Screen has the following command-line options:
-a include all capabilities (with some minor exceptions) in
each window's termcap, even if screen must redraw parts of
the display in order to implement a function.
-A Adapt the sizes of all windows to the size of the current
terminal. By default, screen tries to restore its old
window sizes when attaching to resizable terminals (those
with "WS" in its description, e.g. suncmd or some xterm).
-c file
override the default configuration file from
"$HOME/.screenrc" to file.
-d|-D [pid.tty.host]
does not start screen, but detaches the elsewhere running
screen session. It has the same effect as typing "C-a d"
from screen's controlling terminal. -D is the equivalent to
the power detach key. If no session can be detached, this
option is ignored. In combination with the -r/-R option more
powerful effects can be achieved:
-d -r Reattach a session and if necessary detach it first.
-d -R Reattach a session and if necessary detach or even create
it first.
-d -RR Reattach a session and if necessary detach or create it.
Use the first session if more than one session is
available.
-D -r Reattach a session. If necessary detach and logout
remotely first.
-D -R Attach here and now. In detail this means: If a session
is running, then reattach. If necessary detach and logout
remotely first. If it was not running create it and
notify the user. This is the author's favorite.
-D -RR Attach here and now. Whatever that means, just do it.
Note: It is always a good idea to check the status of your
sessions by means of "screen -list".
-e xy
specifies the command character to be x and the character
generating a literal command character to y (when typed
after the command character). The default is "C-a" and `a',
which can be specified as "-e^Aa". When creating a screen
session, this option sets the default command character. In
a multiuser session all users added will start off with this
command character. But when attaching to an already running
session, this option changes only the command character of
the attaching user. This option is equivalent to either the
commands "defescape" or "escape" respectively.
-f, -fn, and -fa
turns flow-control on, off, or "automatic switching mode".
This can also be defined through the "defflow" .screenrc
command.
-h num
Specifies the history scrollback buffer to be num lines
high.
-i will cause the interrupt key (usually C-c) to interrupt the
display immediately when flow-control is on. See the
"defflow" .screenrc command for details. The use of this
option is discouraged.
-l and -ln
turns login mode on or off (for /etc/utmp updating). This
can also be defined through the "deflogin" .screenrc
command.
-ls [match]
-list [match]
does not start screen, but prints a list of pid.tty.host
strings identifying your screen sessions. Sessions marked
`detached' can be resumed with "screen -r". Those marked
`attached' are running and have a controlling terminal. If
the session runs in multiuser mode, it is marked `multi'.
Sessions marked as `unreachable' either live on a different
host or are `dead'. An unreachable session is considered
dead, when its name matches either the name of the local
host, or the specified parameter, if any. See the -r flag
for a description how to construct matches. Sessions marked
as `dead' should be thoroughly checked and removed. Ask
your system administrator if you are not sure. Remove
sessions with the -wipe option.
-L tells screen to turn on automatic output logging for the
windows.
-Logfile file
By default logfile name is "screenlog.0". You can set new
logfile name with the "-Logfile" option.
-m causes screen to ignore the $STY environment variable. With
"screen -m" creation of a new session is enforced,
regardless whether screen is called from within another
screen session or not. This flag has a special meaning in
connection with the `-d' option:
-d -m Start screen in "detached" mode. This creates a new
session but doesn't attach to it. This is useful for
system startup scripts.
-D -m This also starts screen in "detached" mode, but doesn't
fork a new process. The command exits if the session
terminates.
-O selects an optimal output mode for your terminal rather than
true VT100 emulation (only affects auto-margin terminals
without `LP'). This can also be set in your .screenrc by
specifying `OP' in a "termcap" command.
-p number_or_name|-|=|+
Preselect a window. This is useful when you want to reattach
to a specific window or you want to send a command via the
"-X" option to a specific window. As with screen's select
command, "-" selects the blank window. As a special case for
reattach, "=" brings up the windowlist on the blank window,
while a "+" will create a new window. The command will not
be executed if the specified window could not be found.
-q Suppress printing of error messages. In combination with
"-ls" the exit value is as follows: 9 indicates a directory
without sessions. 10 indicates a directory with running but
not attachable sessions. 11 (or more) indicates 1 (or more)
usable sessions. In combination with "-r" the exit value is
as follows: 10 indicates that there is no session to resume.
12 (or more) indicates that there are 2 (or more) sessions
to resume and you should specify which one to choose. In
all other cases "-q" has no effect.
-Q Some commands now can be queried from a remote session using
this flag, e.g. "screen -Q windows". The commands will send
the response to the stdout of the querying process. If there
was an error in the command, then the querying process will
exit with a non-zero status.
The commands that can be queried now are:
echo
info
lastmsg
number
select
time
title
windows
-r [pid.tty.host]
-r sessionowner/[pid.tty.host]
resumes a detached screen session. No other options (except
combinations with -d/-D) may be specified, though an
optional prefix of [pid.]tty.host may be needed to
distinguish between multiple detached screen sessions. The
second form is used to connect to another user's screen
session which runs in multiuser mode. This indicates that
screen should look for sessions in another user's directory.
This requires setuid-root.
-R resumes screen only when it's unambiguous which one to
attach, usually when only one screen is detached. Otherwise
lists available sessions. -RR attempts to resume the first
detached screen session it finds. If successful, all other
command-line options are ignored. If no detached session
exists, starts a new session using the specified options,
just as if -R had not been specified. The option is set by
default if screen is run as a login-shell (actually screen
uses "-xRR" in that case). For combinations with the -d/-D
option see there.
-s program
sets the default shell to the program specified, instead of
the value in the environment variable $SHELL (or "/bin/sh"
if not defined). This can also be defined through the
"shell" .screenrc command. See also there.
-S sessionname
When creating a new session, this option can be used to
specify a meaningful name for the session. This name
identifies the session for "screen -list" and "screen -r"
actions. It substitutes the default [tty.host] suffix.
-t name
sets the title (a.k.a.) for the default shell or specified
program. See also the "shelltitle" .screenrc command.
-T term
Set the $TERM environment variable using the specified term
as opposed to the default setting of screen.
-U Run screen in UTF-8 mode. This option tells screen that your
terminal sends and understands UTF-8 encoded characters. It
also sets the default encoding for new windows to `utf8'.
-v Print version number.
-wipe [match]
does the same as "screen -ls", but removes destroyed
sessions instead of marking them as `dead'. An unreachable
session is considered dead, when its name matches either the
name of the local host, or the explicitly given parameter,
if any. See the -r flag for a description how to construct
matches.
-x Attach to a not detached screen session. (Multi display
mode). Screen refuses to attach from within itself. But
when cascading multiple screens, loops are not detected;
take care.
-X Send the specified command to a running screen session. You
may use the -S option to specify the screen session if you
have several screen sessions running. You can use the -d or
-r option to tell screen to look only for attached or
detached screen sessions. Note that this command doesn't
work if the session is password protected.
-4 Resolve hostnames only to IPv4 addresses.
-6 Resolve hostnames only to IPv6 addresses.
