This is screen.info, produced by makeinfo version 4.5 from ./screen.texinfo. INFO-DIR-SECTION General Commands START-INFO-DIR-ENTRY * Screen: (screen). Full-screen window manager. END-INFO-DIR-ENTRY This file documents the `Screen' virtual terminal manager. Copyright (c) 1993-2003 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Foundation. File: screen.info, Node: Window Termcap, Next: Dump Termcap, Up: Termcap Choosing the termcap entry for a window ======================================= 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. 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 `$TERMCAP' value used by `screen' by using the `termcap' command, or by defining the variable `$SCREENCAP' prior to startup. When the latter defined, its value will be copied verbatim into each window's `$TERMCAP' variable. This can either be the full terminal definition, or a filename where the terminal `screen' (and/or `screen-w') is defined. Note that `screen' honors the `terminfo' command if the system uses the terminfo database rather than termcap. On such machines the `$TERMCAP' variable has no effect and you must use the `dumptermcap' command (*note Dump Termcap::) and the `tic' program to generate terminfo entries for `screen' windows. 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 with `PRIN' while the printer is active. Some capabilities are only put into the `$TERMCAP' variable of the virtual terminal if they can be efficiently implemented by the physical terminal. For instance, `dl' (delete line) is only put into the `$TERMCAP' variable if the terminal supports either delete line itself or scrolling regions. Note that this may provoke confusion, when the session is reattached on a different terminal, as the value of `$TERMCAP' cannot be modified by parent processes. You can force `screen' to include all capabilities in `$TERMCAP' with the `-a' command-line option (*note Invoking Screen::). The "alternate screen" capability is not enabled by default. Set the `altscreen' `.screenrc' command to enable it. File: screen.info, Node: Dump Termcap, Next: Termcap Syntax, Prev: Window Termcap, Up: Termcap Write out the window's termcap entry ==================================== - Command: dumptermcap (`C-a .') Write the termcap entry for the virtual terminal optimized for the currently active window to the file `.termcap' in the user's `$HOME/.screen' directory (or wherever `screen' stores its sockets. *note Files::). This termcap entry is identical to the value of the environment variable `$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'. File: screen.info, Node: Termcap Syntax, Next: Termcap Examples, Prev: Dump Termcap, Up: Termcap The `termcap' command ===================== - Command: termcap term terminal-tweaks [window-tweaks] - Command: terminfo term terminal-tweaks [window-tweaks] - Command: termcapinfo term terminal-tweaks [window-tweaks] (none) 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 the termcap names of the capabilities should also 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 (*note Virtual Terminal::). File: screen.info, Node: Termcap Examples, Next: Special Capabilities, Prev: Termcap Syntax, Up: Termcap Termcap Examples ================ Some examples: termcap xterm* xn: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 (xn), but they don't really have a status line (no 'hs' - append `@' to turn entries off). Note that we assume `xn' for all terminal names that start with `vt', but only if you don't specify a termcap command for that terminal. termcap vt* xn termcap vt102|vt220 Z0=\E[?3h:Z1=\E[?3l Specifies the firm-margined `xn' 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'. *Note Virtual Terminal::, for the details of the `screen' terminal emulation. *Note Termcap: (termcap)Top, for more information on termcap definitions. File: screen.info, Node: Special Capabilities, Next: Autonuke, Prev: Termcap Examples, Up: Termcap Special Terminal Capabilities ============================= The following table describes all terminal capabilities that are recognized by `screen' and are not in the termcap manual (*note Termcap: (termcap)Top.). 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 -- `screen' now 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 to cursor mode. `AN' (bool) Enable autonuke for displays of this terminal type. (*note Autonuke::). `OL' (num) Set the output buffer limit. See the `obuflimit' command (*note Obuflimit::) for more details. `KJ' (str) Set the encoding of the terminal. See the `encoding' command (*note Character Processing::) 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. (*note Character Translation::). `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). File: screen.info, Node: Autonuke, Next: Obuflimit, Prev: Special Capabilities, Up: Termcap Autonuke ======== - Command: autonuke STATE (none) Sets whether a clear screen sequence should nuke all the output that has not been written to the terminal. *Note Obuflimit::. This property is set per display, not per window. - Command: defautonuke STATE (none) Same as the `autonuke' command except that the default setting for new displays is also changed. Initial setting is `off'. Note that you can use the special `AN' terminal capability if you want to have a terminal type dependent setting. File: screen.info, Node: Obuflimit, Next: Character Translation, Prev: Autonuke, Up: Termcap Obuflimit ========= - Command: obuflimit [LIMIT] (none) If the output buffer contains more bytes than the specified limit, no more data will be read from the windows. The default value is 256. If you have a fast display (like `xterm'), you can set it to some higher value. If no argument is specified, the current setting is displayed. This property is set per display, not per window. - Command: defobuflimit LIMIT (none) Same as the `obuflimit' command except that the default setting for new displays is also changed. Initial setting is 256 bytes. Note that you can use the special `OL' terminal capability if you want to have a terminal type dependent limit. File: screen.info, Node: Character Translation, Prev: Obuflimit, Up: Termcap Character Translation ===================== `Screen' has a powerful mechanism to translate characters to arbitrary strings depending on the current font and terminal type. Use this feature if you want to work with a common standard character set (say ISO8851-latin1) even on terminals that scatter the more unusual characters over several national language font pages. Syntax: XC=<CHARSET-MAPPING>{,,<CHARSET-MAPPING>} <CHARSET-MAPPING> := <DESIGNATOR><TEMPLATE>{,<MAPPING>} <MAPPING> := <CHAR-TO-BE-MAPPED><TEMPLATE-ARG> The things in braces may be repeated any number of times. A <CHARSET-MAPPING> tells screen how to map characters in font <DESIGNATOR> (`B': Ascii, `A': UK, `K': german, etc.) to strings. Every <MAPPING> describes to what string a single character will be translated. A template mechanism is used, as most of the time the codes have a lot in common (for example strings to switch to and from another charset). Each occurrence of `%' in <TEMPLATE> gets substituted with the TEMPLATE-ARG specified together with the character. If your strings are not similar at all, then use `%' as a template and place the full string in <TEMPLATE-ARG>. A quoting mechanism was added to make it possible to use a real `%'. The `\' character quotes the special characters `\', `%', and `,'. Here is an example: termcap hp700 'XC=B\E(K%\E(B,\304[,\326\\\\,\334]' This tells `screen', how to translate ISOlatin1 (charset `B') upper case umlaut characters on a `hp700' terminal that has a german charset. `\304' gets translated to `\E(K[\E(B' and so on. Note that this line gets parsed *three* times before the internal lookup table is built, therefore a lot of quoting is needed to create a single `\'. Another extension was added to allow more emulation: If a mapping translates the unquoted `%' char, it will be sent to the terminal whenever screen switches to the corresponding <DESIGNATOR>. In this special case the template is assumed to be just `%' because the charset switch sequence and the character mappings normally haven't much in common. This example shows one use of the extension: termcap xterm 'XC=K%,%\E(B,[\304,\\\\\326,]\334' Here, a part of the german (`K') charset is emulated on an xterm. If screen has to change to the `K' charset, `\E(B' will be sent to the terminal, i.e. the ASCII charset is used instead. The template is just `%', so the mapping is straightforward: `[' to `\304', `\' to `\326', and `]' to `\334'. File: screen.info, Node: Message Line, Next: Logging, Prev: Termcap, Up: Top The Message Line **************** `screen' displays informational messages and other diagnostics in a "message line" at the bottom of the screen. If your terminal has a status line defined in its termcap, screen will use this for displaying its messages, otherwise the last line of the 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. * Menu: * Privacy Message:: Using the message line from your program. * Hardware Status Line:: Use the terminal's hardware status line. * Last Message:: Redisplay the last message. * Message Wait:: Control how long messages are displayed. File: screen.info, Node: Privacy Message, Next: Hardware Status Line, Up: Message Line Using the message line from your program ======================================== The message line facility can be used by an application running in the current window by means of the ANSI "Privacy message" control sequence. For instance, from within the shell, try something like: echo "^Hello world from window $WINDOW\" where `' is ASCII ESC and `^' is a literal caret or up-arrow. File: screen.info, Node: Hardware Status Line, Next: Last Message, Prev: Privacy Message, Up: Message Line Hardware Status Line ==================== - Command: hardstatus [state] - Command: hardstatus [`always']`lastline'|`message'|`ignore' [string] - Command: hardstatus `string' [string] (none) This command configures the use and emulation of the terminal's hardstatus line. The first form toggles whether `screen' will use the hardware status line to display messages. If the flag is set to `off', these messages are overlaid in reverse video mode at the display line. The default setting is `on'. The second form tells screen what to do if the terminal doesn't have a hardstatus line (i.e. the termcap/terminfo capabilities "hs", "ts", "fs" and "ds" are not set). If the type `lastline' is used, screen will reserve the last line of the display for the hardstatus. `message' uses `screen''s message mechanism and `ignore' tells `screen' never to display the hardstatus. If you prepend the word `always' to the type (e.g., `alwayslastline'), `screen' will use the type even if the terminal supports a hardstatus line. 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;^G' or `ESC_\\') is displayed. You can customize this to any string you like including string escapes (*note String Escapes::). If you leave out the argument STRING, the current string is displayed. You can mix the second and third form by providing the string as additional argument. File: screen.info, Node: Last Message, Next: Message Wait, Prev: Hardware Status Line, Up: Message Line Display Last Message ==================== - Command: lastmsg (`C-a m', `C-a C-m') Repeat the last message displayed in the message line. Useful if you're typing when a message appears, because (unless your terminal has a hardware status line) the message goes away when you press a key. File: screen.info, Node: Message Wait, Prev: Last Message, Up: Message Line Message Wait ============ - Command: msgminwait sec (none) Defines the time `screen' delays a new message when another is currently displayed. Defaults to 1 second. - Command: msgwait sec (none) Defines the time a message is displayed, if `screen' is not disturbed by other activity. Defaults to 5 seconds. File: screen.info, Node: Logging, Next: Startup, Prev: Message Line, Up: Top Logging ******* This section describes the commands for keeping a record of your session. * Menu: * Hardcopy:: Dump the current screen to a file * Log:: Log the output of a window to a file File: screen.info, Node: Hardcopy, Next: Log, Up: Logging hardcopy ======== - Command: hardcopy [-h] [FILE] (`C-a h', `C-a C-h') Writes out the currently displayed image to the file FILE, or, if no filename is specified, to `hardcopy.N' in the default directory, where N is the number of the current window. This either appends or overwrites the file if it exists, as determined by the `hardcopy_append' command. If the option `-h' is specified, dump also the contents of the scrollback buffer. - Command: hardcopy_append state (none) If set to `on', `screen' will append to the `hardcopy.N' files created by the command `hardcopy'; otherwise, these files are overwritten each time. - Command: hardcopydir directory (none) Defines a directory where hardcopy files will be placed. If unset hardcopys are dumped in screen's current working directory. File: screen.info, Node: Log, Prev: Hardcopy, Up: Logging log === - Command: deflog state (none) Same as the `log' command except that the default setting for new windows is changed. Initial setting is `off'. - Command: log [state] (`C-a H') Begins/ends logging of the current window to the file `screenlog.N' in the window's default directory, where N is the number of the current window. This filename can be changed with the `logfile' command. If no parameter is given, the logging state is toggled. The session log is appended to the previous contents of the file if it already exists. The current contents and the contents of the scrollback history are not included in the session log. Default is `off'. - Command: logfile filename - Command: logfile flush secs (none) Defines the name the logfiles will get. The default is `screenlog.%n'. The second form changes the number of seconds `screen' will wait before flushing the logfile buffer to the file-system. The default value is 10 seconds. - Command: logtstamp [state] - Command: logtstamp `after' secs - Command: logtstamp `string' string (none) This command controls logfile time-stamp mechanism of screen. If time-stamps are turned `on', screen adds a string containing the current time to the logfile after two minutes of inactivity. When output continues and more than another two minutes have passed, a second time-stamp is added to document the restart of the output. You can change this timeout with the second form of the command. The third form is used for customizing the time-stamp string (`-- %n:%t -- time-stamp -- %M/%d/%y %c:%s --\n' by default). File: screen.info, Node: Startup, Next: Miscellaneous, Prev: Logging, Up: Top Startup ******* This section describes commands which are only useful in the `.screenrc' file, for use at startup. * Menu: * echo:: Display a message. * sleep:: Pause execution of the `.screenrc'. * Startup Message:: Control display of the copyright notice. File: screen.info, Node: echo, Next: sleep, Up: Startup echo ==== - Command: echo [`-n'] message (none) The echo command may be used to annoy `screen' users with a 'message of the day'. Typically installed in a global 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. File: screen.info, Node: sleep, Next: Startup Message, Prev: echo, Up: Startup sleep ===== - Command: sleep num (none) 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'. File: screen.info, Node: Startup Message, Prev: sleep, Up: Startup Startup Message =============== - Command: startup_message state (none) Select whether you want to see the copyright notice during startup. Default is `on', as you probably noticed. File: screen.info, Node: Miscellaneous, Next: String Escapes, Prev: Startup, Up: Top Miscellaneous commands ********************** The commands described here do not fit well under any of the other categories. * Menu: * At:: Execute a command at other displays or windows. * Break:: Send a break signal to the window. * Debug:: Suppress/allow debugging output. * License:: Display the disclaimer page. * Nethack:: Use `nethack'-like error messages. * Nonblock:: Disable flow-control to a display. * Number:: Change the current window's number. * Silence:: Notify on inactivity. * Time:: Display the time and load average. * Verbose:: Display window creation commands. * Version:: Display the version of `screen'. * Zombie:: Keep dead windows. * Printcmd:: Set command for VT100 printer port emulation. * Sorendition:: Change the text highlighting method. * Attrcolor:: Map attributes to colors. * Setsid:: Change process group management. * Eval:: Parse and execute arguments. * Maxwin:: Set the maximum window number. * Backtick:: Program a command for a backtick string escape. * Screen Saver:: Define a screen safer. * Zmodem:: Define how screen treats zmodem requests. File: screen.info, Node: At, Next: Break, Up: Miscellaneous At == - Command: at [identifier][#|*|%] command [args] (none) Execute a command at other displays or windows as if it had been entered there. `At' changes the context (the `current window' or `current display' setting) of the command. If the first parameter describes a non-unique context, the command will be executed multiple times. If the first parameter is of the form `IDENTIFIER*' then identifier is matched against user names. The command is executed once for each display of the selected user(s). If the first parameter is of the form `IDENTIFIER%' identifier is matched against displays. Displays are named after the ttys they attach. The prefix `/dev/' or `/dev/tty' may be omitted from the identifier. If IDENTIFIER has a `#' or nothing appended it is matched against window numbers and titles. Omitting an identifier in front of the `#', `*' or `%' character selects all users, displays or windows because a prefix-match is performed. Note that on the affected display(s) a short message will describe what happened. Note that the `#' character works as a comment introducer when it is preceded by whitespace. This can be escaped by prefixing `#' with a `\'. Permission is checked for the initiator of the `at' command, not for the owners of the affected display(s). Caveat: When matching against windows, the command is executed at least once per window. Commands that change the internal arrangement of windows (like `other') may be called again. In shared windows the command will be repeated for each attached display. Beware, when issuing toggle commands like `login'! Some commands (e.g. `\*Qprocess') require that a display is associated with the target windows. These commands may not work correctly under `at' looping over windows. File: screen.info, Node: Break, Next: Debug, Prev: At, Up: Miscellaneous Break ===== - Command: break [duration] (none) Send a break signal for DURATION*0.25 seconds to this window. For non-Posix systems the time interval is rounded up to full seconds. Most useful if a character device is attached to the window rather than a shell process (*note Window Types::). The maximum duration of a break signal is limited to 15 seconds. - Command: pow_break (none) Reopen the window's terminal line and send a break condition. - Command: breaktype [tcsendbreak|TIOCSBRK|TCSBRK] (none) 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 setting for the current window. - Command: defbreaktype [tcsendbreak|TIOCSBRK|TCSBRK] (none) Choose one of the available methods of generating a break signal for terminal devices opened afterwards. The preferred methods are `tcsendbreak' and `TIOCSBRK'. The third, `TCSBRK', blocks the complete `screen' session for the duration of the break, but it may be the only way to generate long breaks. `tcsendbreak' and `TIOCSBRK' may or may not produce long breaks with spikes (e.g. 4 per second). This is not only system dependant, this also differs between serial board drivers. Calling `defbreaktype' with no parameter displays the current setting. File: screen.info, Node: Debug, Next: License, Prev: Break, Up: Miscellaneous Debug ===== - Command: debug [on|off] (none) Turns runtime debugging on or off. If `screen' has been compiled with option `-DDEBUG' debugging is 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. File: screen.info, Node: License, Next: Nethack, Prev: Debug, Up: Miscellaneous License ======= - Command: license (none) Display the disclaimer page. This is done whenever `screen' is started without options, which should be often enough. File: screen.info, Node: Nethack, Next: Nonblock, Prev: License, Up: Miscellaneous Nethack ======= - Command: nethack state (none) Changes the kind of error messages used by `screen'. When you are familiar with the game `nethack', you may enjoy the nethack-style messages which will often blur the facts a little, but are much funnier to read. Anyway, standard messages often tend to be unclear as well. This option is only available if `screen' was compiled with the NETHACK flag defined (*note Installation::). The default setting is then determined by the presence of the environment variable `$NETHACKOPTIONS'. File: screen.info, Node: Nonblock, Next: Number, Prev: Nethack, Up: Miscellaneous Nonblock ======== - Command: nonblock [STATE|NUMSECS] Tell screen how to deal with user interfaces (displays) that cease to accept output. This can happen if a user presses ^S or a TCP/modem connection gets cut but no hangup is received. If nonblock is `off' (this is the default) screen waits until the display restarts to accept the output. If nonblock is `on', screen waits until the timeout is reached (`on' is treated as 1s). If the display still doesn't receive characters, screen will consider it "blocked" and stop sending characters to it. If at some time it restarts to accept characters, screen will unblock the display and redisplay the updated window contents. - Command: defnonblock STATE|NUMSECS Same as the `nonblock' command except that the default setting for displays is changed. Initial setting is `off'. File: screen.info, Node: Number, Next: Silence, Prev: Nonblock, Up: Miscellaneous Number ====== - Command: number [N] (`C-a N') Change the current window's number. If the given number N is already used by another window, both windows exchange their numbers. If no argument is specified, the current window number (and title) is shown. File: screen.info, Node: Silence, Next: Time, Prev: Number, Up: Miscellaneous Silence ======= - Command: silence [STATE|SEC] (none) 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. - Command: defsilence state (none) Same as the `silence' command except that the default setting for new windows is changed. Initial setting is `off'. - Command: silencewait SECONDS (none) Define the time that all windows monitored for silence should wait before displaying a message. Default is 30 seconds. File: screen.info, Node: Time, Next: Verbose, Prev: Silence, Up: Miscellaneous Time ==== - Command: time [STRING] (`C-a t', `C-a C-t') 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' (*note Info::). If a STRING is specified, it changes the format of the time report like it is described in the string escapes chapter (*note String Escapes::). Screen uses a default of `%c:%s %M %d %H%? %l%?'. File: screen.info, Node: Verbose, Next: Version, Prev: Time, Up: Miscellaneous Verbose ======= - Command: 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 parameter, the current setting is shown. File: screen.info, Node: Version, Next: Zombie, Prev: Verbose, Up: Miscellaneous Version ======= - Command: version (`C-a v') Display the version and modification date in the message line. File: screen.info, Node: Zombie, Next: Printcmd, Prev: Version, Up: Miscellaneous Zombie ====== - Command: zombie [KEYS] - Command: defzombie [KEYS] (none) Per default 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 the window. Pressing the first key in the dead window has the same effect. Pressing the second key, however, 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 the process terminates. As the zombie setting is affected globally for all windows, this command should only be called `defzombie'. Until we need this as a per window setting, the commands `zombie' and `defzombie' are synonymous. File: screen.info, Node: Printcmd, Next: Sorendition, Prev: Zombie, Up: Miscellaneous Printcmd ======== - Command: printcmd [CMD] (none) If CMD is not an empty string, screen will not use the terminal capabilities `po/pf' for printing if it detects an ansi print sequence `ESC [ 5 i', but pipe the output into CMD. This should normally be a command like `lpr' or `cat > /tmp/scrprint'. `Printcmd' without an argument displays the current setting. The ansi sequence `ESC \' ends printing and closes the pipe. Warning: Be careful with this command! If other user have write access to your terminal, they will be able to fire off print commands. File: screen.info, Node: Sorendition, Next: Attrcolor, Prev: Printcmd, Up: Miscellaneous Sorendition =========== - Command: sorendition [ATTR [COLOR]] (none) Change the way screen does highlighting for text marking and printing messages. See the chapter about string escapes (*note String Escapes::) for the syntax of the modifiers. The default is currently `=s dd' (standout, default colors). File: screen.info, Node: Attrcolor, Next: Setsid, Prev: Sorendition, Up: Miscellaneous Attrcolor ========= - Command: attrcolor ATTRIB [ATTRIBUTE/COLOR-MODIFIER] (none) This command can be used to highlight attributes by changing the color of the text. If the attribute ATTRIB is in use, the specified attribute/color modifier is also applied. If no modifier is given, the current one is deleted. See the chapter about string escapes (*note String Escapes::) for the syntax of the modifier. Screen understands two pseudo-attributes, `i' stands for high-intensity foreground color and `I' for high-intensity background color. Examples: `attrcolor b "R"' Change the color to bright red if bold text is to be printed. `attrcolor u "-u b"' Use blue text instead of underline. `attrcolor b ".I"' Use bright colors for bold text. Most terminal emulators do this already. `attrcolor i "+b"' Make bright colored text also bold. File: screen.info, Node: Setsid, Next: Eval, Prev: Attrcolor, Up: Miscellaneous Setsid ====== - Command: setsid state (none) 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. File: screen.info, Node: Eval, Next: Maxwin, Prev: Setsid, Up: Miscellaneous Eval ==== - Command: eval COMMAND1 [COMMAND2 ...] (none) Parses and executes each argument as separate command. File: screen.info, Node: Maxwin, Next: Backtick, Prev: Eval, Up: Miscellaneous Maxwin ====== - Command: maxwin N (none) Set the maximum window number screen will create. Doesn't affect already existing windows. The number may only be decreased. File: screen.info, Node: Backtick, Next: Screen Saver, Prev: Maxwin, Up: Miscellaneous Backtick ======== - Command: backtick ID LIFESPAN AUTOREFRESH COMMAND [ARGS] - Command: backtick ID (none) Program the backtick command with the numerical id ID. The output of such a command is used for substitution of the `%`' string escape (*note String Escapes::). 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 specified number of seconds. Only the last line of output is used for substitution. If both the LIFESPAN and the AUTOREFRESH parameters are zero, the backtick program is expected to stay in the background and generate output once in a while. In this case, the command is executed right away and screen stores the last line of output. If a new line gets printed screen will automatically refresh the hardstatus or the captions. The second form of the command deletes the backtick command with the numerical id ID. File: screen.info, Node: Screen Saver, Next: Zmodem, Prev: Backtick, Up: Miscellaneous Screen Saver ============ - Command: idle [TIMEOUT [CMD ARGS]] (none) Sets a command that is run after the specified number of seconds inactivity is reached. This command will normally be the `blanker' command to create a screen blanker, but it can be any screen command. If no command is specified, only the timeout is set. A timeout of zero (ot the special timeout `off') disables the timer. If no arguments are given, the current settings are displayed. - Command: blanker (none) 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. - Command: blankerprg [PROGRAM ARGS] Defines a blanker program. Disables the blanker program if no arguments are given. File: screen.info, Node: Zmodem, Prev: Screen Saver, Up: Miscellaneous Zmodem ====== - Command: zmodem [off|auto|catch|pass] - Command: zmodem sendcmd [string] - Command: zmodem recvcmd [string] (none) 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. File: screen.info, Node: String Escapes, Next: Environment, Prev: Miscellaneous, Up: Top String Escapes ************** Screen provides an escape mechanism to insert information like the current time into messages or file names. The escape character is `%' with one exception: inside of a window's hardstatus `^%' (`^E') is used instead. Here is the full list of supported escapes: `%' the escape character itself `a' either `am' or `pm' `A' either `AM' or `PM' `c' current time `HH:MM' in 24h format `C' current time `HH:MM' in 12h format `d' day number `D' weekday name `f' flags of the window `F' sets %? to true if the window has the focus `h' hardstatus of the window `H' hostname of the system `l' current load of the system `m' month number `M' month name `n' window number `s' seconds `t' window title `u' all other users on this window `w' all window numbers and names. With `-' quailifier: up to the current window; with `+' qualifier: starting with the window after the current one. `W' all window numbers and names except the current one `y' last two digits of the year number `Y' full year number `?' the part to the next `%?' is displayed only if a `%' escape inside the part expands to a non-empty string `:' else part of `%?' `=' pad the string to the display's width (like TeX's hfill). If a number is specified, pad to the percentage of the window's width. A `0' qualifier tells screen to treat the number as absolute position. You can specify to pad relative to the last absolute pad position by adding a `+' qualifier or to pad 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. *Note Backtick::. The `c' and `C' escape may be qualified with a `0' to make screen use zero instead of space as fill character. The `n' and `=' escapes understand a length qualifier (e.g. `%3n'), `D' and `M' can be prefixed with `L' to generate long names, `w' and `W' also show the window flags if `L' is given. An attribute/color modifier is is used to change the attributes or the color settings. Its format is `[attribute modifier] [color description]'. The attribute modifier must be prefixed by a change type indicator if it can be confused with a color desciption. The following change types are known: `+' add the specified set to the current attributes `-' remove the set from the current attributes `!' invert the set in the current attributes `=' change the current attributes to the specified set The attribute set can either be specified as a hexadecimal number or a combination of the following letters: `d' dim `u' underline `b' bold `r' reverse `s' standout `B' blinking Colors are coded either as a hexadecimal number or two letters 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 dependant on the current attributes: if reverse mode is set, the background color is changed instead of the foreground color. If you don't like this, prefix the color with a `.'. If you want the same behaviour for two-letter color descriptions, also prefix them with a `.'. As a special case, `%{-}' restores the attributes and colors that were set before the last change was made (i.e. pops one level of the color-change stack). Examples: `G' set color to bright green `+b r' use bold red `= yd' clear all attributes, write in default color on yellow background. `%-Lw%{= BW}%50>%n%f* %t%{-}%+Lw%<' The available windows centered at the current win dow 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'. File: screen.info, Node: Environment, Next: Files, Prev: String Escapes, Up: Top Environment Variables ********************* `COLUMNS' Number of columns on the terminal (overrides termcap entry). `HOME' Directory in which to look for .screenrc. `LINES' Number of lines on the terminal (overrides termcap entry). `LOCKPRG' Screen lock program. `NETHACKOPTIONS' Turns on `nethack' option. `PATH' Used for locating programs to run. `SCREENCAP' For customizing a terminal's `TERMCAP' value. `SCREENDIR' Alternate socket directory. `SCREENRC' Alternate user screenrc file. `SHELL' Default shell program for opening windows (default `/bin/sh'). `STY' Alternate socket name. If `screen' is invoked, and the environment variable `STY' is set, then it creates only a window in the running `screen' session rather than starting a new session. `SYSSCREENRC' Alternate system screenrc file. `TERM' Terminal name. `TERMCAP' Terminal description. `WINDOW' Window number of a window (at creation time).