dChrRbAn

1SCREEN(1)                                                            SCREEN(1)
2
3
4
5NAME
6       screen - screen manager with VT100/ANSI terminal emulation
7
8
9
10SYNOPSIS
11       screen [ -options ] [ cmd [ args ] ]
12       screen -r [[pid.]tty[.host]]
13       screen -r sessionowner/[[pid.]tty[.host]]
14
15
16
17DESCRIPTION
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
85GETTING 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
112COMMAND-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
292DEFAULT 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
471CUSTOMIZATION
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
2281THE 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
2302WINDOW 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
2402STRING 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
2564FLOW-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
2613TITLES (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
2717THE 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
3064INPUT 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
3149SPECIAL 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
3219CHARACTER 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
3272ENVIRONMENT
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
3292FILES
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
3319SEE ALSO
3320       termcap(5), utmp(5), vi(1), captoinfo(1), tic(1)
3321
3322
3323AUTHORS
3324       Originally created by Oliver Laumann, this latest version was  produced
3325       by Wayne Davison, Juergen Weigert and Michael Schroeder.
3326
3327COPYLEFT
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
3345CONTRIBUTORS
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
3375VERSION
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
3381AVAILABILITY
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
3389BUGS
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
34424th Berkeley Distribution          Aug 2003                          SCREEN(1)