SCREEN linux command manual

SCREEN(1)                                                      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 mechanism that
       allows moving text regions between windows.

       When screen is called, it creates a single window with a shell  in  it
       (or  the  specified command) and then gets out of your way so that you
       can use the program as you normally would.  Then, at any time, you can
       create  new (full-screen) windows with other programs in them (includ-
       ing more shells), kill existing windows, view a list of windows,  turn
       output  logging  on and off, copy-and-paste text between windows, view
       the scrollback history, switch between windows in whatever manner  you
       wish,  etc.  All  windows run their programs completely independent of
       each other. Programs continue to run when their  window  is  currently
       not  visible  and  even when the whole screen session is detached from
       the user's terminal.  When a program terminates, screen (per  default)
       kills  the  window that contained it.  If this window was in the fore-
       ground, the display switches to the previous window; if none are left,
       screen exits.

       Everything you type is sent to the program running in the current win-
       dow.  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 bind-
       ings can be fully customized to be anything you like, though they  are
       always two characters in length.

       Screen  does  not  understand the prefix "C-" to mean control.  Please
       use the caret notation ("^A" instead of "C-a") as  arguments  to  e.g.
       the  escape command or the -e option.  Screen will also print out con-
       trol characters in caret notation.

       The standard way to create a new window is to type "C-a c".  This cre-
       ates  a new window running a shell and switches to that window immedi-
       ately, 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 envi-
       ronment variable) who will use it to create the new window.  The above
       example  would  start  the emacs editor (editing prog.c) and switch to
       its window.

       If "/etc/utmp" is writable by screen, an appropriate  record  will  be
       written  to  this file for each window, and removed when the window is
       terminated.  This is useful for working with "talk", "script",  "shut-
       down",  "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  cor-
       rectly  selected  your  terminal type, just as you would for any other
       termcap/terminfo program.  (You can do this by using  tset  for  exam-
       ple.)

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

       If your terminal is a "true" auto-margin terminal  (it  doesn't  allow
       the  last  position  on the screen to be updated without scrolling the
       screen) consider using a version of your terminal's termcap  that  has
       automatic margins turned off. This will ensure an accurate and optimal
       update of the screen in all  circumstances.  Most  terminals  nowadays
       have "magic" margins (automatic margins plus usable last column). This
       is the VT100 style type and  perfectly  suited  for  screen.   If  all
       you've  got is a "true" auto-margin terminal screen will be content to
       use it, but updating a character put into the  last  position  on  the
       screen  may  not be possible until the screen scrolls or the character
       is moved into a safe position in some other way.  This  delay  can  be
       shortened by using a terminal with insert-character capability.



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 termi-
            nal.  By default, screen tries to restore its  old  window  sizes
            when  attaching  to  resizable  terminals (those with "WS" in its
            description, e.g. suncmd or some xterm).

       -c file
            override the default configuration file from "$HOME/.screenrc" to
            file.

       -d|-D [pid.tty.host]
            does  not start screen, but detaches the elsewhere running screen
            session. It has the same effect as typing "C-a d"  from  screen's
            controlling  terminal.  -D  is the equivalent to the power detach
            key.  If no session can be detached, this option is  ignored.  In
            combination  with  the  -r/-R option more powerful effects can be
            achieved:

       -d -r   Reattach a session and if necessary detach it first.

       -d -R   Reattach a session and if necessary detach or even  create  it
               first.

       -d -RR  Reattach  a  session and if necessary detach or create it. Use
               the first session if more than one session is available.

       -D -r   Reattach a session. If necessary detach  and  logout  remotely
               first.

       -D -R   Attach  here  and  now.  In detail this means: If a session is
               running,  then  reattach.  If  necessary  detach  and   logout
               remotely  first.   If  it was not running create it and notify
               the user. This is the author's favorite.

       -D -RR  Attach here and now. Whatever that means, just do it.

            Note: It is always a good idea to check the status of  your  ses-
            sions by means of "screen -list".

       -e xy
            specifies  the command character to be x and the character gener-
            ating a literal command character to y (when typed after the com-
            mand  character).   The  default  is  "C-a" and 'a', which can be
            specified as "-e^Aa".   When  creating  a  screen  session,  this
            option sets the default command character. In a multiuser session
            all users added will start off with this command  character.  But
            when attaching to an already running session, this option changes
            only the command character of the attaching user.  This option is
            equivalent to either the commands "defescape" or "escape" respec-
            tively.

       -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 dis-
            play immediately when flow-control  is  on.   See  the  "defflow"
            .screenrc  command  for  details.  The use of this option is dis-
            couraged.

       -l and -ln
            turns login mode on or off (for /etc/utmp  updating).   This  can
            also be defined through the "deflogin" .screenrc command.

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

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

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

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

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

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

       -p number_or_name
            Preselect  a window. This is usefull when you want to reattach to
            a specific windor or you want to send  a  command  via  the  "-X"
            option to a specific window. As with screen's select commant, "-"
            selects the blank window. As a special  case  for  reattach,  "="
            brings up the windowlist on the blank window.

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

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

       -R   attempts  to  resume  the first detached screen session it finds.
            If successful, all other command-line options are ignored.  If no
            detached session exists, starts a new session using the specified
            options, just as if -R had not been specified. The option is  set
            by  default  if  screen  is run as a login-shell (actually screen
            uses "-xRR" in that  case).   For  combinations  with  the  -d/-D
            option see there.

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

       -S sessionname
            When creating a new session, this option can be used to specify a
            meaningful name for the session. This name identifies the session
            for "screen -list" and "screen -r" actions.  It  substitutes  the
            default [tty.host] suffix.

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

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

       -v   Print version number.

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

       -x   Attach to a not detached screen session. (Multi display mode).

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



DEFAULT KEY BINDINGS
       As  mentioned, each screen command consists of a "C-a" followed by one
       other character.  For your convenience, all commands that are bound to
       lower-case  letters are also bound to their control character counter-
       parts (with the exception of "C-a a"; see below),  thus,  "C-a  c"  as
       well  as  "C-a  C-c" can be used to create a window. See section "CUS-
       TOMIZATION" for a description of the command.


       The following table shows the default key bindings:

       C-a '       (select)      Prompt for a window name or number to switch
                                 to.

       C-a "       (windowlist -b)
                                 Present a list of all windows for selection.

       C-a 0       (select 0)
        ...           ...
       C-a 9       (select 9)
       C-a -       (select -)    Switch to window number 0 -  9,  or  to  the
                                 blank window.

       C-a tab     (focus)       Switch the input focus to the next region.

       C-a C-a     (other)       Toggle  to  the window displayed previously.
                                 Note that this binding defaults to the  com-
                                 mand  character typed twice, unless overrid-
                                 den.  For instance, if you  use  the  option
                                 "-e]x", this command becomes "]]".

       C-a a       (meta)        Send  the command character (C-a) to window.
                                 See escape command.

       C-a A       (title)       Allow the user to enter a name for the  cur-
                                 rent window.

       C-a b
       C-a C-b     (break)       Send a break to window.

       C-a B       (pow_break)   Reopen the terminal line and send a break.

       C-a c
       C-a C-c     (screen)      Create  a new window with a shell and switch
                                 to that window.

       C-a C       (clear)       Clear the screen.

       C-a d
       C-a C-d     (detach)      Detach screen from this terminal.

       C-a D D     (pow_detach)  Detach and logout.

       C-a f
       C-a C-f     (flow)        Toggle flow on, off or auto.

       C-a F       (fit)         Resize the  window  to  the  current  region
                                 size.

       C-a C-g     (vbell)       Toggles screen's visual bell mode.

       C-a h       (hardcopy)    Write  a  hardcopy  of the current window to
                                 the file "hardcopy.n".

       C-a H       (log)         Begins/ends logging of the current window to
                                 the file "screenlog.n".

       C-a i
       C-a C-i     (info)        Show info about this window.

       C-a k
       C-a C-k     (kill)        Destroy current window.

       C-a l
       C-a C-l     (redisplay)   Fully refresh current window.

       C-a L       (login)       Toggle  this  windows  login slot. Available
                                 only if screen is configured to  update  the
                                 utmp database.

       C-a m
       C-a C-m     (lastmsg)     Repeat  the  last  message  displayed in the
                                 message line.

       C-a M       (monitor)     Toggles monitoring of the current window.

       C-a space
       C-a n
       C-a C-n     (next)        Switch to the next window.

       C-a N       (number)      Show the number (and title) of  the  current
                                 window.

       C-a backspace
       C-a h
       C-a p
       C-a C-p     (prev)        Switch  to  the previous window (opposite of
                                 C-a n).

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

       C-a Q       (only)        Delete all regions but the current one.

       C-a r
       C-a C-r     (wrap)        Toggle the current window's  line-wrap  set-
                                 ting  (turn  the  current window's automatic
                                 margins on and off).

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

       C-a S       (split)       Split the current region into two new  ones.

       C-a t
       C-a C-t     (time)        Show system information.

       C-a v       (version)     Display the version and compilation date.

       C-a C-v     (digraph)     Enter digraph.

       C-a w
       C-a C-w     (windows)     Show a list of window.

       C-a W       (width)       Toggle 80/132 columns.

       C-a x
       C-a C-x     (lockscreen)  Lock this terminal.

       C-a X       (remove)      Kill the current region.

       C-a z
       C-a C-z     (suspend)     Suspend  screen.   Your  system must support
                                 BSD-style job-control.

       C-a Z       (reset)       Reset the virtual terminal to its "power-on"
                                 values.

       C-a .       (dumptermcap) Write out a ".termcap" file.

       C-a ?       (help)        Show key bindings.

       C-a C-\     (quit)        Kill all windows and terminate screen.

       C-a :       (colon)       Enter command line mode.

       C-a [
       C-a C-[
       C-a esc     (copy)        Enter copy/scrollback mode.

       C-a ]       (paste .)     Write  the  contents  of the paste buffer to
                                 the stdin queue of the current window.

       C-a {
       C-a }       (history)     Copy and paste a previous (command) line.

       C-a >       (writebuf)    Write paste buffer to a file.

       C-a <       (readbuf)     Reads  the  screen-exchange  file  into  the
                                 paste buffer.

       C-a =       (removebuf)   Removes the file used by C-a < and C-a >.

       C-a ,       (license)     Shows where screen comes from, where it went
                                 to and why you can use it.

       C-a _       (silence)     Start/stop monitoring the current window for
                                 inactivity.

       C-a *       (displays)    Show  a  listing  of  all currently attached
                                 displays.



CUSTOMIZATION
       The "socket directory" defaults either to $HOME/.screen or  simply  to
       /tmp/screens  or  preferably  to /usr/local/screens chosen at compile-
       time. If screen  is  installed  setuid-root,  then  the  administrator
       should compile screen with an adequate (not NFS mounted) socket direc-
       tory. If screen is not running setuid-root, the user can  specify  any
       mode 700 directory in the environment variable $SCREENDIR.

       When  screen  is invoked, it executes initialization commands from the
       files "/etc/screenrc" and ".screenrc" in the  user's  home  directory.
       These  are  the  "programmer's defaults" that can be overridden in the
       following ways: for the global screenrc file screen searches  for  the
       environment  variable  $SYSSCREENRC (this override feature may be dis-
       abled 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 begin-
       ning 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  con-
       tain references to environment variables. The syntax is the shell-like
       "$VAR " or "${VAR}". Note that this causes incompatibility with previ-
       ous screen versions, as now the '$'-character has to be protected with
       '\' if no variable substitution shall be performed. A string  in  sin-
       gle-quotes is also protected from variable substitution.

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

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

       The following commands are available:

       acladd usernames [crypted-pw]
       addacl usernames

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

       aclchg usernames permbits list
       chacl usernames permbits list

       Change  permissions  for  a  comma separated list of users. Permission
       bits are represented as 'r', 'w' and 'x'.  Prefixing  '+'  grants  the
       permission,  '-'  removes it. The third parameter is a comma separated
       list of commands and/or windows (specified either by number or title).
       The  special  list  '#' refers to all windows, '?' to all commands. if
       usernames consists of a single '*', all known users are  affected.   A
       command  can  be  executed  when the user has the 'x' bit for it.  The
       user can type input to a window when he has its 'w'  bit  set  and  no
       other  user  obtains a writelock for this window.  Other bits are cur-
       rently ignored.  To withdraw the writelock from another user in window
       2:  'aclchg  username  -w+w 2'.  To allow read-only access to the ses-
       sion: '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 permis-
       sions 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 com-
       mand.  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 moni-
       tored, screen displays a notification in the message line.  The  noti-
       fication 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  audi-
       ble bell).  The default message is

                   'Activity in window %n'

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

       allpartial on|off

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

       altscreen on|off

       If set to on, "alternate screen" support is enabled in virtual  termi-
       nals, 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 iden-
       tifier 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.  Dis-
       plays  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 '\'.   Per-
       mission  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 issu-
       ing 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 syn-
       tax 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 com-
       mand.   When turned off, a hangup signal will terminate screen and all
       the processes it contains. Autodetach is on by default.

       autonuke on|off

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

       backtick id lifespan autorefresh cmd args...
       backtick id

       Program  the backtick command with the numerical id id.  The output of
       such a command is used for substitution of the "%'" string escape. The
       specified  lifespan  is the number of seconds the output is considered
       valid. After this time, the command is run again  if  a  corresponding
       string  escape  is encountered.  The autorefresh parameter triggers an
       automatic refresh for caption and hardstatus strings after the  speci-
       fied  number of seconds. Only the last line of output is used for sub-
       stitution.
       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  cap-
       tions.
       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 back-
       ground 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 cur-
       rent message is shown.

       bind [-c class] key [command [args]]

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

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

       Some examples:

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

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

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

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

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

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

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

       This command manages screen's input translation tables. Every entry in
       one of the tables tells screen how to react if a certain  sequence  of
       characters  is  encountered.  There  are three tables: one that should
       contain actions programmed by the user, one for  the  default  actions
       used  for terminal emulation and one for screen's copy mode to do cur-
       sor movement. See section "INPUT TRANSLATION" for a  list  of  default
       key bindings.
       If  the  -d  option  is  given, bindkey modifies the default table, -m
       changes the copy mode table and with neither option the user table  is
       selected.   The argument string is the sequence of characters to which
       an action is bound. This can either be a fixed  string  or  a  termcap
       keyboard capability name (selectable with the -k option).
       Some  keys on a VT100 terminal can send a different string if applica-
       tion mode is turned on (e.g the cursor  keys).   Such  keys  have  two
       entries  in the translation table. You can select the application mode
       entry by specifying the -a option.
       The -t option tells screen not to do inter-character timing. One  can-
       not 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 dis-
       carded.
       This command is normally used together with the "idle" command.

       blankerprg [program args]

       Defines a blanker program. Disables the blanker program  if  no  argu-
       ments are given.

       breaktype [tcsendbreak|TIOCSBRK |TCSBRK]

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

       bufferfile [exchange-file]

       Change  the  filename  used  for  reading  and  writing with the paste
       buffer.  If the optional argument to the "bufferfile" command is omit-
       ted, 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

       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 charac-
       ters in the c1 positions may want to turn this off.

       caption always|splitonly [string]
       caption string [string]

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

       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  argu-
       ment.

       charset set

       Change the current character set slot designation and charset mapping.
       The first four character of set are  treated  as  charset  designators
       while  the  fifth  and sixth character must be in range '0' to '3' and
       set the GL/GR charset mapping. On every position a '.' may be used  to
       indicate  that the corresponding charset/mapping should not be changed
       (set is padded to six characters internally by appending '.'   chars).
       New windows have "BBBB02" as default charset, unless a "encoding" com-
       mand 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  win-
       dow's default directory, not the current directory of the process run-
       ning 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 inter-
       actively.

       clear

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

       colon [prefix]

       Allows you to enter ".screenrc" command lines. Useful  for  on-the-fly
       modification  of  key  bindings, specific window creation and changing
       settings. Note that the "set" keyword no longer exists!  Usually  com-
       mands  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 cur-
       rent  window and its history into the paste buffer. In this mode a vi-
       like 'full screen editor' is active:
       Movement keys:
         h, j, k, l move the cursor line by line or column by column.
         0, ^ and $ move to the leftmost column, to the first  or  last  non-
           whitespace character on the line.
         H, M and L move the cursor to the leftmost column of the top, center
           or bottom line of the window.
         + and - positions one line up and down.
         G moves to the specified absolute line (default: end of buffer).
         | moves to the specified absolute column.
         w, b, e move the cursor word by word.
         B, E move the cursor WORD by WORD (as in vi).
         C-u and C-d scroll the display up/down by the  specified  amount  of
           lines while preserving the cursor position. (Default: half screen-
           full).
         C-b and C-f scroll the display up/down a full screen.
         g moves to the beginning of the buffer.
         % jumps to the specified percentage of the buffer.

       Note:
           Emacs style movement keys can be customized by  a  .screenrc  com-
           mand.   (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.

       Marking:
           The copy range is specified by setting two marks. The text between
           these marks will be highlighted. Press
         space to set the first or second mark respectively.
         Y and y used to mark one whole line or to mark from start of line.
         W marks exactly one word.
       Repeat count:
           Any of these commands can be prefixed with a repeat  count  number
           by pressing digits
         0..9 which is taken as a repeat count.
           Example:  "C-a  C-[  H 10 j 5 Y" will copy lines 11 to 15 into the
           paste buffer.
       Searching:
         / Vi-like search forward.
         ? Vi-like search backward.
         C-a s Emacs style incremental search forward.
         C-r Emacs style reverse i-search.
       Specials:
           There are however some keys that act differently than in  vi.   Vi
           does  not allow one to yank rectangular blocks of text, but screen
           does. Press
         c or C to set the left or right margin respectively.  If  no  repeat
           count is given, both default to the current cursor position.
           Example:  Try  this  on  a  rather full text screen: "C-a [ M 20 l
           SPACE c 10 l 5 j C SPACE".

           This moves one to the middle line  of  the  screen,  moves  in  20
           columns  left,  marks  the beginning of the paste buffer, sets the
           left column, moves 5 columns down, sets the right column, and then
           marks the end of the paste buffer. Now try:
           "C-a [ M 20 l SPACE 10 l 5 j SPACE"

           and notice the difference in the amount of text copied.
         J joins lines. It toggles between 4 modes: lines separated by a new-
           line character (012), lines glued seamless, lines separated  by  a
           single  whitespace  and  comma  separated lines. Note that you can
           prepend the newline character with a carriage return character, by
           issuing a "crlf on".
         v  is for all the vi users with ":set numbers" - it toggles the left
           margin between column 9 and 1. Press
         a before the final space key to toggle in append mode. Thus the con-
           tents of the paste buffer will not be overwritten, but is appended
           to.
         A toggles in append mode and sets a (second) mark.
         > sets the (second) mark and writes the contents of the paste buffer
           to  the  screen-exchange  file  (/tmp/screen-exchange per default)
           once copy-mode is finished.
           This example demonstrates how to dump the whole scrollback  buffer
           to that file: "C-A [ g SPACE G $ >".
         C-g gives information about the current line and column.
         x  exchanges the first mark and the current cursor position. You can
           use this to adjust an already placed mark.
         @ does nothing. Does not even exit copy mode.
         All keys not described here exit copy mode.

       copy_reg [key]

       No longer exists, use "readreg" instead.

       crlf [on|off]

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

       debug on|off

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

       defc1 on|off

       Same as the c1 command except that the default setting for new windows
       is changed. Initial setting is 'on'.

       defautonuke on|off

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

       defbce on|off

       Same  as  the bce command except that the default setting for new win-
       dows is changed. Initial setting is 'off'.

       defbreaktype [tcsendbreak|TIOCSBRK |TCSBRK]

       Choose one of the available methods of generating a break  signal  for
       terminal  devices. The preferred methods are tcsendbreak and TIOCSBRK.
       The third, TCSBRK, blocks the complete screen session for the duration
       of  the  break,  but  it  may be the only way to generate long breaks.
       Tcsendbreak and TIOCSBRK may or  may  not  produce  long  breaks  with
       spikes  (e.g.  4  per second). This is not only system dependant, this
       also differs between serial  board  drivers.   Calling  "defbreaktype"
       with no parameter displays the current setting.

       defcharset [set]

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

       defescape xy

       Set the default command characters. This is equivalent to the "escape"
       except  that it is useful multiuser sessions only. In a multiuser ses-
       sion "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  win-
       dows  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 charac-
       ter  is '^E' (octal 005) instead of '%'.  This was done to make a mis-
       interpretation of program generated hardstatus lines  impossible.   If
       the  parameter  status  is omitted, the current default string is dis-
       played.  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  win-
       dows is changed. Initial setting is 'off'.

       deflogin on|off

       Same as the login command except that the default setting for new win-
       dows 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'.

       defnonblock on|off|numsecs

       Same as the nonblock command except that the default setting for  dis-
       plays 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 depen-
       dency on the terminal type.

       defscrollback num

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

       defshell command

       Synonym to the shell command. See there.

       defsilence on|off

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

       defslowpaste msec"

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

       defutf8 on|off

       Same as the utf8 command except that the default setting for new  win-
       dows  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  win-
       dows 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.

       defzombie [keys]

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

       detach [-h]

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

       dinfo

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

       displays

       Shows a tabular listing of all  currently  connected  user  front-ends
       (displays).  This is most useful for multiuser sessions.

       digraph [preset]

       This  command  prompts  the  user for a digraph sequence. The next two
       characters typed are looked up in a builtin table  and  the  resulting
       character  is  inserted  in the input stream. For example, if the user
       enters 'a"', 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 exam-
       ple the command "bindkey ^K digraph '"'" enables the user to  generate
       an a-umlaut by typing CTRL-K a.

       dumptermcap

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

       echo [-n] message

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

       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 differ-
       ent encoding. The optional second parameter overwrites the encoding of
       the  connected  terminal. It should never be needed as screen uses the
       locale setting to detect the encoding.  There is also a way to  select
       a  terminal  encoding depending on the terminal type by using the "KJ"
       termcap entry.

       Supported encodings are eucJP, SJIS, eucKR, eucCN, Big5, GBK,  KOI8-R,
       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  fol-
       lowed 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 filedescriptor pattern
       fdpat.  This pattern is basically a three  character  sequence  repre-
       senting 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 cur-
       rently 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  illustra-
       tion  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 [up|down|top|bottom]

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

       gr [on|off]

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

       hardcopy [-h] [file]

       Writes  out  the currently displayed image to the file file, or, if no
       filename is specified, to hardcopy.n in the default directory, where n
       is  the  number  of  the current window.  This either appends or over-
       writes the file if it exists. See below.  If the option -h  is  speci-
       fied, 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]lastline|message|ignore [string]
       hardstatus string [string]

       This command configures the use and emulation of the terminal's  hard-
       status  line. The first form toggles whether screen will use the hard-
       ware 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). If the type  "lastline"  is  used,  screen
       will  reserve  the  last line of the display for the hardstatus. "mes-
       sage" uses screen's message mechanism and "ignore" tells screen  never
       to  display  the  hardstatus.  If you prepend the word "always" to the
       type (e.g., "alwayslastline"), screen will use the type  even  if  the
       terminal supports a hardstatus.

       The third form specifies the contents of the hardstatus line.  '%h' is
       used as default string, i.e. the stored hardstatus of the current win-
       dow  (settable  via  "ESC]0;^G" or "ESC_ESC\") is dis-
       played.  You can customize this to any string you like  including  the
       escapes  from the "STRING ESCAPES" chapter. If you leave out the argu-
       ment string, the current string is displayed.

       You can mix the second and third form by providing the string as addi-
       tional argument.

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

       Set  the  display height to a specified number of lines. When no argu-
       ment 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 win-
       dow size, -d vice versa.

       help [-c class]

       Not  really  a online help, but displays a help screen showing you all
       the key bindings.  The first pages list all the internal commands fol-
       lowed  by  their  current bindings.  Subsequent pages will display the
       custom commands, one command per key.  Press space  when  you're  done
       reading  each page, or return to exit early.  All other characters are
       ignored. If the "-c" option is given, display all bound  commands  for
       the specified command class.  See also "DEFAULT KEY BINDINGS" section.

       history

       Usually users work with a shell that allows easy  access  to  previous
       commands.   For  example  csh  has the command "!!" to repeat the last
       command executed.  Screen allows you to have a primitive  way  of  re-
       calling "the command that started ...": You just type the first letter
       of that command, then hit 'C-a {' and screen tries to find a  previous
       line  that matches with the 'prompt character' to the left of the cur-
       sor. 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 inac-
       tivity 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 (ot
       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'.

       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  CON-
       TROL):

         +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, applica-
       tion-keypad mode, has output logging, activity monitoring  or  partial
       redraw enabled.

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

       Additional modes depending on the type of the window are displayed  at
       the end of the status line (See also chapter "WINDOW TYPES").
       If  the  state  machine  of  the terminal emulator is in a non-default
       state, the info line is started with a string identifying the  current
       state.
       For system information use the "time" command.

       ins_reg [key]

       No longer exists, use "paste" instead.

       kill

       Kill current window.
       If there is an 'exec' command running then it is killed. Otherwise the
       process (shell) running in the window receives a HANGUP condition, the
       window  structure  is  removed  and  screen (your display) switches to
       another window.  When the last  window  is  destroyed,  screen  exits.
       After a kill screen switches to the previously displayed window.
       Note:  Emacs  users  should  keep this command in mind, when killing a
       line.  It is recommended not to use "C-a" as the screen escape key  or
       to rebind kill to "C-a K".

       lastmsg

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

       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 pro-
       cesses 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  "screen-
       log.n" in the window's default directory, where n is the number of the
       current window. This filename can be changed with the  'logfile'  com-
       mand.  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 scroll-
       back history are not included in the session log.  Default is 'off'.

       logfile filename
       logfile flush secs

       Defines the name the logfiles will get. The default is "screenlog.%n".
       The  second form changes the number of seconds screen will wait before
       flushing the logfile buffer to the file-system. The default  value  is
       10 seconds.

       login [on|off]

       Adds  or  removes  the entry in the utmp database file for the current
       window.  This controls if the window is 'logged in'.  When no  parame-
       ter  is given, the login state of the window is toggled.  Additionally
       to that toggle, it is convenient having a 'log in'  and  a  'log  out'
       key. E.g. 'bind I login on' and 'bind O login off' will map these keys
       to be C-a I and C-a O.  The default setting (in config.h.in) should be
       "on"  for a screen that runs under suid-root.  Use the "deflogin" com-
       mand 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  cur-
       rent time to the logfile after two minutes of inactivity.  When output
       continues and more than another two  minutes  have  passed,  a  second
       time-stamp  is  added  to  document the restart of the output. You can
       change this timeout with the second form of  the  command.  The  third
       form is used for customizing the time-stamp string ('-- %n:%t -- time-
       stamp -- %M/%d/%y %c:%s --\n' by default).

       mapdefault

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

       mapnotnext

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

       maptimeout [timo]

       Set  the inter-character timer for input sequence detection to a time-
       out of timo ms. The default timeout is 300ms. Maptimeout with no argu-
       ments 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  hap-
       pens 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 may only be decreased.

       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  win-
       dows.

       msgminwait sec

       Defines  the time screen delays a new message when one message is cur-
       rently 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 opera-
       tion 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 mes-
       sages which will often blur the facts a little, but are  much  funnier
       to read. Anyway, standard messages often tend to be unclear as well.
       This  option is only available if screen was compiled with the NETHACK
       flag defined. The default setting is then determined by  the  presence
       of the environment variable $NETHACKOPTIONS.

       next

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

       nonblock [on|off|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 charac-
       ters  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 windows number. If the given number  n  is  already
       used  by  another  window,  both windows exchange their numbers. If no
       argument is specified, the current window number (and title) is shown.

       obuflimit [limit]

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

       only

       Kill all regions but the current one.

       other

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

       partial on|off

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

       password [crypted_pw]

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

       paste [registers [dest_reg]]

       Write  the  (concatenated)  contents of the specified registers to the
       stdin queue of the current window. The register '.' is treated as  the
       paste buffer. If no parameter is given the user is prompted for a sin-
       gle 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  sec-
       ond  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 regis-
       ters 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 sig-
       nal  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  capa-
       bilities  "po/pf"  if it detects an ansi print sequence ESC [ 5 i, but
       pipe the output into cmd.  This should  normally  be  a  command  like
       "lpr" or "'cat > /tmp/scrprint'".  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  key-
       board.  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  ter-
       minals  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 win-
       dow no. 4.  Use the empty bind command (as in "bind '^\'") to remove a
       key binding.

       readbuf [-e encoding] [filename]

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

       readreg [-e encoding] [register [filename]]

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

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

       redisplay

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

       register [-e encoding] key string

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

       remove

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

       removebuf

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

       reset

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

       resize

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

              resize +N   increase current region height by N

              resize -N   decrease current region height by N

              resize  N   set current region height to N

              resize  =   make all windows equally high

              resize  max maximize current region height

              resize  min minimize current region height


       screen [-opts] [n] [cmd [args]]

       Establish  a  new window.  The flow-control options (-f, -fn and -fa),
       title (a.k.a.) option (-t), login options (-l and -ln) , terminal type
       option (-T ), the all-capability-flag (-a) and scrollback option
       (-h ) may be specified with each command.  The option (-M)  turns
       monitoring  on  for this window.  The option (-L) turns output logging
       on for this window.  If an optional number n  in  the  range  0..9  is
       given,  the  window  number  n is assigned to the newly created window
       (or, if this number is already in-use, the next available number).  If
       a  command  is  specified after "screen", this command (with the given
       arguments) is started in the window; otherwise, a  shell  is  created.
       Thus, if your ".screenrc" contains the lines

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

       screen  creates a shell window (in window #1) and a window with a TEL-
       NET connection to the machine foobar (with no flow-control  using  the
       title  "foobar" in window #2) and will write a logfile ("screenlog.2")
       of the telnet session.  Note, that unlike previous versions of  screen
       no  additional  default  window  is created when "screen" commands are
       included in your ".screenrc" file. When  the  initialization  is  com-
       pleted, 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  "defscroll-
       back" command and use "C-a i" to view the current setting.

       select [WindowID]

       Switch  to the window identified by WindowID.  This can be a prefix of
       a window title (alphanumeric window name) or  a  window  number.   The
       parameter  is optional and if omitted, you get prompted for an identi-
       fier.  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.  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 still reflects the old name. This may result  in
       confusion.  The default is constructed from the tty and host names.

       setenv [var [string]]

       Set  the  environment  variable  var  to value string.  If only var is
       specified, the user will be prompted to enter a value.  If no  parame-
       ters  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 pro-
       cess. This also breaks job-control, so be careful.  The default is on,
       of course. This command is probably useful only in rare circumstances.

       shell command

       Set the command to be used to create a new shell.  This overrides  the
       value  of  the  environment  variable $SHELL.  This is useful if you'd
       like to run a tty-enhancer which is expecting to execute  the  program
       specified  in  $SHELL. If the command begins with a '-' character, the
       shell will be started as a login-shell.

       shelltitle title

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

       silence [on|off|sec]

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

       silencewait sec

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

       sleep num

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

       slowpaste msec

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

       source file

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

       Note that termcap/terminfo/termcapinfo commands only work  at  startup
       and  reattach  time,  so they must be reached via the default screenrc
       files to have an effect.

       sorendition [attr [color]]

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

       split

       Split the current region into two new ones. All regions on the display
       are resized to make room for the new region. The blank window is  dis-
       played  on  the  new region. Use the "remove" or the "only" command to
       delete regions.

       startup_message on|off

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

       stuff string

       Stuff  the  string  string  in the input buffer of the current window.
       This is like the "paste" command but with  much  less  overhead.   You
       cannot paste large buffers with the "stuff" command. It is most useful
       for key bindings. See also "bindkey".

       su [username [password [password2]]

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

       suspend

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

       term term

       In each window's environment screen opens, the $TERM variable  is  set
       to  "screen"  by  default.   But  when  no description for "screen" is
       installed in the local termcap or terminfo data base, you set $TERM to
       - say - "vt100". This won't do much harm, as screen is VT100/ANSI com-
       patible.  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  win-
       dows.  You have to place these commands in one of the screenrc startup
       files, as they are meaningless once the terminal emulator is booted.
       If your system works uses the terminfo database rather  than  termcap,
       screen  will  understand  the  'terminfo'  command, which has the same
       effects as the 'termcap' command.  Two separate commands are provided,
       as  there are subtle syntactic differences, e.g. when parameter inter-
       polation (using '%') is required. Note that termcap names of the capa-
       bilities 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 identi-
       cal arguments.

       The first argument specifies which terminal(s) should be  affected  by
       this  definition.  You can specify multiple terminal names by separat-
       ing 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 under-
       stands (see the "VIRTUAL TERMINAL" section).

       Some examples:

              termcap xterm*  LP:hs@

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

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

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

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

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

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

       Takes a h19 or z19  termcap  and  turns  off  auto-margins  (am@)  and
       enables the insert mode (im) and end-insert (ei) capabilities (the '@'
       in the 'im' string is after the '=', so it is  part  of  the  string).
       Having  the 'im' and 'ei' definitions put into your terminal's termcap
       will cause screen  to  automatically  advertise  the  character-insert
       capability  in  each  window's termcap.  Each window will also get the
       delete-character capability (dc) added to its  termcap,  which  screen
       will  translate  into a line-update for the terminal (we're pretending
       it doesn't support character deletion).

       If you would like to fully specify each window's  termcap  entry,  you
       should  instead  set  the $SCREENCAP variable prior to running screen.
       See the discussion on the "VIRTUAL TERMINAL" in this manual,  and  the
       termcap(5) man page for more information on termcap definitions.

       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 spec-
       ified, screen prompts for one. This command was known as 'aka' in pre-
       vious releases.

       unsetenv var

       Unset an environment variable.

       utf8 [on|off [on|off]]

       Change  the  encoding  used in the current window. If utf8 is enabled,
       the strings sent to the window will be UTF-8 encoded and  vice  versa.
       Omitting  the  parameter toggles the setting. If a second parameter is
       given, the display's encoding is also changed (this should  rather  be
       done  with  screen's  "-U" option).  See also "defutf8", which changes
       the default setting of a new window.

       vbell [on|off]

       Sets the visual bell setting for this window. Omitting  the  parameter
       toggles  the  setting. If vbell is switched on, but your terminal does
       not support a visual bell, a 'vbell-message' is displayed in the  sta-
       tus  line  when the bell character (^G) is received.  Visual bell sup-
       port of a terminal is defined by the termcap variable 'vb'  (terminfo:
       'flash').
       Per  default,  vbell  is off, thus the audible bell is used.  See also
       'bell_msg'.

       vbell_msg [message]

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

       vbellwait sec

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

       verbose [on|off]

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

       version

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

       wall message

       Write a message to all displays. The message will appear in the termi-
       nal'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]
       windowlist string [string]
       windowlist title [title]

       Display all windows in  a  table  for  visual  window  selection.  The
       desired window can be selected via the standard movement keys (see the
       "copy" command) and activated via the return key.  If the -b option is
       given,  screen  will  switch to the blank window before presenting the
       list, so that the current window is also selectable.   The  -m  option
       changes the order of the windows, instead of sorting by window numbers
       screen uses its internal most-recently-used list.

       The table format can be changed with the string and title option,  the
       title is displayed as table heading, while the lines are made by using
       the string setting. The default setting is "Num Name%=Flags"  for  the
       title  and  "%3n  %t%=%f"  for  the  lines.   See the "STRING ESCAPES"
       chapter for more codes (e.g. color settings).

       windows

       Uses the message line to display a list of all the windows.  Each win-
       dow 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)'; win-
       dows occupied by other users are marked with '&'; windows in the  zom-
       bie 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.

       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 col-
       umn  of  a  line  will wrap to the start of the following line.  As an
       added feature, backspace (^H) will also wrap through the  left  margin
       to the previous line.  Default is 'on'.

       writebuf [-e encoding] [filename]

       Writes  the contents of the paste buffer to the specified file, or the
       public accessible screen-exchange file if no filename is  given.  This
       is  thought  of  as  a primitive means of communication between screen
       users on the same host. If an encoding is specified the  paste  buffer
       is  recoded on the fly to match the encoding.  The filename can be set
       with the bufferfile command and defaults to "/tmp/screen-exchange".

       writelock [on|off|auto]

       In addition to access control lists, not all  users  may  be  able  to
       write  to the same window at once. Per default, writelock is in 'auto'
       mode and grants exclusive input permission to  the  user  who  is  the
       first  to  switch to the particular window. When he leaves the window,
       other users may obtain the writelock (automatically). The writelock of
       the  current window is disabled by the command "writelock off". If the
       user issues the command "writelock on" he keeps  the  exclusive  write
       permission while switching to other windows.

       xoff
       xon

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

       zmodem [off|auto|catch|pass]
       zmodem sendcmd [string]
       zmodem recvcmd [string]

       Define zmodem support for screen.  Screen  understands  two  different
       modes  when  it  detects a zmodem request: "pass" and "catch".  If the
       mode is set to "pass", screen will relay  all  data  to  the  attacher
       until  the end of the transmission is reached.  In "catch" mode screen
       acts as a zmodem endpoint and starts the corresponding rz/sz commands.
       If the mode is set to "auto", screen will use "catch" if the window is
       a tty (e.g. a serial line), otherwise it will use "pass".
       You can define the templates screen uses in "catch" mode via the  sec-
       ond and the third form.
       Note also that this is an experimental feature.

       zombie [keys]
       defzombie [keys]

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

       As  the  zombie-setting  is manipulated globally for all windows, this
       command should only be called defzombie. Until we need this as  a  per
       window setting, the commands zombie and defzombie are synonymous.


THE MESSAGE LINE
       Screen displays informational messages and other diagnostics in a mes-
       sage 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 dur-
       ing compilation.  If your terminal has a status line  defined  in  its
       termcap, screen will use this for displaying its messages, otherwise a
       line of the current screen will be temporarily overwritten and  output
       will  be  momentarily  interrupted.  The message line is automatically
       removed after a few seconds delay, but it can also  be  removed  early
       (on terminals without a status line) by beginning to type.

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

              echo '^Hello world from window '$WINDOW'\\'

       where  '' 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 "CUS-
       TOMIZATION"). 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 con-
          nected 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  con-
          nection  line as busy.  An optional parameter is allowed consisting
          of a comma separated list of flags in the notation used by stty(1):

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

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

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

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

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

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

          For  tty  windows, the info command shows some of the modem control
          lines in the status line. These may include  'RTS',  'CTS',  'DTR',
          'DSR',  'CD' and more.  This depends on the available ioctl()'s and
          system header files as well as the on the physical capabilities  of
          the  serial  board.   Signals  that are logical low (inactive) have
          their name preceded by an exclamation mark (!), otherwise the  sig-
          nal  is  logical high (active).  Signals not supported by the hard-
          ware 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 TIOC-
          SOFTCAR  bit  is set, the signals 'CTS' or 'CD' are shown in paren-
          thesis, respectively.


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

       ?  If the first parameter  is  "//telnet",  the  second  parameter  is
          expected  to  be  a  host name, and an optional third parameter may
          specify a TCP port number (default decimal 23).  Screen  will  con-
          nect  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  con-
          nection 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 oth-
                 erwise (see also the command 'term').

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

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

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

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


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



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

       Here is the full list of supported escapes:

       %      the escape character itself

       a      either 'am' or 'pm'

       A      either 'AM' or 'PM'

       c      current time HH:MM in 24h format

       C      current time HH:MM in 12h format

       d      day number

       D      weekday name

       f      flags of the window

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

       h      hardstatus of the window

       H      hostname of the system

       l      current load of the system

       m      month number

       M      month name

       n      window number

       s      seconds

       t      window title

       u      all other users on this window

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

       W      all window numbers and names except the current one

       y      last two digits of the year number

       Y      full year number

       ?      the  part  to  the  next '%?' is displayed only if 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 rela-
              tive  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  under-
       stand  a  length  qualifier  (e.g. '%3n'), 'D' and 'M' can be prefixed
       with 'L' to generate long names, 'w' and  'W'  also  show  the  window
       flags if 'L' is given.

       An attribute/color modifier is is used to change the attributes or the
       color settings. Its format is "[attribute  modifier]  [color  descrip-
       tion]". The attribute modifier must be prefixed by a change type indi-
       cator if it can be confused with a  color  desciption.  The  following
       change types are known:

       +      add the specified set to the current attributes

       -      remove the set from the current attributes

       !      invert the set in the current attributes

       =      change the current attributes to the specified set

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

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

       Colors are coded either as a hexadecimal number or two letters  speci-
       fying 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 back-
       ground  color  dependant on the current attributes: if reverse mode is
       set, the background color is changed instead of the foreground  color.
       If  you  don't like this, prefix the color with a ".". If you want the
       same behaviour for two-letter color  descriptions,  also  prefix  them
       with a ".".
       As a special case, "%{-}" restores the attributes and colors that were
       set before the last change was made (i.e. pops one level of the color-
       change stack).

       Examples:

       "G"    set color to bright green

       "+b r" use bold red

       "= yd" clear  all  attributes,  write in default color on yellow back-
              ground.

       %-Lw%{= BW}%50>%n%f* %t%{-}%+Lw%<
              The available windows centered at the current window and  trun-
              cated  to  the available width. The current window is displayed
              white on blue.  This can be used with  "hardstatus  alwayslast-
              line".

       %?%F%{.R.}%?%3n %t%? [%h]%?
              The window number and title and the window's hardstatus, if one
              is set.  Also use a red background if this is the active focus.
              Useful for "caption string".

FLOW-CONTROL
       Each  window  has  a  flow-control  setting that determines how screen
       deals with the XON and XOFF  characters  (and  perhaps  the  interrupt
       character).   When  flow-control is turned off, screen ignores the XON
       and XOFF characters, which allows the user to send them to the current
       program  by  simply  typing  them  (useful  for  the emacs editor, for
       instance).  The trade-off is that it will take longer for output  from
       a "normal" program to pause in response to an XOFF.  With flow-control
       turned on, XON and XOFF characters are used to immediately  pause  the
       output  of the current window.  You can still send these characters to
       the current program, but you must use  the  appropriate  two-character
       screen  commands  (typically  "C-a  q" (xon) and "C-a s" (xoff)).  The
       xon/xoff commands are also useful for typing C-s and C-q past a termi-
       nal that intercepts these characters.

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

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

       If you're running with flow-control enabled and find that pressing the
       interrupt  key  (usually  C-c)  does  not  interrupt the display until
       another 6-8 lines have  scrolled  by,  try  running  screen  with  the
       "interrupt"  option (add the "interrupt" flag to the "flow" command in
       your .screenrc, or use the -i command-line option).  This  causes  the
       output  that screen has accumulated from the interrupted program to be
       flushed.  One disadvantage is that the virtual terminal's memory  con-
       tains  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 possi-
       ble 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  "shellti-
       tle"  command  in the .screenrc file, while all other windows are cre-
       ated with a "screen" command and thus can have their name set with the
       -t  option.   Interactively, there is the title-string escape-sequence
       (kname\) 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.

       Finally, screen has a shell-specific heuristic that is enabled by set-
       ting  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 por-
       tion specifies the default shell name for the  window.   If  the  name
       ends  in a ':' screen will add what it believes to be the current com-
       mand 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  (k\)  as a part of your prompt.
       The last part of your prompt must be the same as the string you speci-
       fied 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 previ-
       ously   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-con-
       trol 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  "[0000m"  not only normalizes the character
       attributes, but all the zeros round the length of the invisible  char-
       acters  up  to  8.   Bash  users will probably want to echo the escape
       sequence in the PROMPT_COMMAND:

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

       (I used "134" to output a '\' because of a bug in 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 ter-
       minal 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 emula-
       tion may not be complete. In these cases screen has to tell the appli-
       cations  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.", where  is the contents
       of  your  $TERM  variable.   If  no  such  entry  exists, screen tries
       "screen" (or "screen-w" if the terminal is wide (132 cols  or  more)).
       If even this entry cannot be found, "vt100" is used as a substitute.

       The  idea  is  that  if  you  have a terminal which doesn't support an
       important feature (e.g. delete char or clear to EOS) you can  build  a
       new  termcap/terminfo  entry for screen (named "screen.") 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  vari-
       able  of  all  new  windows.   Screen  also sets the $TERMCAP variable
       reflecting the capabilities of the virtual terminal  emulated.  Notice
       that,  however,  on machines using the terminfo database this variable
       has no effect.  Furthermore, the variable $WINDOW is set to the window
       number of each window.

       The  actual  set  of  capabilities  supported  by the virtual terminal
       depends on the capabilities supported by the physical  terminal.   If,
       for  instance, the physical terminal does not support underscore mode,
       screen does not put the 'us' and 'ue' capabilities into  the  window's
       $TERMCAP variable, accordingly.  However, a minimum number of capabil-
       ities must be supported by a terminal in order to run  screen;  namely
       scrolling,  clear  screen,  and direct cursor addressing (in addition,
       screen does not run on hardcopy terminals or on terminals  that  over-
       strike).

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

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

       When  the  boolean 'G0' capability is present in the termcap entry for
       the terminal on which screen has been called, the  terminal  emulation
       of  screen  supports multiple character sets.  This allows an applica-
       tion to make use of, for instance, the VT100 graphics character set or
       national  character  sets.   The  following control functions from ISO
       2022 are supported: lock shift G0 (SI), lock shift G1 (SO), lock shift
       G2,  lock shift G3, single shift G2, and single shift G3.  When a vir-
       tual terminal is created or reset, the ASCII character set  is  desig-
       nated  as  G0 through G3.  When the 'G0' capability is present, screen
       evaluates the capabilities 'S0', 'E0', and 'C0' if  present.  'S0'  is
       the  sequence the terminal uses to enable and start the graphics char-
       acter 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 win-
       dow'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_ESC\".  As  a  convenience  for  xterm users the sequence
       "ESC]0..2;^G" is also accepted.

       Some capabilities are only put into the $TERMCAP variable of the  vir-
       tual  terminal  if they can be efficiently implemented by the physical
       terminal.  For instance, 'dl' (delete  line)  is  only  put  into  the
       $TERMCAP  variable  if the terminal supports either delete line itself
       or scrolling regions. Note that this may provoke confusion,  when  the
       session  is reattached on a different terminal, as the value of $TERM-
       CAP 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

                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 :win-
                                  dow: -rwx #?" to  create  a  user  with  no
                                  rights  and allow only the needed commands.

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

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

       ESC n                 (A)  Lock Shift G2

       ESC o                 (A)  Lock Shift G3

       ESC N                 (A)  Single Shift G2

       ESC O                 (A)  Single Shift G3

       ESC ( Pcs             (A)  Designate character set as G0

       ESC ) Pcs             (A)  Designate character set as G1

       ESC * Pcs             (A)  Designate character set as G2

       ESC + Pcs             (A)  Designate character set as G3

       ESC [ Pn ; Pn H            Direct Cursor Addressing

       ESC [ Pn ; Pn f            same as above

       ESC [ Pn J                 Erase in Display

             Pn = None or 0       From Cursor to End of Screen

                  1               From Beginning of Screen to Cursor

                  2               Entire Screen

       ESC [ Pn K                 Erase in Line

             Pn = None or 0       From Cursor to End of Line

                  1               From Beginning of Line to Cursor

                  2               Entire Line

       ESC [ Pn X                 Erase character

       ESC [ Pn A                 Cursor Up

       ESC [ Pn B                 Cursor Down

       ESC [ Pn C                 Cursor Right

       ESC [ Pn D                 Cursor Left

       ESC [ Pn E                 Cursor next line

       ESC [ Pn F                 Cursor previous line

       ESC [ Pn G                 Cursor horizontal position

       ESC [ Pn '                 same as above

       ESC [ Pn d                 Cursor vertical position

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

             Ps = None or 0       Default Rendition

                  1               Bold

                  2          (A)  Faint

                  3          (A)  Standout Mode (ANSI: Italicized)

                  4               Underlined

                  5               Blinking

                  7               Negative Image

                  22         (A)  Normal Intensity

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

                  24         (A)  Not Underlined

                  25         (A)  Not Blinking

                  27         (A)  Positive Image

                  30         (A)  Foreground Black

                  31         (A)  Foreground Red

                  32         (A)  Foreground Green

                  33         (A)  Foreground Yellow

                  34         (A)  Foreground Blue

                  35         (A)  Foreground Magenta

                  36         (A)  Foreground Cyan

                  37         (A)  Foreground White

                  39         (A)  Foreground Default

                  40         (A)  Background Black

                  ...

                  49         (A)  Background Default

       ESC [ Pn g                 Tab Clear

             Pn = None or 0       Clear Tab at Current Position

                  3               Clear All Tabs

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

       ESC [ Pn I            (A)  Horizontal Tab

       ESC [ Pn Z            (A)  Backward Tab

       ESC [ Pn L            (A)  Insert Line

       ESC [ Pn M            (A)  Delete Line

       ESC [ Pn @            (A)  Insert Character

       ESC [ Pn P            (A)  Delete Character

       ESC [ Pn S                 Scroll Scrolling Region Up

       ESC [ Pn T                 Scroll Scrolling Region Down

       ESC [ Pn ^                 same as above

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

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

             Ps = 4          (A)  Insert Mode

                  20         (A)  Automatic Linefeed Mode

                  34              Normal Cursor Visibility

                  ?1         (V)  Application Cursor Keys

                  ?3         (V)  Change Terminal Width to 132 columns

                  ?5         (V)  Reverse Video

                  ?6         (V)  Origin Mode

                  ?7         (V)  Wrap Mode

                  ?9              X10 mouse tracking

                  ?25        (V)  Visible Cursor

                  ?47             Alternate Screen (old xterm code)

                  ?1000      (V)  VT200 mouse tracking

                  ?1047           Alternate Screen (new xterm code)

                  ?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 keyboard and insert the  VT100  style  escape  sequence.
       Screen  has a very flexible way of doing this by making it possible to
       map arbitrary commands on arbitrary sequences of characters. For stan-
       dard  VT100  emulation  the command will always insert a string in the
       input buffer of the window (see also command stuff in the command  ta-
       ble).   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. (A) means that the com-
       mand is executed if the keyboard is switched into application mode.

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



SPECIAL TERMINAL CAPABILITIES
       The following table describes all terminal capabilities that are  rec-
       ognized 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' com-
                    mand for valid encodings.

       AF   (str)   Change character foreground color in an ANSI conform way.
                    This  capability  will  almost always be set to '\E[3%dm'
                    ('\E[3%p1%dm' on terminfo machines).

       AB   (str)   Same as 'AF', but change background color.

       AX   (bool)  Does understand ANSI set default fg/bg  color  (\E[39m  /
                    \E[49m).

       XC   (str)   Describe a translation of characters to strings depending
                    on the current font. More details follow in the next sec-
                    tion.

       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 char-
       acters over several national language font pages.

       Syntax:
           XC={,,}
            :=