $HOME/.screen  directory  (or
   wherever  screen stores its sockets. See the FILES section below).  This termcap entry is identical to the value of the environment variable $TERMCAP that is
   set up by screen for each window. For terminfo based systems you will need to run a converter like captoinfo and then compile the entry with tic.

   dynamictitle [ on | off ]

   Change behaviour for windows regarding if screen should change window title when seeing proper escape sequence. See also "TITLES (naming windows)" section.

   echo [-n] message

   The echo command may be used to annoy screen users with a 'message of the day'. Typically installed in a global /etc/screenrc.  The option -n may be used  to
   suppress the line feed.  See also sleep.  Echo is also useful for online checking of environment variables.

   encoding enc [enc]

   Tell  screen how to interpret the input/output. The first argument sets the encoding of the current window. Each window can emulate a different encoding. The
   optional second parameter overwrites the encoding of the connected terminal. It should never be needed as screen uses the locale setting to detect the encod
   ing.  There is also a way to select a terminal encoding depending on the terminal type by using the KJ termcap entry.

   Supported  encodings  are  eucJP,  SJIS,  eucKR,  eucCN,  Big5,  GBK,  KOI8-R,  KOI8-U, CP1251, UTF-8, ISO8859-2, ISO8859-3, ISO8859-4, ISO8859-5, ISO8859-6,
   ISO8859-7, ISO8859-8, ISO8859-9, ISO8859-10, ISO8859-15, jis.

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

   escape xy

   Set the command character to x and the character generating a literal command character (by triggering the meta command) to y (similar  to  the  -e  option).
   Each  argument  is  either a single character, a two-character sequence of the form ^x (meaning C-x), a backslash followed by an octal number (specifying the
   ASCII code of the character), or a backslash followed by a second character, such as \^ or \\.  The default is ^Aa.

   eval command1[command2 ...]

   Parses and executes each argument as separate command.

   exec [[fdpat]newcommand [args ...]]

   Run a unix subprocess (specified by an executable path newcommand and its optional arguments) in the current window. The flow  of  data  between  newcommands
   stdin/stdout/stderr, the process originally started in the window (let us call it "application-process") and screen itself (window) is controlled by the file
   descriptor pattern fdpat.  This pattern is basically a three character sequence representing stdin, stdout and stderr of newcommand. A dot (.)  connects  the
   file  descriptor  to screen.  An exclamation mark (!) causes the file descriptor to be connected to the application-process. A colon (:) combines both.  User
   input will go to newcommand unless newcommand receives the application-process' output (fdpats first character is `!' or `:') or a pipe symbol (|)  is  added
   (as a fourth character) to the end of fdpat.

   Invoking  `exec'  without arguments shows name and arguments of the currently running subprocess in this window. Only one subprocess a time can be running in
   each window.

   When a subprocess is running the `kill' command will affect it instead of the windows process.

   Refer to the postscript file `doc/fdpat.ps' for a confusing illustration of all 21 possible combinations. Each drawing shows the  digits  2,1,0  representing
   the  three file descriptors of newcommand. The box marked `W' is the usual pty that has the application-process on its slave side.  The box marked `P' is the
   secondary pty that now has screen at its master side.

   Abbreviations: Whitespace between the word `exec' and fdpat and the command can be omitted. Trailing dots and a fdpat consisting only of dots can be omitted.
   A simple `|' is synonymous for the pattern `!..|'; the word exec can be omitted here and can always be replaced by `!'.

   Examples:

          exec ... /bin/sh

          exec /bin/sh

          !/bin/sh

                 Creates  another shell in the same window, while the original shell is still running. Output of both shells is displayed and user input is sent
                 to the new /bin/sh.

          exec !.. stty 19200

          exec ! stty 19200

          !!stty 19200

                 Set the speed of the window's tty. If your stty command operates on stdout, then add another `!'.

          exec !..| less

          |less

                 This adds a pager to the window output. The special character `|' is needed to give the user control over the pager although it gets its  input
                 from  the window's process. This works, because less listens on stderr (a behavior that screen would not expect without the `|') when its stdin
                 is not a tty.  Less versions newer than 177 fail miserably here; good old pg still works.

          !:sed -n s/.*Error.*/\007/p

                 Sends window output to both, the user and the sed command. The sed inserts an additional bell character (oct. 007) to the window output seen by
                 screen.  This will cause "Bell in window x" messages, whenever the string "Error" appears in the window.

   fit

   Change  the window size to the size of the current region. This command is needed because screen doesn't adapt the window size automatically if the window is
   displayed more than once.

   flow [ on | off | auto]

   Sets the flow-control mode for this window.  Without parameters it cycles the current window's flow-control setting from "automatic" to "on" to  "off".   See
   the  discussion  on  FLOW-CONTROL  later on in this document for full details and note, that this is subject to change in future releases.  Default is set by
   `defflow'.

   focus [ next | prev | up | down | left | right | top | bottom ]

   Move the input focus to the next region. This is done in a cyclic way so that the top left region is selected after the bottom right one.  If  no  option  is
   given  it defaults to `next'. The next region to be selected is determined by how the regions are layered.  Normally, the next region in the same layer would
   be selected.  However, if that next region contains one or more layers, the first region in the highest layer is selected first. If you are at the  last  re‐
   gion  of  the current layer, `next' will move the focus to the next region in the lower layer (if there is a lower layer).  `Prev' cycles in the opposite or‐
   der. See split for more information about layers.

   The rest of the options (`up', `down', `left', `right', `top', and `bottom') are more indifferent to layers. The option `up' will move the  focus  upward  to
   the  region  that is touching the upper left corner of the current region.  `Down' will move downward to the region that is touching the lower left corner of
   the current region. The option `left' will move the focus leftward to the region that is touching the upper left corner of the current region, while  `right'
   will  move  rightward to the region that is touching the upper right corner of the current region. Moving left from a left most region or moving right from a
   right most region will result in no action.

   The option `top' will move the focus to the very first region in the upper list corner of the screen, and `bottom' will move to  the  region  in  the  bottom
   right corner of the screen. Moving up from a top most region or moving down from a bottom most region will result in no action.

   Useful bindings are (h, j, k, and l as in vi)
       bind h focus left
       bind j focus down
       bind k focus up
       bind l focus right
       bind t focus top
       bind b focus bottom
   Note that k is traditionally bound to the kill command.

   focusminsize [ ( width|max|_ ) ( height|max|_ ) ]

   This  forces  any currently selected region to be automatically resized at least a certain width and height. All other surrounding regions will be resized in
   order to accommodate.  This constraint follows every time the focus command is used. The resize command can be used to increase either dimension of a region,
   but  never  below  what is set with focusminsize. The underscore `_' is a synonym for max. Setting a width and height of `0 0' (zero zero) will undo any con‐
   straints and allow for manual resizing.  Without any parameters, the minimum width and height is shown.

   gr [ on | off ]

   Turn GR charset switching on/off. Whenever screen sees an input character with the 8th bit set, it will use the charset stored in the GR slot and  print  the
   character with the 8th bit stripped. The default (see also defgr) is not to process GR switching because otherwise the ISO88591 charset would not work.

   group [grouptitle]

   Change or show the group the current window belongs to. Windows can be moved around between different groups by specifying the name of the destination group.
   Without specifying a group, the title of the current group is displayed.

   hardcopy [-h] [file]

   Writes out the currently displayed image to the file file, or, if no filename is specified, to hardcopy.n in the default directory, where n is the number  of
   the  current  window.   This  either  appends  or  overwrites the file if it exists. See below.  If the option -h is specified, dump also the contents of the
   scrollback buffer.

   hardcopy_append [ on | off ]

   If set to "on", screen will append to the "hardcopy.n" files created by the command C-a h, otherwise these files  are  overwritten  each  time.   Default  is
   `off'.

   hardcopydir directory

   Defines a directory where hardcopy files will be placed. If unset, hardcopys are dumped in screen's current working directory.

   hardstatus [ on | off ]

   hardstatus [ always ] firstline | lastline | message | ignore [ string ]

   hardstatus string [ string ]

   This  command  configures the use and emulation of the terminal's hardstatus line. The first form toggles whether screen will use the hardware status line to
   display messages. If the flag is set to `off', these messages are overlaid in reverse video mode at the display line. The default setting is `on'.

   The second form tells screen what to do if the terminal doesn't have a hardstatus line (i.e. the termcap/terminfo capabilities "hs", "ts", "fs" and "ds"  are
   not  set).   When firstline/lastline is used, screen will reserve the first/last line of the display for the hardstatus. message uses screen's message mecha
   nism and ignore tells screen never to display the hardstatus.  If you prepend the word always to the type (e.g., alwayslastline), screen will  use  the  type
   even if the terminal supports a hardstatus.

   The  third  form  specifies the contents of the hardstatus line.  '%h' is used as default string, i.e., the stored hardstatus of the current window (settable
   via ESC]0;<string>^G or ESC_<string>ESC\) is displayed.  You can customize this to any string you like including the escapes from the STRING ESCAPES chapter.
   If you leave out the argument string, the current string is displayed.

   You can mix the second and third form by providing the string as additional argument.

   height [-w|-d] [lines [cols]]

   Set  the display height to a specified number of lines. When no argument is given it toggles between 24 and 42 lines display. You can also specify a width if
   you want to change both values.  The -w option tells screen to leave the display size unchanged and just set the window size, -d vice versa.

   help[class]

   Not really a online help, but displays a help screen showing you all the key bindings.  The first pages list all the internal commands followed by their cur
   rent  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  BIND‐
   INGS section.

   history

   Usually  users  work  with  a  shell  that  allows easy access to previous commands.  For example csh has the command !! to repeat the last command executed.
   Screen allows you to have a primitive way of re-calling the command that started ...: You just type the first letter of that command, then hit  `C-a  {'  and
   screen  tries to find a previous line that matches with the `prompt character' to the left of the cursor. This line is pasted into this window's input queue.
   Thus you have a crude command history (made up by the visible window and its scrollback buffer).

   hstatus status

   Change the window's hardstatus line to the string status.

   idle [timeout[cmd-args]]

   Sets a command that is run after the specified number of seconds inactivity is reached. This command will normally be the blanker command to create a  screen
   blanker,  but it can be any screen command.  If no command is specified, only the timeout is set. A timeout of zero (or the special timeout off) disables the
   timer.  If no arguments are given, the current settings are displayed.

   ignorecase [ on | off ]

   Tell screen to ignore the case of characters in searches. Default is `off'. Without any options, the state of ignorecase is toggled.

   info

   Uses the message line to display some information about the current window: the cursor position in the form (column,row) starting with  (1,1),  the  terminal
   width  and  height  plus the size of the scrollback buffer in lines, like in (80,24)+50, the current state of window XON/XOFF flow control is shown like this
   (See also section FLOW CONTROL):

   
   +flow     automatic flow control, currently on.                    
   
   -flow     automatic flow control, currently off.                   
   
   +(+)flow  flow control enabled. Agrees with automatic control.     
   
   -(+)flow  flow control disabled. Disagrees with automatic control. 
   
   +(-)flow  flow control enabled. Disagrees with automatic control.  
   
   -(-)flow  flow control disabled. Agrees with automatic control.    
   
   The current line wrap setting (`+wrap' indicates enabled, `-wrap' not) is also shown. The flags `ins', `org', `app', `log', `mon' or  `nored'  are  displayed
   when the window is in insert mode, origin mode, application-keypad mode, has output logging, activity monitoring or partial redraw enabled.

   The  currently  active character set (G0, G1, G2, or G3) and in square brackets the terminal character sets that are currently designated as G0 through G3 is
   shown. If the window is in UTF-8 mode, the string UTF-8 is shown instead.

   Additional modes depending on the type of the window are displayed at the end of the status line (See also chapter WINDOW TYPES).

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

   For system information use the time command.

   ins_reg [key]

   No longer exists, use paste instead.

   kill

   Kill current window.

   If there is an `exec' command running then it is killed. Otherwise the process (shell) running in the window receives a HANGUP condition, the  window  struc‐
   ture  is removed and screen (your display) switches to another window.  When the last window is destroyed, screen exits.  After a kill screen switches to the
   previously displayed window.

   Note: Emacs users should keep this command in mind, when killing a line.  It is recommended not to use C-a as the screen escape key or to rebind kill to  C-a
   K.

   lastmsg

   Redisplay  the last contents of the message/status line.  Useful if you're typing when a message appears, because  the message goes away when you press a key
   (unless your terminal has a hardware status line).  Refer to the commands msgwait and msgminwait for fine tuning.

   layout new [title]

   Create a new layout. The screen will change to one whole region and be switched to the blank window. From here, you build the regions and  the  windows  they
   show as you desire. The new layout will be numbered with the smallest available integer, starting with zero. You can optionally give a title to your new lay
   out.  Otherwise, it will have a default title of layout. You can always change the title later by using the command layout title.

   layout remove [n|title]

   Remove, or in other words, delete the specified layout. Either the number or the title can be specified. Without either specification, screen will remove the
   current layout.

   Removing a layout does not affect your set windows or regions.

   layout next

   Switch to the next layout available

   layout prev

   Switch to the previous layout available

   layout select [n|title]

   Select the desired layout. Either the number or the title can be specified. Without either specification, screen will prompt and ask which screen is desired.
   To see which layouts are available, use the layout show command.

   layout show

   List on the message line the number(s) and title(s) of the available layout(s). The current layout is flagged.

   layout title [title]

   Change or display the title of the current layout. A string given will be used to name the layout. Without any options, the current title and number is  dis
   played on the message line.

   layout number [n]

   Change  or display the number of the current layout. An integer given will be used to number the layout. Without any options, the current number and title is
   displayed on the message line.

   layout attach [title|:last]

   Change or display which layout to reattach back to. The default is :last, which tells screen to reattach back to the last used layout just before detachment.
   By  supplying  a  title,  You can instruct screen to reattach to a particular layout regardless which one was used at the time of detachment. Without any op
   tions, the layout to reattach to will be shown in the message line.

   layout save [n|title]

   Remember the current arrangement of regions. When used, screen will remember the arrangement of vertically and horizontally split regions.  This  arrangement
   is restored when a screen session is reattached or switched back from a different layout. If the session ends or the screen process dies, the layout arrange
   ments are lost. The layout dump command should help in this siutation. If a number or title is supplied, screen will remember the arrangement of that partic
   ular layout. Without any options, screen will remember the current layout.

   Saving your regions can be done automatically by using the layout autosave command.

   layout autosave [ on | off]

   Change  or  display  the  status of automatcally saving layouts. The default is on, meaning when screen is detached or changed to a different layout, the ar
   rangement of regions and windows will be remembered at the time of change and restored upon return.  If autosave is set to off, that arrangement will only be
   restored  to either to the last manual save, using layout save, or to when the layout was first created, to a single region with a single window. Without ei
   ther an on or off, the current status is displayed on the message line.

   layout dump [filename]

   Write to a file the order of splits made in the current layout. This is useful to recreate the order of your regions used in your current  layout.  Only  the
   current layout is recorded. While the order of the regions are recorded, the sizes of those regions and which windows correspond to which regions are not. If
   no filename is specified, the default is layout-dump, saved in the directory that the screen process was started in. If the file already exists, layout  dump
   will append to that file. As an example:

            C-a : layout dump /home/user/.screenrc

   will save or append the layout to the user's .screenrc file.

   license

   Display the disclaimer page. This is done whenever screen is started without options, which should be often enough. See also the startup_message command.

   lockscreen

   Lock  this  display.   Call  a screenlock program (/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 log files will get. The default is screenlog.%n. The second form changes the number of seconds screen will wait before flushing the log‐
   file 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 lo
   gin 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 de
   flogin command to change the default login state for new windows. Both commands are only present when screen has been compiled with utmp support.

   logtstamp [on|off]

   logtstamp after [secs]

   logtstamp string
   [string]

   This command controls logfile time-stamp mechanism of screen.  If time-stamps are turned on, screen adds a string containing the current time to the  logfile
   after  two  minutes of inactivity.  When output continues and more than another two minutes have passed, a second time-stamp is added to document the restart
   of the output. You can change this timeout with the second form of the command. The third form is used for customizing the time-stamp string  (`--  %n:%t  --
   time-stamp -- %M/%d/%y %c:%s --\n' by default).

   mapdefault

   Tell screen that the next input character should only be looked up in the default bindkey table. See also bindkey.

   mapnotnext

   Like mapdefault, but don't even look in the default bindkey table.

   maptimeout [timeout]

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

   markkeys string

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

   maxwin num

   Set the maximum window number screen will create. Doesn't affect already existing windows. The number can be increased only when there are no  existing  win‐
   dows.

   meta

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

   monitor [ on | off ]

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

   mousetrack [ on | off ]

   This  command  determines  whether  screen will watch for mouse clicks. When this command is enabled, regions that have been split in various ways can be se‐
   lected by pointing to them with a mouse and left-clicking them. Without specifying on or off, the current state is displayed. The default state is determined
   by the defmousetrack command.

   msgminwait sec

   Defines the time screen delays a new message when one message is currently displayed.  The default is 1 second.

   msgwait sec

   Defines the time a message is displayed if screen is not disturbed by other activity. The default is 5 seconds.

   multiuser [ on | off ]

   Switch  between  singleuser  and  multiuser  mode.  Standard  screen operation is singleuser. In multiuser mode the commands `acladd', `aclchg', `aclgrp' and
   `acldel' can be used to enable (and disable) other users accessing this screen session.

   nethack [ on | off ]

   Changes the kind of error messages used by screen.  When you are familiar with the game nethack, you may enjoy the nethack-style messages  which  will  often
   blur the facts a little, but are much funnier to read. Anyway, standard messages often tend to be unclear as well.
   This option is only available if screen was compiled with the NETHACK flag defined. The default setting is then determined by the presence of the environment
   variable $NETHACKOPTIONS and the file ~/.nethackrc - if either one is present, the default is on.

   next

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

   nonblock [ on | off | numsecs ]

   Tell screen how to deal with user interfaces (displays) that cease to accept output. This can happen if a user presses ^S or a TCP/modem connection gets  cut
   but  no  hangup is received. If nonblock is off (this is the default) screen waits until the display restarts to accept the output. If nonblock is on, screen
   waits until the timeout is reached (on is treated as 1s). If the display still doesn't receive characters, screen will consider it blocked and  stop  sending
   characters to it. If at some time it restarts to accept characters, screen will unblock the display and redisplay the updated window contents.

   number [[+|-]n]

   Change  the  current  window's number. If the given number n is already used by another window, both windows exchange their numbers. If no argument is speci‐
   fied, the current window number (and title) is shown. Using `+' or `-' will change the window's number by the relative amount specified.

   obuflimit [limit]

   If the output buffer contains more bytes than the specified limit, no more data will be read from the windows. The default value is 256. If you have  a  fast
   display (like xterm), you can set it to some higher value. If no argument is specified, the current setting is displayed.

   only

   Kill all regions but the current one.

   other

   Switch to the window displayed previously. If this window does no longer exist, other has the same effect as next.

   partial [ on | off ]

   Defines  whether the display should be refreshed (as with redisplay) after switching to the current window. This command only affects the current window.  To
   immediately affect all windows use the allpartial command.  Default is `off', of course.  This default is fixed, as there is currently no defpartial command.

   password [crypted_pw]

   Present a crypted password in your .screenrc file and screen will ask for it, whenever someone attempts to resume a detached.  This is  useful  if  you  have
   privileged programs running under screen and you want to protect your session from reattach attempts by another user masquerading as your uid (i.e. any supe‐
   ruser.)  If no crypted password is specified, screen prompts twice for typing a password and places its encryption in the paste buffer.  Default  is  `none',
   this disables password checking.

   paste [registers [dest_reg]]

   Write the (concatenated) contents of the specified registers to the stdin queue of the current window. The register '.' is treated as the paste buffer. If no
   parameter is given the user is prompted for a single register to paste.  The paste buffer can be filled with the copy, history and readbuf  commands.   Other
   registers can be filled with the register, readreg and paste commands.  If paste is called with a second argument, the contents of the specified registers is
   pasted into the named destination register rather than the window. If '.' is used as the second argument, the  displays  paste  buffer  is  the  destination.
   Note,  that  paste  uses a wide variety of resources: Whenever a second argument is specified no current window is needed. When the source specification only
   contains registers (not the paste buffer) then there need not be a current display (terminal attached), as the registers are a  global  resource.  The  paste
   buffer exists once for every user.

   pastefont [ on | off ]

   Tell  screen  to  include font information in the paste buffer. The default is not to do so. This command is especially useful for multi character fonts like
   kanji.

   pow_break

   Reopen the window's terminal line and send a break condition. See `break'.

   pow_detach

   Power detach.  Mainly the same as detach, but also sends a HANGUP signal to the parent process of screen.  CAUTION: This will result in a logout, when screen
   was started from your login-shell.

   pow_detach_msg [message]

   The  message  specified  here  is output whenever a `Power detach' was performed. It may be used as a replacement for a logout message or to reset baud rate,
   etc.  Without parameter, the current message is shown.

   prev

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

   printcmd [cmd]

   If cmd is not an empty string, screen will not use the terminal capabilities po/pf if it detects an ansi print sequence ESC [ 5 i, but pipe the  output  into
   cmd.   This  should  normally  be  a  command like lpr or printcmd without a command displays the current setting.  The ansi sequence ESC \ ends printing and
   closes the pipe.

   Warning: Be careful with this command! If other user have write access to your terminal, they will be able to fire off print commands.

   process [key]

   Stuff the contents of the specified register into screen's input queue. If no argument is given you are prompted for a register name. The text is  parsed  as
   if it had been typed in from the user's keyboard. This command can be used to bind multiple actions to a single key.

   quit

   Kill all windows and terminate screen.  Note that on VT100-style terminals the keys C-4 and C-\ are identical.  This makes the default bindings dangerous: Be
   careful not to type C-a C-4 when selecting window no. 4.  Use the empty bind command (as in bind '^\') to remove a key binding.

   readbuf [encoding] [filename]

   Reads the contents of the specified file into the paste buffer.  You can tell screen the encoding of the file via the -e option.  If no  file  is  specified,
   the screen-exchange filename is used.  See also bufferfile command.

   readreg [encoding] [register [filename]]

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

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

   redisplay

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

   register [-eencoding]key-string

   Save the specified string to the register key.  The encoding of the string can be specified via the -e option.  See also the paste command.

   remove

   Kill the current region. This is a no-op if there is only one region.

   removebuf

   Unlinks the screen-exchange file used by the commands writebuf and readbuf.

   rendition [ bell | monitor | silence | so ] attr [ color ]

   Change the way screen renders the titles of windows that have monitor or bell flags set in caption or hardstatus or windowlist. See the STRING ESCAPES  chap
   ter  for the syntax of the modifiers.  The default for monitor is currently =b  (bold, active colors), for bell =ub  (underline, bold and active colors), and
   =u for silence.

   reset

   Reset the virtual terminal to its power-on values. Useful when strange settings (like scroll regions or graphics character set) are left over from an  appli
   cation.

   resize [-h|-v|-b|-l|-p] [[+|-] n[%] |=|max|min|_|0]

   Resize  the  current  region. The space will be removed from or added to the surrounding regions depending on the order of the splits.  The available options
   for resizing are `-h'(horizontal), `-v'(vertical), `-b'(both), `-l'(local to layer), and `-p'(perpendicular). Horizontal resizes will add or remove width  to
   a  region,  vertical  will add or remove height, and both will add or remove size from both dimensions. Local and perpendicular are similar to horizontal and
   vertical, but they take in account of how a region was split.  If a region's last split was horizontal, a local resize will work like a vertical resize. If a
   region's last split was vertical, a local resize will work like a horizontal resize. Perpendicular resizes work in opposite of local resizes. If no option is
   specified, local is the default.

   The amount of lines to add or remove can be expressed a couple of different ways. By specifying a number n by itself will resize the region by that  absolute
   amount. You can specify a relative amount by prefixing a plus `+' or minus `-' to the amount, such as adding +n lines or removing -n lines. Resizing can also
   be expressed as an absolute or relative percentage by postfixing a percent sign `%'. Using zero `0' is a synonym for `min' and using an underscore `_'  is  a
   synonym for `max'.

   Some examples are:

   resize +N
          increase current region by N

   resize -N
          decrease current region by N

   resize  N
          set current region to N

   resize 20%
          set current region to 20% of original size

   resize +20%
          increase current region by 20%

   resize -b =
          make all windows equally

   resize  max
          maximize current region

   resize  min
          minimize current region

   Without any arguments, screen will prompt for how you would like to resize the current region.

   See focusminsize if you want to restrict the minimum size a region can have.

   screen [-opts] [n] [cmd [args]|//group]

   Establish  a  new  window.   The  flow-control  options  (-f, -fn and -fa), title (a.k.a.) option (-t), login options (-l and -ln) , terminal type option (-T
   <term>), the all-capability-flag (-a) and scrollback option (-h <num>) may be specified with each command.  The option (-M) turns monitoring on for this win
   dow.  The option (-L) turns output logging on for this window.  If an optional number n in the range 0..MAXWIN-1 is given, the window number n is assigned to
   the newly created window (or, if this number is already in-use, the next available number).  If a command is specified after screen, this command  (with  the
   given  arguments) is started in the window; otherwise, a shell is created.  If //group is supplied, a container-type window is created in which other windows
   may be created inside it.

   Thus, if your .screenrc contains the lines

            # example for .screenrc:
            screen 1
            screen -fn -t foobar -L 2 telnet foobar

   screen creates a shell window (in window #1) and a window with a TELNET connection to the machine foobar (with no flow-control using the title foobar in win‐
   dow  #2) and will write a logfile (screenlog.2) of the telnet session.  Note, that unlike previous versions of screen no additional default window is created
   when screen commands are included in your .screenrc file. When the initialization is completed,  screen  switches  to  the  last  window  specified  in  your
   .screenrc file or, if none, opens a default window #0.

   Screen has built in some functionality of cu and telnet.  See also chapter WINDOW TYPES.

   scrollback num

   Set  the size of the scrollback buffer for the current windows to num lines. The default scrollback is 100 lines.  See also the defscrollback command and use
   info to view the current setting. To access and use the contents in the scrollback buffer, use the copy command.

   select [WindowID]

   Switch to the window identified by WindowID.  This can be a prefix of a window title (alphanumeric window name) or a window number.   The  parameter  is  op
   tional  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  (which  defaults  to
   40).   There  are  two special WindowIDs, - selects the internal blank window and . selects the current window. The latter is useful if used with screen's -X
   option.

   sessionname [name]

   Rename the current session. Note, that for screen -list the name shows up with the process-id prepended. If the argument name is omitted, the  name  of  this
   session  is  displayed.  Caution: The $STY environment variables will still reflect the old name in pre-existing shells. This may result in confusion. Use of
   this command is generally discouraged. Use the -S command-line option if you want to name a new session.  The default is constructed from the  tty  and  host
   names.

   setenv [var [string]]

   Set the environment variable var to value string.  If only var is specified, the user will be prompted to enter a value.  If no parameters are specified, the
   user will be prompted for both variable and value. The environment is inherited by all subsequently forked shells.

   setsid [ on | off ]

   Normally screen uses different sessions and process groups for the windows. If setsid is turned off, this is not done anymore and all windows will be in  the
   same process group as the screen backend process. This also breaks job-control, so be careful.  The default is on, of course. This command is probably useful
   only in rare circumstances.

   shell command

   Set the command to be used to create a new shell.  This overrides the value of the environment variable $SHELL.  This is useful if you'd like to run  a  tty-
   enhancer  which  is  expecting to execute the program specified in $SHELL.  If the command begins with a '-' character, the shell will be started as a login-
   shell. Typical shells do only minimal initialization when not started as a login-shell.  E.g. Bash will not read your ~/.bash_profile unless it is  a  login-
   shell.

   shelltitle title

   Set the title for all shells created during startup or by the C-A C-c command.  For details about what a title is, see the discussion entitled TITLES (naming
   windows).

   silence [ on | off | sec ]

   Toggles silence monitoring of windows.  When silence is turned on and an affected window is switched into the background, you will receive the silence  noti
   fication message in the status line after a specified period of inactivity (silence). The default timeout can be changed with the `silencewait' command or by
   specifying a number of seconds instead of `on' or `off'.  Silence is initially off for all windows.

   silencewait sec

   Define the time that all windows monitored for silence should wait before displaying a message. Default 30 seconds.

   sleep num

   This command will pause the execution of a .screenrc file for num seconds.  Keyboard activity will end the sleep.  It may be used to give users a  chance  to
   read the messages output by echo.

   slowpaste msec

   Define the speed at which text is inserted into the current window by the paste ("C-a ]") command.  If the slowpaste value is nonzero text is written charac‐
   ter by character.  screen will make a pause of msec milliseconds after each single character write to allow the application to process its  input.  Only  use
   slowpaste if your underlying system exposes flow control problems while pasting large amounts of text.

   sort

   Sort the windows in alphabetical order of the window tiles.

   source file

   Read  and  execute  commands from file file. Source commands may be nested to a maximum recursion level of ten. If file is not an absolute path and screen is
   already processing a source command, the parent directory of the running source command file is used to search for the new command file before screen's  cur
   rent 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 ef
   fect.

   sorendition [attr[color]]

   This command is deprecated. See "rendition so" instead.

   split[-v]

   Split the current region into two new ones. All regions on the display are resized to make room for the new region. The blank window is displayed in the  new
   region.  The  default  is to create a horizontal split, putting the new regions on the top and bottom of each other. Using `-v' will create a vertical split,
   causing the new regions to appear side by side of each other.  Use the remove or the only command to delete regions.  Use focus to toggle between regions.

   When a region is split opposite of how it was previously split (that is, vertical then horizontal or horizontal then vertical), a new layer is  created.  The
   layer  is  used  to group together the regions that are split the same. Normally, as a user, you should not see nor have to worry about layers, but they will
   affect how some commands (focus and resize) behave.

   With this current implementation of screen, scrolling data will appear much slower in a vertically split region than one that is not. This  should  be  taken
   into consideration if you need to use system commands such as cat or tail -f.

   startup_message [ on | off ]

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

   status [ top | up | down | bottom ] [ left | right ]

   The  status window by default is in bottom-left corner. This command can move status messages to any corner of the screen. top is the same as up, down is the
   same as bottom.

   stuff [string]

   Stuff the string string in the input buffer of the current window.  This is like the paste command but with much less overhead.  Without a parameter,  screen
   will prompt for a string to stuff.  You cannot paste large buffers with the stuff command. It is most useful for key bindings. See also bindkey.

   su [username [password [password2]]]

   Substitute  the  user of a display. The command prompts for all parameters that are omitted. If passwords are specified as parameters, they have to be speci
   fied un-crypted. The first password is matched against the systems passwd database, the second password is matched against the screen password  as  set  with
   the commands acladd or password.  Su may be useful for the screen administrator to test multiuser setups.  When the identification fails, the user has access
   to the commands available for user nobody.  These are detach, license, version, help and displays.

   suspend

   Suspend screen.  The windows are in the `detached' state, while screen is suspended. This feature relies on the shell being able to do job control.

   term term

   In each window's environment screen opens, the $TERM variable is set to screen by default.  But when no description for screen  is  installed  in  the  local
   termcap  or  terminfo data base, you set $TERM to - say - vt100. This won't do much harm, as screen is VT100/ANSI compatible.  The use of the term command is
   discouraged for non-default purpose.  That is, one may want to specify special $TERM settings (e.g. vt100) for the next screen rlogin  othermachine  command.
   Use the command screen -T vt100 rlogin othermachine rather than setting and resetting the default.

   termcap term terminal-tweaks[window-tweaks]

   terminfo term terminal-tweaks[window-tweaks]

   termcapinfo term terminal-tweaks[window-tweaks]

   Use  this  command  to modify your terminal's termcap entry without going through all the hassles involved in creating a custom termcap entry.  Plus, you can
   optionally customize the termcap generated for the windows.  You have to place these commands in one of the screenrc startup files, as they  are  meaningless
   once the terminal emulator is booted.

   If  your  system  uses  the terminfo database rather than termcap, screen will understand the `terminfo' command, which has the same effects as the `termcap'
   command.  Two separate commands are provided, as there are subtle syntactic differences, e.g. when parameter interpolation (using `%') is required. Note that
   termcap names of the capabilities have to be used with the `terminfo' command.

   In many cases, where the arguments are valid in both terminfo and termcap syntax, you can use the command `termcapinfo', which is just a shorthand for a pair
   of `termcap' and `terminfo' commands with identical arguments.

   The first argument specifies which terminal(s) should be affected by this definition.  You can specify multiple terminal names by separating them with  `|'s.
   Use `*' to match all terminals and `vt*' to match all terminals that begin with vt.

   Each  tweak  argument  contains one or more termcap defines (separated by `:'s) to be inserted at the start of the appropriate termcap entry, enhancing it or
   overriding existing values.  The first tweak modifies your terminal's termcap, and contains definitions that your terminal uses to perform certain functions.
   Specify  a  null string to leave this unchanged (e.g. '').  The second (optional) tweak modifies all the window termcaps, and should contain definitions that
   screen understands (see the VIRTUAL TERMINAL section).

   Some examples:

          termcap xterm*  LP:hs@

   Informs screen that all terminals that begin with `xterm' have firm auto-margins that allow the last position on the screen to  be  updated  (LP),  but  they
   don't  really have a status line (no 'hs' - append `@' to turn entries off).  Note that we assume `LP' for all terminal names that start with vt, but only if
   you don't specify a termcap command for that terminal.
          termcap vt*  LP

   termcap vt102|vt220  Z0=\E[?3h:Z1=\E[?3l

   Specifies the firm-margined `LP' capability for all terminals that begin with `vt', and the second line will also add the  escape-sequences  to  switch  into
   (Z0)  and  back  out  of (Z1) 132-character-per-line mode if this is a VT102 or VT220.  (You must specify Z0 and Z1 in your termcap to use the width-changing
   commands.)

          termcap vt100  ""  l0=PF1:l1=PF2:l2=PF3:l3=PF4

   This leaves your vt100 termcap alone and adds the function key labels to each window's termcap entry.

          termcap h19|z19  am@:im=\E@:ei=\EO  dc=\E[P

   Takes a h19 or z19 termcap and turns off auto-margins (am@) and enables the insert mode (im) and end-insert (ei) capabilities (the `@' in the `im' string  is
   after the `=', so it is part of the string).  Having the `im' and `ei' definitions put into your terminal's termcap will cause screen to automatically adver
   tise 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 "%c:%s %M %d
   %H%? %l%?".

   title [windowtitle]

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

   unbindall

   Unbind all the bindings. This can be useful when screen is used solely for its detaching abilities, such as when letting a console application run as a  dae‐
   mon. If, for some reason, it is necessary to bind commands after this, use 'screen -X'.

   unsetenv var

   Unset an environment variable.

   utf8 [ on | off [ on | off ]]

   Change the encoding used in the current window. If utf8 is enabled, the strings sent to the window will be UTF-8 encoded and vice versa. Omitting the parame‐
   ter 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 vis‐
   ual bell, a `vbell-message' is displayed in the status line when the bell character (^G) is received.  Visual bell support of a terminal is  defined  by  the
   termcap variable `vb' (terminfo: 'flash').

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

   vbell_msg [message]

   Sets  the  visual bell message. message is printed to the status line if the window receives a bell character (^G), vbell is set to on, but the terminal does
   not support a visual bell.  The default message is Wuff, Wuff!!.  Without a parameter, the current message is shown.

   vbellwait sec

   Define a delay in seconds after each display of screen's visual bell message. The default is 1 second.

   verbose [ on | off ]

   If verbose is switched on, the command name is echoed, whenever a window is created (or resurrected from zombie state). Default is off.  Without a parameter,
   the current setting is shown.

   version

   Print the current version and the compile date in the status line.

   wall message

   Write a message to all displays. The message will appear in the terminal's status line.

   width [-w|-d] [cols [lines]]

   Toggle  the  window width between 80 and 132 columns or set it to cols columns if an argument is specified.  This requires a capable terminal and the termcap
   entries Z0 and Z1.  See the termcap command for more information. You can also specify a new height if you want to change both values.  The -w  option  tells
   screen to leave the display size unchanged and just set the window size, -d vice versa.

   windowlist [ -b ] [ -m ] [ -g ]

   windowlist string [string]

   windowlist title [title]

   Display  all windows in a table for visual window selection.  If screen was in a window group, screen will back out of the group and then display the windows
   in that group.  If the -b option is given, screen will switch to the blank window before presenting the list, so that the current window is also  selectable.
   The  -m  option  changes the order of the windows, instead of sorting by window numbers screen uses its internal most-recently-used list.  The -g option will
   show the windows inside any groups in that level and downwards.

   The following keys are used to navigate in windowlist:

   
   k, C-p, or up      Move up one line.
   
   j, C-n, or down    Move down one line.
   
   C-g or escape      Exit windowlist.
   
   C-a or home        Move to the first line.
   
   C-e or end         Move to the last line.
   
   C-u or C-d         Move one half page up or down.
   
   C-b or C-f         Move one full page up or down.
   
   0..9               Using the number keys, move to the selected line.
   
   mouseclick         Move to the selected line. Available when mousetrack is
                      set to on
   
   /                  Search.
   
   n                  Repeat search in the forward direction.
   
   N                  Repeat search in the backward direction.
   
   m                  Toggle MRU.
   
   g                  Toggle group nesting.
   
   a                  All window view.
   
   C-h or backspace   Back out the group.
   
   ,                  Switch numbers with the previous window.
   
   .                  Switch numbers with the next window.
   
   K                  Kill that window.
   
   space or enter     Select that window.
   

   The  table format can be changed with the string and title option, the title is displayed as table heading, while the lines are made by using the string set
   ting. 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  set
   tings).

   Windowlist needs a region size of at least 10 characters wide and 6 characters high in order to display.

   windows [ string ]

   Uses the message line to display a list of all the windows.  Each window is listed by number with the name of process that has been started in the window (or
   its title); the current window is marked with a `*'; the previous window is marked with a `-'; all the windows that are logged in are marked with  a  `$';  a
   background  window  that  has  received a bell is marked with a `!'; a background window that is being monitored and has had activity occur is marked with an
   `@'; a window which has output logging turned on is marked with `(L)'; windows occupied by other users are marked with `&'; windows in the zombie  state  are
   marked with `Z'.  If this list is too long to fit on the terminal's status line only the portion around the current window is displayed.  The optional string
   parameter follows the STRING ESCAPES format.  If string parameter is passed, the output size is unlimited.  The default command without any parameter is lim‐
   ited to a size of 1024 bytes.

   wrap [ on | off ]

   Sets the line-wrap setting for the current window.  When line-wrap is on, the second consecutive printable character output at the last column of a line will
   wrap to the start of the following line.  As an added feature, backspace (^H) will also wrap through the left margin to the previous line.  Default is  `on'.
   Without any options, the state of wrap is toggled.

   writebuf [-e encoding] [filename]

   Writes the contents of the paste buffer to the specified file, or the public accessible screen-exchange file if no filename is given. This is thought of as a
   primitive means of communication between screen users on the same host. If an encoding is specified the paste buffer is recoded on the fly to match  the  en
   coding.  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 ex‐
   clusive 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 ex‐
   clusive write permission while switching to other windows.

   xoff

   xon

   Insert a CTRL-s / CTRL-q character to the stdin queue of the current window.

   zmodem [ off | auto | catch | pass ]

   zmodem sendcmd [string]

   zmodem recvcmd [string]

   Define zmodem support for screen. Screen understands two different modes when it detects a zmodem request: pass and catch.  If  the  mode  is  set  to  pass,
   screen  will relay all data to the attacher until the end of the transmission is reached.  In catch mode screen acts as a zmodem endpoint and starts the cor‐
   responding rz/sz commands. If the mode is set to auto, screen will use catch if the window is a tty (e.g. a serial line), otherwise it will use pass.

   You can define the templates screen uses in catch mode via the second and the third form.

   Note also that this is an experimental feature.

   zombie [keys[onerror]]

   Per default screen windows are removed from the window list as soon as the windows process (e.g. shell) exits. When a string of two keys is specified to  the
   zombie  command, `dead' windows will remain in the list.  The kill command may be used to remove such a window. Pressing the first key in the dead window has
   the same effect. When pressing the second key, screen will attempt to resurrect the window. The process that was initially running  in  the  window  will  be
   launched again. Calling zombie without parameters will clear the zombie setting, thus making windows disappear when their process exits.

   As the zombie-setting is manipulated globally for all windows, this command should probably be called defzombie, but it isn't.

   Optionally  you can put the word onerror after the keys. This will cause screen to monitor exit status of the process running in the window. If it exits nor‐
   mally ('0'), the window disappears. Any other exit value causes the window to become a zombie.

   zombie_timeout[seconds]

   Per default screen windows are removed from the window list as soon as the windows process (e.g. shell) exits. If zombie keys are defined (compare with above
   zombie command), it is possible to also set a timeout when screen tries to automatically reconnect a dead screen window.

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  dis
   playing  its messages, otherwise a line of the current screen will be temporarily overwritten and output will be momentarily interrupted. The message line is
   automatically removed after a few seconds delay, but it can also be removed early (on terminals without a status line) by beginning to type.

   The message line facility can be used by an application running in the current window by means of the ANSI Privacy message control sequence.   For  instance,
   from within the shell, try something like:

          echo '<esc>^Hello world from window '$WINDOW'<esc>\\'

   where '<esc>' is an escape, '^' is a literal up-arrow, and '\\' turns into a single backslash.

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):

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

      cs8 or cs7
             Specify the transmission of eight (or seven) bits per byte.

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

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

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

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

      For  tty  windows, the info command shows some of the modem control lines in the status line. These may include `RTS', `CTS', 'DTR', `DSR', `CD' and more.
      This depends on the available ioctl()'s and system header files as well as the on the physical capabilities of the serial board.  Signals that are logical
      low  (inactive) have their name preceded by an exclamation mark (!), otherwise the signal is logical high (active).  Signals not supported by the hardware
      but available to the ioctl() interface are usually shown low.

      When the CLOCAL status bit is true, the whole set of modem signals is placed inside curly braces ({ and }).  When the CRTSCTS or TIOCSOFTCAR bit  is  set,
      the signals `CTS' or `CD' are shown in parenthesis, respectively.

      For tty windows, the command break causes the Data transmission line (TxD) to go low for a specified period of time. This is expected to be interpreted as
      break signal on the other side.  No data is sent and no modem control line is changed when a break is issued.

     If the first parameter is //telnet, the second parameter is expected to be a host name, and an optional third parameter may specify a TCP port number (de
      fault decimal 23).  Screen will connect to a server listening on the remote host and use the telnet protocol to communicate with that server.

   For telnet windows, the command info shows details about the connection in square brackets ([ and ]) at the end of the status line.

          b      BINARY. The connection is in binary mode.

          e      ECHO. Local echo is disabled.

          c      SGA. The connection is in `character mode' (default: `line mode').

          t      TTYPE. The terminal type has been requested by the remote host.  Screen sends the name screen unless instructed otherwise (see also the command
                 `term').

          w      NAWS. The remote site is notified about window size changes.

          f      LFLOW. The remote host will send flow control information.  (Ignored at the moment.)

          Additional flags for debugging are x, t and n (XDISPLOC, TSPEED and NEWENV).

          For telnet windows, the command break sends the telnet code IAC BREAK (decimal 243) to the remote host.

          This window type is only available if screen was compiled with the ENABLE_TELNET option defined.

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

   E      sets %? to true if the escape character has been pressed.

   e      encoding

   f      flags of the window, see windows for meanings of the various flags

   F      sets %? to true if the window has the focus

   h      hardstatus of the window

   H      hostname of the system

   n      window number

   P      sets %? to true if the current region is in copy/paste mode

   S      session name

   s      window size

   t      window title

   u      all other users on this window

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

   W      all window numbers and names except the current one

   x      the executed command including arguments running in this windows

   X      the executed command without arguments running in this windows

   ?      the part to the next '%?' is displayed only if a '%' escape inside the part expands to a non-empty string

   :      else part of '%?'

   =      pad  the  string  to  the  display's width (like TeX's hfill). If a number is specified, pad to the percentage of the window's width.  A '0' qualifier
          tells screen to treat the number as absolute position.  You can specify to pad relative to the last absolute pad position by adding a '+' qualifier or
          to pad relative to the right margin by using '-'. The padding truncates the string if the specified position lies before the current position. Add the
          'L' qualifier to change this.

   <      same as '%=' but just do truncation, do not fill with spaces

   >      mark the current text position for the next truncation. When screen needs to do truncation, it tries to do it in a way that the marked  position  gets
          moved to the specified percentage of the output area. (The area starts from the last absolute pad position and ends with the position specified by the
          truncation operator.) The 'L' qualifier tells screen to mark the truncated parts with '...'.

   {      attribute/color modifier string terminated by the next }

   `      Substitute with the output of a 'backtick' command. The length qualifier is misused to identify one of the commands.

   The 'c' and 'C' escape may be qualified with a '0' to make screen use zero instead of space as fill character. The '0' qualifier also makes  the  '='  escape
   use  absolute positions. The 'n' and '=' escapes understand a length qualifier (e.g. '%3n'), 'D' and 'M' can be prefixed with 'L' to generate long names, 'w'
   and 'W' also show the window flags if 'L' is given.

   An attribute/color modifier is used to change the attributes or the color settings. Its format is [attribute modifier]  [color  description].  The  attribute
   modifier must be prefixed by a change type indicator if it can be confused with a color description. The following change types are known:

   +      add the specified set to the current attributes

   -      remove the set from the current attributes

   !      invert the set in the current attributes

   =      change the current attributes to the specified set

   The attribute set can either be specified as a hexadecimal number or a combination of the following letters:

   d      dim
   u      underline
   b      bold
   r      reverse
   s      /standout
   B      blinking

   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 dependent 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 behavior for two-letter color de
   scriptions, 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>%n%f* %t%{-}%+Lw%<
          The available windows centered at the current window and truncated to the available width. The current window is displayed white on blue.  This can be
          used with hardstatus alwayslastline.

   %?%F%{.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 cur
   rent program, but you must use the appropriate two-character screen commands (typically C-a q (xon) and C-a s (xoff)).  The xon/xoff commands are also useful
   for typing C-s and C-q past a terminal that intercepts these characters.

   Each  window  has  an initial flow-control value set with either the -f option or the defflow .screenrc command. Per default the windows are set to automatic
   flow-switching.  It can then be toggled between the three states 'fixed on', 'fixed off' and 'automatic' interactively with the flow command  bound  to  "C-a
   f".

   The automatic flow-switching mode deals with flow control using the TIOCPKT mode (like rlogin does). If the tty driver does not support TIOCPKT, screen tries
   to find out the right mode based on the current setting of the application keypad - when it is enabled, flow-control  is  turned  off  and  visa  versa.   Of
   course, you can still manipulate flow-control manually when needed.

   If  you're  running  with  flow-control enabled and find that pressing the interrupt key (usually C-c) does not interrupt the display until another 6-8 lines
   have scrolled by, try running screen with the interrupt option (add the interrupt flag to the flow command in your .screenrc, or use the -i command-line  op‐
   tion).   This causes the output that screen has accumulated from the interrupted program to be flushed.  One disadvantage is that the virtual terminal's mem
   ory 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  com‐
   mand  and thus can have their name set with the -t option.  Interactively, there is the title-string escape-sequence (<esc>kname<esc>\) and the title command
   (C-a A).  The former can be output from an application to control the window's name under software control, and the latter will prompt for a name when typed.
   You  can  also  bind  pre-defined names to keys with the title command to set things quickly without prompting. Changing title by this escape sequence can be
   controlled by defdynamictitle and dynamictitle commands.

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

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

   Here's some .screenrc examples:

                   screen -t top 2 nice top

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

                   shelltitle '> |csh'
                   screen 1

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

                   /usr/joe/src/dir> trn

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

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

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

                   % !em
                   emacs file.c

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

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

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

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

                   set prompt='^[[0000m^[k^[\% '

   The escape-sequence <esc>[0000m not only normalizes the character attributes, but all the zeros round the length of the invisible characters up to  8.   Bash
   users will probably want to echo the escape sequence in the PROMPT_COMMAND:

                   PROMPT_COMMAND='printf "\033k\033\134"'

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

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.<term>, where <term> is the contents of your $TERM vari
   able.  If no such entry exists, screen tries screen (or screen-w if the terminal is wide (132 cols or more)).  If even this entry cannot be found,  vt100  is
   used as a substitute.

   The  idea  is  that if you have a terminal which doesn't support an important feature (e.g. delete char or clear to EOS) you can build a new termcap/terminfo
   entry for screen (named screen.<dumbterm>) in which this capability has been disabled. If this entry is installed on your machines  you  are  able  to  do  a
   rlogin  and still keep the correct termcap/terminfo entry.  The terminal name is put in the $TERM variable of all new windows.  Screen also sets the $TERMCAP
   variable reflecting the capabilities of the virtual terminal emulated. Notice that, however, on machines using the terminfo database this variable has no ef‐
   fect.  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 phys‐
   ical terminal does not support underscore mode, screen does not put the `us' and `ue' capabilities into the window's $TERMCAP  variable,  accordingly.   How
   ever,  a  minimum number of capabilities must be supported by a terminal in order to run screen; namely scrolling, clear screen, and direct cursor addressing
   (in addition, screen does not run on hardcopy terminals or on terminals that over-strike).

   Also, you can customize the $TERMCAP value used by screen by using the termcap .screenrc command, or by defining the variable $SCREENCAP  prior  to  startup.
   When  the  latter  is defined, its value will be copied verbatim into each window's $TERMCAP variable.  This can either be the full terminal definition, or a
   filename where the terminal screen (and/or screen-w) is defined.

   Note that screen honors the terminfo .screenrc command if the system uses the terminfo database rather than termcap.

   When the boolean `G0' capability is present in the termcap entry for the terminal on which screen has been called, the terminal emulation of screen  supports
   multiple  character sets.  This allows an application to make use of, for instance, the VT100 graphics character set or national character sets.  The follow
   ing 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 evalu‐
   ates the capabilities `S0', `E0', and `C0' if present. `S0' is the sequence the terminal uses to enable and start the graphics character set rather than  SI.
   `E0'  is  the corresponding replacement for SO. `C0' gives a character by character translation string that is used during semi-graphics mode. This string is
   built like the `acsc' terminfo capability.

   When the `po' and `pf' capabilities are present in the terminal's termcap entry, applications running in a screen window can send output to the printer  port
   of  the terminal.  This allows a user to have an application in one window sending output to a printer connected to the terminal, while all other windows are
   still active (the printer port is enabled and disabled again for each chunk of output).  As a side-effect, programs running in  different  windows  can  send
   output  to  the printer simultaneously.  Data sent to the printer is not displayed in the window.  The info command displays a line starting `PRIN' while the
   printer is active.

   Screen maintains a hardstatus line for every window. If a window gets selected, the display's hardstatus will be updated to  match  the  window's  hardstatus
   line. If the display has no hardstatus the line will be displayed as a standard screen message.  The hardstatus line can be changed with the ANSI Application
   Program Command (APC): ESC_<string>ESC\. As a convenience for xterm users the sequence ESC]0..2;<string>^G is also accepted.

   Some capabilities are only put into the $TERMCAP variable of the virtual terminal if they can be efficiently implemented by the physical terminal.   For  in
   stance, `dl' (delete line) is only put into the $TERMCAP variable if the terminal supports either delete line itself or scrolling regions. Note that this may
   provoke confusion, when the session is reattached on a different terminal, as the value of $TERMCAP cannot be modified by parent processes.

   The "alternate screen" capability is not enabled by default.  Set the altscreen .screenrc command to enable it.

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

   ESC E                      Next Line

   ESC D                      Index

   ESC M                      Reverse Index

   ESC H                      Horizontal Tab Set

   ESC Z                      Send VT100 Identification String

   ESC 7                 (V)  Save Cursor and Attributes

   ESC 8                 (V)  Restore Cursor and Attributes

   ESC [s                (A)  Save Cursor and Attributes

   ESC [u                (A)  Restore Cursor and Attributes

   ESC c                      Reset to Initial State

   ESC g                      Visual Bell

   ESC Pn p                   Cursor Visibility (97801)

                              Pn = 6                     Invisible

                              Pn = 7                     Visible

   ESC =                 (V)  Application Keypad Mode

   ESC >                 (V)  Numeric Keypad Mode

   ESC # 8               (V)  Fill Screen with E's

   ESC \                 (A)  String Terminator

   ESC ^                 (A)  Privacy Message String (Message Line)

   ESC !                      Global Message String (Message Line)

   ESC k                      A.k.a. Definition String

   ESC P                 (A)  Device Control String.  Outputs a string directly to the host terminal without interpretation.

   ESC _                 (A)  Application Program Command (Hardstatus)

   ESC ] 0 ; string ^G   (A)  Operating System Command (Hardstatus, xterm title hack)

   ESC ] 83 ; cmd ^G     (A)  Execute screen command. This only works if multi-user support is compiled into screen. The pseudo-user :window: is used  to  check
                              the access control list. Use addacl :window: -rwx #? to create a user with no rights and allow only the needed commands.

   Control-N             (A)  Lock Shift G1 (SO)

   Control-O             (A)  Lock Shift G0 (SI)

   ESC n                 (A)  Lock Shift G2

   ESC o                 (A)  Lock Shift G3

   ESC N                 (A)  Single Shift G2

   ESC O                 (A)  Single Shift G3

   ESC ( Pcs             (A)  Designate character set as G0

   ESC ) Pcs             (A)  Designate character set as G1

   ESC * Pcs             (A)  Designate character set as G2

   ESC + Pcs             (A)  Designate character set as G3

   ESC [ Pn ; Pn H            Direct Cursor Addressing

   ESC [ Pn ; Pn f            same as above

   ESC [ Pn J                 Erase in Display

                              Pn = None or 0             From Cursor to End of Screen

                              Pn = 1                     From Beginning of Screen to Cursor

                              Pn = 2                     Entire Screen

   ESC [ Pn K                 Erase in Line

                              Pn = None or 0             From Cursor to End of Line

                              Pn = 1                     From Beginning of Line to Cursor

                              Pn = 2                     Entire Line

   ESC [ Pn X                 Erase character

   ESC [ Pn A                 Cursor Up

   ESC [ Pn B                 Cursor Down

   ESC [ Pn C                 Cursor Right

   ESC [ Pn D                 Cursor Left

   ESC [ Pn E                 Cursor next line

   ESC [ Pn F                 Cursor previous line

   ESC [ Pn G                 Cursor horizontal position

   ESC [ Pn `                 same as above

   ESC [ Pn d                 Cursor vertical position

   ESC [ Ps ;...; Ps m        Select Graphic Rendition

                              Ps = None or 0             Default Rendition

                              Ps = 1                     Bold

                              Ps = 2                (A)  Faint

                              Ps = 3                (A)  Standout Mode (ANSI: Italicized)

                              Ps = 4                     Underlined

                              Ps = 5                     Blinking

                              Ps = 7                     Negative Image

                              Ps = 22               (A)  Normal Intensity

                              Ps = 23               (A)  Standout Mode off (ANSI: Italicized off)

                              Ps = 24               (A)  Not Underlined

                              Ps = 25               (A)  Not Blinking

                              Ps = 27               (A)  Positive Image

                              Ps = 30               (A)  Foreground Black

                              Ps = 31               (A)  Foreground Red

                              Ps = 32               (A)  Foreground Green

                              Ps = 33               (A)  Foreground Yellow

                              Ps = 34               (A)  Foreground Blue

                              Ps = 35               (A)  Foreground Magenta

                              Ps = 36               (A)  Foreground Cyan

                              Ps = 37               (A)  Foreground White

                              Ps = 39               (A)  Foreground Default

                              Ps = 40               (A)  Background Black

                              Ps = ...

                              Ps = 49               (A)  Background Default

   ESC [ Pn g                 Tab Clear

                              Pn = None or 0             Clear Tab at Current Position

                              Pn = 3                     Clear All Tabs

   ESC [ Pn ; Pn r       (V)  Set Scrolling Region

   ESC [ Pn I            (A)  Horizontal Tab

   ESC [ Pn Z            (A)  Backward Tab

   ESC [ Pn L            (A)  Insert Line

   ESC [ Pn M            (A)  Delete Line

   ESC [ Pn @            (A)  Insert Character

   ESC [ Pn P            (A)  Delete Character

   ESC [ Pn S                 Scroll Scrolling Region Up

   ESC [ Pn T                 Scroll Scrolling Region Down

   ESC [ Pn ^                 same as above

   ESC [ Ps ;...; Ps h        Set Mode

   ESC [ Ps ;...; Ps l        Reset Mode

                              Ps = 4                (A)  Insert Mode

                              Ps = 20               (A)  Automatic Linefeed Mode

                              Ps = 34                    Normal Cursor Visibility

                              Ps = ?1               (V)  Application Cursor Keys

                              Ps = ?3               (V)  Change Terminal Width to 132 columns

                              Ps = ?5               (V)  Reverse Video

                              Ps = ?6               (V)  Origin Mode

                              Ps = ?7               (V)  Wrap Mode

                              Ps = ?9                    X10 mouse tracking

                              Ps = ?25              (V)  Visible Cursor

                              Ps = ?47                   Alternate Screen (old xterm code)

                              Ps = ?1000            (V)  VT200 mouse tracking

                              Ps = ?1047                 Alternate Screen (new xterm code)

                              Ps = ?1049                 Alternate Screen (new xterm code)

   ESC [ 5 i             (A)  Start relay to printer (ANSI Media Copy)

   ESC [ 4 i             (A)  Stop relay to printer (ANSI Media Copy)

   ESC [ 8 ; Ph ; Pw t        Resize the window to `Ph' lines and `Pw' columns (SunView special)

   ESC [ c                    Send VT100 Identification String

   ESC [ x                    Send Terminal Parameter Report

   ESC [ > c                  Send VT220 Secondary Device Attributes String

   ESC [ 6 n                  Send Cursor Position Report

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 key
   board 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  com
   mands to the termcap name of the keys.  Screen will insert the correct binding after each reattach. See the bindkey command for further details on the syntax
   and examples.

   Here is the table of the default key bindings. The fourth is what command is executed if the keyboard is switched into application mode.

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

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  ma
                chines).

   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=<charset-mapping>{,,<charset-mapping>}
       <charset-mapping> := <designator><template>{,<mapping>}
       <mapping> := <char-to-be-mapped><template-arg>

   The things in braces may be repeated any number of times.

   A  <charset-mapping>  tells screen how to map characters in font <designator> ('B': Ascii, 'A': UK, 'K': German, etc.)  to strings. Every <mapping> describes
   to what string a single character will be translated. A template mechanism is used, as most of the time the codes have a lot in common (for  example  strings
   to  switch to and from another charset). Each occurrence of '%' in <template> gets substituted with the <template-arg> specified together with the character.
   If your strings are not similar at all, then use '%' as a template and place the full string in <template-arg>. A quoting mechanism was added to make it pos
   sible to use a real '%'. The '\' character quotes the special characters '\', '%', and ','.

   Here is an example:

       termcap hp700 'XC=B\E(K%\E(B,\304[,\326\\\\,\334]'

   This tells screen how to translate ISOlatin1 (charset 'B') upper case umlaut characters on a hp700 terminal that has a German charset. '\304' gets translated
   to '\E(K[\E(B' and so on.  Note that this line gets parsed *three* times before the internal lookup table is built, therefore a lot of quoting is  needed  to
   create a single '\'.

   Another  extension was added to allow more emulation: If a mapping translates the unquoted '%' char, it will be sent to the terminal whenever screen switches
   to the corresponding <designator>. In this special case the template is assumed to be just '%' because the charset switch sequence and the character mappings
   normally haven't much in common.

   This example shows one use of the extension:

       termcap xterm 'XC=K%,%\E(B,[\304,\\\\\326,]\334'

   Here,  a part of the German ('K') charset is emulated on an xterm.  If screen has to change to the 'K' charset, '\E(B' will be sent to the terminal, i.e. the
   ASCII charset is used instead. The template is just '%', so the mapping is straightforward: '[' to '\304', '\' to '\326', and ']' to '\334'.

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).  See also shell .screenrc command.
   STY            Alternate socket name.
   SYSSCREENRC    Alternate system screenrc file.
   TERM           Terminal name.
   TERMCAP        Terminal description.
   WINDOW         Window number of a window (at creation time).

FILES

   .../screen-4.?.??/etc/screenrc
   .../screen-4.?.??/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-<login>
   /run/screen/S-<login>             Socket directories (default)
   /usr/tmp/screens/S-<login>        Alternate socket directories.
   <socket directory>/.termcap       Written by the "termcap" output function
   /usr/tmp/screens/screen-exchange  or
   /tmp/screen-exchange              screen `interprocess communication buffer'
   hardcopy.[0-9]                    Screen images created by the hardcopy function
   screenlog.[0-9]                   Output log files created by the log function
   /usr/lib/terminfo/?/*             or
   /etc/termcap                      Terminal capability databases
   /run/utmp                         Login records
   $LOCKPRG                          Program that locks a terminal.

AUTHORS

   Originally created by Oliver Laumann. For a long time maintained and developed by Juergen Weigert, Michael Schroeder, Micah Cowan and Sadrul Habib Chowdhury.
   Since 2015 maintained and developed by Amadeusz Slawinski <amade@asmblr.net> and Alexander Naumov <alexander_naumov@opensuse.org>.

COPYLEFT

   Copyright (c) 2018-2022
        Alexander Naumov <alexander_naumov@opensuse.org>
        Amadeusz Slawinski <amade@asmblr.net>
   Copyright (c) 2015-2017
        Juergen Weigert <jnweiger@immd4.informatik.uni-erlangen.de>
        Alexander Naumov <alexander_naumov@opensuse.org>
        Amadeusz Slawinski <amade@asmblr.net>
   Copyright (c) 2010-2015
        Juergen Weigert <jnweiger@immd4.informatik.uni-erlangen.de>
        Sadrul Habib Chowdhury <sadrul@users.sourceforge.net>
   Copyright (c) 2008, 2009
        Juergen Weigert <jnweiger@immd4.informatik.uni-erlangen.de>
        Michael Schroeder <mlschroe@immd4.informatik.uni-erlangen.de>
        Micah Cowan <micah@cowan.name>
        Sadrul Habib Chowdhury <sadrul@users.sourceforge.net>
   Copyright (C) 1993-2003
        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 3, or (at your option) any later version.
   This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
   You  should have received a copy of the GNU General Public License along with this program (see the file COPYING); if not, write to the Free Software Founda
   tion, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA

CONTRIBUTORS

   Maarten ter Huurne <maarten@treewalker.org>,
   Jussi Kukkonen <jussi.kukkonen@intel.com>,
   Eric S. Raymond <esr@thyrsus.com>,
   Thomas Renninger <treen@suse.com>,
   Axel Beckert <abe@deuxchevaux.org>,
   Ken Beal <kbeal@amber.ssd.csd.harris.com>,
   Rudolf Koenig <rfkoenig@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@eterna.com.au>,
   Christopher Williams <cgw@pobox.com>,
   Matt Mosley <mattm@access.digex.net>,
   Gregory Neil Shapiro <gshapiro@wpi.WPI.EDU>,
   Johannes Zellner <johannes@zellner.org>,
   Pablo Averbuj <pablo@averbuj.com>.

AVAILABILITY

   The latest official release of screen available via anonymous ftp from ftp.gnu.org/gnu/screen/ or any other GNU distribution site. The home page of screen is
   https://savannah.gnu.org/projects/screen/  and  the git repo is https://git.savannah.gnu.org/cgit/screen.git.  If you want to help, send a note to screen-de
   vel@gnu.org.

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 win‐
      dow.  Special permission may also be required to write the file /run/utmp.

   •  Entries  in  /run/utmp are not removed when screen is killed with SIGKILL.  This will cause some programs (like "w" or "rwho") to advertise that a user is
      logged on who really isn't.

     Screen may give a strange warning when your tty has no utmp entry.

     When the modem line was hung up, screen may not automatically detach (or quit) unless the device driver is configured to send a HANGUP signal.  To  detach
      a screen session use the -D or -d command line option.

     If a password is set, the command line options -d and -D still detach a session without asking.

     Both  breaktype and defbreaktype change the break generating method used by all terminal devices. The first should change a window specific setting, where
      the latter should change only the default for new windows.

     When attaching to a multiuser session, the user's .screenrc file is not sourced. Each user's personal settings have to be included in the  .screenrc  file
      from which the session is booted, or have to be changed manually.

     A weird imagination is most useful to gain full advantage of all the features.

   Send bug-reports, fixes, enhancements, t-shirts, money, beer & pizza to screen-devel@gnu.org.

SEE ALSO

   termcap(5), utmp(5), vi(1), captoinfo(1), tic(1), tty(4), pty(7)

GNU Screen 4.9.0 2022 Jan 30 SCREEN(1)