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SCREEN(1)                            General Commands Manual                            SCREEN(1)



NAME
       screen - screen manager with VT100/ANSI terminal emulation



SYNOPSIS
       screen [ -options ] [ cmd [ args ] ]
       screen -r [[pid.]tty[.host]]
       screen -r sessionowner/[[pid.]tty[.host]]



DESCRIPTION
       Screen  is  a full-screen window manager that multiplexes a physical terminal between sev-
       eral processes (typically interactive shells).  Each virtual terminal provides  the  func-
       tions  of  a  DEC  VT100 terminal and, in addition, several control functions from the ISO
       6429 (ECMA 48, ANSI X3.64) and ISO 2022 standards (e.g. insert/delete line and support for
       multiple  character sets).  There is a scrollback history buffer for each virtual terminal
       and a copy-and-paste mechanism that allows moving text regions between windows.

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

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

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

       The standard way to create a new window is to type "C-a c".  This  creates  a  new  window
       running  a  shell  and switches to that window immediately, regardless of the state of the
       process running in the current window.  Similarly, you can create a new window with a cus-
       tom  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  addi-
       tion, new windows can be created by running a command like:

              screen emacs prog.c

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

       If  "/etc/utmp"  is writable by screen, an appropriate record will be written to this file
       for each window, and removed when the window is terminated.  This is  useful  for  working
       with "talk", "script", "shutdown", "rsend", "sccs" and other similar programs that use the
       utmp file to determine who you are. As long as screen is active on your terminal, the ter-
       minal's own record is removed from the utmp file. See also "C-a L".



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

       If  you're  impatient and want to get started without doing a lot more reading, you should
       remember this one command:  "C-a ?".  Typing these two characters will display a  list  of
       the  available screen commands and their bindings. Each keystroke is discussed in the sec-
       tion "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 per-
       fectly 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  posi-
       tion  in some other way. This delay can be shortened by using a terminal with insert-char-
       acter capability.



COMMAND-LINE OPTIONS
       Screen has the following command-line options:

       -a   include all capabilities (with some minor exceptions) in each window's termcap,  even
            if screen must redraw parts of the display in order to implement a function.

       -A   Adapt  the  sizes  of  all  windows to the size of the current terminal.  By default,
            screen tries to restore its old window sizes when attaching  to  resizable  terminals
            (those with "WS" in its description, e.g. suncmd or some xterm).

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

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

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

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

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

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

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

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

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

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

       -f, -fn, and -fa
            turns flow-control on, off, or "automatic switching mode".  This can also be  defined
            through the "defflow" .screenrc command.

       -h num
            Specifies the history scrollback buffer to be num lines high.

       -i   will  cause the interrupt key (usually C-c) to interrupt the display immediately when
            flow-control is on.  See the "defflow" .screenrc command for  details.   The  use  of
            this option is discouraged.

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

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

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

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

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

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

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

       -r [pid.tty.host]
       -r sessionowner/[pid.tty.host]
            resumes a detached screen session.  No other options (except combinations with -d/-D)
            may  be  specified, though an optional prefix of [pid.]tty.host may be needed to dis-
            tinguish between multiple detached screen sessions.  The second form is used to  con-
            nect  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 program
            sets the default shell to the program specified, instead of the value in the environ-
            ment variable $SHELL (or "/bin/sh" if not defined).  This can also be defined through
            the "shell" .screenrc command.

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

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

       -T term
            Set the $TERM enviroment varible using the spcified term as opposed  to  the  defualt
            setting of screen.

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

       -v   Print version number.

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

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

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

       -4   Resolve hostnames only to IPv4 addresses.

       -6   Resolve hostnames only to IPv6 addresses.


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

       The following table shows the default key bindings:

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

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

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

       C-a tab     (focus)       Switch the input focus to the  next  region.   See  also  split,
                                 remove, only.

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

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

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

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

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

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

       C-a C       (clear)       Clear the screen.

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

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

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

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

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

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

       C-a H       (log)         Begins/ends logging of the current window to the  file  "screen-
                                 log.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 con-
                                 figured 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.  See also split, remove,
                                 focus.

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

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

       C-a S       (split)       Split the current region horizontally into two  new  ones.   See
                                 also only, remove, focus.

       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.  See also split, only, focus.

       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 C-]
       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 |       (split -v)    Split the current region vertically into two new ones.

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



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

       When screen is invoked, it executes initialization commands from the files "/etc/screenrc"
       and ".screenrc" in the user's home directory. These are the "programmer's  defaults"  that
       can  be overridden in the following ways: for the global screenrc file screen searches for
       the environment variable $SYSSCREENRC (this override feature may be disabled  at  compile-
       time).  The  user  specific  screenrc file is searched in $SCREENRC, then $HOME/.screenrc.
       The command line option -c takes precedence over the above user screenrc files.

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

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

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

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

       acldel username

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

       aclgrp username [groupname]

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

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

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

       activity message

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

                   'Activity in window %n'

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

       allpartial on|off

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

       altscreen on|off

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

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

       Execute a command at other displays or windows as if it  had  been  entered  there.   "At"
       changes the context (the `current window' or `current display' setting) of the command. If
       the first parameter describes a non-unique context, the command will be executed  multiple
       times.  If  the  first  parameter  is of the form `identifier*' then identifier is matched
       against user names.  The command is  executed  once  for  each  display  of  the  selected
       user(s). If the first parameter is of the form `identifier%' identifier is matched against
       displays. Displays are named after the ttys they attach. The prefix `/dev/' or  `/dev/tty'
       may  be  omitted  from  the identifier.  If identifier has a `#' or nothing appended it is
       matched against window numbers and titles. Omitting an identifier in front of the `#', `*'
       or  `%'-character  selects  all  users, displays or windows because a prefix-match is per-
       formed. Note that on the affected display(s) a short message will describe what  happened.
       Permission  is  checked  for  initiator  of  the  "at"  command, not for the owners of the
       affected display(s).  Note that the '#' character works as a comment introducer when it is
       preceded by whitespace. This can be escaped by prefixing a '\'.  Permission is checked for
       the initiator of the "at" command, not for the owners of the affected display(s).
       Caveat: When matching against windows, the command is executed at least once  per  window.
       Commands  that  change  the  internal  arrangement of windows (like "other") may be called
       again. In shared windows the command will be repeated for each attached  display.  Beware,
       when  issuing toggle commands like "login"!  Some commands (e.g. "process") require that a
       display is associated with the target windows.  These  commands  may  not  work  correctly
       under "at" looping over windows.

       attrcolor attrib [attribute/color-modifier]

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

       Examples:

              attrcolor b "R"

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

              attrcolor u "-u b"

       Use blue text instead of underline.

              attrcolor b ".I"

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

              attrcolor i "+b"

       Make bright colored text also bold.

       autodetach on|off

       Sets  whether  screen  will automatically detach upon hangup, which saves all your running
       programs until they are resumed with a screen -r command.  When turned off, a hangup  sig-
       nal 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 auto-
       matic refresh for caption and hardstatus strings after the specified  number  of  seconds.
       Only the last line of output is used for substitution.
       If  both  the  lifespan  and  the autorefresh parameters are zero, the backtick program is
       expected to stay in the background and generate output once in a while.  In this case, the
       command  is  executed  right away and screen stores the last line of output. If a new line
       gets printed screen will automatically refresh the hardstatus or the captions.
       The second form of the command deletes the backtick command with the numerical id id.

       bce [on|off]

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

       bell_msg [message]

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

                   'Bell in window %n'

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

       bind [-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  charac-
       ter, 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  cre-
       ate multiple command keys or multi-character bindings.

       Some examples:

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

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

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

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

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

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

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

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

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

               bindkey -k k1 select 1
       Make the "F1" key switch to window one.

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

               bindkey "\024" mapdefault
       This  key-binding  makes  "^T"  an escape character for key-bindings. If you did the above
       "stuff barfoo" binding, you can enter the word "foo" by typing "^Tfoo".  If  you  want  to
       insert a "^T" you have to press the key twice (i.e., escape the escape binding).

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

       break [duration]

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

       blanker

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

       blankerprg [program args]

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

       breaktype [tcsendbreak|TIOCSBRK |TCSBRK]

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

       bufferfile [exchange-file]

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

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

       c1 [on|off]

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

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

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

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

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

       charset set

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

       chdir [directory]

       Change the current directory of screen to the specified directory or, if called without an
       argument, to your home directory (the value of the environment variable $HOME).  All  win-
       dows that are created by means of the "screen" command from within ".screenrc" or by means
       of "C-a : screen ..." or "C-a c" use this as their default  directory.   Without  a  chdir
       command,  this  would  be  the  directory from which screen was invoked.  Hardcopy and log
       files are always written to the window's default directory, not the current  directory  of
       the  process  running  in  the  window.   You  can use this command multiple times in your
       .screenrc to start various windows in different default directories, but  the  last  chdir
       value will affect all the windows you create interactively.

       clear

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

       colon [prefix]

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

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

       command [-c class]

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

       compacthist [on|off]

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

       console [on|off]

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

       copy

       Enter copy/scrollback mode. This allows you to copy text from the current window  and  its
       history into the paste buffer. In this mode a vi-like `full screen editor' is active:
       Movement keys:
         h, C-h, or left arrow move the cursor left.
         j, C-n, or down arrow move the cursor down.
         k, C-p, or up arrow move the cursor up.
         l ('el') or right arrow move the cursor right.
         0 (zero) or C-a move to the leftmost column.
         + and - positions one line up and down.
         H,  M  and L move the cursor to the leftmost column of the top, center or bottom line of
           the window.
         | moves to the specified absolute column.
         g or home moves to the beginning of the buffer.
         G or end moves to the specified absolute line (default: end of buffer).
         % jumps to the specified percentage of the buffer.
         ^ or $ move to the leftmost column, to the first or last non-whitespace character on the
           line.
         w, b, and e move the cursor word by word.
         B, E move the cursor WORD by WORD (as in vi).
         f/F,  t/T  move  the  cursor  forward/backward to the next occurence of the target. (eg,
           '3fy' will move the cursor to the 3rd 'y' to the right.)
         ; and , Repeat the last f/F/t/T command in the same/opposite direction.
         C-e and C-y scroll the display up/down by one line while preserving the cursor position.
         C-u and C-d scroll the display up/down by the specified amount of lines while preserving
           the cursor position. (Default: half screen-full).
         C-b and C-f scroll the display up/down a full screen.

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

       Marking:
           The copy range is specified by setting two marks. The text between these marks will be
           highlighted. Press:
         space or enter to set the first or second mark respectively. If  mousetrack  is  set  to
           `on', marks can also be set using left mouse click.
         Y and y used to mark one whole line or to mark from start of line.
         W marks exactly one word.
       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.
         n Find next search pattern.
         N Find previous search pattern.
       Specials:
           There are however some keys that act differently than in vi.  Vi does not allow one to
           yank rectangular blocks of text, but screen does. Press:
         c or C to set the left or right margin respectively. If no repeat count is  given,  both
           default to the current cursor position.
           Example:  Try  this  on  a  rather  full text screen: "C-a [ M 20 l SPACE c 10 l 5 j C
           SPACE".

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

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

       copy_reg [key]

       No longer exists, use "readreg" instead.

       crlf [on|off]

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

       debug on|off

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

       defc1 on|off

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

       defautonuke on|off

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

       defbce on|off

       Same as the bce command except that the default setting for new windows is  changed.  Ini-
       tial setting is `off'.

       defbreaktype [tcsendbreak|TIOCSBRK |TCSBRK]

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

       defcharset [set]

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

       defescape xy

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

       defflow on|off|auto [interrupt]

       Same as the flow command except that the default setting for new windows is changed.  Ini-
       tial  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 use-
       ful to make the hardstatus of every window display the window number or title or the like.
       Status may contain the same directives as in the window messages, but the directive escape
       character is '^E' (octal 005) instead of '%'.  This was done to make  a  misinterpretation
       of program generated hardstatus lines impossible.  If the parameter status is omitted, the
       current default string is displayed.  Per default the hardstatus line of  new  windows  is
       empty.

       defencoding enc

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

       deflog on|off

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

       deflogin on|off

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

       defmode mode

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

       defmonitor on|off

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

       defmousetrack on|off

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

       defnonblock on|off|numsecs

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

       defobuflimit limit

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

       defscrollback num

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

       defshell command

       Synonym to the shell command. See there.

       defsilence on|off

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

       defslowpaste msec"

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

       defutf8 on|off

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

       defwrap on|off

       Same as the wrap command except that the default setting for new windows is changed.  Ini-
       tially 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 back-
       ground).  This returns you to the shell where you invoked screen.  A detached  screen  can
       be  resumed  by  invoking  screen  with  the  -r  option  (see  also section "COMMAND-LINE
       OPTIONS"). The -h option tells screen to immediately close the connection to the  terminal
       ("hangup").

       dinfo

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

       displays

       Shows a tabular listing of all currently connected user front-ends  (displays).   This  is
       most useful for multiuser sessions.  The following keys can be used in displays list:
         k, C-p, or up Move up one line.
         j, C-n, or down Move down one line.
         C-a or home Move to the first line.
         C-e or end Move to the last line.
         C-u or C-d Move one half page up or down.
         C-b or C-f Move one full page up or down.
         mouseclick Move to the selected line. Available when "mousetrack" is set to on.
         space Refresh the list
         d Detach that display
         D Power detach that display
         C-g, enter, or escape Exit the list

       The following is an example of what "displays" could look like:

              xterm 80x42 jnweiger@/dev/ttyp4     0(m11)   &rWx
              facit 80x24 mlschroe@/dev/ttyhf nb 11(tcsh)   rwx
              xterm 80x42 jnhollma@/dev/ttyp5     0(m11)   &R.x
               (A)   (B)     (C)     (D)     (E) (F)(G)   (H)(I)

       The legend is as follows:
       (A) The terminal type known by screen for this display.
       (B) Displays geometry as width x height.
       (C) Username who is logged in at the display.
       (D) Device name of the display or the attached device
       (E)  Display is in blocking or nonblocking mode. The available modes are "nb", "NB", "Z<",
       "Z>", and "BL".
       (F) Number of the window
       (G) Name/title of window
       (H) Whether the window is shared
       (I) Window permissions. Made up of three characters:
             (1st character)
                `-' : no read
                `r' : read
                `R' : read only due to foreign wlock
             (2nd character)
                `-' : no write
                `.' : write suppressed by foreign wlock
                `w' : write
                `W' : own wlock
             (3rd character)
                `-' : no execute
                `x' : execute

       "Displays" needs a region size of at least 10 characters wide and  5  characters  high  in
       order to display.

       digraph [preset[unicode-value]]

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

       dumptermcap

       Write the termcap entry for the virtual terminal optimized for the currently active window
       to the file ".termcap" in the user's "$HOME/.screen" directory (or wherever screen  stores
       its sockets. See the "FILES" section below).  This termcap entry is identical to the value
       of the environment variable $TERMCAP that is set up by screen for each  window.  For  ter-
       minfo  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  vari-
       ables.

       encoding enc [enc]

       Tell screen how to interpret the input/output. The first argument sets the encoding of the
       current window. Each window can emulate a different encoding. The optional second  parame-
       ter 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 followed by an octal number (specifying the ASCII code of the character),  or  a
       backslash followed by a second character, such as "\^" or "\\".  The default is "^Aa".

       eval command1 [command2 ...]

       Parses and executes each argument as separate command.

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

       Run  a  unix subprocess (specified by an executable path newcommand and its optional argu-
       ments) in the current window. The flow of data  between  newcommands  stdin/stdout/stderr,
       the  process  originally  started in the window (let us call it "application-process") and
       screen itself (window) is controlled by the file descriptor pattern fdpat.   This  pattern
       is  basically  a three character sequence representing stdin, stdout and stderr of newcom-
       mand. 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'  out-
       put  (fdpats  first  character  is  `!' or `:') or a pipe symbol (|) is added (as a fourth
       character) to the end of fdpat.
       Invoking `exec' without arguments shows name and arguments of the currently  running  sub-
       process in this window. Only one subprocess a time can be running in each window.
       When  a  subprocess  is  running  the `kill' command will affect it instead of the windows
       process.
       Refer to the postscript file `doc/fdpat.ps' for a confusing illustration of all 21  possi-
       ble combinations. Each drawing shows the digits 2,1,0 representing the three file descrip-
       tors 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.  Out-
       put 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 win-
       dow'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 subcommand is given it defaults to  `down'.
       `up'  cycles  in  the  opposite  order, `top' and `bottom' go to the top and bottom region
       respectively. Useful bindings are (j and k as in vi)
           bind j focus down
           bind k focus up
           bind t focus top
           bind b focus bottom
       Note that k is traditionally bound to the kill command.

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

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

       gr [on|off]

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

       group [grouptitle]

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

       hardcopy [-h] [file]

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

       hardcopy_append on|off

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

       hardcopydir directory

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

       hardstatus [on|off]
       hardstatus [always]lastline|message|ignore [string]
       hardstatus string [string]

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

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

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

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

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

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

       help [-c class]

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

       history

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

       hstatus status

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

       idle [timeout [cmd args]]

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

       ignorecase [on|off]

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

       info

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

         +flow     automatic flow control, currently on.
         -flow     automatic flow control, currently off.
         +(+)flow  flow control enabled. Agrees with automatic control.
         -(+)flow  flow control disabled. Disagrees with automatic control.
         +(-)flow  flow control enabled. Disagrees with automatic control.
         -(-)flow  flow control disabled. Agrees with automatic control.

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

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

       Additional  modes depending on the type of the window are displayed at the end of the sta-
       tus 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  recom-
       mended not to use "C-a" as the screen escape key or to rebind kill to "C-a K".

       lastmsg

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

       layout new [title]

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

       layout remove [n|title]

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

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

       layout next

       Switch to the next layout available

       layout prev

       Switch to the previous layout available

       layout select [n|title]

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

       layout show

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

       layout title [title]

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

       layout number [n]

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

       layout attach [title|:last]

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

       layout save [n|title]

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

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

       layout autosave [on|off]

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

       layout dump [filename]

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

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

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

       license

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

       lockscreen

       Lock  this  display.   Call  a  screenlock  program  (/local/bin/lck or /usr/bin/lock or a
       builtin if no other is available). Screen does not accept any command keys until this pro-
       gram  terminates.  Meanwhile  processes in the windows may continue, as the windows are in
       the `detached' state. The screenlock program may be changed through the environment  vari-
       able  $LOCKPRG  (which  must be set in the shell from which screen is started) and is exe-
       cuted with the user's uid and gid.
       Warning: When you leave other shells unlocked and you have no password set on screen,  the
       lock  is  void:  One  could  easily  re-attach from an unlocked shell. This feature should
       rather be called `lockterminal'.

       log [on|off]

       Start/stop writing output of the current window to a file "screenlog.n"  in  the  window's
       default  directory,  where  n  is  the  number of the current window. This filename can be
       changed with the `logfile' command. If no parameter is given, the state of logging is tog-
       gled.  The  session  log  is  appended  to the previous contents of the file if it already
       exists. The current contents and the contents of the scrollback history are  not  included
       in the session log.  Default is `off'.

       logfile filename
       logfile flush secs

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

       login [on|off]

       Adds or removes the entry in the utmp database file for the current window.  This controls
       if the window is `logged in'.  When no parameter is given, the login state of  the  window
       is  toggled.   Additionally  to that toggle, it is convenient having a `log in' and a `log
       out' key. E.g. `bind I login on' and `bind O login off' will map these keys to  be  C-a  I
       and  C-a  O.   The  default setting (in config.h.in) should be "on" for a screen that runs
       under suid-root.  Use the "deflogin" command to change the default  login  state  for  new
       windows. Both commands are only present when screen has been compiled with utmp support.

       logtstamp [on|off]
       logtstamp after [secs]
       logtstamp string [string]

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

       mapdefault

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

       mapnotnext

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

       maptimeout [timeout]

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

       markkeys string

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

       maxwin num

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

       meta

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

       monitor [on|off]

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

       mousetrack [on|off]

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

       msgminwait sec

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

       msgwait sec

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

       multiuser on|off

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

       nethack on|off

       Changes the kind of error messages used by screen.  When you are familiar  with  the  game
       "nethack", you may enjoy the nethack-style messages which will often blur the facts a lit-
       tle, 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 $NETHACKOP-
       TIONS and the file ~/.nethackrc - if either one is present, the default is on.

       next

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

       nonblock [on|off|numsecs]

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

       number [[+|-]n]

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

       obuflimit [limit]

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

       only

       Kill all regions but the current one.

       other

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

       partial on|off

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

       password [crypted_pw]

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

       paste [registers [dest_reg]]

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

       pastefont [on|off]

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

       pow_break

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

       pow_detach

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

       pow_detach_msg [message]

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

       prev

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

       printcmd [cmd]

       If cmd is not an empty string, screen will not use the terminal capabilities "po/pf" if it
       detects an ansi print sequence ESC [ 5 i, but pipe the output into cmd.  This should  nor-
       mally be a command like "lpr" or "'cat > /tmp/scrprint'".  printcmd without a command dis-
       plays the current setting.  The ansi sequence ESC \ ends printing and closes the pipe.
       Warning: Be careful with this command! If other user have write access to  your  terminal,
       they will be able to fire off print commands.

       process [key]

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

       quit

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

       readbuf [-e encoding] [filename]

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

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

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

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

       redisplay

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

       register [-e encoding] key string

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

       remove

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

       removebuf

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

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

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

       reset

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

       resize

       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]|//group]

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

       Thus, if your ".screenrc" contains the lines

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

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

       scrollback num

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

       select [WindowID]

       Switch  to  the  window  identified  by  WindowID.  This can be a prefix of a window title
       (alphanumeric window name) or a window number.  The parameter is optional and if  omitted,
       you get prompted for an identifier.  When a new window is established, the first available
       number is assigned to this window.  Thus, the first window can be activated by "select 0".
       The  number  of  windows  is limited at compile-time by the MAXWIN configuration parameter
       (which defaults to 40).  There are two special WindowIDs, "-" selects the  internal  blank
       window and "." selects the current window. The latter is useful if used with screen's "-X"
       option.

       sessionname [name]

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

       setenv [var [string]]

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

       setsid [on|off]

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

       shell command

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

       shelltitle title

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

       silence [on|off|sec]

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

       silencewait sec

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

       sleep num

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

       slowpaste msec

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

       source file

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

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

       sorendition [attr [color]]

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

       split [-v]

       Split the current region into two new ones. All regions on the display are resized to make
       room  for the new region. The blank window is displayed on the new region. Splits are made
       horizontally unless -v is used. Use the "remove" or the "only" command to delete  regions.
       Use "focus" to toggle between 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.  Without a paramter, screen will prompt for a
       string to stuff.  You cannot paste large buffers with the "stuff" command. It is most use-
       ful for key bindings. See also "bindkey".

       su [username [password [password2]]]

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

       suspend

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

       term term

       In each window's environment screen opens, the  $TERM  variable  is  set  to  "screen"  by
       default.   But  when no description for "screen" is installed in the local termcap or ter-
       minfo data base, you set $TERM to - say - "vt100". This won't do much harm, as  screen  is
       VT100/ANSI  compatible.  The use of the "term" command is discouraged for non-default pur-
       pose.  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 otherma-
       chine" rather than setting and resetting the default.

       termcap term terminal-tweaks [window-tweaks]
       terminfo term terminal-tweaks [window-tweaks]
       termcapinfo term terminal-tweaks [window-tweaks]

       Use this command to modify your terminal's termcap entry without  going  through  all  the
       hassles  involved  in creating a custom termcap entry.  Plus, you can optionally customize
       the termcap generated for the windows.  You have to place these commands  in  one  of  the
       screenrc startup files, as they are meaningless once the terminal emulator is booted.
       If  your  system  works uses the terminfo database rather than termcap, screen will under-
       stand the `terminfo' command, which has the same effects as the  `termcap'  command.   Two
       separate  commands  are  provided,  as  there  are subtle syntactic differences, e.g. when
       parameter interpolation (using `%') is required. Note that termcap names of the  capabili-
       ties 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 `ter-
       minfo' commands with identical arguments.

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

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

       Some examples:

              termcap xterm*  LP:hs@

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

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

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

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

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

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

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

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

       time [string]

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

       If a string is specified, it changes the format of the time report like it is described in
       the "STRING ESCAPES" chapter. Screen uses a default of "%c:%s %M %d %H%? %l%?".

       title [windowtitle]

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

       unbindall

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

       unsetenv var

       Unset an environment variable.

       utf8 [on|off [on|off]]

       Change the encoding used in the current window. If utf8 is enabled, the  strings  sent  to
       the  window  will be UTF-8 encoded and vice versa. Omitting the parameter toggles the set-
       ting. 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-mes-
       sage' is displayed in the status line when the bell character (^G)  is  received.   Visual
       bell support of a terminal is defined by the termcap variable `vb' (terminfo: 'flash').
       Per default, vbell is off, thus the audible bell is used.  See also `bell_msg'.

       vbell_msg [message]

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

       vbellwait sec

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

       verbose [on|off]

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

       version

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

       wall message

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

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

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

       windowlist [-b] [-m] [-g]
       windowlist string [string]
       windowlist title [title]

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

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

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

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

       windows

       Uses the message line to display a list of all the windows.  Each window is listed by num-
       ber  with the name of process that has been started in the window (or its title); the cur-
       rent window is marked with a `*'; the previous window is marked with a `-'; all  the  win-
       dows  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  activ-
       ity  occur  is  marked  with an `@'; a window which has output logging turned on is marked
       with `(L)'; windows occupied by other users are marked with `&';  windows  in  the  zombie
       state  are marked with `Z'.  If this list is too long to fit on the terminal's status line
       only the portion around the current window is displayed.

       wrap [on|off]

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

       writebuf [-e encoding] [filename]

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

       writelock [on|off|auto]

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

       xoff
       xon

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

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

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

       zombie [keys[onerror]]
       defzombie [keys]

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

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

       Optionally  you can put the word "onerror" after the keys. This will cause screen to moni-
       tor exit status of the process running in the window. If it exits normally ('0'), the win-
       dow disappears. Any other exit value causes the window to become a zombie.


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

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

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

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


WINDOW TYPES
       Screen provides three different window types. New windows are created with screen's screen
       command (see also the entry in chapter "CUSTOMIZATION"). The first parameter to the screen
       command defines which type of window is created. The different window types are  all  spe-
       cial  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.


       o  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...)


       o  If  a  tty (character special device) name (e.g. "/dev/ttya") is specified as the first
          parameter, then the window is directly connected to this device.  This window  type  is
          similar  to  "screen cu -l /dev/ttya".  Read and write access is required on the device
          node, an exclusive open is attempted on the node to mark the connection line  as  busy.
          An  optional  parameter is allowed consisting of a comma separated list of flags in the
          notation used by stty(1):

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

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

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

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

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

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

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

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

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


       o  If the first parameter is "//telnet", the second parameter is expected  to  be  a  host
          name,  and  an  optional third parameter may specify a TCP port number (default decimal
          23).  Screen will connect to a server listening on the remote host and use  the  telnet
          protocol to communicate with that server.
          For  telnet  windows,  the  command  info  shows details about the connection in square
          brackets ([ and ]) at the end of the status line.

          b      BINARY. The connection is in binary mode.

          e      ECHO. Local echo is disabled.

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

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

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

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

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

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


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



STRING ESCAPES
       Screen provides an escape mechanism to insert information like the current time into  mes-
       sages  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, see "windows" for meanings of the various flags

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

       h      hardstatus of the window

       H      hostname of the system

       l      current load of the system

       m      month number

       M      month name

       n      window number

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

       S      session name

       s      seconds

       t      window title

       u      all other users on this window

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

       W      all window numbers and names except the current one

       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 abso-
              lute  pad position by adding a '+' qualifier or to pad relative to the right margin
              by using '-'. The padding truncates the  string  if  the  specified  position  lies
              before the current position. Add the 'L' qualifier to change this.

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

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

       {      attribute/color modifier string terminated by the next "}"

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

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

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

       +      add the specified set to the current attributes

       -      remove the set from the current attributes

       !      invert the set in the current attributes

       =      change the current attributes to the specified set

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

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

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

       k      black
       r      red
       g      green
       y      yellow
       b      blue
       m      magenta
       c      cyan
       w      white
       d      default color
       .      leave color unchanged

       The capitalized versions of the letter specify bright colors. You can also use the pseudo-
       color 'i' to set just the brightness and leave the color unchanged.
       A one digit/letter color description is treated as foreground or background  color  depen-
       dent  on  the  current attributes: if reverse mode is set, the background color is changed
       instead of the foreground color.  If you don't like this, prefix the color with a ".".  If
       you want the same behavior for two-letter color descriptions, also prefix them with a ".".
       As a special case, "%{-}" restores the attributes and colors that were set before the last
       change was made (i.e., pops one level of the color-change stack).

       Examples:

       "G"    set color to bright green

       "+b r" use bold red

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

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

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

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

       Each window has an initial flow-control value set with either the -f option or  the  "def-
       flow"  .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-con-
       trol manually when needed.

       If you're running with flow-control enabled and find that pressing the interrupt key (usu-
       ally C-c) does not interrupt the display until another 6-8 lines  have  scrolled  by,  try
       running screen with the "interrupt" option (add the "interrupt" flag to the "flow" command
       in your .screenrc, or use the -i command-line option).  This causes the output that screen
       has  accumulated from the interrupted program to be flushed.  One disadvantage is that the
       virtual terminal's memory contains the non-flushed version of the output,  which  in  rare
       cases  can cause minor inaccuracies in the output.  For example, if you switch screens and
       return, or update the screen with "C-a l" you would see the  version  of  the  output  you
       would  have  gotten  without "interrupt" being on.  Also, you might need to turn off flow-
       control (or use auto-flow mode to turn it off automatically) when running a  program  that
       expects  you  to type the interrupt character as input, as it is possible to interrupt the
       output of the virtual terminal to your physical terminal when flow-control is enabled.  If
       this happens, a simple refresh of the screen with "C-a l" will restore it.  Give each mode
       a try, and use whichever mode you find more comfortable.



TITLES (naming windows)
       You can customize each window's name in the window display (viewed with the "windows" com-
       mand  (C-a  w)) by setting it with one of the title commands.  Normally the name displayed
       is the actual command name of the program created in the window.  However, it is sometimes
       useful  to  distinguish various programs of the same name or to change the name on-the-fly
       to reflect the current state of the window.

       The default name for all shell windows can be set with the  "shelltitle"  command  in  the
       .screenrc  file,  while all other windows are created with a "screen" command and thus can
       have their name set with the -t option.  Interactively, there is the title-string  escape-
       sequence  (<esc>kname<esc>\)  and  the  "title" command (C-a A).  The former can be output
       from an application to control the window's name under software control,  and  the  latter
       will  prompt  for a name when typed.  You can also bind pre-defined names to keys with the
       "title" command to set things quickly without prompting.

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

       Here's how it works:  you must modify your shell prompt to  output  a  null  title-escape-
       sequence  (<esc>k<esc>\)  as  a part of your prompt.  The last part of your prompt must be
       the same as the string you specified for the search portion of the title.   Once  this  is
       set  up,  screen will use the title-escape-sequence to clear the previous command name and
       get ready for the next command.  Then, when a newline is received from the shell, a search
       is  made  for  the  end  of  the  prompt.  If found, it will grab the first word after the
       matched string and use it as the command name.  If the command  name  begins  with  either
       '!',  '%', or '^' screen will use the first word on the following line (if found) in pref-
       erence 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" com-
       mand and give it an auto-title name of "root:".  For this auto-title to work,  the  screen
       could look something like this:

                   % !em
                   emacs file.c

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

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

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

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

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

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

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

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



THE VIRTUAL TERMINAL
       Each  window  in  a  screen  session  emulates a VT100 terminal, with some extra functions
       added. The VT100 emulator is hard-coded, no other terminal types can be emulated.
       Usually screen tries to emulate as much of the VT100/ANSI standard  as  possible.  But  if
       your  terminal  lacks  certain  capabilities,  the emulation may not be complete. In these
       cases screen has to tell the applications that some of the features are missing.  This  is
       no problem on machines using termcap, because screen can use the $TERMCAP variable to cus-
       tomize the standard screen termcap.

       But if you do a rlogin on another machine or your  machine  supports  only  terminfo  this
       method  fails. Because of this, screen offers a way to deal with these cases.  Here is how
       it works:

       When screen tries to figure out a terminal name for itself, it first looks  for  an  entry
       named  "screen.<term>",  where  <term> is the contents of your $TERM variable.  If no such
       entry exists, screen tries "screen" (or "screen-w" if the terminal is wide  (132  cols  or
       more)).  If even this entry cannot be found, "vt100" is used as a substitute.

       The  idea  is that if you have a terminal which doesn't support an important feature (e.g.
       delete char or clear to EOS) you can build a new termcap/terminfo entry for screen  (named
       "screen.<dumbterm>")  in  which  this  capability  has  been  disabled.  If  this entry is
       installed on your machines you are able to do a rlogin and still keep  the  correct  term-
       cap/terminfo  entry.   The  terminal name is put in the $TERM variable of all new windows.
       Screen also sets the $TERMCAP variable reflecting the capabilities of the virtual terminal
       emulated.  Notice that, however, on machines using the terminfo database this variable has
       no effect.  Furthermore, the variable $WINDOW is set to the window number of each window.

       The actual set of capabilities supported by the virtual terminal depends on the  capabili-
       ties 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  win-
       dow's  $TERMCAP  variable, accordingly.  However, a minimum number of capabilities must be
       supported by a terminal in order to run screen; namely scrolling, clear screen, and direct
       cursor  addressing (in addition, screen does not run on hardcopy terminals or on terminals
       that over-strike).

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

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

       When the boolean `G0' capability is present in the termcap entry for the terminal on which
       screen has been called, the terminal emulation of screen supports multiple character sets.
       This  allows an application to make use of, for instance, the VT100 graphics character set
       or national character sets.  The following control functions from ISO 2022 are  supported:
       lock shift G0 (SI), lock shift G1 (SO), lock shift G2, lock shift G3, single shift G2, and
       single shift G3.  When a virtual terminal is created or reset, the ASCII character set  is
       designated  as  G0  through G3.  When the `G0' capability is present, screen evaluates the
       capabilities `S0', `E0', and `C0' if present. `S0' is the sequence the  terminal  uses  to
       enable  and  start  the  graphics character set rather than SI.  `E0' is the corresponding
       replacement for SO. `C0' gives a character by character translation string  that  is  used
       during semi-graphics mode. This string is built like the `acsc' terminfo capability.

       When  the `po' and `pf' capabilities are present in the terminal's termcap entry, applica-
       tions 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 con-
       nected 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  dis-
       play's  hardstatus  will  be updated to match the window's hardstatus line. If the display
       has no hardstatus the line will be displayed as a standard screen message.  The hardstatus
       line  can  be changed with the ANSI Application Program Command (APC): "ESC_<string>ESC\".
       As a convenience for xterm users the sequence "ESC]0..2;<string>^G" is also accepted.

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

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

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

       ESC E                      Next Line

       ESC D                      Index

       ESC M                      Reverse Index

       ESC H                      Horizontal Tab Set

       ESC Z                      Send VT100 Identification String

       ESC 7                 (V)  Save Cursor and Attributes

       ESC 8                 (V)  Restore Cursor and Attributes

       ESC [s                (A)  Save Cursor and Attributes

       ESC [u                (A)  Restore Cursor and Attributes

       ESC c                      Reset to Initial State

       ESC g                      Visual Bell

       ESC Pn p                   Cursor Visibility (97801)

           Pn = 6                 Invisible

                7                 Visible

       ESC =                 (V)  Application Keypad Mode

       ESC >                 (V)  Numeric Keypad Mode

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

       ESC \                 (A)  String Terminator

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

       ESC !                      Global Message String (Message Line)

       ESC k                      A.k.a. Definition String

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

       ESC _                 (A)  Application Program Command (Hardstatus)

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

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

       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 spe-
                                  cial)

       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 standard
       VT100 emulation the command will always insert a string in the input buffer of the  window
       (see  also command stuff in the command table).  Because the sequences generated by a key-
       press can change after a reattach from a different terminal type, it is possible  to  bind
       commands  to  the  termcap name of the keys.  Screen will insert the correct binding after
       each reattach. See the bindkey command for further details on the syntax and examples.

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

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



SPECIAL TERMINAL CAPABILITIES
       The  following table describes all terminal capabilities that are recognized by screen and
       are not in the termcap(5) manual.  You  can  place  these  capabilities  in  your  termcap
       entries (in `/etc/termcap') or use them with the commands `termcap', `terminfo' and `term-
       capinfo' 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  argu-
                    ments. SunView(tm) example: '\E[8;%d;%dt'.

       NF   (bool)  Terminal doesn't need flow control. Send ^S and ^Q direct to the application.
                    Same as 'flow off'. The opposite of this capability is 'nx'.

       G0   (bool)  Terminal can deal with ISO 2022 font selection sequences.

       S0   (str)   Switch charset 'G0' to the specified charset. Default is '\E(%.'.

       E0   (str)   Switch charset 'G0' back to standard charset. Default is '\E(B'.

       C0   (str)   Use the string as a conversion table for font '0'. See  the  'ac'  capability
                    for more details.

       CS   (str)   Switch cursor-keys to application mode.

       CE   (str)   Switch cursor-keys back to normal mode.

       AN   (bool)  Turn on autonuke. See the 'autonuke' command for more details.

       OL   (num)   Set the output buffer limit. See the 'obuflimit' command for more details.

       KJ   (str)   Set the encoding of the terminal. See the 'encoding' command for valid encod-
                    ings.

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

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

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

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

       XT   (bool)  Terminal understands special xterm sequences (OSC, mouse tracking).

       C8   (bool)  Terminal needs bold to display high-intensity colors (e.g. Eterm).

       TF   (bool)  Add missing capabilities to the termcap/info entry. (Set by default).


CHARACTER TRANSLATION
       Screen has a powerful mechanism to translate characters to arbitrary strings depending  on
       the  current  font  and terminal type.  Use this feature if you want to work with a common
       standard character set (say ISO8851-latin1)  even  on  terminals  that  scatter  the  more
       unusual characters over several national language font pages.

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

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

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

       Here is an example:

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

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

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

       This example shows one use of the extension:

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

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


ENVIRONMENT
       COLUMNS        Number of columns on the terminal (overrides termcap entry).
       HOME           Directory in which to look for .screenrc.
       LINES          Number of lines on the terminal (overrides termcap entry).
       LOCKPRG        Screen lock program.
       NETHACKOPTIONS Turns on nethack option.
       PATH           Used for locating programs to run.
       SCREENCAP      For customizing a terminal's TERMCAP value.
       SCREENDIR      Alternate socket directory.
       SCREENRC       Alternate user screenrc file.
       SHELL          Default shell program for opening windows (default "/bin/sh").
       STY            Alternate socket name.
       SYSSCREENRC    Alternate system screenrc file.
       TERM           Terminal name.
       TERMCAP        Terminal description.
       WINDOW         Window number of a window (at creation time).

FILES
       .../screen-4.?.??/etc/screenrc
       .../screen-4.?.??/etc/etcscreenrc Examples in the screen distribution package for  private
                                         and global initialization files.
       $SYSSCREENRC
       /etc/screenrc                     screen initialization commands
       $SCREENRC
       $HOME/.screenrc                   Read in after /etc/screenrc
       $SCREENDIR/S-<login>
       /local/screens/S-<login>          Socket directories (default)
       /usr/tmp/screens/S-<login>        Alternate socket directories.
       <socket directory>/.termcap       Written by the "termcap" output function
       /usr/tmp/screens/screen-exchange  or
       /tmp/screen-exchange              screen `interprocess communication buffer'
       hardcopy.[0-9]                    Screen images created by the hardcopy function
       screenlog.[0-9]                   Output log files created by the log function
       /usr/lib/terminfo/?/*             or
       /etc/termcap                      Terminal capability databases
       /etc/utmp                         Login records
       $LOCKPRG                          Program that locks a terminal.


SEE ALSO
       termcap(5), utmp(5), vi(1), captoinfo(1), tic(1)


AUTHORS
       Originally created by Oliver Laumann, this latest version was produced by Juergen Weigert,
       Michael Schroeder, Micah Cowan and Sadrul Habib Chowdhury.

COPYLEFT
       Copyright (c) 2010
            Juergen Weigert (jnweiger AT immd4.de)
            Sadrul Habib Chowdhury (sadrul AT users.net)
       Copyright (c) 2008, 2009
            Juergen Weigert (jnweiger AT immd4.de)
            Michael Schroeder (mlschroe AT immd4.de)
            Micah Cowan (micah AT cowan.name)
            Sadrul Habib Chowdhury (sadrul AT users.net)
       Copyright (C) 1993-2003
            Juergen Weigert (jnweiger AT immd4.de)
            Michael Schroeder (mlschroe AT immd4.de)
       Copyright (C) 1987 Oliver Laumann
       This program is free software; you can redistribute it and/or modify it under the terms of
       the  GNU  General Public License as published by the Free Software Foundation; either ver-
       sion 3, or (at your option) any later version.
       This program is distributed in the hope that it will be useful, but WITHOUT ANY  WARRANTY;
       without  even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU General Public License for more details.
       You should have received a copy of the GNU General Public License along with this  program
       (see  the  file  COPYING);  if not, write to the Free Software Foundation, Inc., 59 Temple
       Place - Suite 330, Boston, MA  02111-1307, USA

CONTRIBUTORS
       Ken Beal (kbeal AT amber.com),
       Rudolf Koenig (rfkoenig AT immd4.de),
       Toerless Eckert (eckert AT immd4.de),
       Wayne Davison (davison AT borland.com),
       Patrick Wolfe (pat AT kai.com, kailand!pat),
       Bart Schaefer (schaefer AT cse.edu),
       Nathan Glasser (nathan AT brokaw.edu),
       Larry W. Virden (lvirden AT cas.org),
       Howard Chu (hyc AT hanauma.gov),
       Tim MacKenzie (tym AT dibbler.au),
       Markku Jarvinen (mta@{cc,cs,ee}.tut.fi),
       Marc Boucher (marc AT CAM.ORG),
       Doug Siebert (dsiebert AT isca.edu),
       Ken Stillson (stillson AT tsfsrv.org),
       Ian Frechett (frechett AT spot.EDU),
       Brian Koehmstedt (bpk AT gnu.edu),
       Don Smith (djs6015 AT ultb.edu),
       Frank van der Linden (vdlinden AT fwi.nl),
       Martin Schweikert (schweik AT cpp.de),
       David Vrona (dave AT sashimi.com),
       E. Tye McQueen (tye%spillman.UUCP AT uunet.net),
       Matthew Green (mrg AT eterna.au),
       Christopher Williams (cgw AT pobox.com),
       Matt Mosley (mattm AT access.net),
       Gregory Neil Shapiro (gshapiro AT wpi.EDU),
       Johannes Zellner (johannes AT zellner.org),
       Pablo Averbuj (pablo AT averbuj.com).


VERSION
       This is version 4.1.0. Its roots are a merge of a custom version 2.3PR7 by  Wayne  Davison
       and  several enhancements to Oliver Laumann's version 2.0. Note that all versions numbered
       2.x are copyright by Oliver Laumann.

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

BUGS
       o  `dm'  (delete  mode)  and  `xs'  are  not handled correctly (they are ignored). `xn' is
          treated as a magic-margin indicator.

       o  Screen has no clue about double-high or double-wide characters.  But this is  the  only
          area where vttest is allowed to fail.

       o  It is not possible to change the environment variable $TERMCAP when reattaching under a
          different terminal type.

       o  The support of terminfo based systems is very limited.  Adding  extra  capabilities  to
          $TERMCAP may not have any effects.

       o  Screen does not make use of hardware tabs.

       o  Screen must be installed as set-uid with owner root on most systems in order to be able
          to correctly change the owner of the tty device file for each window.  Special  permis-
          sion may also be required to write the file "/etc/utmp".

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

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

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

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

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

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

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

       o  Send bug-reports, fixes, enhancements, t-shirts, money, beer  &  pizza  to  screen@uni-
          erlangen.de.




4th Berkeley Distribution                    Aug 2003                                   SCREEN(1)

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