screen - screen manager with VT100/ANSI terminal emulation (具有 VT100/ANSI 終端仿真的屏幕管理器)
1. screen [-opts] [cmd [args]] or screen -r [host.tty]
Options:
-4 Resolve hostnames only to IPv4 addresses.
-6 Resolve hostnames only to IPv6 addresses.
-a Force all capabilities into each window's termcap.
-A -[r|R] Adapt all windows to the new display width & height.
-c file Read configuration file instead of '.screenrc'.
-d (-r) Detach the elsewhere running screen (and reattach here).
-dmS name Start as daemon: Screen session in detached mode.
-D (-r) Detach and logout remote (and reattach here).
-D -RR Do whatever is needed to get a screen session.
-e xy Change command characters.
-f Flow control on, -fn = off, -fa = auto.
-h lines Set the size of the scrollback history buffer.
-i Interrupt output sooner when flow control is on.
-l Login mode on (update /var/run/utmp), -ln = off.
-ls [match] or
-list Do nothing, just list our SockDir [on possible matches].
-L Turn on output logging.
-m ignore $STY variable, do create a new screen session.
-O Choose optimal output rather than exact vt100 emulation.
-p window Preselect the named window if it exists.
-q Quiet startup. Exits with non-zero return code if unsuccessful.
-Q Commands will send the response to the stdout of the querying process.
-r [session] Reattach to a detached screen process.
-R Reattach if possible, otherwise start a new session.
-s shell Shell to execute rather than $SHELL.
-S sockname Name this session <pid>.sockname instead of <pid>.<tty>.<host>.
-t title Set title. (window's name).
-T term Use term as $TERM for windows, rather than "screen".
-U Tell screen to use UTF-8 encoding.
-v Print "Screen version 4.03.01 (GNU) 28-Jun-15".
-wipe [match] Do nothing, just clean up SockDir [on possible matches].
-x Attach to a not detached screen. (Multi display mode).
-X Execute <cmd> as a screen command in the specified session.
resolve [rɪ'zɒlv]：vt. 決定，溶解，使...分解，決心要做... vi. 解決，決心，分解 n. 堅決，決定要做的事
遠程登錄到 Linux 服務器，經常需要很長時間才能完成任務，在此期間不能關掉窗口或者斷開連接，否則這個任務就會被殺掉。可以用 screen 命令解決這個問題。screen 命令可以實現當前窗口與任務分離，即使離線了，服務器仍在後臺運行任務。當重新登錄服務器，可以讀取窗口線程，重新連接任務窗口。只要 screen 本身沒有終止，在其內部運行的會話都可以恢復。這一點對於遠程登錄的用戶特別有用，即使網絡連接中斷，用戶也不會失去對已經打開的命令行會話的控制。screen 在網絡環境不好的地方非常的有用。
screen -v
-v - Print "Screen version 4.03.01 (GNU) 28-Jun-15".
strong@foreverstrong:~$ screen -v
Screen version 4.03.01 (GNU) 28-Jun-15
strong@foreverstrong:~$
screen -ls / screen -list
-ls [match] or -list - Do nothing, just list our SockDir [on possible matches].
strong@foreverstrong:~$ screen -ls
No Sockets found in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -list
No Sockets found in /var/run/screen/S-strong.
strong@foreverstrong:~$
screen -S yong
-S sockname - Name this session <pid>.sockname instead of <pid>.<tty>.<host>.
新建名稱爲 yong 的 session，並進入 yong 的 session。
使用 screen -ls 查看當前存在的 session。Attached 表示這個 screen 會話是活動的。其中 3380.yong 中 3380 表示 screen 會話的進程號，yong 表示 screen 會話名。
strong@foreverstrong:~$ screen -S yong
strong@foreverstrong:~$ screen -ls
There is a screen on:
3380.yong (09/12/2019 07:27:09 PM) (Attached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -list
There is a screen on:
3380.yong (09/12/2019 07:27:09 PM) (Attached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
Ctrl + A D -> detach
暫時離開當前 session，將目前的 screen session 丟到後臺執行，並回到還沒進 screen 時的狀態，此時在 screen session 裏運行的 process 會繼續執行，即使 logout 也不影響。
C-a d / C-a C-d - (detach) Detach screen from this terminal.
[detached from 3380.yong]
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -list
There is a screen on:
3380.yong (09/12/2019 07:27:09 PM) (Detached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -ls
There is a screen on:
3380.yong (09/12/2019 07:27:09 PM) (Detached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
screen -r yong
-r [session] - Reattach to a detached screen process.
恢復離線的 screen 會話，回到會話名 yong。
detach [dɪ'tætʃ]：vt. 分離，派遣，使超然
attach [ə'tætʃ]：vt. 使依附，貼上，繫上，使依戀 vi. 附加，附屬，伴隨
strong@foreverstrong:~$ screen -ls
There is a screen on:
3380.yong (09/12/2019 07:27:08 PM) (Detached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -r yong
......
strong@foreverstrong:~$ screen -list
There is a screen on:
3380.yong (09/12/2019 07:27:08 PM) (Attached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
screen -x 3380
-x - Attach to a not detached screen. (Multi display mode).
screen -x / screen -r + 進程 ID 或者會話名都可以。恢復離線的 screen 作業。
strong@foreverstrong:~$ screen -ls
There is a screen on:
3380.yong (09/12/2019 07:27:08 PM) (Detached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -x 3380
......
strong@foreverstrong:~$ screen -list
There is a screen on:
3380.yong (09/12/2019 07:27:09 PM) (Attached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
新建一個名稱爲 qiang 的會話，並進入到該會話中。
strong@foreverstrong:~$ screen -S qiang
列出所有會話列表。
strong@foreverstrong:~$ screen -ls
There are screens on:
7042.qiang (09/13/2019 05:01:37 PM) (Attached)
3380.yong (09/12/2019 07:27:08 PM) (Detached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
kill 3380
kill 3380 殺死 3380.yong。
strong@foreverstrong:~$ screen -ls
There are screens on:
7042.qiang (09/13/2019 05:01:37 PM) (Detached)
3380.yong (09/12/2019 07:27:08 PM) (Detached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ kill 3380
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -ls
There is a screen on:
7042.qiang (09/13/2019 05:01:38 PM) (Detached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
screen -dmS cheng
-dmS name - Start as daemon: Screen session in detached mode.
新建一個名稱爲 cheng 的會話，不進入到該會話中。
daemon ['diːmən]：n. 守護進程，後臺程序
strong@foreverstrong:~$ screen -ls
There is a screen on:
7042.qiang (09/13/2019 05:01:37 PM) (Detached)
1 Socket in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -dmS cheng
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -ls
There are screens on:
15991.cheng (09/16/2019 08:17:36 AM) (Detached)
7042.qiang (09/13/2019 05:01:38 PM) (Detached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
screen -X -S 16019 quit
screen -X -S 16019 quit 關閉 16019.test。
strong@foreverstrong:~$ screen -ls
There are screens on:
15991.cheng (09/16/2019 08:17:36 AM) (Detached)
7042.qiang (09/13/2019 05:01:38 PM) (Detached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -dmS test
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -ls
There are screens on:
16019.test (09/16/2019 08:23:46 AM) (Detached)
15991.cheng (09/16/2019 08:17:36 AM) (Detached)
7042.qiang (09/13/2019 05:01:38 PM) (Detached)
3 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -X -S 16019 quit
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -ls
There are screens on:
15991.cheng (09/16/2019 08:17:36 AM) (Detached)
7042.qiang (09/13/2019 05:01:38 PM) (Detached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
screen -wipe
-wipe [match] Do nothing, just clean up SockDir [on possible matches].
screen -list 會顯示會話爲 dead 狀態。使用 screen -wipe 命令清除該會話
screen -d 7042
-d (-r) - Detach the elsewhere running screen (and reattach here).
strong@foreverstrong:~$ screen -ls
There are screens on:
15991.cheng (09/16/2019 08:17:36 AM) (Attached)
7042.qiang (09/13/2019 05:01:38 PM) (Attached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -d 15991
......
[remote detached from 15991.cheng]
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -ls
There are screens on:
15991.cheng (09/16/2019 08:17:36 AM) (Detached)
7042.qiang (09/13/2019 05:01:38 PM) (Attached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -d 7042
[7042.qiang detached.]
strong@foreverstrong:~$
strong@foreverstrong:~$ screen -ls
There are screens on:
15991.cheng (09/16/2019 08:17:35 AM) (Detached)
7042.qiang (09/13/2019 05:01:37 PM) (Detached)
2 Sockets in /var/run/screen/S-strong.
strong@foreverstrong:~$