Advertisement
Guest User

Untitled

a guest
Aug 7th, 2017
1,004
0
Never
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
text 159.56 KB | None | 0 0
  1. SCREEN(1) SCREEN(1)
  2.  
  3.  
  4.  
  5. NAME
  6. screen - screen manager with VT100/ANSI terminal emulation
  7.  
  8.  
  9.  
  10. SYNOPSIS
  11. screen [ -options ] [ cmd [ args ] ]
  12. screen -r [[pid.]tty[.host]]
  13. screen -r sessionowner/[[pid.]tty[.host]]
  14.  
  15.  
  16.  
  17. DESCRIPTION
  18. Screen is a full-screen window manager that multiplexes a physical ter‐
  19. minal between several processes (typically interactive shells). Each
  20. virtual terminal provides the functions of a DEC VT100 terminal and, in
  21. addition, several control functions from the ISO 6429 (ECMA 48, ANSI
  22. X3.64) and ISO 2022 standards (e.g. insert/delete line and support for
  23. multiple character sets). There is a scrollback history buffer for
  24. each virtual terminal and a copy-and-paste mechanism that allows moving
  25. text regions between windows.
  26.  
  27. When screen is called, it creates a single window with a shell in it
  28. (or the specified command) and then gets out of your way so that you
  29. can use the program as you normally would. Then, at any time, you can
  30. create new (full-screen) windows with other programs in them (including
  31. more shells), kill existing windows, view a list of windows, turn out‐
  32. put logging on and off, copy-and-paste text between windows, view the
  33. scrollback history, switch between windows in whatever manner you wish,
  34. etc. All windows run their programs completely independent of each
  35. other. Programs continue to run when their window is currently not vis‐
  36. ible and even when the whole screen session is detached from the user's
  37. terminal. When a program terminates, screen (per default) kills the
  38. window that contained it. If this window was in the foreground, the
  39. display switches to the previous window; if none are left, screen
  40. exits.
  41.  
  42. Everything you type is sent to the program running in the current win‐
  43. dow. The only exception to this is the one keystroke that is used to
  44. initiate a command to the window manager. By default, each command
  45. begins with a control-a (abbreviated C-a from now on), and is followed
  46. by one other keystroke. The command character and all the key bindings
  47. can be fully customized to be anything you like, though they are always
  48. two characters in length.
  49.  
  50. Screen does not understand the prefix "C-" to mean control. Please use
  51. the caret notation ("^A" instead of "C-a") as arguments to e.g. the
  52. escape command or the -e option. Screen will also print out control
  53. characters in caret notation.
  54.  
  55. The standard way to create a new window is to type "C-a c". This cre‐
  56. ates a new window running a shell and switches to that window immedi‐
  57. ately, regardless of the state of the process running in the current
  58. window. Similarly, you can create a new window with a custom command
  59. in it by first binding the command to a keystroke (in your .screenrc
  60. file or at the "C-a :" command line) and then using it just like the
  61. "C-a c" command. In addition, new windows can be created by running a
  62. command like:
  63.  
  64. screen emacs prog.c
  65.  
  66. from a shell prompt within a previously created window. This will not
  67. run another copy of screen, but will instead supply the command name
  68. and its arguments to the window manager (specified in the $STY environ‐
  69. ment variable) who will use it to create the new window. The above
  70. example would start the emacs editor (editing prog.c) and switch to its
  71. window. - Note that you cannot transport environment variables from the
  72. invoking shell to the application (emacs in this case), because it is
  73. forked from the parent screen process, not from the invoking shell.
  74.  
  75. If "/var/run/utmp" is writable by screen, an appropriate record will be
  76. written to this file for each window, and removed when the window is
  77. terminated. This is useful for working with "talk", "script", "shut‐
  78. down", "rsend", "sccs" and other similar programs that use the utmp
  79. file to determine who you are. As long as screen is active on your ter‐
  80. minal, the terminal's own record is removed from the utmp file. See
  81. also "C-a L".
  82.  
  83.  
  84.  
  85. GETTING STARTED
  86. Before you begin to use screen you'll need to make sure you have cor‐
  87. rectly selected your terminal type, just as you would for any other
  88. termcap/terminfo program. (You can do this by using tset for example.)
  89.  
  90. If you're impatient and want to get started without doing a lot more
  91. reading, you should remember this one command: "C-a ?". Typing these
  92. two characters will display a list of the available screen commands and
  93. their bindings. Each keystroke is discussed in the section "DEFAULT KEY
  94. BINDINGS". The manual section "CUSTOMIZATION" deals with the contents
  95. of your .screenrc.
  96.  
  97. If your terminal is a "true" auto-margin terminal (it doesn't allow the
  98. last position on the screen to be updated without scrolling the screen)
  99. consider using a version of your terminal's termcap that has automatic
  100. margins turned off. This will ensure an accurate and optimal update of
  101. the screen in all circumstances. Most terminals nowadays have "magic"
  102. margins (automatic margins plus usable last column). This is the VT100
  103. style type and perfectly suited for screen. If all you've got is a
  104. "true" auto-margin terminal screen will be content to use it, but
  105. updating a character put into the last position on the screen may not
  106. be possible until the screen scrolls or the character is moved into a
  107. safe position in some other way. This delay can be shortened by using a
  108. terminal with insert-character capability.
  109.  
  110.  
  111.  
  112. COMMAND-LINE OPTIONS
  113. Screen has the following command-line options:
  114.  
  115. -a include all capabilities (with some minor exceptions) in each win‐
  116. dow's termcap, even if screen must redraw parts of the display in
  117. order to implement a function.
  118.  
  119. -A Adapt the sizes of all windows to the size of the current termi‐
  120. nal. By default, screen tries to restore its old window sizes
  121. when attaching to resizable terminals (those with "WS" in its
  122. description, e.g. suncmd or some xterm).
  123.  
  124. -c file
  125. override the default configuration file from "$HOME/.screenrc" to
  126. file.
  127.  
  128. -d|-D [pid.tty.host]
  129. does not start screen, but detaches the elsewhere running screen
  130. session. It has the same effect as typing "C-a d" from screen's
  131. controlling terminal. -D is the equivalent to the power detach
  132. key. If no session can be detached, this option is ignored. In
  133. combination with the -r/-R option more powerful effects can be
  134. achieved:
  135.  
  136. -d -r Reattach a session and if necessary detach it first.
  137.  
  138. -d -R Reattach a session and if necessary detach or even create it
  139. first.
  140.  
  141. -d -RR Reattach a session and if necessary detach or create it. Use
  142. the first session if more than one session is available.
  143.  
  144. -D -r Reattach a session. If necessary detach and logout remotely
  145. first.
  146.  
  147. -D -R Attach here and now. In detail this means: If a session is run‐
  148. ning, then reattach. If necessary detach and logout remotely
  149. first. If it was not running create it and notify the user.
  150. This is the author's favorite.
  151.  
  152. -D -RR Attach here and now. Whatever that means, just do it.
  153.  
  154. Note: It is always a good idea to check the status of your ses‐
  155. sions by means of "screen -list".
  156.  
  157. -e xy
  158. specifies the command character to be x and the character generat‐
  159. ing a literal command character to y (when typed after the command
  160. character). The default is "C-a" and `a', which can be specified
  161. as "-e^Aa". When creating a screen session, this option sets the
  162. default command character. In a multiuser session all users added
  163. will start off with this command character. But when attaching to
  164. an already running session, this option changes only the command
  165. character of the attaching user. This option is equivalent to
  166. either the commands "defescape" or "escape" respectively.
  167.  
  168. -f, -fn, and -fa
  169. turns flow-control on, off, or "automatic switching mode". This
  170. can also be defined through the "defflow" .screenrc command.
  171.  
  172. -h num
  173. Specifies the history scrollback buffer to be num lines high.
  174.  
  175. -i will cause the interrupt key (usually C-c) to interrupt the dis‐
  176. play immediately when flow-control is on. See the "defflow"
  177. .screenrc command for details. The use of this option is discour‐
  178. aged.
  179.  
  180. -l and -ln
  181. turns login mode on or off (for /var/run/utmp updating). This can
  182. also be defined through the "deflogin" .screenrc command.
  183.  
  184. -ls and -list
  185. does not start screen, but prints a list of pid.tty.host strings
  186. and creation timestamps identifying your screen sessions. Ses‐
  187. sions marked `detached' can be resumed with "screen -r". Those
  188. marked `attached' are running and have a controlling terminal. If
  189. the session runs in multiuser mode, it is marked `multi'. Sessions
  190. marked as `unreachable' either live on a different host or are
  191. `dead'. An unreachable session is considered dead, when its name
  192. matches either the name of the local host, or the specified param‐
  193. eter, if any. See the -r flag for a description how to construct
  194. matches. Sessions marked as `dead' should be thoroughly checked
  195. and removed. Ask your system administrator if you are not sure.
  196. Remove sessions with the -wipe option.
  197.  
  198. -L tells screen to turn on automatic output logging for the windows.
  199.  
  200. -m causes screen to ignore the $STY environment variable. With
  201. "screen -m" creation of a new session is enforced, regardless
  202. whether screen is called from within another screen session or
  203. not. This flag has a special meaning in connection with the `-d'
  204. option:
  205.  
  206. -d -m Start screen in "detached" mode. This creates a new session but
  207. doesn't attach to it. This is useful for system startup
  208. scripts.
  209.  
  210. -D -m This also starts screen in "detached" mode, but doesn't fork a
  211. new process. The command exits if the session terminates.
  212.  
  213. -O selects a more optimal output mode for your terminal rather than
  214. true VT100 emulation (only affects auto-margin terminals without
  215. `LP'). This can also be set in your .screenrc by specifying `OP'
  216. in a "termcap" command.
  217.  
  218. -p number_or_name
  219. Preselect a window. This is useful when you want to reattach to a
  220. specific window or you want to send a command via the "-X" option
  221. to a specific window. As with screen's select command, "-" selects
  222. the blank window. As a special case for reattach, "=" brings up
  223. the windowlist on the blank window.
  224.  
  225. -q Suppress printing of error messages. In combination with "-ls" the
  226. exit value is as follows: 9 indicates a directory without ses‐
  227. sions. 10 indicates a directory with running but not attachable
  228. sessions. 11 (or more) indicates 1 (or more) usable sessions. In
  229. combination with "-r" the exit value is as follows: 10 indicates
  230. that there is no session to resume. 12 (or more) indicates that
  231. there are 2 (or more) sessions to resume and you should specify
  232. which one to choose. In all other cases "-q" has no effect.
  233.  
  234. -r [pid.tty.host]
  235. -r sessionowner/[pid.tty.host]
  236. resumes a detached screen session. No other options (except com‐
  237. binations with -d/-D) may be specified, though an optional prefix
  238. of [pid.]tty.host may be needed to distinguish between multiple
  239. detached screen sessions. The second form is used to connect to
  240. another user's screen session which runs in multiuser mode. This
  241. indicates that screen should look for sessions in another user's
  242. directory. This requires setuid-root.
  243.  
  244. -R attempts to resume the youngest (in terms of creation time)
  245. detached screen session it finds. If successful, all other com‐
  246. mand-line options are ignored. If no detached session exists,
  247. starts a new session using the specified options, just as if -R
  248. had not been specified. The option is set by default if screen is
  249. run as a login-shell (actually screen uses "-xRR" in that case).
  250. For combinations with the -d/-D option see there. Note: Time-
  251. based session selection is a Debian addition.
  252.  
  253. -s sets the default shell to the program specified, instead of the
  254. value in the environment variable $SHELL (or "/bin/sh" if not
  255. defined). This can also be defined through the "shell" .screenrc
  256. command.
  257.  
  258. -S sessionname
  259. When creating a new session, this option can be used to specify a
  260. meaningful name for the session. This name identifies the session
  261. for "screen -list" and "screen -r" actions. It substitutes the
  262. default [tty.host] suffix.
  263.  
  264. -t name
  265. sets the title (a.k.a.) for the default shell or specified pro‐
  266. gram. See also the "shelltitle" .screenrc command.
  267.  
  268. -U Run screen in UTF-8 mode. This option tells screen that your ter‐
  269. minal sends and understands UTF-8 encoded characters. It also sets
  270. the default encoding for new windows to `utf8'.
  271.  
  272. -v Print version number.
  273.  
  274. -wipe [match]
  275. does the same as "screen -ls", but removes destroyed sessions
  276. instead of marking them as `dead'. An unreachable session is con‐
  277. sidered dead, when its name matches either the name of the local
  278. host, or the explicitly given parameter, if any. See the -r flag
  279. for a description how to construct matches.
  280.  
  281. -x Attach to a not detached screen session. (Multi display mode).
  282. Screen refuses to attach from within itself. But when cascading
  283. multiple screens, loops are not detected; take care.
  284.  
  285. -X Send the specified command to a running screen session. You can
  286. use the -d or -r option to tell screen to look only for attached
  287. or detached screen sessions. Note that this command doesn't work
  288. if the session is password protected.
  289.  
  290.  
  291.  
  292. DEFAULT KEY BINDINGS
  293. As mentioned, each screen command consists of a "C-a" followed by one
  294. other character. For your convenience, all commands that are bound to
  295. lower-case letters are also bound to their control character counter‐
  296. parts (with the exception of "C-a a"; see below), thus, "C-a c" as well
  297. as "C-a C-c" can be used to create a window. See section "CUSTOMIZA‐
  298. TION" for a description of the command.
  299.  
  300. The following table shows the default key bindings:
  301.  
  302. C-a ' (select) Prompt for a window name or number to switch
  303. to.
  304.  
  305. C-a " (windowlist -b)
  306. Present a list of all windows for selection.
  307.  
  308. C-a 0 (select 0)
  309. ... ...
  310. C-a 9 (select 9)
  311. C-a - (select -) Switch to window number 0 - 9, or to the
  312. blank window.
  313.  
  314. C-a tab (focus) Switch the input focus to the next region.
  315. See also split, remove, only.
  316.  
  317. C-a C-a (other) Toggle to the window displayed previously.
  318. Note that this binding defaults to the com‐
  319. mand character typed twice, unless overrid‐
  320. den. For instance, if you use the option
  321. "-e]x", this command becomes "]]".
  322.  
  323. C-a a (meta) Send the command character (C-a) to window.
  324. See escape command.
  325.  
  326. C-a A (title) Allow the user to enter a name for the cur‐
  327. rent window.
  328.  
  329. C-a b
  330. C-a C-b (break) Send a break to window.
  331.  
  332. C-a B (pow_break) Reopen the terminal line and send a break.
  333.  
  334. C-a c
  335. C-a C-c (screen) Create a new window with a shell and switch
  336. to that window.
  337.  
  338. C-a C (clear) Clear the screen.
  339.  
  340. C-a d
  341. C-a C-d (detach) Detach screen from this terminal.
  342.  
  343. C-a D D (pow_detach) Detach and logout.
  344.  
  345. C-a f
  346. C-a C-f (flow) Toggle flow on, off or auto.
  347.  
  348. C-a F (fit) Resize the window to the current region size.
  349.  
  350. C-a C-g (vbell) Toggles screen's visual bell mode.
  351.  
  352. C-a h (hardcopy) Write a hardcopy of the current window to the
  353. file "hardcopy.n".
  354.  
  355. C-a H (log) Begins/ends logging of the current window to
  356. the file "screenlog.n".
  357.  
  358. C-a i
  359. C-a C-i (info) Show info about this window.
  360.  
  361. C-a k
  362. C-a C-k (kill) Destroy current window.
  363.  
  364. C-a l
  365. C-a C-l (redisplay) Fully refresh current window.
  366.  
  367. C-a L (login) Toggle this windows login slot. Available
  368. only if screen is configured to update the
  369. utmp database.
  370.  
  371. C-a m
  372. C-a C-m (lastmsg) Repeat the last message displayed in the mes‐
  373. sage line.
  374.  
  375. C-a M (monitor) Toggles monitoring of the current window.
  376.  
  377. C-a space
  378. C-a n
  379. C-a C-n (next) Switch to the next window.
  380.  
  381. C-a N (number) Show the number (and title) of the current
  382. window.
  383.  
  384. C-a backspace
  385. C-a h
  386. C-a p
  387. C-a C-p (prev) Switch to the previous window (opposite of C-
  388. a n).
  389.  
  390. C-a q
  391. C-a C-q (xon) Send a control-q to the current window.
  392.  
  393. C-a Q (only) Delete all regions but the current one. See
  394. also split, remove, focus.
  395.  
  396. C-a r
  397. C-a C-r (wrap) Toggle the current window's line-wrap setting
  398. (turn the current window's automatic margins
  399. on and off).
  400.  
  401. C-a s
  402. C-a C-s (xoff) Send a control-s to the current window.
  403.  
  404. C-a S (split) Split the current region horizontally into
  405. two new ones. See also only, remove, focus.
  406.  
  407. C-a t
  408. C-a C-t (time) Show system information.
  409.  
  410. C-a v (version) Display the version and compilation date.
  411.  
  412. C-a C-v (digraph) Enter digraph.
  413.  
  414. C-a w
  415. C-a C-w (windows) Show a list of window.
  416.  
  417. C-a W (width) Toggle 80/132 columns.
  418.  
  419. C-a x
  420. C-a C-x (lockscreen) Lock this terminal.
  421.  
  422. C-a X (remove) Kill the current region. See also split,
  423. only, focus.
  424.  
  425. C-a z
  426. C-a C-z (suspend) Suspend screen. Your system must support
  427. BSD-style job-control.
  428.  
  429. C-a Z (reset) Reset the virtual terminal to its "power-on"
  430. values.
  431.  
  432. C-a . (dumptermcap) Write out a ".termcap" file.
  433.  
  434. C-a ? (help) Show key bindings.
  435.  
  436. C-a C-\ (quit) Kill all windows and terminate screen.
  437.  
  438. C-a : (colon) Enter command line mode.
  439.  
  440. C-a [
  441. C-a C-[
  442. C-a esc (copy) Enter copy/scrollback mode.
  443.  
  444. C-a ] (paste .) Write the contents of the paste buffer to the
  445. stdin queue of the current window.
  446.  
  447. C-a {
  448. C-a } (history) Copy and paste a previous (command) line.
  449.  
  450. C-a > (writebuf) Write paste buffer to a file.
  451.  
  452. C-a < (readbuf) Reads the screen-exchange file into the paste
  453. buffer.
  454.  
  455. C-a = (removebuf) Removes the file used by C-a < and C-a >.
  456.  
  457. C-a , (license) Shows where screen comes from, where it went
  458. to and why you can use it.
  459.  
  460. C-a _ (silence) Start/stop monitoring the current window for
  461. inactivity.
  462.  
  463. C-a | (split -v) Split the current region vertically into two
  464. new ones.
  465.  
  466. C-a * (displays) Show a listing of all currently attached dis‐
  467. plays.
  468.  
  469.  
  470.  
  471. CUSTOMIZATION
  472. The "socket directory" defaults either to $HOME/.screen or simply to
  473. /tmp/screens or preferably to /var/run/screen chosen at compile-time.
  474. If screen is installed setuid-root, then the administrator should com‐
  475. pile screen with an adequate (not NFS mounted) socket directory. If
  476. screen is not running setuid-root, the user can specify any mode 700
  477. directory in the environment variable $SCREENDIR.
  478.  
  479. When screen is invoked, it executes initialization commands from the
  480. files "/etc/screenrc" and ".screenrc" in the user's home directory.
  481. These are the "programmer's defaults" that can be overridden in the
  482. following ways: for the global screenrc file screen searches for the
  483. environment variable $SYSSCREENRC (this override feature may be dis‐
  484. abled at compile-time). The user specific screenrc file is searched in
  485. $SCREENRC, then $HOME/.screenrc. The command line option -c takes
  486. precedence over the above user screenrc files.
  487.  
  488. Commands in these files are used to set options, bind functions to
  489. keys, and to automatically establish one or more windows at the begin‐
  490. ning of your screen session. Commands are listed one per line, with
  491. empty lines being ignored. A command's arguments are separated by tabs
  492. or spaces, and may be surrounded by single or double quotes. A `#'
  493. turns the rest of the line into a comment, except in quotes. Unintel‐
  494. ligible lines are warned about and ignored. Commands may contain ref‐
  495. erences to environment variables. The syntax is the shell-like "$VAR "
  496. or "${VAR}". Note that this causes incompatibility with previous screen
  497. versions, as now the '$'-character has to be protected with '\' if no
  498. variable substitution shall be performed. A string in single-quotes is
  499. also protected from variable substitution.
  500.  
  501. Two configuration files are shipped as examples with your screen dis‐
  502. tribution: "etc/screenrc" and "etc/etcscreenrc". They contain a number
  503. of useful examples for various commands.
  504.  
  505. Customization can also be done 'on-line'. To enter the command mode
  506. type `C-a :'. Note that commands starting with "def" change default
  507. values, while others change current settings.
  508.  
  509. The following commands are available:
  510.  
  511. acladd usernames [crypted-pw]
  512. addacl usernames
  513.  
  514. Enable users to fully access this screen session. Usernames can be one
  515. user or a comma separated list of users. This command enables to attach
  516. to the screen session and performs the equivalent of `aclchg usernames
  517. +rwx "#?"'. executed. To add a user with restricted access, use the
  518. `aclchg' command below. If an optional second parameter is supplied,
  519. it should be a crypted password for the named user(s). `Addacl' is a
  520. synonym to `acladd'. Multi user mode only.
  521.  
  522. aclchg usernames permbits list
  523. chacl usernames permbits list
  524.  
  525. Change permissions for a comma separated list of users. Permission bits
  526. are represented as `r', `w' and `x'. Prefixing `+' grants the permis‐
  527. sion, `-' removes it. The third parameter is a comma separated list of
  528. commands and/or windows (specified either by number or title). The spe‐
  529. cial list `#' refers to all windows, `?' to all commands. if usernames
  530. consists of a single `*', all known users are affected. A command can
  531. be executed when the user has the `x' bit for it. The user can type
  532. input to a window when he has its `w' bit set and no other user obtains
  533. a writelock for this window. Other bits are currently ignored. To
  534. withdraw the writelock from another user in window 2: `aclchg username
  535. -w+w 2'. To allow read-only access to the session: `aclchg username -w
  536. "#"'. As soon as a user's name is known to screen he can attach to the
  537. session and (per default) has full permissions for all command and win‐
  538. dows. Execution permission for the acl commands, `at' and others should
  539. also be removed or the user may be able to regain write permission.
  540. Rights of the special username nobody cannot be changed (see the "su"
  541. command). `Chacl' is a synonym to `aclchg'. Multi user mode only.
  542.  
  543. acldel username
  544.  
  545. Remove a user from screen's access control list. If currently attached,
  546. all the user's displays are detached from the session. He cannot attach
  547. again. Multi user mode only.
  548.  
  549. aclgrp username [groupname]
  550.  
  551. Creates groups of users that share common access rights. The name of
  552. the group is the username of the group leader. Each member of the group
  553. inherits the permissions that are granted to the group leader. That
  554. means, if a user fails an access check, another check is made for the
  555. group leader. A user is removed from all groups the special value
  556. "none" is used for groupname. If the second parameter is omitted all
  557. groups the user is in are listed.
  558.  
  559. aclumask [[users]+bits |[users]-bits .... ]
  560. umask [[users]+bits |[users]-bits .... ]
  561.  
  562. This specifies the access other users have to windows that will be cre‐
  563. ated by the caller of the command. Users may be no, one or a comma
  564. separated list of known usernames. If no users are specified, a list of
  565. all currently known users is assumed. Bits is any combination of
  566. access control bits allowed defined with the "aclchg" command. The spe‐
  567. cial username "?" predefines the access that not yet known users will
  568. be granted to any window initially. The special username "??" prede‐
  569. fines the access that not yet known users are granted to any command.
  570. Rights of the special username nobody cannot be changed (see the "su"
  571. command). `Umask' is a synonym to `aclumask'.
  572.  
  573. activity message
  574.  
  575. When any activity occurs in a background window that is being moni‐
  576. tored, screen displays a notification in the message line. The notifi‐
  577. cation message can be re-defined by means of the "activity" command.
  578. Each occurrence of `%' in message is replaced by the number of the win‐
  579. dow in which activity has occurred, and each occurrence of `^G' is
  580. replaced by the definition for bell in your termcap (usually an audible
  581. bell). The default message is
  582.  
  583. 'Activity in window %n'
  584.  
  585. Note that monitoring is off for all windows by default, but can be
  586. altered by use of the "monitor" command (C-a M).
  587.  
  588. allpartial on|off
  589.  
  590. If set to on, only the current cursor line is refreshed on window
  591. change. This affects all windows and is useful for slow terminal
  592. lines. The previous setting of full/partial refresh for each window is
  593. restored with "allpartial off". This is a global flag that immediately
  594. takes effect on all windows overriding the "partial" settings. It does
  595. not change the default redraw behavior of newly created windows.
  596.  
  597. altscreen on|off
  598.  
  599. If set to on, "alternate screen" support is enabled in virtual termi‐
  600. nals, just like in xterm. Initial setting is `off'.
  601.  
  602. at [identifier][#|*|%] command [args ... ]
  603.  
  604. Execute a command at other displays or windows as if it had been
  605. entered there. "At" changes the context (the `current window' or `cur‐
  606. rent display' setting) of the command. If the first parameter describes
  607. a non-unique context, the command will be executed multiple times. If
  608. the first parameter is of the form `identifier*' then identifier is
  609. matched against user names. The command is executed once for each dis‐
  610. play of the selected user(s). If the first parameter is of the form
  611. `identifier%' identifier is matched against displays. Displays are
  612. named after the ttys they attach. The prefix `/dev/' or `/dev/tty' may
  613. be omitted from the identifier. If identifier has a `#' or nothing
  614. appended it is matched against window numbers and titles. Omitting an
  615. identifier in front of the `#', `*' or `%'-character selects all users,
  616. displays or windows because a prefix-match is performed. Note that on
  617. the affected display(s) a short message will describe what happened.
  618. Permission is checked for initiator of the "at" command, not for the
  619. owners of the affected display(s). Note that the '#' character works
  620. as a comment introducer when it is preceded by whitespace. This can be
  621. escaped by prefixing a '\'. Permission is checked for the initiator of
  622. the "at" command, not for the owners of the affected display(s).
  623. Caveat: When matching against windows, the command is executed at least
  624. once per window. Commands that change the internal arrangement of win‐
  625. dows (like "other") may be called again. In shared windows the command
  626. will be repeated for each attached display. Beware, when issuing toggle
  627. commands like "login"! Some commands (e.g. "process") require that a
  628. display is associated with the target windows. These commands may not
  629. work correctly under "at" looping over windows.
  630.  
  631. attrcolor attrib [attribute/color-modifier]
  632.  
  633. This command can be used to highlight attributes by changing the color
  634. of the text. If the attribute attrib is in use, the specified
  635. attribute/color modifier is also applied. If no modifier is given, the
  636. current one is deleted. See the "STRING ESCAPES" chapter for the syntax
  637. of the modifier. Screen understands two pseudo-attributes, "i" stands
  638. for high-intensity foreground color and "I" for high-intensity back‐
  639. ground color.
  640.  
  641. Examples:
  642.  
  643. attrcolor b "R"
  644.  
  645. Change the color to bright red if bold text is to be printed.
  646.  
  647. attrcolor u "-u b"
  648.  
  649. Use blue text instead of underline.
  650.  
  651. attrcolor b ".I"
  652.  
  653. Use bright colors for bold text. Most terminal emulators do this
  654. already.
  655.  
  656. attrcolor i "+b"
  657.  
  658. Make bright colored text also bold.
  659.  
  660. autodetach on|off
  661.  
  662. Sets whether screen will automatically detach upon hangup, which saves
  663. all your running programs until they are resumed with a screen -r com‐
  664. mand. When turned off, a hangup signal will terminate screen and all
  665. the processes it contains. Autodetach is on by default.
  666.  
  667. autonuke on|off
  668.  
  669. Sets whether a clear screen sequence should nuke all the output that
  670. has not been written to the terminal. See also "obuflimit".
  671.  
  672. backtick id lifespan autorefresh cmd args...
  673. backtick id
  674.  
  675. Program the backtick command with the numerical id id. The output of
  676. such a command is used for substitution of the "%`" string escape. The
  677. specified lifespan is the number of seconds the output is considered
  678. valid. After this time, the command is run again if a corresponding
  679. string escape is encountered. The autorefresh parameter triggers an
  680. automatic refresh for caption and hardstatus strings after the speci‐
  681. fied number of seconds. Only the last line of output is used for sub‐
  682. stitution.
  683. If both the lifespan and the autorefresh parameters are zero, the back‐
  684. tick program is expected to stay in the background and generate output
  685. once in a while. In this case, the command is executed right away and
  686. screen stores the last line of output. If a new line gets printed
  687. screen will automatically refresh the hardstatus or the captions.
  688. The second form of the command deletes the backtick command with the
  689. numerical id id.
  690.  
  691. bce [on|off]
  692.  
  693. Change background-color-erase setting. If "bce" is set to on, all char‐
  694. acters cleared by an erase/insert/scroll/clear operation will be dis‐
  695. played in the current background color. Otherwise the default back‐
  696. ground color is used.
  697.  
  698. bell_msg [message]
  699.  
  700. When a bell character is sent to a background window, screen displays a
  701. notification in the message line. The notification message can be re-
  702. defined by this command. Each occurrence of `%' in message is replaced
  703. by the number of the window to which a bell has been sent, and each
  704. occurrence of `^G' is replaced by the definition for bell in your term‐
  705. cap (usually an audible bell). The default message is
  706.  
  707. 'Bell in window %n'
  708.  
  709. An empty message can be supplied to the "bell_msg" command to suppress
  710. output of a message line (bell_msg ""). Without parameter, the current
  711. message is shown.
  712.  
  713. bind [-c class] key [command [args]]
  714.  
  715. Bind a command to a key. By default, most of the commands provided by
  716. screen are bound to one or more keys as indicated in the "DEFAULT KEY
  717. BINDINGS" section, e.g. the command to create a new window is bound to
  718. "C-c" and "c". The "bind" command can be used to redefine the key
  719. bindings and to define new bindings. The key argument is either a sin‐
  720. gle character, a two-character sequence of the form "^x" (meaning "C-
  721. x"), a backslash followed by an octal number (specifying the ASCII code
  722. of the character), or a backslash followed by a second character, such
  723. as "\^" or "\\". The argument can also be quoted, if you like. If no
  724. further argument is given, any previously established binding for this
  725. key is removed. The command argument can be any command listed in this
  726. section.
  727.  
  728. If a command class is specified via the "-c" option, the key is bound
  729. for the specified class. Use the "command" command to activate a class.
  730. Command classes can be used to create multiple command keys or multi-
  731. character bindings.
  732.  
  733. Some examples:
  734.  
  735. bind ' ' windows
  736. bind ^k
  737. bind k
  738. bind K kill
  739. bind ^f screen telnet foobar
  740. bind \033 screen -ln -t root -h 1000 9 su
  741.  
  742. would bind the space key to the command that displays a list of windows
  743. (so that the command usually invoked by "C-a C-w" would also be avail‐
  744. able as "C-a space"). The next three lines remove the default kill
  745. binding from "C-a C-k" and "C-a k". "C-a K" is then bound to the kill
  746. command. Then it binds "C-f" to the command "create a window with a
  747. TELNET connection to foobar", and bind "escape" to the command that
  748. creates an non-login window with a.k.a. "root" in slot #9, with a supe‐
  749. ruser shell and a scrollback buffer of 1000 lines.
  750.  
  751. bind -c demo1 0 select 10
  752. bind -c demo1 1 select 11
  753. bind -c demo1 2 select 12
  754. bindkey "^B" command -c demo1
  755.  
  756. makes "C-b 0" select window 10, "C-b 1" window 11, etc.
  757.  
  758. bind -c demo2 0 select 10
  759. bind -c demo2 1 select 11
  760. bind -c demo2 2 select 12
  761. bind - command -c demo2
  762.  
  763. makes "C-a - 0" select window 10, "C-a - 1" window 11, etc.
  764.  
  765. bindkey [-d] [-m] [-a] [[-k|-t] string [cmd args]]
  766.  
  767. This command manages screen's input translation tables. Every entry in
  768. one of the tables tells screen how to react if a certain sequence of
  769. characters is encountered. There are three tables: one that should con‐
  770. tain actions programmed by the user, one for the default actions used
  771. for terminal emulation and one for screen's copy mode to do cursor
  772. movement. See section "INPUT TRANSLATION" for a list of default key
  773. bindings.
  774. If the -d option is given, bindkey modifies the default table, -m
  775. changes the copy mode table and with neither option the user table is
  776. selected. The argument string is the sequence of characters to which
  777. an action is bound. This can either be a fixed string or a termcap key‐
  778. board capability name (selectable with the -k option).
  779. Some keys on a VT100 terminal can send a different string if applica‐
  780. tion mode is turned on (e.g the cursor keys). Such keys have two
  781. entries in the translation table. You can select the application mode
  782. entry by specifying the -a option.
  783. The -t option tells screen not to do inter-character timing. One cannot
  784. turn off the timing if a termcap capability is used.
  785. Cmd can be any of screen's commands with an arbitrary number of args.
  786. If cmd is omitted the key-binding is removed from the table.
  787. Here are some examples of keyboard bindings:
  788.  
  789. bindkey -d
  790. Show all of the default key bindings. The application mode entries are
  791. marked with [A].
  792.  
  793. bindkey -k k1 select 1
  794. Make the "F1" key switch to window one.
  795.  
  796. bindkey -t foo stuff barfoo
  797. Make "foo" an abbreviation of the word "barfoo". Timeout is disabled so
  798. that users can type slowly.
  799.  
  800. bindkey "\024" mapdefault
  801. This key-binding makes "^T" an escape character for key-bindings. If
  802. you did the above "stuff barfoo" binding, you can enter the word "foo"
  803. by typing "^Tfoo". If you want to insert a "^T" you have to press the
  804. key twice (i.e., escape the escape binding).
  805.  
  806. bindkey -k F1 command
  807. Make the F11 (not F1!) key an alternative screen escape (besides ^A).
  808.  
  809. break [duration]
  810.  
  811. Send a break signal for duration*0.25 seconds to this window. For non-
  812. Posix systems the time interval may be rounded up to full seconds.
  813. Most useful if a character device is attached to the window rather than
  814. a shell process (See also chapter "WINDOW TYPES"). The maximum duration
  815. of a break signal is limited to 15 seconds.
  816.  
  817. blanker
  818.  
  819. Activate the screen blanker. First the screen is cleared. If no blanker
  820. program is defined, the cursor is turned off, otherwise, the program is
  821. started and it's output is written to the screen. The screen blanker
  822. is killed with the first keypress, the read key is discarded.
  823. This command is normally used together with the "idle" command.
  824.  
  825. blankerprg [program args]
  826.  
  827. Defines a blanker program. Disables the blanker program if no arguments
  828. are given.
  829.  
  830. breaktype [tcsendbreak|TIOCSBRK |TCSBRK]
  831.  
  832. Choose one of the available methods of generating a break signal for
  833. terminal devices. This command should affect the current window only.
  834. But it still behaves identical to "defbreaktype". This will be changed
  835. in the future. Calling "breaktype" with no parameter displays the
  836. break method for the current window.
  837.  
  838. bufferfile [exchange-file]
  839.  
  840. Change the filename used for reading and writing with the paste buffer.
  841. If the optional argument to the "bufferfile" command is omitted, the
  842. default setting ("/tmp/screen-exchange") is reactivated. The following
  843. example will paste the system's password file into the screen window
  844. (using the paste buffer, where a copy remains):
  845.  
  846. C-a : bufferfile /etc/passwd
  847. C-a < C-a ]
  848. C-a : bufferfile
  849.  
  850. c1 [on|off]
  851.  
  852. Change c1 code processing. "C1 on" tells screen to treat the input
  853. characters between 128 and 159 as control functions. Such an 8-bit
  854. code is normally the same as ESC followed by the corresponding 7-bit
  855. code. The default setting is to process c1 codes and can be changed
  856. with the "defc1" command. Users with fonts that have usable characters
  857. in the c1 positions may want to turn this off.
  858.  
  859. caption always|splitonly [string]
  860. caption string [string]
  861.  
  862. This command controls the display of the window captions. Normally a
  863. caption is only used if more than one window is shown on the display
  864. (split screen mode). But if the type is set to always screen shows a
  865. caption even if only one window is displayed. The default is splitonly.
  866.  
  867. The second form changes the text used for the caption. You can use all
  868. escapes from the "STRING ESCAPES" chapter. Screen uses a default of
  869. `%3n %t'.
  870.  
  871. You can mix both forms by providing a string as an additional argument.
  872.  
  873. charset set
  874.  
  875. Change the current character set slot designation and charset mapping.
  876. The first four character of set are treated as charset designators
  877. while the fifth and sixth character must be in range '0' to '3' and set
  878. the GL/GR charset mapping. On every position a '.' may be used to indi‐
  879. cate that the corresponding charset/mapping should not be changed (set
  880. is padded to six characters internally by appending '.' chars). New
  881. windows have "BBBB02" as default charset, unless a "encoding" command
  882. is active.
  883. The current setting can be viewed with the "info" command.
  884.  
  885. chdir [directory]
  886.  
  887. Change the current directory of screen to the specified directory or,
  888. if called without an argument, to your home directory (the value of the
  889. environment variable $HOME). All windows that are created by means of
  890. the "screen" command from within ".screenrc" or by means of "C-a :
  891. screen ..." or "C-a c" use this as their default directory. Without a
  892. chdir command, this would be the directory from which screen was
  893. invoked. Hardcopy and log files are always written to the window's
  894. default directory, not the current directory of the process running in
  895. the window. You can use this command multiple times in your .screenrc
  896. to start various windows in different default directories, but the last
  897. chdir value will affect all the windows you create interactively.
  898.  
  899. clear
  900.  
  901. Clears the current window and saves its image to the scrollback buffer.
  902.  
  903. colon [prefix]
  904.  
  905. Allows you to enter ".screenrc" command lines. Useful for on-the-fly
  906. modification of key bindings, specific window creation and changing
  907. settings. Note that the "set" keyword no longer exists! Usually com‐
  908. mands affect the current window rather than default settings for future
  909. windows. Change defaults with commands starting with 'def...'.
  910.  
  911. If you consider this as the `Ex command mode' of screen, you may regard
  912. "C-a esc" (copy mode) as its `Vi command mode'.
  913.  
  914. command [-c class]
  915.  
  916. This command has the same effect as typing the screen escape character
  917. (^A). It is probably only useful for key bindings. If the "-c" option
  918. is given, select the specified command class. See also "bind" and
  919. "bindkey".
  920.  
  921. compacthist [on|off]
  922.  
  923. This tells screen whether to suppress trailing blank lines when
  924. scrolling up text into the history buffer.
  925.  
  926. console [on|off]
  927.  
  928. Grabs or un-grabs the machines console output to a window. Note: Only
  929. the owner of /dev/console can grab the console output. This command is
  930. only available if the machine supports the ioctl TIOCCONS.
  931.  
  932. copy
  933.  
  934. Enter copy/scrollback mode. This allows you to copy text from the cur‐
  935. rent window and its history into the paste buffer. In this mode a vi-
  936. like `full screen editor' is active:
  937. Movement keys:
  938. h, j, k, l move the cursor line by line or column by column.
  939. 0, ^ and $ move to the leftmost column, to the first or last non-
  940. whitespace character on the line.
  941. H, M and L move the cursor to the leftmost column of the top, center
  942. or bottom line of the window.
  943. + and - positions one line up and down.
  944. G moves to the specified absolute line (default: end of buffer).
  945. | moves to the specified absolute column.
  946. w, b, e move the cursor word by word.
  947. B, E move the cursor WORD by WORD (as in vi).
  948. C-u and C-d scroll the display up/down by the specified amount of
  949. lines while preserving the cursor position. (Default: half screen-
  950. full).
  951. C-b and C-f scroll the display up/down a full screen.
  952. g moves to the beginning of the buffer.
  953. % jumps to the specified percentage of the buffer.
  954.  
  955. Note:
  956. Emacs style movement keys can be customized by a .screenrc command.
  957. (E.g. markkeys "h=^B:l=^F:$=^E") There is no simple method for a
  958. full emacs-style keymap, as this involves multi-character codes.
  959.  
  960. Marking:
  961. The copy range is specified by setting two marks. The text between
  962. these marks will be highlighted. Press
  963. space to set the first or second mark respectively.
  964. Y and y used to mark one whole line or to mark from start of line.
  965. W marks exactly one word.
  966. Repeat count:
  967. Any of these commands can be prefixed with a repeat count number by
  968. pressing digits
  969. 0..9 which is taken as a repeat count.
  970. Example: "C-a C-[ H 10 j 5 Y" will copy lines 11 to 15 into the
  971. paste buffer.
  972. Searching:
  973. / Vi-like search forward.
  974. ? Vi-like search backward.
  975. C-a s Emacs style incremental search forward.
  976. C-r Emacs style reverse i-search.
  977. Specials:
  978. There are however some keys that act differently than in vi. Vi
  979. does not allow one to yank rectangular blocks of text, but screen
  980. does. Press
  981. c or C to set the left or right margin respectively. If no repeat
  982. count is given, both default to the current cursor position.
  983. Example: Try this on a rather full text screen: "C-a [ M 20 l SPACE
  984. c 10 l 5 j C SPACE".
  985.  
  986. This moves one to the middle line of the screen, moves in 20 col‐
  987. umns left, marks the beginning of the paste buffer, sets the left
  988. column, moves 5 columns down, sets the right column, and then marks
  989. the end of the paste buffer. Now try:
  990. "C-a [ M 20 l SPACE 10 l 5 j SPACE"
  991.  
  992. and notice the difference in the amount of text copied.
  993. J joins lines. It toggles between 4 modes: lines separated by a new‐
  994. line character (012), lines glued seamless, lines separated by a
  995. single whitespace and comma separated lines. Note that you can
  996. prepend the newline character with a carriage return character, by
  997. issuing a "crlf on".
  998. v is for all the vi users with ":set numbers" - it toggles the left
  999. margin between column 9 and 1. Press
  1000. a before the final space key to toggle in append mode. Thus the con‐
  1001. tents of the paste buffer will not be overwritten, but is appended
  1002. to.
  1003. A toggles in append mode and sets a (second) mark.
  1004. > sets the (second) mark and writes the contents of the paste buffer
  1005. to the screen-exchange file (/tmp/screen-exchange per default) once
  1006. copy-mode is finished.
  1007. This example demonstrates how to dump the whole scrollback buffer
  1008. to that file: "C-A [ g SPACE G $ >".
  1009. C-g gives information about the current line and column.
  1010. x exchanges the first mark and the current cursor position. You can
  1011. use this to adjust an already placed mark.
  1012. @ does nothing. Does not even exit copy mode.
  1013. All keys not described here exit copy mode.
  1014.  
  1015. copy_reg [key]
  1016.  
  1017. No longer exists, use "readreg" instead.
  1018.  
  1019. crlf [on|off]
  1020.  
  1021. This affects the copying of text regions with the `C-a [' command. If
  1022. it is set to `on', lines will be separated by the two character
  1023. sequence `CR' - `LF'. Otherwise (default) only `LF' is used. When no
  1024. parameter is given, the state is toggled.
  1025.  
  1026. debug on|off
  1027.  
  1028. Turns runtime debugging on or off. If screen has been compiled with
  1029. option -DDEBUG debugging available and is turned on per default. Note
  1030. that this command only affects debugging output from the main "SCREEN"
  1031. process correctly. Debug output from attacher processes can only be
  1032. turned off once and forever.
  1033.  
  1034. defc1 on|off
  1035.  
  1036. Same as the c1 command except that the default setting for new windows
  1037. is changed. Initial setting is `on'.
  1038.  
  1039. defautonuke on|off
  1040.  
  1041. Same as the autonuke command except that the default setting for new
  1042. displays is changed. Initial setting is `off'. Note that you can use
  1043. the special `AN' terminal capability if you want to have a dependency
  1044. on the terminal type.
  1045.  
  1046. defbce on|off
  1047.  
  1048. Same as the bce command except that the default setting for new windows
  1049. is changed. Initial setting is `off'.
  1050.  
  1051. defbreaktype [tcsendbreak|TIOCSBRK |TCSBRK]
  1052.  
  1053. Choose one of the available methods of generating a break signal for
  1054. terminal devices. The preferred methods are tcsendbreak and TIOCSBRK.
  1055. The third, TCSBRK, blocks the complete screen session for the duration
  1056. of the break, but it may be the only way to generate long breaks.
  1057. Tcsendbreak and TIOCSBRK may or may not produce long breaks with spikes
  1058. (e.g. 4 per second). This is not only system-dependent, this also dif‐
  1059. fers between serial board drivers. Calling "defbreaktype" with no
  1060. parameter displays the current setting.
  1061.  
  1062. defcharset [set]
  1063.  
  1064. Like the charset command except that the default setting for new win‐
  1065. dows is changed. Shows current default if called without argument.
  1066.  
  1067. defescape xy
  1068.  
  1069. Set the default command characters. This is equivalent to the "escape"
  1070. except that it is useful multiuser sessions only. In a multiuser ses‐
  1071. sion "escape" changes the command character of the calling user, where
  1072. "defescape" changes the default command characters for users that will
  1073. be added later.
  1074.  
  1075. defflow on|off|auto [interrupt]
  1076.  
  1077. Same as the flow command except that the default setting for new win‐
  1078. dows is changed. Initial setting is `auto'. Specifying "defflow auto
  1079. interrupt" is the same as the command-line options -fa and -i.
  1080.  
  1081. defgr on|off
  1082.  
  1083. Same as the gr command except that the default setting for new windows
  1084. is changed. Initial setting is `off'.
  1085.  
  1086. defhstatus [status]
  1087.  
  1088. The hardstatus line that all new windows will get is set to status.
  1089. This command is useful to make the hardstatus of every window display
  1090. the window number or title or the like. Status may contain the same
  1091. directives as in the window messages, but the directive escape charac‐
  1092. ter is '^E' (octal 005) instead of '%'. This was done to make a misin‐
  1093. terpretation of program generated hardstatus lines impossible. If the
  1094. parameter status is omitted, the current default string is displayed.
  1095. Per default the hardstatus line of new windows is empty.
  1096.  
  1097. defencoding enc
  1098.  
  1099. Same as the encoding command except that the default setting for new
  1100. windows is changed. Initial setting is the encoding taken from the ter‐
  1101. minal.
  1102.  
  1103. deflog on|off
  1104.  
  1105. Same as the log command except that the default setting for new windows
  1106. is changed. Initial setting is `off'.
  1107.  
  1108. deflogin on|off
  1109.  
  1110. Same as the login command except that the default setting for new win‐
  1111. dows is changed. This is initialized with `on' as distributed (see con‐
  1112. fig.h.in).
  1113.  
  1114. defmode mode
  1115.  
  1116. The mode of each newly allocated pseudo-tty is set to mode. Mode is an
  1117. octal number. When no "defmode" command is given, mode 0622 is used.
  1118.  
  1119. defmonitor on|off
  1120.  
  1121. Same as the monitor command except that the default setting for new
  1122. windows is changed. Initial setting is `off'.
  1123.  
  1124. defnonblock on|off|numsecs
  1125.  
  1126. Same as the nonblock command except that the default setting for dis‐
  1127. plays is changed. Initial setting is `off'.
  1128.  
  1129. defobuflimit limit
  1130.  
  1131. Same as the obuflimit command except that the default setting for new
  1132. displays is changed. Initial setting is 256 bytes. Note that you can
  1133. use the special 'OL' terminal capability if you want to have a depen‐
  1134. dency on the terminal type.
  1135.  
  1136. defscrollback num
  1137.  
  1138. Same as the scrollback command except that the default setting for new
  1139. windows is changed. Initial setting is 100.
  1140.  
  1141. defshell command
  1142.  
  1143. Synonym to the shell command. See there.
  1144.  
  1145. defsilence on|off
  1146.  
  1147. Same as the silence command except that the default setting for new
  1148. windows is changed. Initial setting is `off'.
  1149.  
  1150. defslowpaste msec"
  1151.  
  1152. Same as the slowpaste command except that the default setting for new
  1153. windows is changed. Initial setting is 0 milliseconds, meaning `off'.
  1154.  
  1155. defutf8 on|off
  1156.  
  1157. Same as the utf8 command except that the default setting for new win‐
  1158. dows is changed. Initial setting is `on' if screen was started with
  1159. "-U", otherwise `off'.
  1160.  
  1161. defwrap on|off
  1162.  
  1163. Same as the wrap command except that the default setting for new win‐
  1164. dows is changed. Initially line-wrap is on and can be toggled with the
  1165. "wrap" command ("C-a r") or by means of "C-a : wrap on|off".
  1166.  
  1167. defwritelock on|off|auto
  1168.  
  1169. Same as the writelock command except that the default setting for new
  1170. windows is changed. Initially writelocks will off.
  1171.  
  1172. defzombie [keys]
  1173.  
  1174. Synonym to the zombie command. Both currently change the default. See
  1175. there.
  1176.  
  1177. detach [-h]
  1178.  
  1179. Detach the screen session (disconnect it from the terminal and put it
  1180. into the background). This returns you to the shell where you invoked
  1181. screen. A detached screen can be resumed by invoking screen with the
  1182. -r option (see also section "COMMAND-LINE OPTIONS"). The -h option
  1183. tells screen to immediately close the connection to the terminal
  1184. ("hangup").
  1185.  
  1186. dinfo
  1187.  
  1188. Show what screen thinks about your terminal. Useful if you want to know
  1189. why features like color or the alternate charset don't work.
  1190.  
  1191. displays
  1192.  
  1193. Shows a tabular listing of all currently connected user front-ends
  1194. (displays). This is most useful for multiuser sessions.
  1195.  
  1196. digraph [preset]
  1197.  
  1198. This command prompts the user for a digraph sequence. The next two
  1199. characters typed are looked up in a builtin table and the resulting
  1200. character is inserted in the input stream. For example, if the user
  1201. enters 'a"', an a-umlaut will be inserted. If the first character
  1202. entered is a 0 (zero), screen will treat the following characters (up
  1203. to three) as an octal number instead. The optional argument preset is
  1204. treated as user input, thus one can create an "umlaut" key. For exam‐
  1205. ple the command "bindkey ^K digraph '"'" enables the user to generate
  1206. an a-umlaut by typing CTRL-K a.
  1207.  
  1208. dumptermcap
  1209.  
  1210. Write the termcap entry for the virtual terminal optimized for the cur‐
  1211. rently active window to the file ".termcap" in the user's
  1212. "$HOME/.screen" directory (or wherever screen stores its sockets. See
  1213. the "FILES" section below). This termcap entry is identical to the
  1214. value of the environment variable $TERMCAP that is set up by screen for
  1215. each window. For terminfo based systems you will need to run a con‐
  1216. verter like captoinfo and then compile the entry with tic.
  1217.  
  1218. echo [-n] message
  1219.  
  1220. The echo command may be used to annoy screen users with a 'message of
  1221. the day'. Typically installed in a global /etc/screenrc. The option
  1222. "-n" may be used to suppress the line feed. See also "sleep". Echo is
  1223. also useful for online checking of environment variables.
  1224.  
  1225. encoding enc [enc]
  1226.  
  1227. Tell screen how to interpret the input/output. The first argument sets
  1228. the encoding of the current window. Each window can emulate a different
  1229. encoding. The optional second parameter overwrites the encoding of the
  1230. connected terminal. It should never be needed as screen uses the locale
  1231. setting to detect the encoding. There is also a way to select a termi‐
  1232. nal encoding depending on the terminal type by using the "KJ" termcap
  1233. entry.
  1234.  
  1235. Supported encodings are eucJP, SJIS, eucKR, eucCN, Big5, GBK, KOI8-R,
  1236. CP1251, UTF-8, ISO8859-2, ISO8859-3, ISO8859-4, ISO8859-5, ISO8859-6,
  1237. ISO8859-7, ISO8859-8, ISO8859-9, ISO8859-10, ISO8859-15, jis.
  1238.  
  1239. See also "defencoding", which changes the default setting of a new win‐
  1240. dow.
  1241.  
  1242. escape xy
  1243.  
  1244. Set the command character to x and the character generating a literal
  1245. command character (by triggering the "meta" command) to y (similar to
  1246. the -e option). Each argument is either a single character, a two-
  1247. character sequence of the form "^x" (meaning "C-x"), a backslash fol‐
  1248. lowed by an octal number (specifying the ASCII code of the character),
  1249. or a backslash followed by a second character, such as "\^" or "\\".
  1250. The default is "^Aa".
  1251.  
  1252. eval command1 [command2 ...]
  1253.  
  1254. Parses and executes each argument as separate command.
  1255.  
  1256. exec [[fdpat] newcommand [args ...]]
  1257.  
  1258. Run a unix subprocess (specified by an executable path newcommand and
  1259. its optional arguments) in the current window. The flow of data between
  1260. newcommands stdin/stdout/stderr, the process originally started in the
  1261. window (let us call it "application-process") and screen itself (win‐
  1262. dow) is controlled by the file descriptor pattern fdpat. This pattern
  1263. is basically a three character sequence representing stdin, stdout and
  1264. stderr of newcommand. A dot (.) connects the file descriptor to screen.
  1265. An exclamation mark (!) causes the file descriptor to be connected to
  1266. the application-process. A colon (:) combines both. User input will go
  1267. to newcommand unless newcommand receives the application-process' out‐
  1268. put (fdpats first character is `!' or `:') or a pipe symbol (|) is
  1269. added (as a fourth character) to the end of fdpat.
  1270. Invoking `exec' without arguments shows name and arguments of the cur‐
  1271. rently running subprocess in this window. Only one subprocess a time
  1272. can be running in each window.
  1273. When a subprocess is running the `kill' command will affect it instead
  1274. of the windows process.
  1275. Refer to the postscript file `doc/fdpat.ps' for a confusing illustra‐
  1276. tion of all 21 possible combinations. Each drawing shows the digits
  1277. 2,1,0 representing the three file descriptors of newcommand. The box
  1278. marked `W' is the usual pty that has the application-process on its
  1279. slave side. The box marked `P' is the secondary pty that now has
  1280. screen at its master side.
  1281.  
  1282. Abbreviations:
  1283. Whitespace between the word `exec' and fdpat and the command can be
  1284. omitted. Trailing dots and a fdpat consisting only of dots can be omit‐
  1285. ted. A simple `|' is synonymous for the pattern `!..|'; the word exec
  1286. can be omitted here and can always be replaced by `!'.
  1287.  
  1288. Examples:
  1289.  
  1290. exec ... /bin/sh
  1291. exec /bin/sh
  1292. !/bin/sh
  1293.  
  1294. Creates another shell in the same window, while the original shell is
  1295. still running. Output of both shells is displayed and user input is
  1296. sent to the new /bin/sh.
  1297.  
  1298. exec !.. stty 19200
  1299. exec ! stty 19200
  1300. !!stty 19200
  1301.  
  1302. Set the speed of the window's tty. If your stty command operates on
  1303. stdout, then add another `!'.
  1304.  
  1305. exec !..| less
  1306. |less
  1307.  
  1308. This adds a pager to the window output. The special character `|' is
  1309. needed to give the user control over the pager although it gets its
  1310. input from the window's process. This works, because less listens on
  1311. stderr (a behavior that screen would not expect without the `|') when
  1312. its stdin is not a tty. Less versions newer than 177 fail miserably
  1313. here; good old pg still works.
  1314.  
  1315. !:sed -n s/.*Error.*/\007/p
  1316.  
  1317. Sends window output to both, the user and the sed command. The sed
  1318. inserts an additional bell character (oct. 007) to the window output
  1319. seen by screen. This will cause "Bell in window x" messages, whenever
  1320. the string "Error" appears in the window.
  1321.  
  1322. fit
  1323.  
  1324. Change the window size to the size of the current region. This command
  1325. is needed because screen doesn't adapt the window size automatically if
  1326. the window is displayed more than once.
  1327.  
  1328. flow [on|off|auto]
  1329.  
  1330. Sets the flow-control mode for this window. Without parameters it
  1331. cycles the current window's flow-control setting from "automatic" to
  1332. "on" to "off". See the discussion on "FLOW-CONTROL" later on in this
  1333. document for full details and note, that this is subject to change in
  1334. future releases. Default is set by `defflow'.
  1335.  
  1336. focus [up|down|top|bottom]
  1337.  
  1338. Move the input focus to the next region. This is done in a cyclic way
  1339. so that the top region is selected after the bottom one. If no subcom‐
  1340. mand is given it defaults to `down'. `up' cycles in the opposite order,
  1341. `top' and `bottom' go to the top and bottom region respectively. Useful
  1342. bindings are (j and k as in vi)
  1343. bind j focus down
  1344. bind k focus up
  1345. bind t focus top
  1346. bind b focus bottom
  1347. Note that k is traditionally bound to the kill command.
  1348.  
  1349. gr [on|off]
  1350.  
  1351. Turn GR charset switching on/off. Whenever screen sees an input charac‐
  1352. ter with the 8th bit set, it will use the charset stored in the GR slot
  1353. and print the character with the 8th bit stripped. The default (see
  1354. also "defgr") is not to process GR switching because otherwise the
  1355. ISO88591 charset would not work.
  1356.  
  1357. hardcopy [-h] [file]
  1358.  
  1359. Writes out the currently displayed image to the file file, or, if no
  1360. filename is specified, to hardcopy.n in the default directory, where n
  1361. is the number of the current window. This either appends or overwrites
  1362. the file if it exists. See below. If the option -h is specified, dump
  1363. also the contents of the scrollback buffer.
  1364.  
  1365. hardcopy_append on|off
  1366.  
  1367. If set to "on", screen will append to the "hardcopy.n" files created by
  1368. the command "C-a h", otherwise these files are overwritten each time.
  1369. Default is `off'.
  1370.  
  1371. hardcopydir directory
  1372.  
  1373. Defines a directory where hardcopy files will be placed. If unset,
  1374. hardcopys are dumped in screen's current working directory.
  1375.  
  1376. hardstatus [on|off]
  1377. hardstatus [always]lastline|message|ignore [string]
  1378. hardstatus string [string]
  1379.  
  1380. This command configures the use and emulation of the terminal's hard‐
  1381. status line. The first form toggles whether screen will use the hard‐
  1382. ware status line to display messages. If the flag is set to `off',
  1383. these messages are overlaid in reverse video mode at the display line.
  1384. The default setting is `on'.
  1385.  
  1386. The second form tells screen what to do if the terminal doesn't have a
  1387. hardstatus line (i.e. the termcap/terminfo capabilities "hs", "ts",
  1388. "fs" and "ds" are not set). If the type "lastline" is used, screen will
  1389. reserve the last line of the display for the hardstatus. "message" uses
  1390. screen's message mechanism and "ignore" tells screen never to display
  1391. the hardstatus. If you prepend the word "always" to the type (e.g.,
  1392. "alwayslastline"), screen will use the type even if the terminal sup‐
  1393. ports a hardstatus.
  1394.  
  1395. The third form specifies the contents of the hardstatus line. '%h' is
  1396. used as default string, i.e., the stored hardstatus of the current win‐
  1397. dow (settable via "ESC]0;<string>^G" or "ESC_<string>ESC\") is dis‐
  1398. played. You can customize this to any string you like including the
  1399. escapes from the "STRING ESCAPES" chapter. If you leave out the argu‐
  1400. ment string, the current string is displayed.
  1401.  
  1402. You can mix the second and third form by providing the string as addi‐
  1403. tional argument.
  1404.  
  1405. height [-w|-d] [lines [cols]]
  1406.  
  1407. Set the display height to a specified number of lines. When no argument
  1408. is given it toggles between 24 and 42 lines display. You can also spec‐
  1409. ify a width if you want to change both values. The -w option tells
  1410. screen to leave the display size unchanged and just set the window
  1411. size, -d vice versa.
  1412.  
  1413. help [-c class]
  1414.  
  1415. Not really a online help, but displays a help screen showing you all
  1416. the key bindings. The first pages list all the internal commands fol‐
  1417. lowed by their current bindings. Subsequent pages will display the
  1418. custom commands, one command per key. Press space when you're done
  1419. reading each page, or return to exit early. All other characters are
  1420. ignored. If the "-c" option is given, display all bound commands for
  1421. the specified command class. See also "DEFAULT KEY BINDINGS" section.
  1422.  
  1423. history
  1424.  
  1425. Usually users work with a shell that allows easy access to previous
  1426. commands. For example csh has the command "!!" to repeat the last com‐
  1427. mand executed. Screen allows you to have a primitive way of re-calling
  1428. "the command that started ...": You just type the first letter of that
  1429. command, then hit `C-a {' and screen tries to find a previous line that
  1430. matches with the `prompt character' to the left of the cursor. This
  1431. line is pasted into this window's input queue. Thus you have a crude
  1432. command history (made up by the visible window and its scrollback buf‐
  1433. fer).
  1434.  
  1435. hstatus status
  1436.  
  1437. Change the window's hardstatus line to the string status.
  1438.  
  1439. idle [timeout [cmd args]]
  1440.  
  1441. Sets a command that is run after the specified number of seconds inac‐
  1442. tivity is reached. This command will normally be the "blanker" command
  1443. to create a screen blanker, but it can be any screen command. If no
  1444. command is specified, only the timeout is set. A timeout of zero (ot
  1445. the special timeout off) disables the timer. If no arguments are
  1446. given, the current settings are displayed.
  1447.  
  1448. ignorecase [on|off]
  1449.  
  1450. Tell screen to ignore the case of characters in searches. Default is
  1451. `off'.
  1452.  
  1453. info
  1454.  
  1455. Uses the message line to display some information about the current
  1456. window: the cursor position in the form "(column,row)" starting with
  1457. "(1,1)", the terminal width and height plus the size of the scrollback
  1458. buffer in lines, like in "(80,24)+50", the current state of window
  1459. XON/XOFF flow control is shown like this (See also section FLOW CON‐
  1460. TROL):
  1461.  
  1462. +flow automatic flow control, currently on.
  1463. -flow automatic flow control, currently off.
  1464. +(+)flow flow control enabled. Agrees with automatic control.
  1465. -(+)flow flow control disabled. Disagrees with automatic control.
  1466. +(-)flow flow control enabled. Disagrees with automatic control.
  1467. -(-)flow flow control disabled. Agrees with automatic control.
  1468.  
  1469. The current line wrap setting (`+wrap' indicates enabled, `-wrap' not)
  1470. is also shown. The flags `ins', `org', `app', `log', `mon' or `nored'
  1471. are displayed when the window is in insert mode, origin mode, applica‐
  1472. tion-keypad mode, has output logging, activity monitoring or partial
  1473. redraw enabled.
  1474.  
  1475. The currently active character set (G0, G1, G2, or G3) and in square
  1476. brackets the terminal character sets that are currently designated as
  1477. G0 through G3 is shown. If the window is in UTF-8 mode, the string
  1478. "UTF-8" is shown instead.
  1479.  
  1480. Additional modes depending on the type of the window are displayed at
  1481. the end of the status line (See also chapter "WINDOW TYPES").
  1482. If the state machine of the terminal emulator is in a non-default
  1483. state, the info line is started with a string identifying the current
  1484. state.
  1485. For system information use the "time" command.
  1486.  
  1487. ins_reg [key]
  1488.  
  1489. No longer exists, use "paste" instead.
  1490.  
  1491. kill
  1492.  
  1493. Kill current window.
  1494. If there is an `exec' command running then it is killed. Otherwise the
  1495. process (shell) running in the window receives a HANGUP condition, the
  1496. window structure is removed and screen (your display) switches to
  1497. another window. When the last window is destroyed, screen exits.
  1498. After a kill screen switches to the previously displayed window.
  1499. Note: Emacs users should keep this command in mind, when killing a
  1500. line. It is recommended not to use "C-a" as the screen escape key or
  1501. to rebind kill to "C-a K".
  1502.  
  1503. lastmsg
  1504.  
  1505. Redisplay the last contents of the message/status line. Useful if
  1506. you're typing when a message appears, because the message goes away
  1507. when you press a key (unless your terminal has a hardware status line).
  1508. Refer to the commands "msgwait" and "msgminwait" for fine tuning.
  1509.  
  1510. license
  1511.  
  1512. Display the disclaimer page. This is done whenever screen is started
  1513. without options, which should be often enough. See also the
  1514. "startup_message" command.
  1515.  
  1516. lockscreen
  1517.  
  1518. Lock this display. Call a screenlock program (/local/bin/lck or
  1519. /usr/bin/lock or a builtin if no other is available). Screen does not
  1520. accept any command keys until this program terminates. Meanwhile pro‐
  1521. cesses in the windows may continue, as the windows are in the
  1522. `detached' state. The screenlock program may be changed through the
  1523. environment variable $LOCKPRG (which must be set in the shell from
  1524. which screen is started) and is executed with the user's uid and gid.
  1525. Warning: When you leave other shells unlocked and you have no password
  1526. set on screen, the lock is void: One could easily re-attach from an
  1527. unlocked shell. This feature should rather be called `lockterminal'.
  1528.  
  1529. log [on|off]
  1530.  
  1531. Start/stop writing output of the current window to a file "screenlog.n"
  1532. in the window's default directory, where n is the number of the current
  1533. window. This filename can be changed with the `logfile' command. If no
  1534. parameter is given, the state of logging is toggled. The session log is
  1535. appended to the previous contents of the file if it already exists. The
  1536. current contents and the contents of the scrollback history are not
  1537. included in the session log. Default is `off'.
  1538.  
  1539. logfile filename
  1540. logfile flush secs
  1541.  
  1542. Defines the name the log files will get. The default is "screenlog.%n".
  1543. The second form changes the number of seconds screen will wait before
  1544. flushing the logfile buffer to the file-system. The default value is 10
  1545. seconds.
  1546.  
  1547. login [on|off]
  1548.  
  1549. Adds or removes the entry in the utmp database file for the current
  1550. window. This controls if the window is `logged in'. When no parameter
  1551. is given, the login state of the window is toggled. Additionally to
  1552. that toggle, it is convenient having a `log in' and a `log out' key.
  1553. E.g. `bind I login on' and `bind O login off' will map these keys to be
  1554. C-a I and C-a O. The default setting (in config.h.in) should be "on"
  1555. for a screen that runs under suid-root. Use the "deflogin" command to
  1556. change the default login state for new windows. Both commands are only
  1557. present when screen has been compiled with utmp support.
  1558.  
  1559. logtstamp [on|off]
  1560. logtstamp after [secs]
  1561. logtstamp string [string]
  1562.  
  1563. This command controls logfile time-stamp mechanism of screen. If time-
  1564. stamps are turned "on", screen adds a string containing the current
  1565. time to the logfile after two minutes of inactivity. When output con‐
  1566. tinues and more than another two minutes have passed, a second time-
  1567. stamp is added to document the restart of the output. You can change
  1568. this timeout with the second form of the command. The third form is
  1569. used for customizing the time-stamp string (`-- %n:%t -- time-stamp --
  1570. %M/%d/%y %c:%s --\n' by default).
  1571.  
  1572. mapdefault
  1573.  
  1574. Tell screen that the next input character should only be looked up in
  1575. the default bindkey table. See also "bindkey".
  1576.  
  1577. mapnotnext
  1578.  
  1579. Like mapdefault, but don't even look in the default bindkey table.
  1580.  
  1581. maptimeout [timo]
  1582.  
  1583. Set the inter-character timer for input sequence detection to a timeout
  1584. of timo ms. The default timeout is 300ms. Maptimeout with no arguments
  1585. shows the current setting. See also "bindkey".
  1586.  
  1587. markkeys string
  1588.  
  1589. This is a method of changing the keymap used for copy/history mode.
  1590. The string is made up of oldchar=newchar pairs which are separated by
  1591. `:'. Example: The string "B=^B:F=^F" will change the keys `C-b' and `C-
  1592. f' to the vi style binding (scroll up/down fill page). This happens to
  1593. be the default binding for `B' and `F'. The command "markkeys
  1594. h=^B:l=^F:$=^E" would set the mode for an emacs-style binding. If your
  1595. terminal sends characters, that cause you to abort copy mode, then this
  1596. command may help by binding these characters to do nothing. The no-op
  1597. character is `@' and is used like this: "markkeys @=L=H" if you do not
  1598. want to use the `H' or `L' commands any longer. As shown in this exam‐
  1599. ple, multiple keys can be assigned to one function in a single state‐
  1600. ment.
  1601.  
  1602. maxwin num
  1603.  
  1604. Set the maximum window number screen will create. Doesn't affect
  1605. already existing windows. The number may only be decreased.
  1606.  
  1607. meta
  1608.  
  1609. Insert the command character (C-a) in the current window's input
  1610. stream.
  1611.  
  1612. monitor [on|off]
  1613.  
  1614. Toggles activity monitoring of windows. When monitoring is turned on
  1615. and an affected window is switched into the background, you will
  1616. receive the activity notification message in the status line at the
  1617. first sign of output and the window will also be marked with an `@' in
  1618. the window-status display. Monitoring is initially off for all win‐
  1619. dows.
  1620.  
  1621. msgminwait sec
  1622.  
  1623. Defines the time screen delays a new message when one message is cur‐
  1624. rently displayed. The default is 1 second.
  1625.  
  1626. msgwait sec
  1627.  
  1628. Defines the time a message is displayed if screen is not disturbed by
  1629. other activity. The default is 5 seconds.
  1630.  
  1631. multiuser on|off
  1632.  
  1633. Switch between singleuser and multiuser mode. Standard screen operation
  1634. is singleuser. In multiuser mode the commands `acladd', `aclchg',
  1635. `aclgrp' and `acldel' can be used to enable (and disable) other users
  1636. accessing this screen session.
  1637.  
  1638. nethack on|off
  1639.  
  1640. Changes the kind of error messages used by screen. When you are famil‐
  1641. iar with the game "nethack", you may enjoy the nethack-style messages
  1642. which will often blur the facts a little, but are much funnier to read.
  1643. Anyway, standard messages often tend to be unclear as well.
  1644. This option is only available if screen was compiled with the NETHACK
  1645. flag defined. The default setting is then determined by the presence of
  1646. the environment variable $NETHACKOPTIONS and the file ~/.nethackrc - if
  1647. either one is present, the default is on.
  1648.  
  1649. next
  1650.  
  1651. Switch to the next window. This command can be used repeatedly to
  1652. cycle through the list of windows.
  1653.  
  1654. nonblock [on|off|numsecs]
  1655.  
  1656. Tell screen how to deal with user interfaces (displays) that cease to
  1657. accept output. This can happen if a user presses ^S or a TCP/modem con‐
  1658. nection gets cut but no hangup is received. If nonblock is off (this is
  1659. the default) screen waits until the display restarts to accept the out‐
  1660. put. If nonblock is on, screen waits until the timeout is reached (on
  1661. is treated as 1s). If the display still doesn't receive characters,
  1662. screen will consider it "blocked" and stop sending characters to it. If
  1663. at some time it restarts to accept characters, screen will unblock the
  1664. display and redisplay the updated window contents.
  1665.  
  1666. number [n]
  1667.  
  1668. Change the current windows number. If the given number n is already
  1669. used by another window, both windows exchange their numbers. If no
  1670. argument is specified, the current window number (and title) is shown.
  1671.  
  1672. obuflimit [limit]
  1673.  
  1674. If the output buffer contains more bytes than the specified limit, no
  1675. more data will be read from the windows. The default value is 256. If
  1676. you have a fast display (like xterm), you can set it to some higher
  1677. value. If no argument is specified, the current setting is displayed.
  1678.  
  1679. only
  1680.  
  1681. Kill all regions but the current one.
  1682.  
  1683. other
  1684.  
  1685. Switch to the window displayed previously. If this window does no
  1686. longer exist, other has the same effect as next.
  1687.  
  1688. partial on|off
  1689.  
  1690. Defines whether the display should be refreshed (as with redisplay)
  1691. after switching to the current window. This command only affects the
  1692. current window. To immediately affect all windows use the allpartial
  1693. command. Default is `off', of course. This default is fixed, as there
  1694. is currently no defpartial command.
  1695.  
  1696. password [crypted_pw]
  1697.  
  1698. Present a crypted password in your ".screenrc" file and screen will ask
  1699. for it, whenever someone attempts to resume a detached. This is useful
  1700. if you have privileged programs running under screen and you want to
  1701. protect your session from reattach attempts by another user masquerad‐
  1702. ing as your uid (i.e. any superuser.) If no crypted password is speci‐
  1703. fied, screen prompts twice for typing a password and places its encryp‐
  1704. tion in the paste buffer. Default is `none', this disables password
  1705. checking.
  1706.  
  1707. paste [registers [dest_reg]]
  1708.  
  1709. Write the (concatenated) contents of the specified registers to the
  1710. stdin queue of the current window. The register '.' is treated as the
  1711. paste buffer. If no parameter is given the user is prompted for a sin‐
  1712. gle register to paste. The paste buffer can be filled with the copy,
  1713. history and readbuf commands. Other registers can be filled with the
  1714. register, readreg and paste commands. If paste is called with a second
  1715. argument, the contents of the specified registers is pasted into the
  1716. named destination register rather than the window. If '.' is used as
  1717. the second argument, the displays paste buffer is the destination.
  1718. Note, that "paste" uses a wide variety of resources: Whenever a second
  1719. argument is specified no current window is needed. When the source
  1720. specification only contains registers (not the paste buffer) then there
  1721. need not be a current display (terminal attached), as the registers are
  1722. a global resource. The paste buffer exists once for every user.
  1723.  
  1724. pastefont [on|off]
  1725.  
  1726. Tell screen to include font information in the paste buffer. The
  1727. default is not to do so. This command is especially useful for multi
  1728. character fonts like kanji.
  1729.  
  1730. pow_break
  1731.  
  1732. Reopen the window's terminal line and send a break condition. See
  1733. `break'.
  1734.  
  1735. pow_detach
  1736.  
  1737. Power detach. Mainly the same as detach, but also sends a HANGUP sig‐
  1738. nal to the parent process of screen. CAUTION: This will result in a
  1739. logout, when screen was started from your login shell.
  1740.  
  1741. pow_detach_msg [message]
  1742.  
  1743. The message specified here is output whenever a `Power detach' was per‐
  1744. formed. It may be used as a replacement for a logout message or to
  1745. reset baud rate, etc. Without parameter, the current message is shown.
  1746.  
  1747. prev
  1748.  
  1749. Switch to the window with the next lower number. This command can be
  1750. used repeatedly to cycle through the list of windows.
  1751.  
  1752. printcmd [cmd]
  1753.  
  1754. If cmd is not an empty string, screen will not use the terminal capa‐
  1755. bilities "po/pf" if it detects an ansi print sequence ESC [ 5 i, but
  1756. pipe the output into cmd. This should normally be a command like "lpr"
  1757. or "'cat > /tmp/scrprint'". printcmd without a command displays the
  1758. current setting. The ansi sequence ESC \ ends printing and closes the
  1759. pipe.
  1760. Warning: Be careful with this command! If other user have write access
  1761. to your terminal, they will be able to fire off print commands.
  1762.  
  1763. process [key]
  1764.  
  1765. Stuff the contents of the specified register into screen's input queue.
  1766. If no argument is given you are prompted for a register name. The text
  1767. is parsed as if it had been typed in from the user's keyboard. This
  1768. command can be used to bind multiple actions to a single key.
  1769.  
  1770. quit
  1771.  
  1772. Kill all windows and terminate screen. Note that on VT100-style termi‐
  1773. nals the keys C-4 and C-\ are identical. This makes the default bind‐
  1774. ings dangerous: Be careful not to type C-a C-4 when selecting window
  1775. no. 4. Use the empty bind command (as in "bind '^\'") to remove a key
  1776. binding.
  1777.  
  1778. readbuf [-e encoding] [filename]
  1779.  
  1780. Reads the contents of the specified file into the paste buffer. You
  1781. can tell screen the encoding of the file via the -e option. If no file
  1782. is specified, the screen-exchange filename is used. See also "buffer‐
  1783. file" command.
  1784.  
  1785. readreg [-e encoding] [register [filename]]
  1786.  
  1787. Does one of two things, dependent on number of arguments: with zero or
  1788. one arguments it it duplicates the paste buffer contents into the reg‐
  1789. ister specified or entered at the prompt. With two arguments it reads
  1790. the contents of the named file into the register, just as readbuf reads
  1791. the screen-exchange file into the paste buffer. You can tell screen
  1792. the encoding of the file via the -e option. The following example will
  1793. paste the system's password file into the screen window (using register
  1794. p, where a copy remains):
  1795.  
  1796. C-a : readreg p /etc/passwd
  1797. C-a : paste p
  1798.  
  1799. redisplay
  1800.  
  1801. Redisplay the current window. Needed to get a full redisplay when in
  1802. partial redraw mode.
  1803.  
  1804. register [-e encoding] key string
  1805.  
  1806. Save the specified string to the register key. The encoding of the
  1807. string can be specified via the -e option. See also the "paste" com‐
  1808. mand.
  1809.  
  1810. remove
  1811.  
  1812. Kill the current region. This is a no-op if there is only one region.
  1813.  
  1814. removebuf
  1815.  
  1816. Unlinks the screen-exchange file used by the commands "writebuf" and
  1817. "readbuf".
  1818.  
  1819. reset
  1820.  
  1821. Reset the virtual terminal to its "power-on" values. Useful when
  1822. strange settings (like scroll regions or graphics character set) are
  1823. left over from an application.
  1824.  
  1825. resize
  1826.  
  1827. Resize the current region. The space will be removed from or added to
  1828. the region below or if there's not enough space from the region above.
  1829.  
  1830. resize +N increase current region height by N
  1831.  
  1832. resize -N decrease current region height by N
  1833.  
  1834. resize N set current region height to N
  1835.  
  1836. resize = make all windows equally high
  1837.  
  1838. resize max maximize current region height
  1839.  
  1840. resize min minimize current region height
  1841.  
  1842. screen [-opts] [n] [cmd [args]]
  1843.  
  1844. Establish a new window. The flow-control options (-f, -fn and -fa),
  1845. title (a.k.a.) option (-t), login options (-l and -ln) , terminal type
  1846. option (-T <term>), the all-capability-flag (-a) and scrollback option
  1847. (-h <num>) may be specified with each command. The option (-M) turns
  1848. monitoring on for this window. The option (-L) turns output logging on
  1849. for this window. If an optional number n in the range 0..MAXWIN-1 is
  1850. given, the window number n is assigned to the newly created window (or,
  1851. if this number is already in-use, the next available number). If a
  1852. command is specified after "screen", this command (with the given argu‐
  1853. ments) is started in the window; otherwise, a shell is created. Thus,
  1854. if your ".screenrc" contains the lines
  1855.  
  1856. # example for .screenrc:
  1857. screen 1
  1858. screen -fn -t foobar -L 2 telnet foobar
  1859.  
  1860. screen creates a shell window (in window #1) and a window with a TELNET
  1861. connection to the machine foobar (with no flow-control using the title
  1862. "foobar" in window #2) and will write a logfile ("screenlog.2") of the
  1863. telnet session. Note, that unlike previous versions of screen no addi‐
  1864. tional default window is created when "screen" commands are included in
  1865. your ".screenrc" file. When the initialization is completed, screen
  1866. switches to the last window specified in your .screenrc file or, if
  1867. none, opens a default window #0.
  1868. Screen has built in some functionality of "cu" and "telnet". See also
  1869. chapter "WINDOW TYPES".
  1870.  
  1871. scrollback num
  1872.  
  1873. Set the size of the scrollback buffer for the current windows to num
  1874. lines. The default scrollback is 100 lines. See also the "defscroll‐
  1875. back" command and use "C-a i" to view the current setting.
  1876.  
  1877. select [WindowID]
  1878.  
  1879. Switch to the window identified by WindowID. This can be a prefix of a
  1880. window title (alphanumeric window name) or a window number. The param‐
  1881. eter is optional and if omitted, you get prompted for an identifier.
  1882. When a new window is established, the first available number is
  1883. assigned to this window. Thus, the first window can be activated by
  1884. "select 0". The number of windows is limited at compile-time by the
  1885. MAXWIN configuration parameter (which defaults to 40 in Debian). There
  1886. are two special WindowIDs, "-" selects the internal blank window and
  1887. "." selects the current window. The latter is useful if used with
  1888. screen's "-X" option.
  1889.  
  1890. sessionname [name]
  1891.  
  1892. Rename the current session. Note, that for "screen -list" the name
  1893. shows up with the process-id prepended. If the argument "name" is omit‐
  1894. ted, the name of this session is displayed. Caution: Among other prob‐
  1895. lems, the $STY environment variable still reflects the old name. Use
  1896. of this command is strongly discouraged. Use the "-S" commandline
  1897. option if you need this feature. The default is constructed from the
  1898. tty and host names.
  1899.  
  1900. setenv [var [string]]
  1901.  
  1902. Set the environment variable var to value string. If only var is spec‐
  1903. ified, the user will be prompted to enter a value. If no parameters
  1904. are specified, the user will be prompted for both variable and value.
  1905. The environment is inherited by all subsequently forked shells.
  1906.  
  1907. setsid [on|off]
  1908.  
  1909. Normally screen uses different sessions and process groups for the win‐
  1910. dows. If setsid is turned off, this is not done anymore and all windows
  1911. will be in the same process group as the screen backend process. This
  1912. also breaks job-control, so be careful. The default is on, of course.
  1913. This command is probably useful only in rare circumstances.
  1914.  
  1915. shell command
  1916.  
  1917. Set the command to be used to create a new shell. This overrides the
  1918. value of the environment variable $SHELL. This is useful if you'd like
  1919. to run a tty-enhancer which is expecting to execute the program speci‐
  1920. fied in $SHELL. If the command begins with a '-' character, the shell
  1921. will be started as a login-shell.
  1922.  
  1923. shelltitle title
  1924.  
  1925. Set the title for all shells created during startup or by the C-A C-c
  1926. command. For details about what a title is, see the discussion enti‐
  1927. tled "TITLES (naming windows)".
  1928.  
  1929. silence [on|off|sec]
  1930.  
  1931. Toggles silence monitoring of windows. When silence is turned on and
  1932. an affected window is switched into the background, you will receive
  1933. the silence notification message in the status line after a specified
  1934. period of inactivity (silence). The default timeout can be changed with
  1935. the `silencewait' command or by specifying a number of seconds instead
  1936. of `on' or `off'. Silence is initially off for all windows.
  1937.  
  1938. silencewait sec
  1939.  
  1940. Define the time that all windows monitored for silence should wait
  1941. before displaying a message. Default 30 seconds.
  1942.  
  1943. sleep num
  1944.  
  1945. This command will pause the execution of a .screenrc file for num sec‐
  1946. onds. Keyboard activity will end the sleep. It may be used to give
  1947. users a chance to read the messages output by "echo".
  1948.  
  1949. slowpaste msec
  1950.  
  1951. Define the speed at which text is inserted into the current window by
  1952. the paste ("C-a ]") command. If the slowpaste value is nonzero text is
  1953. written character by character. screen will make a pause of msec mil‐
  1954. liseconds after each single character write to allow the application to
  1955. process its input. Only use slowpaste if your underlying system exposes
  1956. flow control problems while pasting large amounts of text.
  1957.  
  1958. source file
  1959.  
  1960. Read and execute commands from file file. Source commands may be nested
  1961. to a maximum recursion level of ten. If file is not an absolute path
  1962. and screen is already processing a source command, the parent directory
  1963. of the running source command file is used to search for the new com‐
  1964. mand file before screen's current directory.
  1965.  
  1966. Note that termcap/terminfo/termcapinfo commands only work at startup
  1967. and reattach time, so they must be reached via the default screenrc
  1968. files to have an effect.
  1969.  
  1970. sorendition [attr [color]]
  1971.  
  1972. Change the way screen does highlighting for text marking and printing
  1973. messages. See the "STRING ESCAPES" chapter for the syntax of the modi‐
  1974. fiers. The default is currently "=s dd" (standout, default colors).
  1975.  
  1976. split [-v]
  1977.  
  1978. Split the current region into two new ones. All regions on the display
  1979. are resized to make room for the new region. The blank window is dis‐
  1980. played on the new region. Splits are made horizontally unless -v is
  1981. used. Use the "remove" or the "only" command to delete regions. Use
  1982. "focus" to toggle between regions.
  1983.  
  1984. startup_message on|off
  1985.  
  1986. Select whether you want to see the copyright notice during startup.
  1987. Default is `on', as you probably noticed.
  1988.  
  1989. stuff string
  1990.  
  1991. Stuff the string string in the input buffer of the current window.
  1992. This is like the "paste" command but with much less overhead. You can‐
  1993. not paste large buffers with the "stuff" command. It is most useful for
  1994. key bindings. See also "bindkey".
  1995.  
  1996. su [username [password [password2]]
  1997.  
  1998. Substitute the user of a display. The command prompts for all parame‐
  1999. ters that are omitted. If passwords are specified as parameters, they
  2000. have to be specified un-crypted. The first password is matched against
  2001. the systems passwd database, the second password is matched against the
  2002. screen password as set with the commands "acladd" or "password". "Su"
  2003. may be useful for the screen administrator to test multiuser setups.
  2004. When the identification fails, the user has access to the commands
  2005. available for user nobody. These are "detach", "license", "version",
  2006. "help" and "displays".
  2007.  
  2008. suspend
  2009.  
  2010. Suspend screen. The windows are in the `detached' state, while screen
  2011. is suspended. This feature relies on the shell being able to do job
  2012. control.
  2013.  
  2014. term term
  2015.  
  2016. In each window's environment screen opens, the $TERM variable is set to
  2017. "screen" by default. But when no description for "screen" is installed
  2018. in the local termcap or terminfo data base, you set $TERM to - say -
  2019. "vt100". This won't do much harm, as screen is VT100/ANSI compatible.
  2020. The use of the "term" command is discouraged for non-default purpose.
  2021. That is, one may want to specify special $TERM settings (e.g. vt100)
  2022. for the next "screen rlogin othermachine" command. Use the command
  2023. "screen -T vt100 rlogin othermachine" rather than setting and resetting
  2024. the default.
  2025.  
  2026. termcap term terminal-tweaks [window-tweaks]
  2027. terminfo term terminal-tweaks [window-tweaks]
  2028. termcapinfo term terminal-tweaks [window-tweaks]
  2029.  
  2030. Use this command to modify your terminal's termcap entry without going
  2031. through all the hassles involved in creating a custom termcap entry.
  2032. Plus, you can optionally customize the termcap generated for the win‐
  2033. dows. You have to place these commands in one of the screenrc startup
  2034. files, as they are meaningless once the terminal emulator is booted.
  2035. If your system works uses the terminfo database rather than termcap,
  2036. screen will understand the `terminfo' command, which has the same
  2037. effects as the `termcap' command. Two separate commands are provided,
  2038. as there are subtle syntactic differences, e.g. when parameter interpo‐
  2039. lation (using `%') is required. Note that termcap names of the capabil‐
  2040. ities have to be used with the `terminfo' command.
  2041. In many cases, where the arguments are valid in both terminfo and term‐
  2042. cap syntax, you can use the command `termcapinfo', which is just a
  2043. shorthand for a pair of `termcap' and `terminfo' commands with identi‐
  2044. cal arguments.
  2045.  
  2046. The first argument specifies which terminal(s) should be affected by
  2047. this definition. You can specify multiple terminal names by separating
  2048. them with `|'s. Use `*' to match all terminals and `vt*' to match all
  2049. terminals that begin with "vt".
  2050.  
  2051. Each tweak argument contains one or more termcap defines (separated by
  2052. `:'s) to be inserted at the start of the appropriate termcap entry,
  2053. enhancing it or overriding existing values. The first tweak modifies
  2054. your terminal's termcap, and contains definitions that your terminal
  2055. uses to perform certain functions. Specify a null string to leave this
  2056. unchanged (e.g. ''). The second (optional) tweak modifies all the win‐
  2057. dow termcaps, and should contain definitions that screen understands
  2058. (see the "VIRTUAL TERMINAL" section).
  2059.  
  2060. Some examples:
  2061.  
  2062. termcap xterm* LP:hs@
  2063.  
  2064. Informs screen that all terminals that begin with `xterm' have firm
  2065. auto-margins that allow the last position on the screen to be updated
  2066. (LP), but they don't really have a status line (no 'hs' - append `@' to
  2067. turn entries off). Note that we assume `LP' for all terminal names
  2068. that start with "vt", but only if you don't specify a termcap command
  2069. for that terminal.
  2070.  
  2071. termcap vt* LP
  2072. termcap vt102|vt220 Z0=\E[?3h:Z1=\E[?3l
  2073.  
  2074. Specifies the firm-margined `LP' capability for all terminals that
  2075. begin with `vt', and the second line will also add the escape-sequences
  2076. to switch into (Z0) and back out of (Z1) 132-character-per-line mode if
  2077. this is a VT102 or VT220. (You must specify Z0 and Z1 in your termcap
  2078. to use the width-changing commands.)
  2079.  
  2080. termcap vt100 "" l0=PF1:l1=PF2:l2=PF3:l3=PF4
  2081.  
  2082. This leaves your vt100 termcap alone and adds the function key labels
  2083. to each window's termcap entry.
  2084.  
  2085. termcap h19|z19 am@:im=\E@:ei=\EO dc=\E[P
  2086.  
  2087. Takes a h19 or z19 termcap and turns off auto-margins (am@) and enables
  2088. the insert mode (im) and end-insert (ei) capabilities (the `@' in the
  2089. `im' string is after the `=', so it is part of the string). Having the
  2090. `im' and `ei' definitions put into your terminal's termcap will cause
  2091. screen to automatically advertise the character-insert capability in
  2092. each window's termcap. Each window will also get the delete-character
  2093. capability (dc) added to its termcap, which screen will translate into
  2094. a line-update for the terminal (we're pretending it doesn't support
  2095. character deletion).
  2096.  
  2097. If you would like to fully specify each window's termcap entry, you
  2098. should instead set the $SCREENCAP variable prior to running screen.
  2099. See the discussion on the "VIRTUAL TERMINAL" in this manual, and the
  2100. termcap(5) man page for more information on termcap definitions.
  2101.  
  2102. time [string]
  2103.  
  2104. Uses the message line to display the time of day, the host name, and
  2105. the load averages over 1, 5, and 15 minutes (if this is available on
  2106. your system). For window specific information use "info".
  2107.  
  2108. If a string is specified, it changes the format of the time report like
  2109. it is described in the "STRING ESCAPES" chapter. Screen uses a default
  2110. of "%c:%s %M %d %H%? %l%?".
  2111.  
  2112. title [windowtitle]
  2113.  
  2114. Set the name of the current window to windowtitle. If no name is speci‐
  2115. fied, screen prompts for one. This command was known as `aka' in previ‐
  2116. ous releases.
  2117.  
  2118. unsetenv var
  2119.  
  2120. Unset an environment variable.
  2121.  
  2122. utf8 [on|off [on|off]]
  2123.  
  2124. Change the encoding used in the current window. If utf8 is enabled, the
  2125. strings sent to the window will be UTF-8 encoded and vice versa. Omit‐
  2126. ting the parameter toggles the setting. If a second parameter is given,
  2127. the display's encoding is also changed (this should rather be done with
  2128. screen's "-U" option). See also "defutf8", which changes the default
  2129. setting of a new window.
  2130.  
  2131. vbell [on|off]
  2132.  
  2133. Sets the visual bell setting for this window. Omitting the parameter
  2134. toggles the setting. If vbell is switched on, but your terminal does
  2135. not support a visual bell, a `vbell-message' is displayed in the status
  2136. line when the bell character (^G) is received. Visual bell support of
  2137. a terminal is defined by the termcap variable `vb' (terminfo: 'flash').
  2138. Per default, vbell is off, thus the audible bell is used. See also
  2139. `bell_msg'.
  2140.  
  2141. vbell_msg [message]
  2142.  
  2143. Sets the visual bell message. message is printed to the status line if
  2144. the window receives a bell character (^G), vbell is set to "on", but
  2145. the terminal does not support a visual bell. The default message is
  2146. "Wuff, Wuff!!". Without parameter, the current message is shown.
  2147.  
  2148. vbellwait sec
  2149.  
  2150. Define a delay in seconds after each display of screen's visual bell
  2151. message. The default is 1 second.
  2152.  
  2153. verbose [on|off]
  2154.  
  2155. If verbose is switched on, the command name is echoed, whenever a win‐
  2156. dow is created (or resurrected from zombie state). Default is off.
  2157. Without parameter, the current setting is shown.
  2158.  
  2159. version
  2160.  
  2161. Print the current version and the compile date in the status line.
  2162.  
  2163. wall message
  2164.  
  2165. Write a message to all displays. The message will appear in the termi‐
  2166. nal's status line.
  2167.  
  2168. width [-w|-d] [cols [lines]]
  2169.  
  2170. Toggle the window width between 80 and 132 columns or set it to cols
  2171. columns if an argument is specified. This requires a capable terminal
  2172. and the termcap entries "Z0" and "Z1". See the "termcap" command for
  2173. more information. You can also specify a new height if you want to
  2174. change both values. The -w option tells screen to leave the display
  2175. size unchanged and just set the window size, -d vice versa.
  2176.  
  2177. windowlist [-b] [-m]
  2178. windowlist string [string]
  2179. windowlist title [title]
  2180.  
  2181. Display all windows in a table for visual window selection. The desired
  2182. window can be selected via the standard movement keys (see the "copy"
  2183. command) and activated via the return key. If the -b option is given,
  2184. screen will switch to the blank window before presenting the list, so
  2185. that the current window is also selectable. The -m option changes the
  2186. order of the windows, instead of sorting by window numbers screen uses
  2187. its internal most-recently-used list.
  2188.  
  2189. The table format can be changed with the string and title option, the
  2190. title is displayed as table heading, while the lines are made by using
  2191. the string setting. The default setting is "Num Name%=Flags" for the
  2192. title and "%3n %t%=%f" for the lines. See the "STRING ESCAPES" chapter
  2193. for more codes (e.g. color settings).
  2194.  
  2195. windows
  2196.  
  2197. Uses the message line to display a list of all the windows. Each win‐
  2198. dow is listed by number with the name of process that has been started
  2199. in the window (or its title); the current window is marked with a `*';
  2200. the previous window is marked with a `-'; all the windows that are
  2201. "logged in" are marked with a `$'; a background window that has
  2202. received a bell is marked with a `!'; a background window that is being
  2203. monitored and has had activity occur is marked with an `@'; a window
  2204. which has output logging turned on is marked with `(L)'; windows occu‐
  2205. pied by other users are marked with `&'; windows in the zombie state
  2206. are marked with `Z'. If this list is too long to fit on the terminal's
  2207. status line only the portion around the current window is displayed.
  2208.  
  2209. wrap [on|off]
  2210.  
  2211. Sets the line-wrap setting for the current window. When line-wrap is
  2212. on, the second consecutive printable character output at the last col‐
  2213. umn of a line will wrap to the start of the following line. As an
  2214. added feature, backspace (^H) will also wrap through the left margin to
  2215. the previous line. Default is `on'.
  2216.  
  2217. writebuf [-e encoding] [filename]
  2218.  
  2219. Writes the contents of the paste buffer to the specified file, or the
  2220. public accessible screen-exchange file if no filename is given. This is
  2221. thought of as a primitive means of communication between screen users
  2222. on the same host. If an encoding is specified the paste buffer is
  2223. recoded on the fly to match the encoding. The filename can be set with
  2224. the bufferfile command and defaults to "/tmp/screen-exchange".
  2225.  
  2226. writelock [on|off|auto]
  2227.  
  2228. In addition to access control lists, not all users may be able to write
  2229. to the same window at once. Per default, writelock is in `auto' mode
  2230. and grants exclusive input permission to the user who is the first to
  2231. switch to the particular window. When he leaves the window, other users
  2232. may obtain the writelock (automatically). The writelock of the current
  2233. window is disabled by the command "writelock off". If the user issues
  2234. the command "writelock on" he keeps the exclusive write permission
  2235. while switching to other windows.
  2236.  
  2237. xoff
  2238. xon
  2239.  
  2240. Insert a CTRL-s / CTRL-q character to the stdin queue of the current
  2241. window.
  2242.  
  2243. zmodem [off|auto|catch|pass]
  2244. zmodem sendcmd [string]
  2245. zmodem recvcmd [string]
  2246.  
  2247. Define zmodem support for screen. Screen understands two different
  2248. modes when it detects a zmodem request: "pass" and "catch". If the
  2249. mode is set to "pass", screen will relay all data to the attacher until
  2250. the end of the transmission is reached. In "catch" mode screen acts as
  2251. a zmodem endpoint and starts the corresponding rz/sz commands. If the
  2252. mode is set to "auto", screen will use "catch" if the window is a tty
  2253. (e.g. a serial line), otherwise it will use "pass".
  2254. You can define the templates screen uses in "catch" mode via the second
  2255. and the third form.
  2256. Note also that this is an experimental feature.
  2257.  
  2258. zombie [keys[onerror]]
  2259. defzombie [keys]
  2260.  
  2261. Per default screen windows are removed from the window list as soon as
  2262. the windows process (e.g. shell) exits. When a string of two keys is
  2263. specified to the zombie command, `dead' windows will remain in the
  2264. list. The kill command may be used to remove such a window. Pressing
  2265. the first key in the dead window has the same effect. When pressing the
  2266. second key, screen will attempt to resurrect the window. The process
  2267. that was initially running in the window will be launched again. Call‐
  2268. ing zombie without parameters will clear the zombie setting, thus mak‐
  2269. ing windows disappear when their process exits.
  2270.  
  2271. As the zombie-setting is manipulated globally for all windows, this
  2272. command should only be called defzombie. Until we need this as a per
  2273. window setting, the commands zombie and defzombie are synonymous.
  2274.  
  2275. Optionally you can put the word "onerror" after the keys. This will
  2276. cause screen to monitor exit status of the process running in the win‐
  2277. dow. If it exits normally ('0'), the window disappears. Any other exit
  2278. value causes the window to become a zombie.
  2279.  
  2280.  
  2281. THE MESSAGE LINE
  2282. Screen displays informational messages and other diagnostics in a mes‐
  2283. sage line. While this line is distributed to appear at the bottom of
  2284. the screen, it can be defined to appear at the top of the screen during
  2285. compilation. If your terminal has a status line defined in its term‐
  2286. cap, screen will use this for displaying its messages, otherwise a line
  2287. of the current screen will be temporarily overwritten and output will
  2288. be momentarily interrupted. The message line is automatically removed
  2289. after a few seconds delay, but it can also be removed early (on termi‐
  2290. nals without a status line) by beginning to type.
  2291.  
  2292. The message line facility can be used by an application running in the
  2293. current window by means of the ANSI Privacy message control sequence.
  2294. For instance, from within the shell, try something like:
  2295.  
  2296. echo '<esc>^Hello world from window '$WINDOW'<esc>\\'
  2297.  
  2298. where '<esc>' is an escape, '^' is a literal up-arrow, and '\\' turns
  2299. into a single backslash.
  2300.  
  2301.  
  2302. WINDOW TYPES
  2303. Screen provides three different window types. New windows are created
  2304. with screen's screen command (see also the entry in chapter "CUSTOMIZA‐
  2305. TION"). The first parameter to the screen command defines which type of
  2306. window is created. The different window types are all special cases of
  2307. the normal type. They have been added in order to allow screen to be
  2308. used efficiently as a console multiplexer with 100 or more windows.
  2309.  
  2310.  
  2311. · The normal window contains a shell (default, if no parameter is
  2312. given) or any other system command that could be executed from a
  2313. shell (e.g. slogin, etc...)
  2314.  
  2315.  
  2316. · If a tty (character special device) name (e.g. "/dev/ttya") is spec‐
  2317. ified as the first parameter, then the window is directly connected
  2318. to this device. This window type is similar to "screen cu -l
  2319. /dev/ttya". Read and write access is required on the device node,
  2320. an exclusive open is attempted on the node to mark the connection
  2321. line as busy. An optional parameter is allowed consisting of a
  2322. comma separated list of flags in the notation used by stty(1):
  2323.  
  2324. <baud_rate>
  2325. Usually 300, 1200, 9600 or 19200. This affects transmission
  2326. as well as receive speed.
  2327.  
  2328. cs8 or cs7
  2329. Specify the transmission of eight (or seven) bits per byte.
  2330.  
  2331. ixon or -ixon
  2332. Enables (or disables) software flow-control (CTRL-S/CTRL-Q)
  2333. for sending data.
  2334.  
  2335. ixoff or -ixoff
  2336. Enables (or disables) software flow-control for receiving
  2337. data.
  2338.  
  2339. istrip or -istrip
  2340. Clear (or keep) the eight bit in each received byte.
  2341.  
  2342. You may want to specify as many of these options as applicable.
  2343. Unspecified options cause the terminal driver to make up the parame‐
  2344. ter values of the connection. These values are system dependent and
  2345. may be in defaults or values saved from a previous connection.
  2346.  
  2347. For tty windows, the info command shows some of the modem control
  2348. lines in the status line. These may include `RTS', `CTS', 'DTR',
  2349. `DSR', `CD' and more. This depends on the available ioctl()'s and
  2350. system header files as well as the on the physical capabilities of
  2351. the serial board. Signals that are logical low (inactive) have
  2352. their name preceded by an exclamation mark (!), otherwise the signal
  2353. is logical high (active). Signals not supported by the hardware but
  2354. available to the ioctl() interface are usually shown low.
  2355. When the CLOCAL status bit is true, the whole set of modem signals
  2356. is placed inside curly braces ({ and }). When the CRTSCTS or TIOC‐
  2357. SOFTCAR bit is set, the signals `CTS' or `CD' are shown in parenthe‐
  2358. sis, respectively.
  2359.  
  2360.  
  2361. For tty windows, the command break causes the Data transmission line
  2362. (TxD) to go low for a specified period of time. This is expected to
  2363. be interpreted as break signal on the other side. No data is sent
  2364. and no modem control line is changed when a break is issued.
  2365.  
  2366. · If the first parameter is "//telnet", the second parameter is
  2367. expected to be a host name, and an optional third parameter may
  2368. specify a TCP port number (default decimal 23). Screen will connect
  2369. to a server listening on the remote host and use the telnet protocol
  2370. to communicate with that server.
  2371. For telnet windows, the command info shows details about the connec‐
  2372. tion in square brackets ([ and ]) at the end of the status line.
  2373.  
  2374. b BINARY. The connection is in binary mode.
  2375.  
  2376. e ECHO. Local echo is disabled.
  2377.  
  2378. c SGA. The connection is in `character mode' (default: `line
  2379. mode').
  2380.  
  2381. t TTYPE. The terminal type has been requested by the remote
  2382. host. Screen sends the name "screen" unless instructed oth‐
  2383. erwise (see also the command `term').
  2384.  
  2385. w NAWS. The remote site is notified about window size changes.
  2386.  
  2387. f LFLOW. The remote host will send flow control information.
  2388. (Ignored at the moment.)
  2389.  
  2390. Additional flags for debugging are x, t and n (XDISPLOC, TSPEED and
  2391. NEWENV).
  2392.  
  2393. For telnet windows, the command break sends the telnet code IAC
  2394. BREAK (decimal 243) to the remote host.
  2395.  
  2396.  
  2397. This window type is only available if screen was compiled with the
  2398. BUILTIN_TELNET option defined.
  2399.  
  2400.  
  2401.  
  2402. STRING ESCAPES
  2403. Screen provides an escape mechanism to insert information like the cur‐
  2404. rent time into messages or file names. The escape character is '%' with
  2405. one exception: inside of a window's hardstatus '^%' ('^E') is used
  2406. instead.
  2407.  
  2408. Here is the full list of supported escapes:
  2409.  
  2410. % the escape character itself
  2411.  
  2412. a either 'am' or 'pm'
  2413.  
  2414. A either 'AM' or 'PM'
  2415.  
  2416. c current time HH:MM in 24h format
  2417.  
  2418. C current time HH:MM in 12h format
  2419.  
  2420. d day number
  2421.  
  2422. D weekday name
  2423.  
  2424. f flags of the window
  2425.  
  2426. F sets %? to true if the window has the focus
  2427.  
  2428. h hardstatus of the window
  2429.  
  2430. H hostname of the system
  2431.  
  2432. l current load of the system
  2433.  
  2434. m month number
  2435.  
  2436. M month name
  2437.  
  2438. n window number
  2439.  
  2440. s seconds
  2441.  
  2442. t window title
  2443.  
  2444. u all other users on this window
  2445.  
  2446. w all window numbers and names. With '-' qualifier: up to the cur‐
  2447. rent window; with '+' qualifier: starting with the window after
  2448. the current one.
  2449.  
  2450. W all window numbers and names except the current one
  2451.  
  2452. y last two digits of the year number
  2453.  
  2454. Y full year number
  2455.  
  2456. ? the part to the next '%?' is displayed only if a '%' escape
  2457. inside the part expands to a non-empty string
  2458.  
  2459. : else part of '%?'
  2460.  
  2461. = pad the string to the display's width (like TeX's hfill). If a
  2462. number is specified, pad to the percentage of the window's
  2463. width. A '0' qualifier tells screen to treat the number as
  2464. absolute position. You can specify to pad relative to the last
  2465. absolute pad position by adding a '+' qualifier or to pad rela‐
  2466. tive to the right margin by using '-'. The padding truncates the
  2467. string if the specified position lies before the current posi‐
  2468. tion. Add the 'L' qualifier to change this.
  2469.  
  2470. < same as '%=' but just do truncation, do not fill with spaces
  2471.  
  2472. > mark the current text position for the next truncation. When
  2473. screen needs to do truncation, it tries to do it in a way that
  2474. the marked position gets moved to the specified percentage of
  2475. the output area. (The area starts from the last absolute pad
  2476. position and ends with the position specified by the truncation
  2477. operator.) The 'L' qualifier tells screen to mark the truncated
  2478. parts with '...'.
  2479.  
  2480. { attribute/color modifier string terminated by the next "}"
  2481.  
  2482. ` Substitute with the output of a 'backtick' command. The length
  2483. qualifier is misused to identify one of the commands.
  2484.  
  2485. The 'c' and 'C' escape may be qualified with a '0' to make screen use
  2486. zero instead of space as fill character. The '0' qualifier also makes
  2487. the '=' escape use absolute positions. The 'n' and '=' escapes under‐
  2488. stand a length qualifier (e.g. '%3n'), 'D' and 'M' can be prefixed with
  2489. 'L' to generate long names, 'w' and 'W' also show the window flags if
  2490. 'L' is given.
  2491.  
  2492. An attribute/color modifier is is used to change the attributes or the
  2493. color settings. Its format is "[attribute modifier] [color descrip‐
  2494. tion]". The attribute modifier must be prefixed by a change type indi‐
  2495. cator if it can be confused with a color description. The following
  2496. change types are known:
  2497.  
  2498. + add the specified set to the current attributes
  2499.  
  2500. - remove the set from the current attributes
  2501.  
  2502. ! invert the set in the current attributes
  2503.  
  2504. = change the current attributes to the specified set
  2505.  
  2506. The attribute set can either be specified as a hexadecimal number or a
  2507. combination of the following letters:
  2508.  
  2509. d dim
  2510. u underline
  2511. b bold
  2512. r reverse
  2513. s standout
  2514. B blinking
  2515.  
  2516. Colors are coded either as a hexadecimal number or two letters specify‐
  2517. ing the desired background and foreground color (in that order). The
  2518. following colors are known:
  2519.  
  2520. k black
  2521. r red
  2522. g green
  2523. y yellow
  2524. b blue
  2525. m magenta
  2526. c cyan
  2527. w white
  2528. d default color
  2529. . leave color unchanged
  2530.  
  2531. The capitalized versions of the letter specify bright colors. You can
  2532. also use the pseudo-color 'i' to set just the brightness and leave the
  2533. color unchanged.
  2534. A one digit/letter color description is treated as foreground or back‐
  2535. ground color dependent on the current attributes: if reverse mode is
  2536. set, the background color is changed instead of the foreground color.
  2537. If you don't like this, prefix the color with a ".". If you want the
  2538. same behavior for two-letter color descriptions, also prefix them with
  2539. a ".".
  2540. As a special case, "%{-}" restores the attributes and colors that were
  2541. set before the last change was made (i.e., pops one level of the color-
  2542. change stack).
  2543.  
  2544. Examples:
  2545.  
  2546. "G" set color to bright green
  2547.  
  2548. "+b r" use bold red
  2549.  
  2550. "= yd" clear all attributes, write in default color on yellow back‐
  2551. ground.
  2552.  
  2553. %-Lw%{= BW}%50>%n%f* %t%{-}%+Lw%<
  2554. The available windows centered at the current window and trun‐
  2555. cated to the available width. The current window is displayed
  2556. white on blue. This can be used with "hardstatus alwayslast‐
  2557. line".
  2558.  
  2559. %?%F%{.R.}%?%3n %t%? [%h]%?
  2560. The window number and title and the window's hardstatus, if one
  2561. is set. Also use a red background if this is the active focus.
  2562. Useful for "caption string".
  2563.  
  2564. FLOW-CONTROL
  2565. Each window has a flow-control setting that determines how screen deals
  2566. with the XON and XOFF characters (and perhaps the interrupt character).
  2567. When flow-control is turned off, screen ignores the XON and XOFF char‐
  2568. acters, which allows the user to send them to the current program by
  2569. simply typing them (useful for the emacs editor, for instance). The
  2570. trade-off is that it will take longer for output from a "normal" pro‐
  2571. gram to pause in response to an XOFF. With flow-control turned on, XON
  2572. and XOFF characters are used to immediately pause the output of the
  2573. current window. You can still send these characters to the current
  2574. program, but you must use the appropriate two-character screen commands
  2575. (typically "C-a q" (xon) and "C-a s" (xoff)). The xon/xoff commands
  2576. are also useful for typing C-s and C-q past a terminal that intercepts
  2577. these characters.
  2578.  
  2579. Each window has an initial flow-control value set with either the -f
  2580. option or the "defflow" .screenrc command. Per default the windows are
  2581. set to automatic flow-switching. It can then be toggled between the
  2582. three states 'fixed on', 'fixed off' and 'automatic' interactively with
  2583. the "flow" command bound to "C-a f".
  2584.  
  2585. The automatic flow-switching mode deals with flow control using the
  2586. TIOCPKT mode (like "rlogin" does). If the tty driver does not support
  2587. TIOCPKT, screen tries to find out the right mode based on the current
  2588. setting of the application keypad - when it is enabled, flow-control is
  2589. turned off and visa versa. Of course, you can still manipulate flow-
  2590. control manually when needed.
  2591.  
  2592. If you're running with flow-control enabled and find that pressing the
  2593. interrupt key (usually C-c) does not interrupt the display until
  2594. another 6-8 lines have scrolled by, try running screen with the "inter‐
  2595. rupt" option (add the "interrupt" flag to the "flow" command in your
  2596. .screenrc, or use the -i command-line option). This causes the output
  2597. that screen has accumulated from the interrupted program to be flushed.
  2598. One disadvantage is that the virtual terminal's memory contains the
  2599. non-flushed version of the output, which in rare cases can cause minor
  2600. inaccuracies in the output. For example, if you switch screens and
  2601. return, or update the screen with "C-a l" you would see the version of
  2602. the output you would have gotten without "interrupt" being on. Also,
  2603. you might need to turn off flow-control (or use auto-flow mode to turn
  2604. it off automatically) when running a program that expects you to type
  2605. the interrupt character as input, as it is possible to interrupt the
  2606. output of the virtual terminal to your physical terminal when flow-con‐
  2607. trol is enabled. If this happens, a simple refresh of the screen with
  2608. "C-a l" will restore it. Give each mode a try, and use whichever mode
  2609. you find more comfortable.
  2610.  
  2611.  
  2612.  
  2613. TITLES (naming windows)
  2614. You can customize each window's name in the window display (viewed with
  2615. the "windows" command (C-a w)) by setting it with one of the title com‐
  2616. mands. Normally the name displayed is the actual command name of the
  2617. program created in the window. However, it is sometimes useful to dis‐
  2618. tinguish various programs of the same name or to change the name on-
  2619. the-fly to reflect the current state of the window.
  2620.  
  2621. The default name for all shell windows can be set with the "shelltitle"
  2622. command in the .screenrc file, while all other windows are created with
  2623. a "screen" command and thus can have their name set with the -t option.
  2624. Interactively, there is the title-string escape-sequence
  2625. (<esc>kname<esc>\) and the "title" command (C-a A). The former can be
  2626. output from an application to control the window's name under software
  2627. control, and the latter will prompt for a name when typed. You can
  2628. also bind pre-defined names to keys with the "title" command to set
  2629. things quickly without prompting.
  2630.  
  2631. Finally, screen has a shell-specific heuristic that is enabled by set‐
  2632. ting the window's name to "search|name" and arranging to have a null
  2633. title escape-sequence output as a part of your prompt. The search por‐
  2634. tion specifies an end-of-prompt search string, while the name portion
  2635. specifies the default shell name for the window. If the name ends in a
  2636. `:' screen will add what it believes to be the current command running
  2637. in the window to the end of the window's shell name (e.g. "name:cmd").
  2638. Otherwise the current command name supersedes the shell name while it
  2639. is running.
  2640.  
  2641. Here's how it works: you must modify your shell prompt to output a
  2642. null title-escape-sequence (<esc>k<esc>\) as a part of your prompt.
  2643. The last part of your prompt must be the same as the string you speci‐
  2644. fied for the search portion of the title. Once this is set up, screen
  2645. will use the title-escape-sequence to clear the previous command name
  2646. and get ready for the next command. Then, when a newline is received
  2647. from the shell, a search is made for the end of the prompt. If found,
  2648. it will grab the first word after the matched string and use it as the
  2649. command name. If the command name begins with either '!', '%', or '^'
  2650. screen will use the first word on the following line (if found) in
  2651. preference to the just-found name. This helps csh users get better
  2652. command names when using job control or history recall commands.
  2653.  
  2654. Here's some .screenrc examples:
  2655.  
  2656. screen -t top 2 nice top
  2657.  
  2658. Adding this line to your .screenrc would start a nice-d version of the
  2659. "top" command in window 2 named "top" rather than "nice".
  2660.  
  2661. shelltitle '> |csh'
  2662. screen 1
  2663.  
  2664. These commands would start a shell with the given shelltitle. The
  2665. title specified is an auto-title that would expect the prompt and the
  2666. typed command to look something like the following:
  2667.  
  2668. /usr/joe/src/dir> trn
  2669.  
  2670. (it looks after the '> ' for the command name). The window status
  2671. would show the name "trn" while the command was running, and revert to
  2672. "csh" upon completion.
  2673.  
  2674. bind R screen -t '% |root:' su
  2675.  
  2676. Having this command in your .screenrc would bind the key sequence "C-a
  2677. R" to the "su" command and give it an auto-title name of "root:". For
  2678. this auto-title to work, the screen could look something like this:
  2679.  
  2680. % !em
  2681. emacs file.c
  2682.  
  2683. Here the user typed the csh history command "!em" which ran the previ‐
  2684. ously entered "emacs" command. The window status would show
  2685. "root:emacs" during the execution of the command, and revert to simply
  2686. "root:" at its completion.
  2687.  
  2688. bind o title
  2689. bind E title ""
  2690. bind u title (unknown)
  2691.  
  2692. The first binding doesn't have any arguments, so it would prompt you
  2693. for a title. when you type "C-a o". The second binding would clear an
  2694. auto-title's current setting (C-a E). The third binding would set the
  2695. current window's title to "(unknown)" (C-a u).
  2696.  
  2697. One thing to keep in mind when adding a null title-escape-sequence to
  2698. your prompt is that some shells (like the csh) count all the non-con‐
  2699. trol characters as part of the prompt's length. If these invisible
  2700. characters aren't a multiple of 8 then backspacing over a tab will
  2701. result in an incorrect display. One way to get around this is to use a
  2702. prompt like this:
  2703.  
  2704. set prompt='^[[0000m^[k^[\% '
  2705.  
  2706. The escape-sequence "<esc>[0000m" not only normalizes the character
  2707. attributes, but all the zeros round the length of the invisible charac‐
  2708. ters up to 8. Bash users will probably want to echo the escape
  2709. sequence in the PROMPT_COMMAND:
  2710.  
  2711. PROMPT_COMMAND='echo -n -e "\033k\033\134"'
  2712.  
  2713. (I used "134" to output a `\' because of a bug in bash v1.04).
  2714.  
  2715.  
  2716.  
  2717. THE VIRTUAL TERMINAL
  2718. Each window in a screen session emulates a VT100 terminal, with some
  2719. extra functions added. The VT100 emulator is hard-coded, no other ter‐
  2720. minal types can be emulated.
  2721. Usually screen tries to emulate as much of the VT100/ANSI standard as
  2722. possible. But if your terminal lacks certain capabilities, the emula‐
  2723. tion may not be complete. In these cases screen has to tell the appli‐
  2724. cations that some of the features are missing. This is no problem on
  2725. machines using termcap, because screen can use the $TERMCAP variable to
  2726. customize the standard screen termcap.
  2727.  
  2728. But if you do a rlogin on another machine or your machine supports only
  2729. terminfo this method fails. Because of this, screen offers a way to
  2730. deal with these cases. Here is how it works:
  2731.  
  2732. When screen tries to figure out a terminal name for itself, it first
  2733. looks for an entry named "screen.<term>", where <term> is the contents
  2734. of your $TERM variable. If no such entry exists, screen tries "screen"
  2735. (or "screen-w" if the terminal is wide (132 cols or more)). If even
  2736. this entry cannot be found, "vt100" is used as a substitute.
  2737.  
  2738. The idea is that if you have a terminal which doesn't support an impor‐
  2739. tant feature (e.g. delete char or clear to EOS) you can build a new
  2740. termcap/terminfo entry for screen (named "screen.<dumbterm>") in which
  2741. this capability has been disabled. If this entry is installed on your
  2742. machines you are able to do a rlogin and still keep the correct term‐
  2743. cap/terminfo entry. The terminal name is put in the $TERM variable of
  2744. all new windows. Screen also sets the $TERMCAP variable reflecting the
  2745. capabilities of the virtual terminal emulated. Notice that, however, on
  2746. machines using the terminfo database this variable has no effect. Fur‐
  2747. thermore, the variable $WINDOW is set to the window number of each win‐
  2748. dow.
  2749.  
  2750. The actual set of capabilities supported by the virtual terminal
  2751. depends on the capabilities supported by the physical terminal. If,
  2752. for instance, the physical terminal does not support underscore mode,
  2753. screen does not put the `us' and `ue' capabilities into the window's
  2754. $TERMCAP variable, accordingly. However, a minimum number of capabili‐
  2755. ties must be supported by a terminal in order to run screen; namely
  2756. scrolling, clear screen, and direct cursor addressing (in addition,
  2757. screen does not run on hardcopy terminals or on terminals that over-
  2758. strike).
  2759.  
  2760. Also, you can customize the $TERMCAP value used by screen by using the
  2761. "termcap" .screenrc command, or by defining the variable $SCREENCAP
  2762. prior to startup. When the is latter defined, its value will be copied
  2763. verbatim into each window's $TERMCAP variable. This can either be the
  2764. full terminal definition, or a filename where the terminal "screen"
  2765. (and/or "screen-w") is defined.
  2766.  
  2767. Note that screen honors the "terminfo" .screenrc command if the system
  2768. uses the terminfo database rather than termcap.
  2769.  
  2770. When the boolean `G0' capability is present in the termcap entry for
  2771. the terminal on which screen has been called, the terminal emulation of
  2772. screen supports multiple character sets. This allows an application to
  2773. make use of, for instance, the VT100 graphics character set or national
  2774. character sets. The following control functions from ISO 2022 are sup‐
  2775. ported: lock shift G0 (SI), lock shift G1 (SO), lock shift G2, lock
  2776. shift G3, single shift G2, and single shift G3. When a virtual termi‐
  2777. nal is created or reset, the ASCII character set is designated as G0
  2778. through G3. When the `G0' capability is present, screen evaluates the
  2779. capabilities `S0', `E0', and `C0' if present. `S0' is the sequence the
  2780. terminal uses to enable and start the graphics character set rather
  2781. than SI. `E0' is the corresponding replacement for SO. `C0' gives a
  2782. character by character translation string that is used during semi-
  2783. graphics mode. This string is built like the `acsc' terminfo capabil‐
  2784. ity.
  2785.  
  2786. When the `po' and `pf' capabilities are present in the terminal's term‐
  2787. cap entry, applications running in a screen window can send output to
  2788. the printer port of the terminal. This allows a user to have an appli‐
  2789. cation in one window sending output to a printer connected to the ter‐
  2790. minal, while all other windows are still active (the printer port is
  2791. enabled and disabled again for each chunk of output). As a side-
  2792. effect, programs running in different windows can send output to the
  2793. printer simultaneously. Data sent to the printer is not displayed in
  2794. the window. The info command displays a line starting `PRIN' while the
  2795. printer is active.
  2796.  
  2797. Screen maintains a hardstatus line for every window. If a window gets
  2798. selected, the display's hardstatus will be updated to match the win‐
  2799. dow's hardstatus line. If the display has no hardstatus the line will
  2800. be displayed as a standard screen message. The hardstatus line can be
  2801. changed with the ANSI Application Program Command (APC):
  2802. "ESC_<string>ESC\". As a convenience for xterm users the sequence
  2803. "ESC]0..2;<string>^G" is also accepted.
  2804.  
  2805. Some capabilities are only put into the $TERMCAP variable of the vir‐
  2806. tual terminal if they can be efficiently implemented by the physical
  2807. terminal. For instance, `dl' (delete line) is only put into the $TERM‐
  2808. CAP variable if the terminal supports either delete line itself or
  2809. scrolling regions. Note that this may provoke confusion, when the ses‐
  2810. sion is reattached on a different terminal, as the value of $TERMCAP
  2811. cannot be modified by parent processes.
  2812.  
  2813. The "alternate screen" capability is not enabled by default. Set the
  2814. altscreen .screenrc command to enable it.
  2815.  
  2816. The following is a list of control sequences recognized by screen.
  2817. "(V)" and "(A)" indicate VT100-specific and ANSI- or ISO-specific func‐
  2818. tions, respectively.
  2819.  
  2820. ESC E Next Line
  2821.  
  2822. ESC D Index
  2823.  
  2824. ESC M Reverse Index
  2825.  
  2826. ESC H Horizontal Tab Set
  2827.  
  2828. ESC Z Send VT100 Identification String
  2829.  
  2830. ESC 7 (V) Save Cursor and Attributes
  2831.  
  2832. ESC 8 (V) Restore Cursor and Attributes
  2833.  
  2834. ESC [s (A) Save Cursor and Attributes
  2835.  
  2836. ESC [u (A) Restore Cursor and Attributes
  2837.  
  2838. ESC c Reset to Initial State
  2839.  
  2840. ESC g Visual Bell
  2841.  
  2842. ESC Pn p Cursor Visibility (97801)
  2843.  
  2844. Pn = 6 Invisible
  2845.  
  2846. 7 Visible
  2847.  
  2848. ESC = (V) Application Keypad Mode
  2849.  
  2850. ESC > (V) Numeric Keypad Mode
  2851.  
  2852. ESC # 8 (V) Fill Screen with E's
  2853.  
  2854. ESC \ (A) String Terminator
  2855.  
  2856. ESC ^ (A) Privacy Message String (Message Line)
  2857.  
  2858. ESC ! Global Message String (Message Line)
  2859.  
  2860. ESC k A.k.a. Definition String
  2861.  
  2862. ESC P (A) Device Control String. Outputs a string
  2863. directly to the host terminal without inter‐
  2864. pretation.
  2865.  
  2866. ESC _ (A) Application Program Command (Hardstatus)
  2867.  
  2868. ESC ] 0 ; string ^G (A) Operating System Command (Hardstatus, xterm
  2869. title hack)
  2870.  
  2871. ESC ] 83 ; cmd ^G (A) Execute screen command. This only works if
  2872. multi-user support is compiled into screen.
  2873. The pseudo-user ":window:" is used to check
  2874. the access control list. Use "addacl :win‐
  2875. dow: -rwx #?" to create a user with no
  2876. rights and allow only the needed commands.
  2877.  
  2878. Control-N (A) Lock Shift G1 (SO)
  2879.  
  2880. Control-O (A) Lock Shift G0 (SI)
  2881.  
  2882. ESC n (A) Lock Shift G2
  2883.  
  2884. ESC o (A) Lock Shift G3
  2885.  
  2886. ESC N (A) Single Shift G2
  2887.  
  2888. ESC O (A) Single Shift G3
  2889.  
  2890. ESC ( Pcs (A) Designate character set as G0
  2891.  
  2892. ESC ) Pcs (A) Designate character set as G1
  2893.  
  2894. ESC * Pcs (A) Designate character set as G2
  2895.  
  2896. ESC + Pcs (A) Designate character set as G3
  2897.  
  2898. ESC [ Pn ; Pn H Direct Cursor Addressing
  2899.  
  2900. ESC [ Pn ; Pn f same as above
  2901.  
  2902. ESC [ Pn J Erase in Display
  2903.  
  2904. Pn = None or 0 From Cursor to End of Screen
  2905.  
  2906. 1 From Beginning of Screen to Cursor
  2907.  
  2908. 2 Entire Screen
  2909.  
  2910. ESC [ Pn K Erase in Line
  2911.  
  2912. Pn = None or 0 From Cursor to End of Line
  2913.  
  2914. 1 From Beginning of Line to Cursor
  2915.  
  2916. 2 Entire Line
  2917.  
  2918. ESC [ Pn X Erase character
  2919.  
  2920. ESC [ Pn A Cursor Up
  2921.  
  2922. ESC [ Pn B Cursor Down
  2923.  
  2924. ESC [ Pn C Cursor Right
  2925.  
  2926. ESC [ Pn D Cursor Left
  2927.  
  2928. ESC [ Pn E Cursor next line
  2929.  
  2930. ESC [ Pn F Cursor previous line
  2931.  
  2932. ESC [ Pn G Cursor horizontal position
  2933.  
  2934. ESC [ Pn ` same as above
  2935.  
  2936. ESC [ Pn d Cursor vertical position
  2937.  
  2938. ESC [ Ps ;...; Ps m Select Graphic Rendition
  2939.  
  2940. Ps = None or 0 Default Rendition
  2941.  
  2942. 1 Bold
  2943.  
  2944. 2 (A) Faint
  2945.  
  2946. 3 (A) Standout Mode (ANSI: Italicized)
  2947.  
  2948. 4 Underlined
  2949.  
  2950. 5 Blinking
  2951.  
  2952. 7 Negative Image
  2953.  
  2954. 22 (A) Normal Intensity
  2955.  
  2956. 23 (A) Standout Mode off (ANSI: Italicized off)
  2957.  
  2958. 24 (A) Not Underlined
  2959.  
  2960. 25 (A) Not Blinking
  2961.  
  2962. 27 (A) Positive Image
  2963.  
  2964. 30 (A) Foreground Black
  2965.  
  2966. 31 (A) Foreground Red
  2967.  
  2968. 32 (A) Foreground Green
  2969.  
  2970. 33 (A) Foreground Yellow
  2971.  
  2972. 34 (A) Foreground Blue
  2973.  
  2974. 35 (A) Foreground Magenta
  2975.  
  2976. 36 (A) Foreground Cyan
  2977.  
  2978. 37 (A) Foreground White
  2979.  
  2980. 39 (A) Foreground Default
  2981.  
  2982. 40 (A) Background Black
  2983.  
  2984. ... ...
  2985.  
  2986. 49 (A) Background Default
  2987.  
  2988. ESC [ Pn g Tab Clear
  2989.  
  2990. Pn = None or 0 Clear Tab at Current Position
  2991.  
  2992. 3 Clear All Tabs
  2993.  
  2994. ESC [ Pn ; Pn r (V) Set Scrolling Region
  2995.  
  2996. ESC [ Pn I (A) Horizontal Tab
  2997.  
  2998. ESC [ Pn Z (A) Backward Tab
  2999.  
  3000. ESC [ Pn L (A) Insert Line
  3001.  
  3002. ESC [ Pn M (A) Delete Line
  3003.  
  3004. ESC [ Pn @ (A) Insert Character
  3005.  
  3006. ESC [ Pn P (A) Delete Character
  3007.  
  3008. ESC [ Pn S Scroll Scrolling Region Up
  3009.  
  3010. ESC [ Pn T Scroll Scrolling Region Down
  3011.  
  3012. ESC [ Pn ^ same as above
  3013.  
  3014. ESC [ Ps ;...; Ps h Set Mode
  3015.  
  3016. ESC [ Ps ;...; Ps l Reset Mode
  3017.  
  3018. Ps = 4 (A) Insert Mode
  3019.  
  3020. 20 (A) Automatic Linefeed Mode
  3021.  
  3022. 34 Normal Cursor Visibility
  3023.  
  3024. ?1 (V) Application Cursor Keys
  3025.  
  3026. ?3 (V) Change Terminal Width to 132 columns
  3027.  
  3028. ?5 (V) Reverse Video
  3029.  
  3030. ?6 (V) Origin Mode
  3031.  
  3032. ?7 (V) Wrap Mode
  3033.  
  3034. ?9 X10 mouse tracking
  3035.  
  3036. ?25 (V) Visible Cursor
  3037.  
  3038. ?47 Alternate Screen (old xterm code)
  3039.  
  3040. ?1000 (V) VT200 mouse tracking
  3041.  
  3042. ?1047 Alternate Screen (new xterm code)
  3043.  
  3044. ?1049 Alternate Screen (new xterm code)
  3045.  
  3046. ESC [ 5 i (A) Start relay to printer (ANSI Media Copy)
  3047.  
  3048. ESC [ 4 i (A) Stop relay to printer (ANSI Media Copy)
  3049.  
  3050. ESC [ 8 ; Ph ; Pw t Resize the window to `Ph' lines and `Pw'
  3051. columns (SunView special)
  3052.  
  3053. ESC [ c Send VT100 Identification String
  3054.  
  3055. ESC [ x Send Terminal Parameter Report
  3056.  
  3057. ESC [ > c Send VT220 Secondary Device Attributes
  3058. String
  3059.  
  3060. ESC [ 6 n Send Cursor Position Report
  3061.  
  3062.  
  3063.  
  3064. INPUT TRANSLATION
  3065. In order to do a full VT100 emulation screen has to detect that a
  3066. sequence of characters in the input stream was generated by a keypress
  3067. on the user's keyboard and insert the VT100 style escape sequence.
  3068. Screen has a very flexible way of doing this by making it possible to
  3069. map arbitrary commands on arbitrary sequences of characters. For stan‐
  3070. dard VT100 emulation the command will always insert a string in the
  3071. input buffer of the window (see also command stuff in the command ta‐
  3072. ble). Because the sequences generated by a keypress can change after a
  3073. reattach from a different terminal type, it is possible to bind com‐
  3074. mands to the termcap name of the keys. Screen will insert the correct
  3075. binding after each reattach. See the bindkey command for further
  3076. details on the syntax and examples.
  3077.  
  3078. Here is the table of the default key bindings. (A) means that the com‐
  3079. mand is executed if the keyboard is switched into application mode.
  3080.  
  3081. Key name Termcap name Command
  3082. ______________________________________________________
  3083. Cursor up ku stuff \033[A
  3084. stuff \033OA (A)
  3085. Cursor down kd stuff \033[B
  3086. stuff \033OB (A)
  3087. Cursor right kr stuff \033[C
  3088. stuff \033OC (A)
  3089. Cursor left kl stuff \033[D
  3090. stuff \033OD (A)
  3091. Function key 0 k0 stuff \033[10~
  3092. Function key 1 k1 stuff \033OP
  3093. Function key 2 k2 stuff \033OQ
  3094. Function key 3 k3 stuff \033OR
  3095. Function key 4 k4 stuff \033OS
  3096. Function key 5 k5 stuff \033[15~
  3097. Function key 6 k6 stuff \033[17~
  3098. Function key 7 k7 stuff \033[18~
  3099. Function key 8 k8 stuff \033[19~
  3100. Function key 9 k9 stuff \033[20~
  3101. Function key 10 k; stuff \033[21~
  3102. Function key 11 F1 stuff \033[23~
  3103. Function key 12 F2 stuff \033[24~
  3104. Home kh stuff \033[1~
  3105. End kH stuff \033[4~
  3106. Insert kI stuff \033[2~
  3107. Delete kD stuff \033[3~
  3108. Page up kP stuff \033[5~
  3109. Page down kN stuff \033[6~
  3110. Keypad 0 f0 stuff 0
  3111. stuff \033Op (A)
  3112. Keypad 1 f1 stuff 1
  3113. stuff \033Oq (A)
  3114. Keypad 2 f2 stuff 2
  3115. stuff \033Or (A)
  3116. Keypad 3 f3 stuff 3
  3117. stuff \033Os (A)
  3118. Keypad 4 f4 stuff 4
  3119. stuff \033Ot (A)
  3120. Keypad 5 f5 stuff 5
  3121. stuff \033Ou (A)
  3122. Keypad 6 f6 stuff 6
  3123. stuff \033Ov (A)
  3124. Keypad 7 f7 stuff 7
  3125. stuff \033Ow (A)
  3126. Keypad 8 f8 stuff 8
  3127. stuff \033Ox (A)
  3128. Keypad 9 f9 stuff 9
  3129. stuff \033Oy (A)
  3130. Keypad + f+ stuff +
  3131. stuff \033Ok (A)
  3132. Keypad - f- stuff -
  3133. stuff \033Om (A)
  3134. Keypad * f* stuff *
  3135. stuff \033Oj (A)
  3136. Keypad / f/ stuff /
  3137. stuff \033Oo (A)
  3138. Keypad = fq stuff =
  3139. stuff \033OX (A)
  3140. Keypad . f. stuff .
  3141. stuff \033On (A)
  3142. Keypad , f, stuff ,
  3143. stuff \033Ol (A)
  3144. Keypad enter fe stuff \015
  3145. stuff \033OM (A)
  3146.  
  3147.  
  3148.  
  3149. SPECIAL TERMINAL CAPABILITIES
  3150. The following table describes all terminal capabilities that are recog‐
  3151. nized by screen and are not in the termcap(5) manual. You can place
  3152. these capabilities in your termcap entries (in `/etc/termcap') or use
  3153. them with the commands `termcap', `terminfo' and `termcapinfo' in your
  3154. screenrc files. It is often not possible to place these capabilities in
  3155. the terminfo database.
  3156.  
  3157. LP (bool) Terminal has VT100 style margins (`magic margins'). Note
  3158. that this capability is obsolete because screen uses the
  3159. standard 'xn' instead.
  3160.  
  3161. Z0 (str) Change width to 132 columns.
  3162.  
  3163. Z1 (str) Change width to 80 columns.
  3164.  
  3165. WS (str) Resize display. This capability has the desired width and
  3166. height as arguments. SunView(tm) example: '\E[8;%d;%dt'.
  3167.  
  3168. NF (bool) Terminal doesn't need flow control. Send ^S and ^Q direct
  3169. to the application. Same as 'flow off'. The opposite of
  3170. this capability is 'nx'.
  3171.  
  3172. G0 (bool) Terminal can deal with ISO 2022 font selection sequences.
  3173.  
  3174. S0 (str) Switch charset 'G0' to the specified charset. Default is
  3175. '\E(%.'.
  3176.  
  3177. E0 (str) Switch charset 'G0' back to standard charset. Default is
  3178. '\E(B'.
  3179.  
  3180. C0 (str) Use the string as a conversion table for font '0'. See the
  3181. 'ac' capability for more details.
  3182.  
  3183. CS (str) Switch cursor-keys to application mode.
  3184.  
  3185. CE (str) Switch cursor-keys back to normal mode.
  3186.  
  3187. AN (bool) Turn on autonuke. See the 'autonuke' command for more
  3188. details.
  3189.  
  3190. OL (num) Set the output buffer limit. See the 'obuflimit' command
  3191. for more details.
  3192.  
  3193. KJ (str) Set the encoding of the terminal. See the 'encoding' com‐
  3194. mand for valid encodings.
  3195.  
  3196. AF (str) Change character foreground color in an ANSI conform way.
  3197. This capability will almost always be set to '\E[3%dm'
  3198. ('\E[3%p1%dm' on terminfo machines).
  3199.  
  3200. AB (str) Same as 'AF', but change background color.
  3201.  
  3202. AX (bool) Does understand ANSI set default fg/bg color (\E[39m /
  3203. \E[49m).
  3204.  
  3205. XC (str) Describe a translation of characters to strings depending
  3206. on the current font. More details follow in the next sec‐
  3207. tion.
  3208.  
  3209. XT (bool) Terminal understands special xterm sequences (OSC, mouse
  3210. tracking).
  3211.  
  3212. C8 (bool) Terminal needs bold to display high-intensity colors (e.g.
  3213. Eterm).
  3214.  
  3215. TF (bool) Add missing capabilities to the termcap/info entry. (Set
  3216. by default).
  3217.  
  3218.  
  3219. CHARACTER TRANSLATION
  3220. Screen has a powerful mechanism to translate characters to arbitrary
  3221. strings depending on the current font and terminal type. Use this fea‐
  3222. ture if you want to work with a common standard character set (say
  3223. ISO8851-latin1) even on terminals that scatter the more unusual charac‐
  3224. ters over several national language font pages.
  3225.  
  3226. Syntax:
  3227. XC=<charset-mapping>{,,<charset-mapping>}
  3228. <charset-mapping> := <designator><template>{,<mapping>}
  3229. <mapping> := <char-to-be-mapped><template-arg>
  3230.  
  3231. The things in braces may be repeated any number of times.
  3232.  
  3233. A <charset-mapping> tells screen how to map characters in font <desig‐
  3234. nator> ('B': Ascii, 'A': UK, 'K': German, etc.) to strings. Every
  3235. <mapping> describes to what string a single character will be trans‐
  3236. lated. A template mechanism is used, as most of the time the codes have
  3237. a lot in common (for example strings to switch to and from another
  3238. charset). Each occurrence of '%' in <template> gets substituted with
  3239. the <template-arg> specified together with the character. If your
  3240. strings are not similar at all, then use '%' as a template and place
  3241. the full string in <template-arg>. A quoting mechanism was added to
  3242. make it possible to use a real '%'. The '\' character quotes the spe‐
  3243. cial characters '\', '%', and ','.
  3244.  
  3245. Here is an example:
  3246.  
  3247. termcap hp700 'XC=B\E(K%\E(B,\304[,\326\\\\,\334]'
  3248.  
  3249. This tells screen how to translate ISOlatin1 (charset 'B') upper case
  3250. umlaut characters on a hp700 terminal that has a German charset. '\304'
  3251. gets translated to '\E(K[\E(B' and so on. Note that this line gets
  3252. parsed *three* times before the internal lookup table is built, there‐
  3253. fore a lot of quoting is needed to create a single '\'.
  3254.  
  3255. Another extension was added to allow more emulation: If a mapping
  3256. translates the unquoted '%' char, it will be sent to the terminal when‐
  3257. ever screen switches to the corresponding <designator>. In this special
  3258. case the template is assumed to be just '%' because the charset switch
  3259. sequence and the character mappings normally haven't much in common.
  3260.  
  3261. This example shows one use of the extension:
  3262.  
  3263. termcap xterm 'XC=K%,%\E(B,[\304,\\\\\326,]\334'
  3264.  
  3265. Here, a part of the German ('K') charset is emulated on an xterm. If
  3266. screen has to change to the 'K' charset, '\E(B' will be sent to the
  3267. terminal, i.e. the ASCII charset is used instead. The template is just
  3268. '%', so the mapping is straightforward: '[' to '\304', '\' to '\326',
  3269. and ']' to '\334'.
  3270.  
  3271.  
  3272. ENVIRONMENT
  3273. COLUMNS Number of columns on the terminal (overrides termcap
  3274. entry).
  3275. HOME Directory in which to look for .screenrc.
  3276. LINES Number of lines on the terminal (overrides termcap
  3277. entry).
  3278. LOCKPRG Screen lock program.
  3279. NETHACKOPTIONS Turns on nethack option.
  3280. PATH Used for locating programs to run.
  3281. SCREENCAP For customizing a terminal's TERMCAP value.
  3282. SCREENDIR Alternate socket directory.
  3283. SCREENRC Alternate user screenrc file.
  3284. SHELL Default shell program for opening windows (default
  3285. "/bin/sh").
  3286. STY Alternate socket name.
  3287. SYSSCREENRC Alternate system screenrc file.
  3288. TERM Terminal name.
  3289. TERMCAP Terminal description.
  3290. WINDOW Window number of a window (at creation time).
  3291.  
  3292. FILES
  3293. .../screen-4.?.??/etc/screenrc
  3294. .../screen-4.?.??/etc/etcscreenrc Examples in the screen distribution
  3295. package for private and global ini‐
  3296. tialization files.
  3297. $SYSSCREENRC
  3298. /etc/screenrc screen initialization commands
  3299. $SCREENRC
  3300. $HOME/.screenrc Read in after /etc/screenrc
  3301. $SCREENDIR/S-<login>
  3302. /var/run/screen/S-<login> Socket directories (default)
  3303. /usr/tmp/screens/S-<login> Alternate socket directories.
  3304. <socket directory>/.termcap Written by the "termcap" output func‐
  3305. tion
  3306. /usr/tmp/screens/screen-exchange or
  3307. /tmp/screen-exchange screen `interprocess communication
  3308. buffer'
  3309. hardcopy.[0-9] Screen images created by the hardcopy
  3310. function
  3311. screenlog.[0-9] Output log files created by the log
  3312. function
  3313. /usr/lib/terminfo/?/* or
  3314. /etc/termcap Terminal capability databases
  3315. /var/run/utmp Login records
  3316. $LOCKPRG Program that locks a terminal.
  3317.  
  3318.  
  3319. SEE ALSO
  3320. termcap(5), utmp(5), vi(1), captoinfo(1), tic(1)
  3321.  
  3322.  
  3323. AUTHORS
  3324. Originally created by Oliver Laumann, this latest version was produced
  3325. by Wayne Davison, Juergen Weigert and Michael Schroeder.
  3326.  
  3327. COPYLEFT
  3328. Copyright (C) 1993-2003
  3329. Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
  3330. Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
  3331. Copyright (C) 1987 Oliver Laumann
  3332. This program is free software; you can redistribute it and/or modify it
  3333. under the terms of the GNU General Public License as published by the
  3334. Free Software Foundation; either version 2, or (at your option) any
  3335. later version.
  3336. This program is distributed in the hope that it will be useful, but
  3337. WITHOUT ANY WARRANTY; without even the implied warranty of MER‐
  3338. CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  3339. Public License for more details.
  3340. You should have received a copy of the GNU General Public License along
  3341. with this program (see the file COPYING); if not, write to the Free
  3342. Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  3343. 02111-1307, USA
  3344.  
  3345. CONTRIBUTORS
  3346. Ken Beal (kbeal@amber.ssd.csd.harris.com),
  3347. Rudolf Koenig (rfkoenig@immd4.informatik.uni-erlangen.de),
  3348. Toerless Eckert (eckert@immd4.informatik.uni-erlangen.de),
  3349. Wayne Davison (davison@borland.com),
  3350. Patrick Wolfe (pat@kai.com, kailand!pat),
  3351. Bart Schaefer (schaefer@cse.ogi.edu),
  3352. Nathan Glasser (nathan@brokaw.lcs.mit.edu),
  3353. Larry W. Virden (lvirden@cas.org),
  3354. Howard Chu (hyc@hanauma.jpl.nasa.gov),
  3355. Tim MacKenzie (tym@dibbler.cs.monash.edu.au),
  3356. Markku Jarvinen (mta@{cc,cs,ee}.tut.fi),
  3357. Marc Boucher (marc@CAM.ORG),
  3358. Doug Siebert (dsiebert@isca.uiowa.edu),
  3359. Ken Stillson (stillson@tsfsrv.mitre.org),
  3360. Ian Frechett (frechett@spot.Colorado.EDU),
  3361. Brian Koehmstedt (bpk@gnu.ai.mit.edu),
  3362. Don Smith (djs6015@ultb.isc.rit.edu),
  3363. Frank van der Linden (vdlinden@fwi.uva.nl),
  3364. Martin Schweikert (schweik@cpp.ob.open.de),
  3365. David Vrona (dave@sashimi.lcu.com),
  3366. E. Tye McQueen (tye%spillman.UUCP@uunet.uu.net),
  3367. Matthew Green (mrg@eterna.com.au),
  3368. Christopher Williams (cgw@pobox.com),
  3369. Matt Mosley (mattm@access.digex.net),
  3370. Gregory Neil Shapiro (gshapiro@wpi.WPI.EDU),
  3371. Johannes Zellner (johannes@zellner.org),
  3372. Pablo Averbuj (pablo@averbuj.com).
  3373.  
  3374.  
  3375. VERSION
  3376. This is version 4.0.2. Its roots are a merge of a custom version 2.3PR7
  3377. by Wayne Davison and several enhancements to Oliver Laumann's version
  3378. 2.0. Note that all versions numbered 2.x are copyright by Oliver Lau‐
  3379. mann.
  3380.  
  3381. AVAILABILITY
  3382. The latest official release of screen available via anonymous ftp from
  3383. gnudist.gnu.org, nic.funet.fi or any other GNU distribution site. The
  3384. home site of screen is ftp.uni-erlangen.de, in the directory pub/utili‐
  3385. ties/screen. The subdirectory `private' contains the latest beta test‐
  3386. ing release. If you want to help, send a note to screen@uni-erlan‐
  3387. gen.de.
  3388.  
  3389. BUGS
  3390. · `dm' (delete mode) and `xs' are not handled correctly (they are
  3391. ignored). `xn' is treated as a magic-margin indicator.
  3392.  
  3393. · Screen has no clue about double-high or double-wide characters. But
  3394. this is the only area where vttest is allowed to fail.
  3395.  
  3396. · It is not possible to change the environment variable $TERMCAP when
  3397. reattaching under a different terminal type.
  3398.  
  3399. · The support of terminfo based systems is very limited. Adding extra
  3400. capabilities to $TERMCAP may not have any effects.
  3401.  
  3402. · Screen does not make use of hardware tabs.
  3403.  
  3404. · Screen must be installed as set-uid with owner root on most systems
  3405. in order to be able to correctly change the owner of the tty device
  3406. file for each window. Special permission may also be required to
  3407. write the file "/var/run/utmp".
  3408.  
  3409. · Entries in "/var/run/utmp" are not removed when screen is killed
  3410. with SIGKILL. This will cause some programs (like "w" or "rwho") to
  3411. advertise that a user is logged on who really isn't.
  3412.  
  3413. · Screen may give a strange warning when your tty has no utmp entry.
  3414.  
  3415. · When the modem line was hung up, screen may not automatically detach
  3416. (or quit) unless the device driver is configured to send a HANGUP
  3417. signal. To detach a screen session use the -D or -d command line
  3418. option.
  3419.  
  3420. · If a password is set, the command line options -d and -D still
  3421. detach a session without asking.
  3422.  
  3423. · Both "breaktype" and "defbreaktype" change the break generating
  3424. method used by all terminal devices. The first should change a win‐
  3425. dow specific setting, where the latter should change only the
  3426. default for new windows.
  3427.  
  3428. · When attaching to a multiuser session, the user's .screenrc file is
  3429. not sourced. Each user's personal settings have to be included in
  3430. the .screenrc file from which the session is booted, or have to be
  3431. changed manually.
  3432.  
  3433. · A weird imagination is most useful to gain full advantage of all the
  3434. features.
  3435.  
  3436. · Send bug-reports, fixes, enhancements, t-shirts, money, beer & pizza
  3437. to screen@uni-erlangen.de.
  3438.  
  3439.  
  3440.  
  3441.  
  3442. 4th Berkeley Distribution Aug 2003 SCREEN(1)
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement