Version 5.0.1 (12/05/25):
  * Fixes:
	- CVE-2025-46805: do NOT send signals with root privileges
	- CVE-2025-46804: avoid file existence test information leaks
	- CVE-2025-46803: apply safe PTY default mode of 0620
	- CVE-2025-46802: prevent temporary 0666 mode on PTYs in attacher
	- CVE-2025-23395: reintroduce lf_secreopen() for logfile
	- buffer overflow due bad strncpy()
	- uninitialized variables warnings
	- typos
	- combining char handling that could lead to a segfault

Version 5.0.0 (28/08/24):
  * Rewritten authentication mechanism
  * Add escape %T to show current tty for window
  * Add escape %O to show number of currently open windows
  * Use wcwdith() instead of UTF-8 hard-coded tables
  * New commands:
	- auth [on|off]
	  Provides password protection
	- status [top|up|down|bottom] [left|right]
	  The status window by default is in bottom-left corner.
	  This command can move status messages to any corner of the screen.
	- truecolor [on|off]
	- multiinput
	  Input to multiple windows at the same time
  * Removed commands:
	- time
	- debug
	- password
	- maxwin
	- nethack
  * Fixes:
	- Screen buffers ESC keypresses indefinitely
	- Crashes after passing through a zmodem transfer
	- Fix double -U issue

Version 4.9.1 (20/08/2023):
  * Support stop/parity bits on serial port (#23952)
  * Add needed system headers in checks and return values
    for implicit function declarations
  * Fixes:
	- Avoid zombies after shell exit (#25089)
	- Missed signal sending permission check on failed query
	  messages (CVE-2023-24626)
	- manpage fixes
	- source code fixes during cleanup
	- UTF-8 encoding can emit invalid UTF-8 sequences for out of
	  range unicode values (#62097)

Version 4.9.0 (30/01/2022):
  * Hardstatus option for used encoding (escape string '%e')
  * OpenBSD uses native openpty() from its utils.h
  * Fixes:
	- fix combining char handling that could lead to a segfault
	- CVE-2021-26937: possible denial of service via a crafted
	  UTF-8 character sequence (bug #60030)
	- make screen exit code be 0 when checking --help
	- session names limit is 80 symbols (bug #61534)
	- option -X ignores specified user in multiuser env (bug #37437)
	- a lot of reformations/fixes/cleanups (man page and source code)

Version 4.8.0 (05/02/2020):
  * Improve startup time by only polling for files to close
  * Fixes:
	- Fix for segfault if termcap doesn't have Km entry
	- Make screen exit code be 0 when checking --version
	- Fix potential memory corruption when using OSC 49

Version 4.7.0 (02/10/2019):
  * Add support for SGR (1006) mouse mode
  * Add support for OSC 11
  * Update Unicode ambiguous and wide tables to 12.1.0
  * Fixes:
	- cross-compilation support (bug #43223)
	- a lot of manpage fixes and cleanups

Version 4.6.2 (23/10/2017):
  * Fixes:
	- revert changes to cursor position restore behavour (bug #51832)
	- set freed pointer to NULL (bug #52133)
	- documentation fixes
	- fix windowlist crashes (bug #43054 & #51500)

Version 4.6.1 (10/07/2017):
  * Fixes:
	- problems with starting session in some cases
	- parallel make install
	- segfault when querying info on nonUTF locale (bug #51402)

Version 4.6.0 (28/06/2017):
  * Update Unicode wide tables to 9.0 (bug #50044)
  * Support more serial speeds
  * Improved namespaces support
  * Migrate from fifos to sockets
  * Start viewing scrollback at first line of output (bug #49377)

Version 4.5.1 (25/02/2017):
  * Fixes:
	- logfile permissions problem (CVE-2017-5618)
	- SunOS build problem (bug #50089)
	- FreeBSD core dumps (bug #50143)

Version 4.5.0 (10/12/2016):
  * Allow specifying logfile's name via command line parameter '-L'
  * Fixes:
	- broken handling of "bind u digraph U+" (bug #48691)
	- crash with long $TERM (bug #48983)
	- crash when bumping blank window
	- build for AIX (bug #49149)
	- %x improperly separating arguments
	- install with custom DESTDIR (bug #48370)

Version 4.4.0 (19/06/2016):
  * Support up to 24 function keys
  * Fix runtime issues
  * 'logfile' command, starts logging into new file upon changing

Version 4.3.1 (28/06/2015):
  * Fix resize bug

Version 4.3.0 (13/06/2015):
  * Introduce Xx string escape showing the executed command of a window
  * Implement dead/zombie window polling, allowing for auto reconnecting
  * Allow setting hardstatus on first line
  * New Commands:
	- 'sort' command sorting windows by title
	- 'bumpleft', 'bumpright' - manually move windows on window list
	- 'collapse' removing numbering 'gaps' between windows, by renumbering
	- 'windows' command now accepts arguments for use with querying

Version 4.2.1 (28/04/2014):
  * allow for terminal with long $TERM (up to 32 characters)
  * allow to use long logins
  * documentation fixes
  * runtime fixes

Version 4.2.0 (17/04/2014):
  New Commands:
  * 'unbindall' to unbind all commands
  * 'up', 'down', 'left', 'right' sub-commands for 'focus'
  * 'rendition' to specify rendition to use in caption/hardstatus for
     window-names that have bell/monitor/silence/so turned on.
  * 'layout', with the following sub-commands
	- 'title'
	- 'number'
	- 'autosave' ('autosave on' or 'autosave off')
	- 'new'
	- 'save' ('save <name>')
	- 'select'
	- 'next'
	- 'prev'
	- 'attach'
	- 'show'
	- 'remove'
	- 'dump'
  * 'group' for moving window(s) into a group.
  * 'defmousetrack' and 'mousetrack', to turn on/off mouse-tracking for
    displays. It's turned off by default. With mouse-tracking turned on, it's
    possible to switch to a region ('focus') using mouse clicks. It's also
    possible to select a text region in copy-mode using a mouse click to place
    a mark and the scroll wheel to scroll through the buffer. Additional
    features might be to allow clicking on window-titles in the caption to
    switch to that window.
  * All commands prefixed '@' are treated as 'quiet', i.e. '@'-prefixed commands
    do not trigger any display messages.

  Changed Commands:
  * '-v' parameter to 'split' command for vertical splits.
  * 'sorendition' deprecated in favour of 'rendition so'.
  * 'digraph' can take a second parameter to specify custom digraphs. For
    example,
	'digraph >= ≥' or 'digraph >= U+2265'
    Using '0' as the second parameter will remove the digraph.
  * 'stuff' will prompt for input if there's nothing to stuff.
  * The argument to ":number"
    can be prefixed with '+' or '-' to use it as a relative argument.
  * '-g' parameter to 'windowlist' to show nested list of windows.
  * '//group' parameter to 'screen' to create a grouped window.
  * 'blankerprg' shows the currently set command on no argument.
  * 'maxwin' can now be used to increase the number of maximum windows.

  .screenrc:
  * $PID expands to the PID of the screen session.
  * $PWD expands to the current working directory of the session.
  * $STY expands to the session name.
  * Tilde-expansion in pathnames (e.g. for the 'source' command)
  * C-style escapes can be used (e.g. "\n" to get a newline with 'stuff')
  * '%p' in caption/hardstatus string expands to the PID of the backend, and
    '%+p' expands to the PID of the frontend (display).
  * '%S' in caption/hardstatus string expands to the session name.
  * '%P' in the caption string evaluates to true if the region is in copy mode.
  * '%E' in the caption string evaluates to true if the escape character has
    currently been pressed.

  Window List:
  * Nested views when there are window groups (with 'windowlist -g').
  * Press 'm' to toggle the most-recent view.
  * Press 'g' to toggle nestedness.
  * Press 'a' to view all windows in the list.
  * Press '/' to search in the list.
  * Press ',' and '.' to re-order windows in the list.
  * Press 'K' to kill a window (requires confirmation).

  Display List:
  * Press 'd' to detach a display, 'D' to power-detach.

  Others:
  * Start using 'ChangeLog' for logging changes again.
  * Terminfo update for 256-color support.
  * Multiple input history (partially from Romain Francoise).
  * vi-like fFtT;, searching in copy mode.
  * In copy mode, search in reverse direction when 'N' is pressed.
  * Tab-completion for command input.
  * Some more readline-like bindings in input mode (e.g. ^W, ^D, ^P, ^N etc.)
  * Fix displaying unicode characters in the caption/hardstatus on UTF8 locale.
  * A revamped displays list (for 'displays' command)
  * Increased default maximum number of windows from 40 to 100.
  * Increased number color/attribute changes in caption/hardstatus string from 16 to 256.
  * Some commands can be remotely queried using the -Q command-line flag.

  In-Progress:
  * Scripting support (thanks to Google Summer of Code 2009 project by Rui Guo)

  Developers:
  * Alexander Naumov <alexander_naumov@opensuse.org>
  * Amadeusz Sławiński <amade@asmblr.net>
  * Juergen Weigert <jw@suse.de>
  * Michael Schroeder <mls@suse.de>
  * Micah Cowan <micah@cowan.name>
  * Sadrul Habib Chowdhury <sadrul@users.sourceforge.net>

  Contributors:
  * Clavelito <maromomo@hotmail.com>
  * Dick <dick@mrns.nl>
  * Gabriel <g2p.code@gmail.com>
  * Benjamin Andresen <bandresen@gmail.com>
  * Takeshi Banse <takebi@laafc.net>
  * Maarten Billemont <lhunath@gmail.com>
  * Curtis Brown <mrbrown8@juno.com>
  * Cyril Brulebois <kibi@debian.org>
  * Trent W Buck <trentbuck@gmail.com>
  * Stephane Chazelas <stephane_chazelas@yahoo.fr>
  * Kees Cook <kees@ubuntu.com>
  * Thomas Dickey <tom@invisible-island.net>
  * Christian Ebert <blacktrash@gmx.net>
  * Geraint Edwards <gedge-lists-screen@yadn.org>
  * Romain Francoise <romain@orebokech.com>
  * Alexander Gattin <xrgtn@yandex.ru>
  * Emanuele Giaquinta <e.giaquinta@glauco.it>
  * Yi-Hsuan Hsin <mhsin@mhsin.org>
  * Kipling Inscore <kinscore@synaptics.com>
  * Chris Jones <cjns1989@gmail.com>
  * Max Kalashnikov <mmt@maxkalashnikov.com>
  * Steve Kemp <steve@steve.org.uk>
  * Ryan Niebur <ryan@debian.org>
  * Jan Christoph Nordholz <hesso@pool.math.tu-berlin.de>
  * William Pursell <bill.pursell@gmail.com>
  * Michael Scherer <misc@mandriva.org>
  * Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
  * Peter Teichman <peter@teichman.org>

30.10.94

This is a quick overview of screen's life story. But it is not up
to date.  You'll find more details about the revision history in
patchlevel.h and newer changes are only documented there. 

31.7.93	-- 3.5.1
================

* writelock, number, paste with arg, at, zombie and wall commands added.

* Access Control Lists and more multi-user support added.

* select and setenv commands enhanced.

* socket.c: motorola bugfix.

* configure.in: --srcdir support.

* configure.in: recognize alpha and SUNOS3 correctly.

* doc/screen.texinfo: Documentation by Jason Merrill.

13.05.93 -- 3.3.3
=================

* defautonuke, silence commands added.

* exec command added.

* hardcopydir, logdir commands added.

* Made a superb configure script.

* BROKEN_PIPE, SOCK_NOT_IN_FS added for braindamaged systems.

* multi display, multi user support.

* process command. CS, CE switch cursorkeycap in application mode.

* lockprg pow_detaches on SIGHUP

* ins_reg copy_reg commands.

* new screenrc syntax.

* split up screen.c and ansi.c

21.10.92 -- 3.2.9
================

* ChangeLog: replaces CHANGES and is in GNUish format.

* Makefile (CFLAGS, M_CFLAGS, LIBS, OPTIONS): moved user config here, 
	merged all Makefiles, GNUified

* socket.c (FindSocket): ignoring bad files in $SCREENDIR

* config/config.linux: ported.

* utmp.c, exec.c, loadav.c: split apart from screen.c/fileio.c

15.07.92 -- 3.2.8
=================

* ansi.c (WriteString): automatic character set switching for 8bit support

3.2.3-3.2.7
===========

* concept changes: Display structure, Multi attacher 

...

3.2.2
=====

* screen.c (main): -m option, "_M_ake always new session", ignore $STY

* screen.c (main):  -Ssessionname 
* fileio.c (RcLine): ^A:sessionname give your session a nicer name.

* screen.c (main): supporting detached startup via screen -d -m -Ssockname

* fileio.c (stripdev): moved, could not compile

* overlay.h: "stackable overlay concept"

* search.c: vi-like / and ? search AND emacs-like ^S and ^R incremental search
	in scrollback

* mark.c: I meant BSDI not BSD

* concept change: struct display and struct newwin introduced.

* screen.c (main): -v option prints version.

* screen.c (MakeWindow): ^A:screen /dev/ttya opens a character device 
	instead of forking ShellProg with a pty pair.

3.2.0
=====

Ultrix port

Irix 3.3 SGI port

shadow password suite supported

data loss on stdin overflow fixed

"refresh off" keyword added.

3.1.1
------

Screen is now under the GNU copyleft license. See file COPYING.

command line option -A. $LINES, $COLUMNS improved.

C-A : vbellwait <sec>

XENIX support (Ronald Khoo)

SYSV has uname() instead of gethostname().

hpux has setresuid.

ClearScreen now saves image to scrollback buffer.

mips has setenv.

numerous bugfixes.

3.1 finally released version.
=============================

3.0.99: last minute changes:
----------------------------

MIPS support (J{rvinen Markku)

SVR4 support (Marc Boucher)

secopen() secfopen() calls replace stat/access/open.
C-a : echo improved.
'register int'

Changes up to Screen 3.0 Patchlevel 7
=====================================

Better terminfo support: Screen now checks if a termcap/info
entry which the name "screen.$TERM" does exist. Look in the
"VIRTUAL TERMINAL" section of the manual for more details.

Many security improvements.

ScrollRegion() bug fixed which caused slow scrolling if AL
or DL was used.

Pyramid and Ultrix support added. (Tim and Larry)
  
ENVIRONMENT support.
  /local/etc/screenrc checks for $SYSSCREENRC
  $HOME/.screenrc checks for $ISCREENRC and $SCREENRC
  /local/screens checks for $ISCREENDIR and $SCREENDIR
  .screenrc understands ${VAR} and $VAR .

screen 3.0 Patchlevel 6
=======================

.screenrc:
  screen now only opens the windows you explicitly ask for.
  If you specify none, you still get one window, of course.

screen 3.0. Patchlevel 5
========================

Ansi prototyping by Christos.

copy mode: CTRL-U / CTRL-D exchanged. code cleanup.

changes to screen 3.0 patchlevel 4
==================================

markkeys "string"
  allows to rebind the keys used in copy/history mode.
  string is made up of pairs "<oldchar>=<newchar>" which are separated
  by a colon. Oldchar and newchar are either single ascii characters, 
  or the two character sequence ^x, where x is an ascii character, or
  a 3 digit octal value prepended with '\'. the string "\040=.:^M=q"
  rebinds '.' to set marks, and the return key will abort copy mode.

set scrollback 100
  resizes the scrollback history buffer to 100 lines. a default of 50
  is installed. 

A Howard Chu like scrollback history is installed. Many vi-like keys
  are added to the copy mode. The '?' key reports on cursor position.

screen 3.0 Patchlevel 3
=======================

WriteString fixed, it did kill the display variable.

Yet another LP bugfix.

non vt100 semi-graphics character support.

waynes patch fixed

screen 3.0 Patchlevel 2
=======================

wayne patches cursor motion outside scrollregions.

.screenrc 
  monitor on|off

changes in Screen 3.0 Patchlevel 1
==================================

screen -wipe

^A : set vbell_msg "Wuff Wuff"

Thousand enhancements: help resizable, copy'n'paste in main
  socket loop, and no more '\0' hackin'. :WS=\E8;%d;%dt:

screen can now resize windows under sunview.

^A : set crlf on|off
  effects markroutine join.

screen learned about sized windows under X

screen -ls (-d) -q
  quiet option. We count the number of detached (attached) sessions and set
  a return value of 10+n. The -q option inhibits all startup
  warnings/messages. i.e. screen -R -q may return with code 12 or higher
  or start a new/old session.

pow_detach_msg "text string"
  new command, allows messages, terminal reset, etc. on logout caused
  by pow_detach.

^A : learned a new keyword "set":
  commands like "login on" , "vbell off", ... affect the default for
  windows to be created. But commands like "set login off" affect
  the actual setting of this window. and not the default.
  such commands may be bound to keys. example: 
  bind 'O' set login off
  is valid in your .screenrc as well as typed at the ':' prompt.
  a bonus is ":set all" which is synonym to ":help".
  At the Colon prompt also KeyNames can be entered, although that makes
  not always sense.

^A x uses a builtin lockprg, if 
  a) we don't find our lockprg, or
  b) user supplies us with the environment variable LOCKPRG set to "builtin"
  the builtin locks until your login password is typed. on systems using
  "shadow password files" you are prompted for a password.

markroutine can append joined.

screen removes the "controlling tty" from utmp while ptys are attached.

markroutine performs CR+NL when '\n' is pressed

screen may die quietly, when no TERMCAP entry for "screen" is
found, and screen is run under X-windows

_SEQUENT_ marks sequent386_ptx

screen runs now under SunOS4.1.1 (we need setsid()!).

bug in SetForeWindow fixed.

rare markroutine bug fixed.

we don't open every file the attacher tells us.

we have now our wonderful "Wuff, Wuff" visual_bell

we have now the interprocess-communication-buffer. secure version.

'^A =' removes the interprocess-communication-buffer.

markroutine as in 2.1

markroutine: 'a' toggles append mode,
             '>' like ' ', but immediately WriteFile(DUMP_EXCHANGE) then.
             'A' like ' ', but first switch to append mode.

.screenrc understands "screen 2:faui09 rlogin faui09 -l jnweiger"
                  and "password none"
                  and "vbell [on|off]"

'^A :' allows .screenrc commands "online".

screen now receives new $TERM from attacher, when it is reattached 

MakeClientSocket() fifo version does now test for access.

.screenrc learns "hardstatus {on|off}"

termcap's VB is used for vbell if available.

Attach() code rewritten:
	screen now lists socket directory, if it does not find a suitable socket
	screen -d [host.tty] detaches a running screen. 

screen -[ls|list]
	list all sockets that we find in our sockdir

when the socket has been removed, send a SIGCHLD to the poor SCREEN 
process and it will try to recover. then try a 'screen -r' again.
all the socket stuff lives now in an extra file.

Major changes in version 2.4:
=============================

*  Test version that presents the erlangen extensions from 2.0 in a 2.3
   screen.

*  window resize support

*  screen locking C-a x

*  support for SYSV

*  password protection

*  copy & paste across screens

*  remote detach and power detach

Major changes in version 2.3:

*  Terminal emulation has been significantly enhanced and bugfixed.

*  We now fully update the last character on the screen for true auto-
   margin terminals, though there may be some delay before the character
   can be safely added to the screen.  If your terminal has character
   insert it will be used to shorten the delay.

*  Added the "termcap" .screenrc command to tweak your terminal's termcap
   entry AND to customize the termcap generated for the virtual terminals.
   See also the -L and -O command-line options, and the SCREENCAP environ-
   ment variable.

*  Fixed screen's character handling when detached or suspended to NOT block
   the child processes in their windows -- output continues to be processed
   in the background.

*  Added a.k.a.s (window-name aliases) that allow you to customize the
   window-information line, including being able to change the name on-
   the-fly to reflect what's currently running in the window (see the
   -k option, shellaka command, and ALSO KNOWN AS discussion in the doc).

*  Added the ability to log the output of a window to a file (see the
   "C-a H" (log) command).

*  Flow-control can now be set for each window and switched interactively
   (see the "flow" command, -f option, and FLOW CONTROL discussion).

*  Individual windows can be included or excluded from mention in the
   /etc/utmp file (see the "login" command and -l option).

*  Added an activity monitor, which allows you to have a window watched for
   the start of any output and alert you when it occurs (see the "C-a M"
   (monitor) command).

*  Enhanced the information in the window-information line to keep track of
   windows that have: logging turned on '(L)'; beeped in the background '!';
   became active while being monitored '@' (see the "C-a w" (windows) command).

*  Added an on-line help display that lists all the commands and their
   key bindings (see the "C-a ?" (help) command).

*  Extended handling of the beep message (and also the new activity message)
   to allow '~' to specify a literal beep (see the "beep" and "activity"
   .screenrc commands).

*  You can now set the default action on receipt of a hangup signal:  detach
   or terminate (see the "autodetach" .screenrc command).

*  Routing of characters to their virtual terminals has been enhanced to
   not drop characters nor (in rare circumstances) hang up screen.

*  The NFS compatibility has been enhanced.

Major changes in version 2.0a:

*  Screen allows you to `detach' the "screen" session from the physical
   terminal and resume it at a later point in time (possibly on a
   different terminal or in a different login session).

  To get an impression of this functionality do the following:

     - call "screen" and create a couple of windows
     - type Control-A Control-D (screen terminates; you are back
       in the shell)
     - call "screen -r" to resume the detached screen

*  Screen supports multiple character sets and the ISO 2022 control
   functions to designate and switch between character sets.
   This allows you, for instance, to make use of the VT100 graphics
   character set or national character sets.
