How to record your ssh session using screen.
Per the man page – “Screen is a full-screen window manager that multiplexes a physical terminal between several processes (typically interactive shells)”.
Screen is most commonly used to create multiple sessions to remote hosts within a single terminal window or even run multiple commands locally without leaving your shell terminal. For instance, you could be tailing the log file in one session, then run a long process, then ssh into other machine etc. all within a single window.
Screen is the go to tool when setting up a remote connection, such as ssh, and you want to continue your work at any time or from any other host without worrying of a dropped connection.
In this post, I will show you how you can record your bash session.
Installation –
yum install screen (Debian/Ubuntu) apt-get install screen (Redhat/CentOS)
My local environment and the remote host I am sshing to –
daniel@linubuvma:/tmp$ screen -v Screen version 4.01.00devel (GNU) 2-May-06 daniel@linubuvma:/tmp$ uname -r 3.13.0-106-generic daniel@linubuvma:/tmp$ cat /etc/issue Ubuntu 14.04.5 LTS \n \l daniel@linubuvma:/tmp$ ssh ns2 'uname -r ; cat /etc/issue' 2.6.32-642.6.1.el6.x86_64 CentOS release 6.8 (Final) Kernel \r on an \m
The ‘-L’ option of screen is used to record your session, the session log is automatically saved in a file named ‘screenlog.n’ in your current directory.
daniel@linubuvma:/tmp$ ls
config-err-hbzs5e one ssh-4yheApHRgMBF ssh-RK7GpeFuzUB8 VMwareDnD vmware-root-2347660412
gpg-kZux7q screenlog.0 ssh-BBblvGtb5284 vmware-daniel vmware-root
daniel@linubuvma:/tmp$ free -m
total used free shared buffers cached
Mem: 3946 2489 1457 6 547 1031
-/+ buffers/cache: 911 3035
Swap: 4092 0 4092
daniel@linubuvma:/tmp$ exit
[screen is terminating]
daniel@linubuvma:/tmp$
The whole bash session will be logged in screenlog.0 in this case –
daniel@linubuvma:/tmp$ cat screenlog.0
daniel@linubuvma:/tmp$ ls
config-err-hbzs5e one ssh-4yheApHRgMBF ssh-RK7GpeFuzUB8 VMwareDnD vmware-root-2347660412
gpg-kZux7q screenlog.0 ssh-BBblvGtb5284 vmware-daniel vmware-root
daniel@linubuvma:/tmp$ free -m
total used free shared buffers cached
Mem: 3946 2489 1457 6 547 1031
-/+ buffers/cache: 911 3035
Swap: 4092 0 4092
daniel@linubuvma:/tmp$ exit
exit
daniel@linubuvma:/tmp$
Recording your session of an ssh connection to a remote host is also similar, with ‘-L’ option followed by the command to ssh to remote host.
Option -fn (with no flow-control)
Option -t (title bar name) in this case ‘practice’.
daniel@linubuvma:/tmp$ screen -fn -t practice -L ssh ns2 Last login: Tue Dec 27 09:46:10 2016 from linubuvma.home.net [daniel@kauai ~]$ hostname -f kauai.example.net [daniel@kauai ~]$ uptime 10:08:18 up 18 days, 10:02, 14 users, load average: 0.19, 0.49, 0.64 [daniel@kauai ~]$ exit [screen is terminating] daniel@linubuvma:/tmp$ cat screenlog.0 Last login: Tue Dec 27 09:46:10 2016 from linubuvma.home.net [daniel@kauai ~]$ hostname -f kauai.example.net [daniel@kauai ~]$ uptime 10:08:18 up 18 days, 10:02, 14 users, load average: 0.19, 0.49, 0.64 [daniel@kauai ~]$ exit logout Connection to ns2 closed. daniel@linubuvma:/tmp$
Additional resources –
https://www.rackaid.com/blog/linux-screen-tutorial-and-how-to/
https://linux.die.net/man/1/screen
