neulab/tldr huggingface dataset:
Redisplay the current window. Needed to get a full redisplay when in partial redraw mode.
register [-eencoding]key-string
Save the specified string to the register key.  The encoding of the string can be specified via the -e option.  See also the "paste" command.
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 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 [-h|-v|-b|-l|-p] [[+|-] n[%] |=|max|min|_|0]
Resize the current region. The space will be removed from or added to the surrounding regions depending on the order of the splits.  The available options for resizing are `-h'(horizontal), `-v'(vertical), `-b'(both), `-l'(local to layer), and `-p'(perpendicular). Horizontal resizes will add or remove width to a region, vertical will add or remove height, and both will add or remove size from both dimensions. Local and perpendicular are similar to horizontal and vertical, but they take in account of how a region was split.  If a region's last split was horizontal, a local resize will work like a vertical resize. If a region's last split was vertical, a local resize will work like a horizontal resize. Perpendicular resizes work in opposite of local resizes. If no option is specified, local is the default.
The amount of lines to add or remove can be expressed a couple of different ways. By specifying a number n by itself will resize the region by that absolute amount. You can specify a relative amount by prefixing a plus `+' or minus `-' to the amount, such as adding +n lines or removing -n lines. Resizing can also be expressed as an absolute or relative percentage by postfixing a percent sign `%'. Using zero `0' is a synonym for `min' and using an underscore `_' is a synonym for `max'.
resize +N increase current region by N
resize -N decrease current region by N
resize  N set current region to N
resize 20% set current region to 20% of original size
resize +20% increase current region by 20%
resize -b = make all windows equally
resize  max maximize current region
resize  min minimize current region
Without any arguments, screen will prompt for how you would like to resize the current region.
See "focusminsize" if you want to restrict the minimun size a region can have.
screen [-opts] [n] [cmd [args]|//group]
Establish a new window.  The flow-control options (-f, -fn and -fa), title (a.k.a.) option (-t), login options (-l and -ln) , terminal type option (-T <term>), the all-capability-flag (-a) and scrollback option (-h <num>) may be specified with each command.  The option (-M) turns monitoring on for this 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 supplied, a container-type window is created in which other windows may be created inside it.
Thus, if your ".screenrc" contains the lines
# example for .screenrc: screen 1 screen -fn -t foobar -L 2 telnet foobar
screen creates a shell window (in window #1) and a window with a TELNET connection to the machine foobar (with no flow-control using the title "foobar" in 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 displayed. Caution: The $STY environment variables will still reflect the old name in pre-existing shells. This may result in confusion. Use of this command is generally discouraged. Use the "-S" command-line option if you want to name a new session.  The default is constructed from the tty and host names.
setenv [var [string]]
Set the environment variable var to value string.  If only var is specified, the user will be prompted to enter a value.  If no parameters are specified, the user will be prompted for both variable and value. The environment is inherited by all subsequently forked shells.
setsid [on|off]
Normally screen uses different sessions and process groups for the windows. If setsid is turned off, this is not done anymore and all windows will be in the same process group as the screen backend process. This also breaks job-control, so be careful.  The default is on, of course. This command is probably useful only in rare circumstances.
Set the command to be used to create a new shell.  This overrides the value of the environment variable $SHELL.  This is useful if you'd like to run a tty-enhancer which is expecting to execute the program specified in $SHELL.  If the command begins with a '-' character, the shell will be started as a login-shell. Typical shells do only minimal initialization when not started as a login-shell.  E.g. Bash will not read your "~/.bashrc" unless it is a login-shell.
shelltitle title
Set the title for all shells created during startup or by the C-A C-c command.  For details about what a title is, see the discussion entitled "TITLES (naming windows)".
silence [on|off|sec]
Toggles silence monitoring of windows.  When silence is turned on and an affected window is switched into the background, you will receive the silence 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.
Sort the windows in alphabetical order of the window tiles.
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 in the new region. The default is to create a horizontal split, putting the new regions on the top and bottom of each other. Using `-v' will create a vertical split, causing the new regions to appear side by side of each other.  Use the "remove" or the "only" command to delete regions.  Use "focus" to toggle between regions.
When a region is split opposite of how it was previously split (that is, vertical then horizontal or horizontal then vertical), a new layer is created. The layer is used to group together the regions that are split the same. Normally, as a user, you should not see nor have to worry about layers, but they will affect how some commands ("focus" and "resize") behave.
With this current implementation of screen, scrolling data will appear much slower in a vertically split region than one that is not. This should be taken into consideration if you need to use system commands such as "cat" or "tail -f".
startup_message on|off
Select whether you want to see the copyright notice during startup. Default is `on', as you probably noticed.
status [top|up|down|bottom] [left|right]
The status window by default is in bottom-left corner. This command can move status messages to any corner of the screen. top is the same as up, down is the same as bottom.
stuff [string]
Stuff the string string in the input buffer of the current window.  This is like the "paste" command but with much less overhead.  Without a parameter, screen will prompt for a string to stuff.  You cannot paste large buffers with the "stuff" command. It is most useful for key bindings. See also "bindkey".
su [username [password [password2]]]
Substitute the user of a display. The command prompts for all parameters that are omitted. If passwords are specified as parameters, they have to be 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 screen.  The windows are in the `detached' state, while screen is suspended. This feature relies on the shell being able to do job control.
term term
In each window's environment screen opens, the $TERM variable is set to "screen" by default.  But when no description for "screen" is installed in the local termcap or terminfo data base, you set $TERM to - say - "vt100". This won't do much harm, as screen is VT100/ANSI compatible. The use of the "term" command is discouraged for non-default purpose. That is, one may want to specify special $TERM settings (e.g. vt100) for the next "screen rlogin othermachine" command. Use the command "screen -T vt100 rlogin othermachine" rather than setting and resetting the default.
termcap term terminal-tweaks[window-tweaks]
terminfo term terminal-tweaks[window-tweaks]
termcapinfo term terminal-tweaks[window-tweaks]
Use this command to modify your terminal's termcap entry without going through all the hassles involved in creating a custom termcap entry. Plus, you can optionally customize the termcap generated for the windows. You have to place these commands in one of the screenrc startup files, as they are meaningless once the terminal emulator is booted.
If your system uses the terminfo database rather than termcap, screen will understand the `terminfo' command, which has the same effects as the `termcap' command.  Two separate commands are provided, as there are subtle syntactic differences, e.g. when parameter interpolation (using `%') is required. Note that termcap names of the capabilities have to be used with the `terminfo' command.
In many cases, where the arguments are valid in both terminfo and termcap syntax, you can use the command `termcapinfo', which is just a shorthand for a pair of `termcap' and `terminfo' commands with identical arguments.
The first argument specifies which terminal(s) should be affected by this definition.  You can specify multiple terminal names by separating them with `|'s.  Use `*' to match all terminals and `vt*' to match all terminals that begin with "vt".
Each tweak argument contains one or more termcap defines (separated by `:'s) to be inserted at the start of the appropriate termcap entry, enhancing it or overriding existing values.  The first tweak modifies your terminal's termcap, and contains definitions that your terminal uses to perform certain functions.  Specify a null string to leave this unchanged (e.g. '').  The second (optional) tweak modifies all the window termcaps, and should contain definitions that screen understands (see the "VIRTUAL TERMINAL" section).
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 reason, it is necessary to bind commands after this, use 'screen -X'.
unsetenv var
Unset an environment variable.
utf8 [on|off[on|off]]
Change the encoding used in the current window. If utf8 is enabled, the strings sent to the window will be UTF-8 encoded and vice versa. Omitting the parameter toggles the setting. If a second parameter is given, the display's encoding is also changed (this should rather be done with screen's "-U" option).  See also "defutf8", which changes the default setting of a new window.
vbell [on|off]
Sets the visual bell setting for this window. Omitting the parameter toggles the setting. If vbell is switched on, but your terminal does not support a visual bell, a `vbell-message' is displayed in the status line when the bell character (^G) is received.  Visual bell support of a terminal is defined by the termcap variable `vb' (terminfo: 'flash').
Per default, vbell is off, thus the audible bell is used.  See also `bell_msg'.
vbell_msg [message]
Sets the visual bell message. message is printed to the status line if the window receives a bell character (^G), vbell is set to "on", but the terminal does not support a visual bell.  The default message is "Wuff, Wuff!!".  Without 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.
Print the current version and the compile date in the status line.
wall message
Write a message to all displays. The message will appear in the terminal's status line.
width [-w|-d] [cols [lines]]
Toggle the window width between 80 and 132 columns or set it to cols columns if an argument is specified.  This requires a capable terminal and the termcap entries "Z0" and "Z1".  See the "termcap" command for more information. You can also specify a new height if you want to change both values.  The -w option tells screen to leave the display size unchanged and just set the window size, -d vice versa.
windowlist [-b] [-m] [-g]
windowlist string [string]
windowlist title [title]
Display all windows in a table for visual window selection.  If screen was in a window group, screen will back out of the group and then display the windows in that group.  If the -b option is given, screen will switch to the blank window before presenting the list, so that the current window is also selectable.  The -m option changes the order of the windows, instead of sorting by window numbers screen uses its internal most-recently-used list.  The -g option will show the windows inside any groups in that level and downwards.
The following keys are used to navigate in "windowlist":
───────────────────────────────────────────────────────────────────── k, C-p, or up      Move up one line. ───────────────────────────────────────────────────────────────────── j, C-n, or down    Move down one line. ───────────────────────────────────────────────────────────────────── C-g or escape      Exit windowlist. ───────────────────────────────────────────────────────────────────── C-a or home        Move to the first line. ───────────────────────────────────────────────────────────────────── C-e or end         Move to the last line. ───────────────────────────────────────────────────────────────────── C-u or C-d         Move one half page up or down. ───────────────────────────────────────────────────────────────────── C-b or C-f         Move one full page up or down. ───────────────────────────────────────────────────────────────────── 0..9               Using the number keys, move to the selected line. ───────────────────────────────────────────────────────────────────── mouseclick         Move to the selected line. Available when "mousetrack" is set to "on" ───────────────────────────────────────────────────────────────────── /                  Search. ───────────────────────────────────────────────────────────────────── n                  Repeat search in the forward direction. ───────────────────────────────────────────────────────────────────── N                  Repeat search in the backward direction. ───────────────────────────────────────────────────────────────────── m                  Toggle MRU. ───────────────────────────────────────────────────────────────────── g                  Toggle group nesting. ───────────────────────────────────────────────────────────────────── a                  All window view. ───────────────────────────────────────────────────────────────────── C-h or backspace   Back out the group. ───────────────────────────────────────────────────────────────────── ,                  Switch numbers with the previous window. ───────────────────────────────────────────────────────────────────── .                  Switch numbers with the next window. ───────────────────────────────────────────────────────────────────── K                  Kill that window. ───────────────────────────────────────────────────────────────────── space or enter     Select that window. ─────────────────────────────────────────────────────────────────────
The table format can be changed with the string and title option, the title is displayed as table heading, while the lines are made by using the string setting. The default setting is "Num Name%=Flags" for the title and "%3n %t%=%f" for the lines.  See the "STRING ESCAPES" chapter for more codes (e.g. color settings).
"Windowlist" needs a region size of at least 10 characters wide and 6 characters high in order to display.
windows [ string ]
Uses the message line to display a list of all the windows.  Each window is listed by number with the name of process that has been started in the window (or its title); the current window is marked with a `*'; the previous window is marked with a `-'; all the windows that are "logged in" are marked with a `$'; a background window that has received a bell is marked with a `!'; a background window that is being monitored and has had activity occur is marked with an `@'; a window which has output logging turned on is marked with `(L)'; windows occupied by other users are marked with `&'; windows in the zombie state are marked with `Z'.  If this list is too long to fit on the terminal's status line only the portion around the current window is displayed.  The optional string parameter follows the "STRING ESCAPES" format.  If string parameter is passed, the output size is unlimited.  The default command without any parameter is limited to a size of 1024 bytes.
wrap [on|off]
Sets the line-wrap setting for the current window.  When line-wrap is on, the second consecutive printable character output at the last column of a line will wrap to the start of the following line.  As an added feature, backspace (^H) will also wrap through the left margin to the previous line.  Default is `on'. Without any options, the state of wrap is toggled.
writebuf [-e encoding] [filename]
Writes the contents of the paste buffer to the specified file, or the public accessible screen-exchange file if no filename is given. This is thought of as a primitive means of communication between screen users on the same host. If an encoding is specified the paste buffer is recoded on the fly to match the 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.
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]]
Per default screen windows are removed from the window list as soon as the windows process (e.g. shell) exits. When a string of two keys is specified to the zombie command, `dead' windows will remain in the list. The kill command may be used to remove such a window. Pressing the first key in the dead window has the same effect. When pressing the second key, screen will attempt to resurrect the window. The process that was initially running in the window will be launched again. Calling zombie without parameters will clear the zombie setting, thus making windows disappear when their process exits.
As the zombie-setting is manipulated globally for all windows, this command should probably be called defzombie, but it isn't.
Optionally you can put the word "onerror" after the keys. This will cause screen to monitor exit status of the process running in the window. If it exits normally ('0'), the window disappears. Any other exit value causes the window to become a zombie.
zombie_timeout[seconds]
Per default screen windows are removed from the window list as soon as the windows process (e.g. shell) exits. If zombie keys are defined (compare with above zombie command), it is possible to also set a timeout when screen tries to automatically reconnect a dead screen window.
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 backslash.
Screen provides three different window types. New windows are created with screen's screen command (see also the entry in chapter "CUSTOMIZATION"). The first parameter to the screen command defines which type of window is created. The different window types are all special cases of the normal type. They have been added in order to allow screen to be used efficiently as a console multiplexer with 100 or more windows.
•  The normal window contains a shell (default, if no parameter is given) or any other system command that could be executed from a shell (e.g. slogin, etc...)
•  If a tty (character special device) name (e.g. "/dev/ttya") is specified as the first parameter, then the window is directly connected to this device.  This window type is similar to "screen cu -l /dev/ttya".  Read and write access is required on the device node, an exclusive open is attempted on the node to mark the connection line as busy.  An optional parameter is allowed consisting of a comma separated list of flags in the notation used by stty(1):
<baud_rate> Usually 300, 1200, 9600 or 19200. This affects transmission as well as receive speed.
cs8 or cs7 Specify the transmission of eight (or seven) bits per byte.
ixon or -ixon Enables (or disables) software flow-control (CTRL-S/CTRL-Q) for sending data.
ixoff or -ixoff Enables (or disables) software flow-control for receiving data.
istrip or -istrip Clear (or keep) the eight bit in each received byte.
You may want to specify as many of these options as applicable. Unspecified options cause the terminal driver to make up the parameter values of the connection.  These values are system dependent and may be in defaults or values saved from a previous connection.
For tty windows, the info command shows some of the modem control lines in the status line. These may include `RTS', `CTS', 'DTR', `DSR', `CD' and more.  This depends on the available ioctl()'s and system header files as well as the on the physical capabilities of the serial board.  Signals that are logical low (inactive) have their name preceded by an exclamation mark (!), otherwise the signal is logical high (active).  Signals not supported by the hardware but available to the ioctl() interface are usually shown low.
When the CLOCAL status bit is true, the whole set of modem signals is placed inside curly braces ({ and }).  When the CRTSCTS or TIOCSOFTCAR bit is set, the signals `CTS' or `CD' are shown in parenthesis, respectively.
For tty windows, the command break causes the Data transmission line (TxD) to go low for a specified period of time. This is expected to be interpreted as break signal on the other side.  No data is sent and no modem control line is changed when a break is issued.
•  If the first parameter is "//telnet", the second parameter is expected to be a host name, and an optional third parameter may specify a TCP port number (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 ENABLE_TELNET option defined.
Screen provides an escape mechanism to insert information like the current time into messages or file names. The escape character is '%' with one exception: inside of a window's hardstatus '^%' ('^E') is used instead.
Here is the full list of supported escapes:
%      the escape character itself
E      sets %? to true if the escape character has been pressed.
f      flags of the window, see "windows" for meanings of the various flags
F      sets %? to true if the window has the focus
h      hardstatus of the window
H      hostname of the system
n      window number
P      sets %? to true if the current region is in copy/paste mode
S      session name
s      window size
t      window title
u      all other users on this window
w      all window numbers and names. With '-' qualifier: up to the current window; with '+' qualifier: starting with the window after the current one.
W      all window numbers and names except the current one
x      the executed command including arguments running in this windows
X      the executed command without arguments running in this windows
?      the part to the next '%?' is displayed only if a '%' escape inside the part expands to a non-empty string
:      else part of '%?'
=      pad the string to the display's width (like TeX's hfill). If a number is specified, pad to the percentage of the window's width. A '0' qualifier tells screen to treat the number as absolute position.  You can specify to pad relative to the last absolute pad position by adding a '+' qualifier or to pad relative to the right margin by using '-'. The padding truncates the string if the specified position lies before the current position. Add the 'L' qualifier to change this.
<      same as '%=' but just do truncation, do not fill with spaces
>      mark the current text position for the next truncation. When screen needs to do truncation, it tries to do it in a way that the marked position gets moved to the specified percentage of the output area. (The area starts from the last absolute pad position and ends with the position specified by the truncation operator.) The 'L' qualifier tells screen to mark the truncated parts with '...'.
{      attribute/color modifier string terminated by the next "}"
`      Substitute with the output of a 'backtick' command. The length qualifier is misused to identify one of the commands.
The 'c' and 'C' escape may be qualified with a '0' to make screen use zero instead of space as fill character. The '0' qualifier also makes the '=' escape use absolute positions. The 'n' and '=' escapes understand a length qualifier (e.g. '%3n'), 'D' and 'M' can be prefixed with 'L' to generate long names, 'w' and 'W' also show the window flags if 'L' is given.
An attribute/color modifier is used to change the attributes or the color settings. Its format is "[attribute modifier] [color description]". The attribute modifier must be prefixed by a change type indicator if it can be confused with a color description. The following change types are known:
+      add the specified set to the current attributes
-      remove the set from the current attributes
!      invert the set in the current attributes
=      change the current attributes to the specified set
The attribute set can either be specified as a hexadecimal number or a combination of the following letters:
d      dim u      underline b      bold r      reverse s      standout B      blinking
Colors are coded either as a hexadecimal number or two letters specifying the desired background and foreground color (in that order). The following colors are known:
k      black r      red g      green y      yellow b      blue m      magenta c      cyan w      white d      default color .      leave color unchanged
The capitalized versions of the letter specify bright colors. You can also use the pseudo-color 'i' to set just the brightness and leave the color unchanged. A one digit/letter color description is treated as foreground or background color dependent on the current attributes: if reverse mode is set, the background color is changed instead of the foreground color.  If you don't like this, prefix the color with a ".". If you want the same behavior for two-letter color 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).
"G"    set color to bright green
"+b r" use bold red
"= yd" clear all attributes, write in default color on yellow background.
%-Lw%{= BW}%50>%n%f* %t%{-}%+Lw%< The available windows centered at the current window and truncated to the available width. The current window is displayed white on blue.  This can be used with "hardstatus alwayslastline".
%?%F%{.R.}%?%3n %t%? [%h]%? The window number and title and the window's hardstatus, if one is set.  Also use a red background if this is the active focus. Useful for "caption string".
FLOW-CONTROL Each window has a flow-control setting that determines how screen deals with the XON and XOFF characters (and perhaps the interrupt character). When flow-control is turned off, screen ignores the XON and XOFF characters, which allows the user to send them to the current program by simply typing them (useful for the emacs editor, for instance).  The trade-off is that it will take longer for output from a "normal" program to pause in response to an XOFF.  With flow-control turned on, XON and XOFF characters are used to immediately pause the output of the current window.  You can still send these characters to the current program, but you must use the appropriate two-character screen commands (typically "C- a q" (xon) and "C-a s" (xoff)).  The xon/xoff commands are also useful for typing C-s and C-q past a terminal that intercepts these characters.
Each window has an initial flow-control value set with either the -f option or the "defflow" .screenrc command. Per default the windows are set to automatic flow-switching.  It can then be toggled between the three states 'fixed on', 'fixed off' and 'automatic' interactively with the "flow" command bound to "C-a f".
The automatic flow-switching mode deals with flow control using the TIOCPKT mode (like "rlogin" does). If the tty driver does not support TIOCPKT, screen tries to find out the right mode based on the current setting of the application keypad - when it is enabled, flow-control is turned off and visa versa.  Of course, you can still manipulate flow- control manually when needed.
If you're running with flow-control enabled and find that pressing the interrupt key (usually C-c) does not interrupt the display until another 6-8 lines have scrolled by, try running screen with the "interrupt" option (add the "interrupt" flag to the "flow" command in your .screenrc, or use the -i command-line option).  This causes the output that screen has accumulated from the interrupted program to be flushed.  One disadvantage is that the virtual terminal's memory contains the non- flushed version of the output, which in rare cases can cause minor inaccuracies in the output.  For example, if you switch screens and return, or update the screen with "C-a l" you would see the version of the output you would have gotten without "interrupt" being on.  Also, you might need to turn off flow-control (or use auto-flow mode to turn it off automatically) when running a program that expects you to type the interrupt character as input, as it is possible to interrupt the output of the virtual terminal to your physical terminal when flow-control is enabled.  If this happens, a simple refresh of the screen with "C-a l" will restore it.  Give each mode a try, and use whichever mode you find more comfortable.
TITLES (naming windows) You can customize each window's name in the window display (viewed with the "windows" command (C-a w)) by setting it with one of the title commands.  Normally the name displayed is the actual command name of the program created in the window.  However, it is sometimes useful to distinguish various programs of the same name or to change the name on- the-fly to reflect the current state of the window.
The default name for all shell windows can be set with the "shelltitle" command in the .screenrc file, while all other windows are created with a "screen" command and thus can have their name set with the -t option. Interactively, there is the title-string escape-sequence (<esc>kname<esc>\) and the "title" command (C-a A).  The former can be output from an application to control the window's name under software control, and the latter will prompt for a name when typed.  You can also bind pre-defined names to keys with the "title" command to set things quickly without prompting. Changing title by this escape sequence can be controlled by defdynamictitle and dynamictitle commands.
Finally, screen has a shell-specific heuristic that is enabled by setting the window's name to "search|name" and arranging to have a null title escape-sequence output as a part of your prompt.  The search portion specifies an end-of-prompt search string, while the name portion specifies the default shell name for the window.  If the name ends in a `:' screen will add what it believes to be the current command running in the window to the end of the window's shell name (e.g. "name:cmd"). Otherwise the current command name supersedes the shell name while it is running.
Here's how it works:  you must modify your shell prompt to output a null title-escape-sequence (<esc>k<esc>\) as a part of your prompt.  The last part of your prompt must be the same as the string you specified for the search portion of the title.  Once this is set up, screen will use the title-escape-sequence to clear the previous command name and get ready for the next command.  Then, when a newline is received from the shell, a search is made for the end of the prompt.  If found, it will grab the first word after the matched string and use it as the command name.  If the command name begins with either '!', '%', or '^' screen will use the first word on the following line (if found) in preference to the just- found name.  This helps csh users get better command names when using job control or history recall commands.
Here's some .screenrc examples:
screen -t top 2 nice top
Adding this line to your .screenrc would start a nice-d version of the "top" command in window 2 named "top" rather than "nice".
shelltitle '> |csh' screen 1
These commands would start a shell with the given shelltitle.  The title specified is an auto-title that would expect the prompt and the typed command to look something like the following:
/usr/joe/src/dir> trn
(it looks after the '> ' for the command name).  The window status would show the name "trn" while the command was running, and revert to "csh" upon completion.
bind R screen -t '% |root:' su
Having this command in your .screenrc would bind the key sequence "C-a R" to the "su" command and give it an auto-title name of "root:".  For this auto-title to work, the screen could look something like this:
% !em emacs file.c
Here the user typed the csh history command "!em" which ran the previously entered "emacs" command.  The window status would show "root:emacs" during the execution of the command, and revert to simply "root:" at its completion.
bind o title bind E title "" bind u title (unknown)
The first binding doesn't have any arguments, so it would prompt you for a title when you type "C-a o".  The second binding would clear an auto- title's current setting (C-a E).  The third binding would set the current window's title to "(unknown)" (C-a u).
One thing to keep in mind when adding a null title-escape-sequence to your prompt is that some shells (like the csh) count all the non-control characters as part of the prompt's length.  If these invisible characters aren't a multiple of 8 then backspacing over a tab will result in an incorrect display.  One way to get around this is to use a prompt like this:
set prompt='^[[0000m^[k^[\% '
The escape-sequence "<esc>[0000m" not only normalizes the character attributes, but all the zeros round the length of the invisible characters up to 8.  Bash users will probably want to echo the escape sequence in the PROMPT_COMMAND:
PROMPT_COMMAND='printf "\033k\033\134"'
(I used "\134" to output a `\' because of a bug in bash v1.04).
Each window in a screen session emulates a VT100 terminal, with some extra functions added. The VT100 emulator is hard-coded, no other terminal types can be emulated. Usually screen tries to emulate as much of the VT100/ANSI standard as possible. But if your terminal lacks certain capabilities, the emulation may not be complete. In these cases screen has to tell the applications that some of the features are missing. This is no problem on machines using termcap, because screen can use the $TERMCAP variable to customize the standard screen termcap.
But if you do a rlogin on another machine or your machine supports only terminfo this method fails. Because of this, screen offers a way to deal with these cases.  Here is how it works:
When screen tries to figure out a terminal name for itself, it first looks for an entry named "screen.<term>", where <term> is the contents of your $TERM 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 termcap/terminfo entry.  The terminal name is put in the $TERM variable of all new windows.  Screen also sets the $TERMCAP variable reflecting the capabilities of the virtual terminal emulated. Notice that, however, on machines using the terminfo database this variable has no effect. Furthermore, the variable $WINDOW is set to the window number of each window.
The actual set of capabilities supported by the virtual terminal depends on the capabilities supported by the physical terminal.  If, for instance, the physical terminal does not support underscore mode, screen does not put the `us' and `ue' capabilities into the window's $TERMCAP variable, accordingly.  However, a minimum number of capabilities must be supported by a terminal in order to run screen; namely scrolling, clear screen, and direct cursor addressing (in addition, screen does not run on hardcopy terminals or on terminals that over-strike).
Also, you can customize the $TERMCAP value used by screen by using the "termcap" .screenrc command, or by defining the variable $SCREENCAP prior to startup.  When the latter is defined, its value will be copied verbatim into each window's $TERMCAP variable.  This can either be the full terminal definition, or a filename where the terminal "screen" (and/or "screen-w") is defined.
Note that screen honors the "terminfo" .screenrc command if the system uses the terminfo database rather than termcap.
When the boolean `G0' capability is present in the termcap entry for the terminal on which screen has been called, the terminal emulation of screen supports multiple character sets.  This allows an application to make use of, for instance, the VT100 graphics character set or national character sets.  The following control functions from ISO 2022 are supported: lock shift G0 (SI), lock shift G1 (SO), lock shift G2, lock shift G3, single shift G2, and single shift G3.  When a virtual terminal is created or reset, the ASCII character set is designated as G0 through G3.  When the `G0' capability is present, screen evaluates the capabilities `S0', `E0', and `C0' if present. `S0' is the sequence the terminal uses to enable and start the graphics character set rather than SI.  `E0' is the corresponding replacement for SO. `C0' gives a character by character translation string that is used during semi-graphics mode. This string is built like the `acsc' terminfo capability.
When the `po' and `pf' capabilities are present in the terminal's termcap entry, applications running in a screen window can send output to the printer port of the terminal.  This allows a user to have an application in one window sending output to a printer connected to the terminal, while all other windows are still active (the printer port is enabled and disabled again for each chunk of output).  As a side-effect, programs running in different windows can send output to the printer simultaneously.  Data sent to the printer is not displayed in the window. The info command displays a line starting `PRIN' while the printer is active.
Screen maintains a hardstatus line for every window. If a window gets selected, the display's hardstatus will be updated to match the window's hardstatus line. If the display has no hardstatus the line will be displayed as a standard screen message.  The hardstatus line can be changed with the ANSI Application Program Command (APC): "ESC_<string>ESC\". As a convenience for xterm users the sequence "ESC]0..2;<string>^G" is also accepted.