screen
screen manager with VT100/ANSI terminal emulation
TLDR
Start a new screen session
Start a new named screen session
Start a new daemon and log the output to screenlog.x
Show open screen sessions
Reattach to an open screen
Detach from inside a screen
Kill the current screen session
Kill a detached screen
SYNOPSIS
screen [ -options ] [ cmd [ args ] ] screen -r [[pid.]tty[.host]] screen -r sessionowner/[[pid.]tty[.host]]
INPUT TRANSLATION
In order to do a full VT100 emulation screen has to detect that a se‐ quence 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 ar‐ bitrary commands on arbitrary sequences of characters. For standard VT100 emulation the command will always insert a string in the input buffer of the window (see also command stuff in the command table). Because the sequences generated by a keypress can change after a reat‐ tach 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. The fourth is what com‐ mand is executed if the keyboard is switched into application mode. ┌────────────────┬──────────────┬──────────┬──────────┐ │Key name │ Termcap name │ Command │ App mode │ ├────────────────┼──────────────┼──────────┼──────────┤ │Cursor up │ ku │ \033[A │ \033OA │ ├────────────────┼──────────────┼──────────┼──────────┤ │Cursor down │ kd │ \033[B │ \033OB │ ├────────────────┼──────────────┼──────────┼──────────┤ │Cursor right │ kr │ \033[C │ \033OC │ ├────────────────┼──────────────┼──────────┼──────────┤ │Cursor left │ kl │ \033[D │ \033OD │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 0 │ k0 │ \033[10~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 1 │ k1 │ \033OP │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 2 │ k2 │ \033OQ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 3 │ k3 │ \033OR │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 4 │ k4 │ \033OS │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 5 │ k5 │ \033[15~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 6 │ k6 │ \033[17~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 7 │ k7 │ \033[18~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 8 │ k8 │ \033[19~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 9 │ k9 │ \033[20~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 10 │ k; │ \033[21~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 11 │ F1 │ \033[23~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Function key 12 │ F2 │ \033[24~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Home │ kh │ \033[1~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │End │ kH │ \033[4~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Insert │ kI │ \033[2~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Delete │ kD │ \033[3~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Page up │ kP │ \033[5~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Page down │ kN │ \033[6~ │ │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 0 │ f0 │ 0 │ \033Op │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 1 │ f1 │ 1 │ \033Oq │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 2 │ f2 │ 2 │ \033Or │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 3 │ f3 │ 3 │ \033Os │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 4 │ f4 │ 4 │ \033Ot │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 5 │ f5 │ 5 │ \033Ou │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 6 │ f6 │ 6 │ \033Ov │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 7 │ f7 │ 7 │ \033Ow │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 8 │ f8 │ 8 │ \033Ox │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad 9 │ f9 │ 9 │ \033Oy │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad + │ f+ │ + │ \033Ok │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad - │ f- │ - │ \033Om │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad * │ f* │ * │ \033Oj │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad / │ f/ │ / │ \033Oo │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad = │ fq ├──────────┤ \033OX │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad . │ f. │ . │ \033On │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad , │ f, │ , │ \033Ol │ ├────────────────┼──────────────┼──────────┼──────────┤ │Keypad enter │ fe │ \015 │ \033OM │ └────────────────┴──────────────┴──────────┴──────────┘
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 com‐
mands. Normally the name displayed is the actual command name of the
program created in the window. However, it is sometimes useful to dis‐
tinguish 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
(
THE VIRTUAL TERMINAL
Each window in a screen session emulates a VT100 terminal, with some
extra functions added. The VT100 emulator is hard-coded, no other ter‐
minal types can be emulated.
Usually screen tries to emulate as much of the VT100/ANSI standard as
possible. But if your terminal lacks certain capabilities, the emula‐
tion may not be complete. In these cases screen has to tell the appli‐
cations that some of the features are missing. This is no problem on
machines using termcap, because screen can use the $TERMCAP variable to
customize the standard screen termcap.
But if you do a rlogin on another machine or your machine supports only
terminfo this method fails. Because of this, screen offers a way to
deal with these cases. Here is how it works:
When screen tries to figure out a terminal name for itself, it first
looks for an entry named "screen.
SPECIAL TERMINAL CAPABILITIES
The following table describes all terminal capabilities that are recog‐ nized by screen and are not in the termcap(5) manual. You can place these capabilities in your termcap entries (in `/etc/termcap') or use them with the commands `termcap', `terminfo' and `termcapinfo' in your screenrc files. It is often not possible to place these capabilities in the terminfo database. LP (bool) Terminal has VT100 style margins (`magic margins'). Note that this capability is obsolete because screen uses the standard 'xn' instead. Z0 (str) Change width to 132 columns. Z1 (str) Change width to 80 columns. WS (str) Resize display. This capability has the desired width and height as arguments. SunView(tm) example: '\E[8;%d;%dt'. NF (bool) Terminal doesn't need flow control. Send ^S and ^Q direct to the application. Same as 'flow off'. The opposite of this capability is 'nx'. G0 (bool) Terminal can deal with ISO 2022 font selection sequences. S0 (str) Switch charset 'G0' to the specified charset. Default is '\E(%.'. E0 (str) Switch charset 'G0' back to standard charset. Default is '\E(B'. C0 (str) Use the string as a conversion table for font '0'. See the 'ac' capability for more details. CS (str) Switch cursor-keys to application mode. CE (str) Switch cursor-keys back to normal mode. AN (bool) Turn on autonuke. See the 'autonuke' command for more de‐ tails. OL (num) Set the output buffer limit. See the 'obuflimit' command for more details. KJ (str) Set the encoding of the terminal. See the 'encoding' com‐ mand for valid encodings. AF (str) Change character foreground color in an ANSI conform way. This capability will almost always be set to '\E[3%dm' ('\E[3%p1%dm' on terminfo machines). AB (str) Same as 'AF', but change background color. AX (bool) Does understand ANSI set default fg/bg color (\E[39m / \E[49m). XC (str) Describe a translation of characters to strings depending on the current font. More details follow in the next sec‐ tion. XT (bool) Terminal understands special xterm sequences (OSC, mouse tracking). C8 (bool) Terminal needs bold to display high-intensity colors (e.g. Eterm). TF (bool) Add missing capabilities to the termcap/info entry. (Set by default).
CHARACTER TRANSLATION
Screen has a powerful mechanism to translate characters to arbitrary
strings depending on the current font and terminal type. Use this fea‐
ture if you want to work with a common standard character set (say
ISO8851-latin1) even on terminals that scatter the more unusual charac‐
ters over several national language font pages.
Syntax:
XC=
ENVIRONMENT
COLUMNS Number of columns on the terminal (overrides termcap en‐ try). HOME Directory in which to look for .screenrc. LINES Number of lines on the terminal (overrides termcap en‐ try). LOCKPRG Screen lock program. NETHACKOPTIONS Turns on nethack option. PATH Used for locating programs to run. SCREENCAP For customizing a terminal's TERMCAP value. SCREENDIR Alternate socket directory. SCREENRC Alternate user screenrc file. SHELL Default shell program for opening windows (default "/bin/sh"). See also "shell" .screenrc command. STY Alternate socket name. SYSSCREENRC Alternate system screenrc file. TERM Terminal name. TERMCAP Terminal description. WINDOW Window number of a window (at creation time).
FILES
…/screen-4.?.??/etc/screenrc
…/screen-4.?.??/etc/etcscreenrc Examples in the screen distribution
package for private and global ini‐
tialization files.
$SYSSCREENRC
/etc/screenrc screen initialization commands
$SCREENRC
$HOME/.screenrc Read in after /etc/screenrc
$SCREENDIR/S-
THE MESSAGE LINE
Screen displays informational messages and other diagnostics in a mes‐
sage line. While this line is distributed to appear at the bottom of
the screen, it can be defined to appear at the top of the screen during
compilation. If your terminal has a status line defined in its term‐
cap, 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 termi‐
nals 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 '
WINDOW TYPES
Screen provides three different window types. New windows are created
with screen's screen command (see also the entry in chapter "CUSTOMIZA‐
TION"). 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 spec‐
ified 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):
STRING ESCAPES
Screen provides an escape mechanism to insert information like the cur‐ rent time into messages or file names. The escape character is '%' with one exception: inside of a window's hardstatus '^%' ('^E') is used in‐ stead. 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 cur‐ rent 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 in‐ side 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 ab‐ solute position. You can specify to pad relative to the last absolute pad position by adding a '+' qualifier or to pad rela‐ tive to the right margin by using '-'. The padding truncates the string if the specified position lies before the current posi‐ tion. 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 po‐ sition and ends with the position specified by the truncation operator.) The 'L' qualifier tells screen to mark the truncated parts with '…'. { attribute/color modifier string terminated by the next "}" ` Substitute with the output of a 'backtick' command. The length qualifier is misused to identify one of the commands. The 'c' and 'C' escape may be qualified with a '0' to make screen use zero instead of space as fill character. The '0' qualifier also makes the '=' escape use absolute positions. The 'n' and '=' escapes under‐ stand a length qualifier (e.g. '%3n'), 'D' and 'M' can be prefixed with 'L' to generate long names, 'w' and 'W' also show the window flags if 'L' is given. An attribute/color modifier is is used to change the attributes or the color settings. Its format is "[attribute modifier] [color descrip‐ tion]". The attribute modifier must be prefixed by a change type indi‐ cator if it can be confused with a color 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 specify‐ ing the desired background and foreground color (in that order). The following colors are known: k black r red g green y yellow b blue m magenta c cyan w white d default color . leave color unchanged The capitalized versions of the letter specify bright colors. You can also use the pseudo-color 'i' to set just the brightness and leave the color unchanged. A one digit/letter color description is treated as foreground or back‐ ground color 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). Examples: "G" set color to bright green "+b r" use bold red "= yd" clear all attributes, write in default color on yellow back‐ ground. %-Lw%{= BW}%50>%n%f* %t%{-}%+Lw%< The available windows centered at the current window and trun‐ cated to the available width. The current window is displayed white on blue. This can be used with "hardstatus alwayslast‐ line". %?%F%{.R.}%?%3n %t%? [%h]%? The window number and title and the window's hardstatus, if one is set. Also use a red background if this is the active focus. Useful for "caption string".
FLOW-CONTROL
Each window has a flow-control setting that determines how screen deals with the XON and XOFF characters (and perhaps the interrupt character). When flow-control is turned off, screen ignores the XON and XOFF char‐ acters, 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" pro‐ gram 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 TI‐ OCPKT mode (like "rlogin" does). If the tty driver does not support TI‐ OCPKT, 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 an‐ other 6-8 lines have scrolled by, try running screen with the "inter‐ rupt" 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 re‐ turn, 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-con‐ trol 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.
DESCRIPTION
Screen is a full-screen window manager that multiplexes a physical ter‐ minal between several processes (typically interactive shells). Each virtual terminal provides the functions of a DEC VT100 terminal and, in addition, several control functions from the ISO 6429 (ECMA 48, ANSI X3.64) and ISO 2022 standards (e.g. insert/delete line and support for multiple character sets). There is a scrollback history buffer for each virtual terminal and a copy-and-paste mechanism that allows moving text regions between windows. When screen is called, it creates a single window with a shell in it (or the specified command) and then gets out of your way so that you can use the program as you normally would. Then, at any time, you can create new (full-screen) windows with other programs in them (including more shells), kill existing windows, view a list of windows, turn out‐ put logging on and off, copy-and-paste text between windows, view the scrollback history, switch between windows in whatever manner you wish, etc. All windows run their programs completely independent of each other. Programs continue to run when their window is currently not vis‐ ible and even when the whole screen session is detached from the user's terminal. When a program terminates, screen (per default) kills the window that contained it. If this window was in the foreground, the display switches to the previous window; if none are left, screen ex‐ its. Shells usually distinguish between running as login-shell or sub- shell. Screen runs them as sub-shells, unless told otherwise (See "shell" .screenrc command). Everything you type is sent to the program running in the current win‐ dow. The only exception to this is the one keystroke that is used to initiate a command to the window manager. By default, each command be‐ gins with a control-a (abbreviated C-a from now on), and is followed by one other keystroke. The command character and all the key bindings can be fully customized to be anything you like, though they are always two characters in length. Screen does not understand the prefix "C-" to mean control, although this notation is used in this manual for readability. Please use the caret notation ("^A" instead of "C-a") as arguments to e.g. the escape command or the -e option. Screen will also print out control charac‐ ters in caret notation. The standard way to create a new window is to type "C-a c". This cre‐ ates a new window running a shell and switches to that window immedi‐ ately, regardless of the state of the process running in the current window. Similarly, you can create a new window with a custom command in it by first binding the command to a keystroke (in your .screenrc file or at the "C-a :" command line) and then using it just like the "C-a c" command. In addition, new windows can be created by running a command like: screen emacs prog.c from a shell prompt within a previously created window. This will not run another copy of screen, but will instead supply the command name and its arguments to the window manager (specified in the $STY environ‐ ment variable) who will use it to create the new window. The above ex‐ ample would start the emacs editor (editing prog.c) and switch to its window. - Note that you cannot transport environment variables from the invoking shell to the application (emacs in this case), because it is forked from the parent screen process, not from the invoking shell. If "/run/utmp" is writable by screen, an appropriate record will be written to this file for each window, and removed when the window is terminated. This is useful for working with "talk", "script", "shut‐ down", "rsend", "sccs" and other similar programs that use the utmp file to determine who you are. As long as screen is active on your ter‐ minal, the terminal's own record is removed from the utmp file. See also "C-a L".
GETTING STARTED
Before you begin to use screen you'll need to make sure you have cor‐ rectly selected your terminal type, just as you would for any other termcap/terminfo program. (You can do this by using tset for example.) If you're impatient and want to get started without doing a lot more reading, you should remember this one command: "C-a ?". Typing these two characters will display a list of the available screen commands and their bindings. Each keystroke is discussed in the section "DEFAULT KEY BINDINGS". The manual section "CUSTOMIZATION" deals with the contents of your .screenrc. If your terminal is a "true" auto-margin terminal (it doesn't allow the last position on the screen to be updated without scrolling the screen) consider using a version of your terminal's termcap that has automatic margins turned off. This will ensure an accurate and optimal update of the screen in all circumstances. Most terminals nowadays have "magic" margins (automatic margins plus usable last column). This is the VT100 style type and perfectly suited for screen. If all you've got is a "true" auto-margin terminal screen will be content to use it, but up‐ dating a character put into the last position on the screen may not be possible until the screen scrolls or the character is moved into a safe position in some other way. This delay can be shortened by using a ter‐ minal with insert-character capability.
COMMAND-LINE OPTIONS
Screen has the following command-line options: -a include all capabilities (with some minor exceptions) in each win‐ dow's termcap, even if screen must redraw parts of the display in order to implement a function. -A Adapt the sizes of all windows to the size of the current termi‐ nal. By default, screen tries to restore its old window sizes when attaching to resizable terminals (those with "WS" in its de‐ scription, e.g. suncmd or some xterm). -c file override the default configuration file from "$HOME/.screenrc" to file. -d|-D [pid.tty.host] does not start screen, but detaches the elsewhere running screen session. It has the same effect as typing "C-a d" from screen's controlling terminal. -D is the equivalent to the power detach key. If no session can be detached, this option is ignored. In combination with the -r/-R option more powerful effects can be achieved: -d -r Reattach a session and if necessary detach it first. -d -R Reattach a session and if necessary detach or even create it first. -d -RR Reattach a session and if necessary detach or create it. Use the first session if more than one session is available. -D -r Reattach a session. If necessary detach and logout remotely first. -D -R Attach here and now. In detail this means: If a session is run‐ ning, then reattach. If necessary detach and logout remotely first. If it was not running create it and notify the user. This is the author's favorite. -D -RR Attach here and now. Whatever that means, just do it. Note: It is always a good idea to check the status of your ses‐ sions by means of "screen -list". -e xy specifies the command character to be x and the character generat‐ ing a literal command 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 ei‐ ther 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 dis‐ play immediately when flow-control is on. See the "defflow" .screenrc command for details. The use of this option is discour‐ aged. -l and -ln turns login mode on or off (for /run/utmp updating). This can also be defined through the "deflogin" .screenrc command. -ls [match] -list [match] does not start screen, but prints a list of pid.tty.host strings and creation timestamps identifying your screen sessions. Ses‐ sions 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 param‐ eter, if any. See the -r flag for a description how to construct matches. Sessions marked as `dead' should be thoroughly checked and removed. Ask your system administrator if you are not sure. Remove sessions with the -wipe option. -L tells screen to turn on automatic output logging for the windows. -Logfile file By default logfile name is "screenlog.0". You can set new logfile name with the "-Logfile" option. -m causes screen to ignore the $STY environment variable. With "screen -m" creation of a new session is enforced, regardless whether screen is called from within another screen session or not. This flag has a special meaning in connection with the `-d' option: -d -m Start screen in "detached" mode. This creates a new session but doesn't attach to it. This is useful for system startup scripts. -D -m This also starts screen in "detached" mode, but doesn't fork a new process. The command exits if the session terminates. -O selects 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 ses‐ sions. 10 indicates a directory with running 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 re‐ sponse to the stdout of the querying process. If there was an er‐ ror 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 com‐ binations with -d/-D) may be specified, though an optional prefix of [pid.]tty.host may be needed to distinguish between multiple detached screen sessions. The second form is used to connect to another user's screen session which runs in multiuser mode. This indicates that screen should look for sessions in another user's directory. This requires setuid-root. -R resumes screen only when it's unambiguous which one to attach, usually when only one screen is detached. Otherwise lists avail‐ able sessions. -RR attempts to resume the youngest (in terms of creation time) detached screen session it finds. If successful, all other command-line options are ignored. If no detached ses‐ sion exists, starts a new session using the specified options, just as if -R had not been specified. The option is set by default if screen is run as a login-shell (actually screen uses "-xRR" in that case). For combinations with the -d/-D option see there. Note: Time-based session selection is a Debian addition. -s program sets the default shell to the program specified, instead of the value in the environment variable $SHELL (or "/bin/sh" if not de‐ fined). This can also be defined through the "shell" .screenrc command. See also there. -S sessionname When creating a new session, this option can be used to specify a meaningful name for the session. This name identifies the session for "screen -list" and "screen -r" actions. It substitutes the de‐ fault [tty.host] suffix. -t name sets the title (a.k.a.) for the default shell or specified pro‐ gram. See also the "shelltitle" .screenrc command. -T term Set the $TERM environment variable using the specified term as op‐ posed to the default setting of screen. -U Run screen in UTF-8 mode. This option tells screen that your ter‐ minal sends and understands UTF-8 encoded characters. It also sets the default encoding for new windows to `utf8'. -v Print version number. -wipe [match] does the same as "screen -ls", but removes destroyed sessions in‐ stead of marking them as `dead'. An unreachable session is con‐ sidered dead, when its name matches either the name of the local host, or the explicitly given parameter, if any. See the -r flag for a description how to construct matches. -x Attach to a not detached screen session. (Multi display mode). Screen refuses to attach from within itself. But when cascading multiple screens, loops are not detected; take care. -X Send the specified command to a running screen session. You may use the -S option to specify the screen session if you have sev‐ eral screen sessions running. 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 counter‐ parts (with the exception of "C-a a"; see below), thus, "C-a c" as well as "C-a C-c" can be used to create a window. See section "CUSTOMIZA‐ TION" for a description of the command. The following table shows the default key bindings. The trailiing com‐ mas in boxes with multiple keystroke entries are separators, not part of the bindings. ┌─────────────────┬─────────────────┬─────────────────────┐ │C-a ' │ (select) │ Prompt for a window │ │ │ │ name or number to │ │ │ │ switch to. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a " │ (windowlist -b) │ Present a list of │ │ │ │ all windows for se‐ │ │ │ │ lection. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a digit │ (select 0-9) │ Switch to window │ │ │ │ number 0 - 9 │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a - │ (select -) │ Switch to window │ │ │ │ number 0 - 9, or to │ │ │ │ the blank window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a tab │ (focus) │ Switch the input │ │ │ │ focus to the next │ │ │ │ region. See also │ │ │ │ split, remove, │ │ │ │ only. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a C-a │ (other) │ Toggle to the win‐ │ │ │ │ dow displayed pre‐ │ │ │ │ viously. Note that │ │ │ │ this binding de‐ │ │ │ │ faults to the com‐ │ │ │ │ mand character │ │ │ │ typed twice, unless │ │ │ │ overridden. 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, │ (break) │ Send a break to │ │C-a C-b │ │ window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a B │ (pow_break) │ Reopen the terminal │ │ │ │ line and send a │ │ │ │ break. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a c, │ (screen) │ Create a new window │ │C-a C-c │ │ with a shell and │ │ │ │ switch to that win‐ │ │ │ │ dow. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a C │ (clear) │ Clear the screen. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a d, │ (detach) │ Detach screen from │ │C-a C-d │ │ this terminal. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a D D │ (pow_detach) │ Detach and logout. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a f, │ (flow) │ Toggle flow on, off │ │C-a C-f │ │ or auto. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a F │ (fit) │ Resize the window │ │ │ │ to the current re‐ │ │ │ │ gion 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 "hard‐ │ │ │ │ copy.n". │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a H │ (log) │ Begins/ends logging │ │ │ │ of the current win‐ │ │ │ │ dow to the file │ │ │ │ "screenlog.n". │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a i, │ (info) │ Show info about │ │C-a C-i │ │ this window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a k, │ (kill) │ Destroy current │ │C-a C-k │ │ window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a l, │ (redisplay) │ Fully refresh cur‐ │ │C-a C-l │ │ rent window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a L │ (login) │ Toggle this windows │ │ │ │ login slot. Avail‐ │ │ │ │ able only if screen │ │ │ │ is configured to │ │ │ │ update the utmp │ │ │ │ database. T{ C-a │ │ │ │ m, │ │ │ │ C-a C-m │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a M │ (monitor) │ Toggles monitoring │ │ │ │ of the current win‐ │ │ │ │ dow. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a space, │ (next) │ Switch to the next │ │C-a n, │ │ window. │ │C-a C-n │ │ │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a N │ (number) │ Show the number │ │ │ │ (and title) of the │ │ │ │ current window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a backspace, │ (prev) │ Switch to the pre‐ │ │C-a C-h, │ │ vious window (oppo‐ │ │C-a p, │ │ site of C-a n). │ │C-a C-p │ │ │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a q, │ (xon) │ Send a control-q to │ │C-a C-q │ │ the current window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a Q │ (only) │ Delete all regions │ │ │ │ but the current │ │ │ │ one. See also │ │ │ │ split, remove, fo‐ │ │ │ │ cus. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a r, │ (wrap) │ Toggle the current │ │C-a C-r │ │ window's line-wrap │ │ │ │ setting (turn the │ │ │ │ current window's │ │ │ │ automatic margins │ │ │ │ on and off). │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a s, │ (xoff) │ Send a control-s to │ │C-a C-s; │ │ the current window. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a S │ (split) │ Split the current │ │ │ │ region horizontally │ │ │ │ into two new ones. │ │ │ │ See also only, re‐ │ │ │ │ move, focus. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a t, │ (time) │ Show system infor‐ │ │C-a C-t │ │ mation. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a v │ (version) │ Display the version │ │ │ │ and compilation │ │ │ │ date. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a C-v │ (digraph) │ Enter digraph. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a w, │ (windows) │ Show a list of win‐ │ │C-a C-w │ │ dow. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a W │ (width) │ Toggle 80/132 col‐ │ │ │ │ umns. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a x or C-a C-x │ (lockscreen) │ Lock this terminal. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a X │ (remove) │ Kill the current │ │ │ │ region. See also │ │ │ │ split, only, focus. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a z, │ (suspend) │ Suspend screen. │ │C-a C-z │ │ 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 ".term‐ │ │ │ │ cap" file. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a ? │ (help) │ Show key bindings. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a \ │ (quit) │ Kill all windows │ │ │ │ and terminate │ │ │ │ screen. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a : │ (colon) │ Enter command line │ │ │ │ mode. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a [, │ (copy) │ Enter copy/scroll‐ │ │C-a C-[, │ │ back mode. │ │C-a esc │ │ │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a C-], │ (paste .) │ Write the contents │ │C-a ] │ │ of the paste buffer │ │ │ │ to the stdin queue │ │ │ │ of the current win‐ │ │ │ │ dow. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a {, │ (history) │ Copy and paste a │ │C-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 monitor‐ │ │ │ │ ing the current │ │ │ │ window for inactiv‐ │ │ │ │ ity. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a | │ (split -v) │ Split the current │ │ │ │ region vertically │ │ │ │ into two new ones. │ ├─────────────────┼─────────────────┼─────────────────────┤ │C-a * │ (displays) │ Show a listing of │ │ │ │ all currently at‐ │ │ │ │ tached displays. │ └─────────────────┴─────────────────┴─────────────────────┘
CUSTOMIZATION
The "socket directory" defaults either to $HOME/.screen or simply to
/tmp/screens or preferably to /run/screen chosen at compile-time. If
screen is installed setuid-root, then the administrator should compile
screen with an adequate (not NFS mounted) socket directory. If screen
is not running setuid-root, the user can specify any mode 700 directory
in the environment variable $SCREENDIR.
When screen is invoked, it executes initialization commands from the
files "/etc/screenrc" and ".screenrc" in the user's home directory.
These are the "programmer's defaults" that can be overridden in the
following ways: for the global screenrc file screen searches for the
environment variable $SYSSCREENRC (this override feature may be dis‐
abled at compile-time). The user specific screenrc file is searched in
$SCREENRC, then $HOME/.screenrc. The command line option -c takes
precedence over the above user screenrc files.
Commands in these files are used to set options, bind functions to
keys, and to automatically establish one or more windows at the begin‐
ning of your screen session. Commands are listed one per line, with
empty lines being ignored. A command's arguments are separated by tabs
or spaces, and may be surrounded by single or double quotes. A `#'
turns the rest of the line into a comment, except in quotes. Unintel‐
ligible lines are warned about and ignored. Commands may contain ref‐
erences to environment variables. The syntax is the shell-like "$VAR "
or "${VAR}". Note that this causes incompatibility with previous screen
versions, as now the '$'-character has to be protected with '\' if no
variable substitution shall be performed. A string in single-quotes is
also protected from variable substitution.
Two configuration files are shipped as examples with your screen dis‐
tribution: "etc/screenrc" and "etc/etcscreenrc". They contain a number
of useful examples for various commands.
Customization can also be done 'on-line'. To enter the command mode
type `C-a :'. Note that commands starting with "def" change default
values, while others change current settings.
The following commands are available:
acladd usernames [crypted-pw]
addacl usernames
Enable users to fully access this screen session. Usernames can be one
user or a comma separated list of users. This command enables to attach
to the screen session and performs the equivalent of `aclchg usernames
+rwx "#?"'. executed. To add a user with restricted access, use the
`aclchg' command below. If an optional second parameter is supplied,
it should be a crypted password for the named user(s). `Addacl' is a
synonym to `acladd'. Multi user mode only.
aclchg usernames permbits list
chacl usernames permbits list
Change permissions for a comma separated list of users. Permission bits
are represented as `r', `w' and `x'. Prefixing `+' grants the permis‐
sion, `-' removes it. The third parameter is a comma separated list of
commands and/or windows (specified either by number or title). The spe‐
cial list `#' refers to all windows, `?' to all commands. if usernames
consists of a single `*', all known users are affected.
A command can be executed when the user has the `x' bit for it. The
user can type input to a window when he has its `w' bit set and no
other user obtains a writelock for this window. Other bits are cur‐
rently ignored. To withdraw the writelock from another user in window
2: `aclchg username -w+w 2'. To allow read-only access to the 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 re‐
gain 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 cre‐
ated by the caller of the command. Users may be no, one or a comma
separated list of known usernames. If no users are specified, a list of
all currently known users is assumed. Bits is any combination of ac‐
cess control bits allowed defined with the "aclchg" command. The spe‐
cial username "?" predefines the access that not yet known users will
be granted to any window initially. The special username "??" prede‐
fines 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 moni‐
tored, screen displays a notification in the message line. The notifi‐
cation message can be re-defined by means of the "activity" command.
Each occurrence of `%' in message is replaced by the number of the win‐
dow in which activity has occurred, and each occurrence of `^G' is re‐
placed 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 al‐
tered 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 termi‐
nals, just like in xterm. Initial setting is `off'.
at [identifier][#|*|%] command [args … ]
Execute a command at other displays or windows as if it had been en‐
tered there. "At" changes the context (the `current window' or `cur‐
rent 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 dis‐
play 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 ap‐
pended it is matched against window numbers and titles. Omitting an
identifier in front of the `#', `*' or `%'-character selects all users,
displays or windows because a prefix-match is performed. Note that on
the affected display(s) a short 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 win‐
dows (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 attri‐
bute/color modifier is also applied. If no modifier is given, the cur‐
rent 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 al‐
ready.
attrcolor i "+b"
Make bright colored text also bold.
autodetach on|off
Sets whether screen will automatically detach upon hangup, which saves
all your running programs until they are resumed with a screen -r com‐
mand. When turned off, a hangup signal will terminate screen and all
the processes it contains. Autodetach is on by default.
autonuke on|off
Sets whether a clear screen sequence should nuke all the output that
has not been written to the terminal. See also "obuflimit".
backtick id lifespan autorefresh cmd args…
backtick id
Program the backtick command with the numerical id id. The output of
such a command is used for substitution of the "%`" string escape. The
specified lifespan is the number of seconds the output is considered
valid. After this time, the command is run again if a corresponding
string escape is encountered. The autorefresh parameter triggers an
automatic refresh for caption and hardstatus strings after the speci‐
fied number of seconds. Only the last line of output is used for sub‐
stitution.
If both the lifespan and the autorefresh parameters are zero, the back‐
tick 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 char‐
acters cleared by an erase/insert/scroll/clear operation will be dis‐
played in the current background color. Otherwise the default back‐
ground color is used.
bell_msg [message]
When a bell character is sent to a background window, screen displays a
notification in the message line. The notification message can be re-
defined by this command. Each occurrence of `%' in message is replaced
by the number of the window to which a bell has been sent, and each oc‐
currence of `^G' is replaced by the definition for bell in your termcap
(usually an audible bell). The default message is
'Bell in window %n'
An empty message can be supplied to the "bell_msg" command to suppress
output of a message line (bell_msg ""). Without parameter, the current
message is shown.
bind [class] key [command [args]]
Bind a command to a key. By default, most of the commands provided by
screen are bound to one or more keys as indicated in the "DEFAULT KEY
BINDINGS" section, e.g. the command to create a new window is bound to
"C-c" and "c". The "bind" command can be used to redefine the key
bindings and to define new bindings. The key argument is either a sin‐
gle character, a two-character sequence of the form "^x" (meaning "C-
x"), a backslash followed by an octal number (specifying the ASCII code
of the character), or a backslash followed by a second character, such
as "\^" or "\\". The argument can also be quoted, if you like. If no
further argument is given, any previously established binding for this
key is removed. The command argument can be any command listed in this
section.
If a command class is specified via the "-c" option, the key is bound
for the specified class. Use the "command" command to activate a class.
Command classes can be used to create multiple command keys or multi-
character bindings.
Some examples:
bind ' ' windows
bind ^k
bind k
bind K kill
bind ^f screen telnet foobar
bind \033 screen -ln -t root -h 1000 9 su
would bind the space key to the command that displays a list of windows
(so that the command usually invoked by "C-a C-w" would also be avail‐
able 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 supe‐
ruser 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 con‐
tain 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 key‐
board capability name (selectable with the -k option).
Some keys on a VT100 terminal can send a different string if applica‐
tion mode is turned on (e.g the cursor keys). Such keys have two en‐
tries in the translation table. You can select the application mode en‐
try by specifying the -a option.
The -t option tells screen not to do inter-character timing. One cannot
turn off the timing if a termcap capability is used.
Cmd can be any of screen's commands with an arbitrary number of args.
If cmd is omitted the key-binding is removed from the table.
Here are some examples of keyboard bindings:
bindkey -d
Show all of the default key bindings. The application mode entries are
marked with [A].
bindkey -k k1 select 1
Make the "F1" key switch to window one.
bindkey -t foo stuff barfoo
Make "foo" an abbreviation of the word "barfoo". Timeout is disabled so
that users can type slowly.
bindkey "\024" mapdefault
This key-binding makes "^T" an escape character for key-bindings. If
you did the above "stuff barfoo" binding, you can enter the word "foo"
by typing "^Tfoo". If you want to insert a "^T" you have to press the
key twice (i.e., escape the escape binding).
bindkey -k F1 command
Make the F11 (not F1!) key an alternative screen escape (besides ^A).
break[duration]
Send a break signal for duration*0.25 seconds to this window. For non-
Posix systems the time interval may be rounded up to full seconds.
Most useful if a character device is attached to the window rather than
a shell process (See also chapter "WINDOW TYPES"). The maximum duration
of a break signal is limited to 15 seconds.
blanker
Activate the screen blanker. First the screen is cleared. If no blanker
program is defined, the cursor is turned off, otherwise, the program is
started and it's output is written to the screen. The screen blanker
is killed with the first keypress, the read key is discarded.
This command is normally used together with the "idle" command.
blankerprg [program-args]
Defines a blanker program. Disables the blanker program if an empty ar‐
gument is given. Shows the currently set blanker program if no argu‐
ments are given.
breaktype [tcsendbreak|TIOCSBRK|TCSBRK]
Choose one of the available methods of generating a break signal for
terminal devices. This command should affect the current window only.
But it still behaves identical to "defbreaktype". This will be changed
in the future. Calling "breaktype" with no parameter displays the
break method for the current window.
bufferfile [exchange-file]
Change the filename used for reading and writing with the paste buffer.
If the optional argument to the "bufferfile" command is omitted, the
default setting ("/tmp/screen-exchange") is reactivated. The following
example will paste the system's password file into the screen window
(using the paste buffer, where a copy remains):
C-a : bufferfile /etc/passwd
C-a < C-a ]
C-a : bufferfile
bumpleft
Swaps window with previous one on window list.
bumpright
Swaps window with next one on window list.
c1 [on|off]
Change c1 code processing. "C1 on" tells screen to treat the input
characters between 128 and 159 as control functions. Such an 8-bit
code is normally the same as ESC followed by the corresponding 7-bit
code. The default setting is to process c1 codes and can be changed
with the "defc1" command. Users with fonts that have usable characters
in the c1 positions may want to turn this off.
caption [ top | bottom ] always|splitonly[string]
caption string [string]
This command controls the display of the window captions. Normally a
caption is only used if more than one window is shown on the display
(split screen mode). But if the type is set to always screen shows a
caption even if only one window is displayed. The default is splitonly.
The second form changes the text used for the caption. You can use all
escapes from the "STRING ESCAPES" chapter. Screen uses a default of
`%3n %t'.
You can mix both forms by providing a string as an additional argument.
You can have the caption displayed either at the top or bottom of the
window. The default is bottom.
charset set
Change the current character set slot designation and charset mapping.
The first four character of set are treated as charset designators
while the fifth and sixth character must be in range '0' to '3' and set
the GL/GR charset mapping. On every position a '.' may be used to indi‐
cate 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 windows that are created by means of
the "screen" command from within ".screenrc" or by means of "C-a :
screen …" or "C-a c" use this as their default directory. Without a
chdir command, this would be the directory from which screen was in‐
voked.
Hardcopy and log files are always written to the window's default di‐
rectory, not the current directory of the process running in the win‐
dow. You can use this command multiple times in your .screenrc to
start various windows in different default directories, but the last
chdir value will affect all the windows you create interactively.
cjkwidth [ on | off ]
Treat ambiguous width characters as full/half width.
clear
Clears the current window and saves its image to the scrollback buffer.
collapse
Reorders window on window list, removing number gaps between them.
colon [prefix]
Allows you to enter ".screenrc" command lines. Useful for on-the-fly
modification of key bindings, specific window creation and changing
settings. Note that the "set" keyword no longer exists! Usually com‐
mands affect the current window rather than default settings for future
windows. Change defaults with commands starting with 'def…'.
If you consider this as the `Ex command mode' of screen, you may regard
"C-a esc" (copy mode) as its `Vi command mode'.
command [-c class]
This command has the same effect as typing the screen escape character
(^A). It is probably only useful for key bindings. If the "-c" option
is given, select the specified command class. See also "bind" and
"bindkey".
compacthist [on|off]
This tells screen whether to suppress trailing blank lines when
scrolling up text into the history buffer.
console [on|off]
Grabs or un-grabs the machines console output to a window. Note: Only
the owner of /dev/console can grab the console output. This command is
only available if the machine supports the ioctl TIOCCONS.
copy
Enter copy/scrollback mode. This allows you to copy text from the cur‐
rent window and its history into the paste buffer. In this mode a vi-
like `full screen editor' is active:
The editor's movement keys are:
┌─────────────┬──────────────────────────────────────────────────┐
│h, C-h, │ move the cursor left. │
│left arrow │ │
├─────────────┼──────────────────────────────────────────────────┤
│j, C-n, │ move the cursor down. │
│down arrow │ │
├─────────────┼──────────────────────────────────────────────────┤
│k, C-p, │ move the cursor up. │
│up arrow │ │
├─────────────┼──────────────────────────────────────────────────┤
│l ('el'), │ move the cursor right. │
│right arrow │ │
├─────────────┼──────────────────────────────────────────────────┤
│0 (zero) C-a │ move to the leftmost column. │
├─────────────┼──────────────────────────────────────────────────┤
│+ and - │ positions one line up and down. │
├─────────────┼──────────────────────────────────────────────────┤
│H, M and L │ move the cursor to the leftmost column of the │
│ │ top, 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 oc‐ │
│ │ currence 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/op‐ │
│ │ posite 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 po‐ │
│ │ sition. (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 com‐
mand. (E.g. markkeys "h=^B:l=^F:$=^E") There is no simple method for a
full emacs-style keymap, as this involves multi-character codes.
Some keys are defined to do mark and replace operations.
The copy range is specified by setting two marks. The text between
these marks will be highlighted. Press:
space or enter to set the first or second mark respectively. If
mousetrack is set to `on', marks can also be set using left
mouse click.
Y and y used to mark one whole line or to mark from start of
line.
W marks exactly one word.
Any of these commands can be prefixed with a repeat count number by
pressing digits
0..9 which is taken as a repeat count.
Example: "C-a C-[ H 10 j 5 Y" will copy lines 11 to 15 into the paste
buffer.
The following search keys are defined:
/ Vi-like search forward.
? Vi-like search backward.
C-a s Emacs style incremental search forward.
C-r Emacs style reverse i-search.
n Find next search pattern.
N Find previous search pattern.
There are however some keys that act differently than in vi. Vi does
not allow one to yank rectangular blocks of text, but screen does.
Press: c or C to set the left or right margin respectively. If no re‐
peat count is given, both default to the current cursor position.
Example: Try this on a rather full text screen:
"C-a [ M 20 l SPACE c 10 l 5 j C SPACE".
This moves one to the middle line of the screen, moves in 20 columns
left, marks the beginning of the paste buffer, sets the left column,
moves 5 columns down, sets the right column, and then marks the end of
the paste buffer. Now try:
"C-a [ M 20 l SPACE 10 l 5 j SPACE"
and notice the difference in the amount of text copied.
J joins lines. It toggles between 4 modes: lines separated by a newline
character (012), lines glued seamless, lines separated by a single
whitespace and comma separated lines. Note that you can prepend the
newline character with a carriage return character, by issuing a "crlf
on".
v or V is for all the vi users with ":set numbers" - it toggles the
left margin between column 9 and 1. Press
a before the final space key to toggle in append mode. Thus the con‐
tents of the paste buffer will not be overwritten, but is appended to.
A toggles in append mode and sets a (second) mark.
> sets the (second) mark and writes the contents of the paste buffer to
the screen-exchange file (/tmp/screen-exchange per default) once copy-
mode is finished.
This example demonstrates how to dump the whole scrollback buffer to
that file: "C-A [ g SPACE G $ >".
C-g gives information about the current line and column.
x 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 se‐
quence `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 op‐
tion -DDEBUG debugging available and is turned on per default. Note
that this command only affects debugging output from the main "SCREEN"
process correctly. Debug output from attacher processes can only be
turned off once and forever.
defc1 on|off
Same as the c1 command except that the default setting for new windows
is changed. Initial setting is `on'.
defautonuke on|off
Same as the autonuke command except that the default setting for new
displays is changed. Initial setting is `off'. Note that you can use
the special `AN' terminal capability if you want to have a dependency
on the terminal type.
defbce on|off
Same as the bce command except that the default setting for new windows
is changed. Initial setting is `off'.
defbreaktype [tcsendbreak|TIOCSBRK|TCSBRK]
Choose one of the available methods of generating a break signal for
terminal devices. The preferred methods are tcsendbreak and TIOCSBRK.
The third, TCSBRK, blocks the complete screen session for the duration
of the break, but it may be the only way to generate long breaks. Tc‐
sendbreak and TIOCSBRK may or may not produce long breaks with spikes
(e.g. 4 per second). This is not only system-dependent, this also dif‐
fers between serial board drivers. Calling "defbreaktype" with no pa‐
rameter displays the current setting.
defcharset [set]
Like the charset command except that the default setting for new win‐
dows is changed. Shows current default if called without argument.
defdynamictitle on|off
Set default behaviour for new windows regarding if screen should change
window title when seeing proper escape sequence. See also "TITLES (nam‐
ing windows)" section.
defescape xy
Set the default command characters. This is equivalent to the "escape"
except that it is useful multiuser sessions only. In a multiuser ses‐
sion "escape" changes the command character of the calling user, where
"defescape" changes the default command characters for users that will
be added later.
defflow on|off|auto [interrupt]
Same as the flow command except that the default setting for new win‐
dows is changed. Initial setting is `auto'. Specifying "defflow auto
interrupt" is the same as the command-line options -fa and -i.
defgr on|off
Same as the gr command except that the default setting for new windows
is changed. Initial setting is `off'.
defhstatus [status]
The hardstatus line that all new windows will get is set to status.
This command is useful to make the hardstatus of every window display
the window number or title or the like. Status may contain the same
directives as in the window messages, but the directive escape charac‐
ter is '^E' (octal 005) instead of '%'. This was done to make a misin‐
terpretation 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 ter‐
minal.
deflog on|off
Same as the log command except that the default setting for new windows
is changed. Initial setting is `off'.
deflogin on|off
Same as the login command except that the default setting for new win‐
dows is changed. This is initialized with `on' as distributed (see con‐
fig.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 dis‐
plays is changed. Initial setting is `off'.
defobuflimit limit
Same as the obuflimit command except that the default setting for new
displays is changed. Initial setting is 256 bytes. Note that you can
use the special 'OL' terminal capability if you want to have a depen‐
dency on the terminal type.
defscrollback num
Same as the scrollback command except that the default setting for new
windows is changed. Initial setting is 100.
defshell command
Synonym to the shell .screenrc command. See there.
defsilence on|off
Same as the silence command except that the default setting for new
windows is changed. Initial setting is `off'.
defslowpaste msec
Same as the slowpaste command except that the default setting for new
windows is changed. Initial setting is 0 milliseconds, meaning `off'.
defutf8 on|off
Same as the utf8 command except that the default setting for new win‐
dows is changed. Initial setting is `on' if screen was started with
"-U", otherwise `off'.
defwrap on|off
Same as the wrap command except that the default setting for new win‐
dows is changed. Initially line-wrap is on and can be toggled with the
"wrap" command ("C-a r") or by means of "C-a : wrap on|off".
defwritelock on|off|auto
Same as the writelock command except that the default setting for new
windows is changed. Initially writelocks will off.
detach [-h]
Detach the screen session (disconnect it from the terminal and put it
into the background). This returns you to the shell where you invoked
screen. A detached screen can be resumed by invoking screen with the
-r option (see also section "COMMAND-LINE OPTIONS"). The -h option
tells screen to immediately close the connection to the terminal
("hangup").
dinfo
Show what screen thinks about your terminal. Useful if you want to know
why features like color or the alternate charset don't work.
displays
Shows a tabular listing of all currently connected user front-ends
(displays). This is most useful for multiuser sessions. 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 exam‐
ple, 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 di‐
graph 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 sock‐
ets. See the "FILES" section below). This termcap entry is
identical to the value of the environment variable $TERMCAP that
is set up by screen for each window. For terminfo based systems
you will need to run a converter like captoinfo and then compile
the entry with tic.
dynamictitle on|off
Change behaviour for windows regarding if screen should change
window title when seeing proper escape sequence. See also "TI‐
TLES (naming windows)" section.
echo [-n] message
The echo command may be used to annoy screen users with a 'mes‐
sage of the day'. Typically installed in a global /etc/screenrc.
The option "-n" may be used to suppress the line feed. See also
"sleep". Echo is also useful for online checking of environment
variables.
encoding enc [enc]
Tell screen how to interpret the input/output. The first argu‐
ment sets the encoding of the current window. Each window can
emulate a different encoding. The optional second parameter
overwrites the encoding of the connected terminal. It should
never be needed as screen uses the locale setting to detect the
encoding. There is also a way to select a terminal encoding de‐
pending on the terminal type by using the "KJ" termcap entry.
Supported encodings are eucJP, SJIS, eucKR, eucCN, Big5, GBK,
KOI8-R, KOI8-U, CP1251, UTF-8, ISO8859-2, ISO8859-3, ISO8859-4,
ISO8859-5, ISO8859-6, ISO8859-7, ISO8859-8, ISO8859-9,
ISO8859-10, ISO8859-15, jis.
See also "defencoding", which changes the default setting of a
new window.
escape xy
Set the command character to x and the character generating a
literal command character (by triggering the "meta" command) to
y (similar to the -e option). Each argument is either a single
character, a two-character sequence of the form "^x" (meaning
"C-x"), a backslash followed by an octal number (specifying the
ASCII code of the character), or a backslash followed by a sec‐
ond 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 newcom‐
mand and its optional arguments) in the current window. The flow
of data between newcommands stdin/stdout/stderr, the process
originally started in the window (let us call it "application-
process") and screen itself (window) is controlled by the file
descriptor pattern fdpat. This pattern is basically a three
character sequence representing stdin, stdout and stderr of new‐
command. 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 in‐
put will go to newcommand unless newcommand receives the appli‐
cation-process' output (fdpats first character is `!' or `:') or
a pipe symbol (|) is added (as a fourth character) to the end of
fdpat.
Invoking `exec' without arguments shows name and arguments of
the currently running subprocess in this window. Only one sub‐
process 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 il‐
lustration of all 21 possible combinations. Each drawing shows
the digits 2,1,0 representing the three file descriptors of new‐
command. The box marked `W' is the usual pty that has the appli‐
cation-process on its slave side. The box marked `P' is the
secondary pty that now has screen at its master side.
Abbreviations: Whitespace between the word `exec' and fdpat and
the command can be omitted. Trailing dots and a fdpat consisting
only of dots can be omitted. A simple `|' is synonymous for the
pattern `!..|'; the word exec can be omitted here and can always
be replaced by `!'.
Examples:
exec … /bin/sh
exec /bin/sh
!/bin/sh
Creates another shell in the same window, while
the original shell is still running. Output of
both shells is displayed and user input is sent to
the new /bin/sh.
exec !.. stty 19200
exec ! stty 19200
!!stty 19200
Set the speed of the window's tty. If your stty
command operates on stdout, then add another `!'.
exec !..| less
|less
This adds a pager to the window output. The spe‐
cial character `|' is needed to give the user con‐
trol 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 char‐
acter (oct. 007) to the window output seen by
screen. This will cause "Bell in window x" mes‐
sages, whenever the string "Error" appears in the
window.
fit
Change the window size to the size of the current region. This
command is needed because screen doesn't adapt the window size
automatically if the window is displayed more than once.
flow [on|off|auto]
Sets the flow-control mode for this window. Without parameters
it cycles the current window's flow-control setting from "auto‐
matic" to "on" to "off". See the discussion on "FLOW-CONTROL"
later on in this document for full details and note, that this
is subject to change in future releases. Default is set by
`defflow'.
focus [next|prev|up|down|left|right|top|bottom]
Move the input focus to the next region. This is done in a
cyclic way so that the top left region is selected after the
bottom right one. If no option is given it defaults to `next'.
The next region to be selected is determined by how the regions
are layered. Normally, the next region in the same layer would
be selected. However, if that next region contains one or more
layers, the first region in the highest layer is selected first.
If you are at the last region of the current layer, `next' will
move the focus to the next region in the lower layer (if there
is a lower layer). `Prev' cycles in the opposite order. See
"split" for more information about layers.
The rest of the options (`up', `down', `left', `right', `top',
and `bottom') are more indifferent to layers. The option `up'
will move the focus upward to the region that is touching the
upper left corner of the current region. `Down' will move down‐
ward to the region that is touching the lower left corner of the
current region. The option `left' will move the focus leftward
to the region that is touching the upper left corner of the cur‐
rent region, while `right' will move rightward to the region
that is touching the upper right corner of the current region.
Moving left from a left most region or moving right from a right
most region will result in no action.
The option `top' will move the focus to the very first region in
the upper list corner of the screen, and `bottom' will move to
the region in the bottom right corner of the screen. Moving up
from a top most region or moving down from a bottom most region
will result in no action.
Useful bindings are (h, j, k, and l as in vi)
bind h focus left
bind j focus down
bind k focus up
bind l focus right
bind t focus top
bind b focus bottom
Note that k is traditionally bound to the kill command.
focusminsize [ ( width|max|_ ) ( height|max|_ ) ]
This forces any currently selected region to be automatically
resized at least a certain width and height. All other surround‐
ing regions will be resized in order to accommodate. This con‐
straint follows every time the "focus" command is used. The "re‐
size" command can be used to increase either dimension of a re‐
gion, but never below what is set with "focusminsize". The un‐
derscore `_' 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 otherwise the ISO88591 charset would not work.
group [grouptitle]
Change or show the group the current window belongs to. Windows
can be moved around between different groups by specifying the
name of the destination group. Without specifying a group, the
title of the current group is displayed.
hardcopy [-h] [file]
Writes out the currently displayed image to the file file, or,
if no filename is specified, to hardcopy.n in the default direc‐
tory, 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 over‐
written each time. Default is `off'.
hardcopydir directory
Defines a directory where hardcopy files will be placed. If un‐
set, hardcopys are dumped in screen's current working directory.
hardstatus [on|off]
hardstatus [always]firstline|lastline|message|ignore[string]
hardstatus string[string]
This command configures the use and emulation of the terminal's
hardstatus line. The first form toggles whether screen will use
the hardware status line to display messages. If the flag is set
to `off', these messages are overlaid in reverse video mode at
the display line. The default setting is `on'.
The second form tells screen what to do if the terminal doesn't
have a hardstatus line (i.e. the termcap/terminfo capabilities
"hs", "ts", "fs" and "ds" are not set). When "firstline/last‐
line" is used, screen will reserve the first/last line of the
display for the hardstatus. "message" uses screen's message
mechanism and "ignore" tells screen never to display the hard‐
status. 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;
AUTHORS
Originally created by Oliver Laumann. For a long time maintained and
developed by Juergen Weigert, Michael Schroeder, Micah Cowan and Sadrul
Habib Chowdhury. This latest version was produced by Amadeusz Slawinski
COPYLEFT
Copyright (c) 2015-2017
Juergen Weigert
CONTRIBUTORS
Eric S. Raymond
AVAILABILITY
The latest official release of screen available via anonymous ftp from ftp.gnu.org/gnu/screen/ or any other GNU distribution site. The home site of screen is savannah.gnu.org/projects/screen/. If you want to help, send a note to screen-devel@gnu.org.
BUGS
• `dm' (delete mode) and `xs' are not handled correctly (they are ig‐ nored). `xn' is treated as a magic-margin indicator. • Screen has no clue about double-high or double-wide characters. But this is the only area where vttest is allowed to fail. • It is not possible to change the environment variable $TERMCAP when reattaching under a different terminal type. • The support of terminfo based systems is very limited. Adding extra capabilities to $TERMCAP may not have any effects. • Screen does not make use of hardware tabs. • Screen must be installed as set-uid with owner root on most systems in order to be able to correctly change the owner of the tty device file for each window. Special permission may also be required to write the file "/run/utmp". • Entries in "/run/utmp" are not removed when screen is killed with SIGKILL. This will cause some programs (like "w" or "rwho") to ad‐ vertise that a user is logged on who really isn't. • Screen may give a strange warning when your tty has no utmp entry. • When the modem line was hung up, screen may not automatically detach (or quit) unless the device driver is configured to send a HANGUP signal. To detach a screen session use the -D or -d command line option. • If a password is set, the command line options -d and -D still de‐ tach a session without asking. • Both "breaktype" and "defbreaktype" change the break generating method used by all terminal devices. The first should change a win‐ dow specific setting, where the latter should change only the de‐ fault for new windows. • When attaching to a multiuser session, the user's .screenrc file is not sourced. Each user's personal settings have to be included in the .screenrc file from which the session is booted, or have to be changed manually. • A weird imagination is most useful to gain full advantage of all the features. • Send bug-reports, fixes, enhancements, t-shirts, money, beer & pizza to screen-devel@gnu.org.
