RHEL - Trouble Shoot with 2 screen in 1 SSH session

Install the screen package.

• Create a screen RC file called /root/monitor.scr:

screen -t "Log Monitor" 1 tail -f /var/log/messages
screen -t "Command Window" 2 bash
split
select 1
focus
select 2
startup_message off
 

• Start the split screen log monitor:

# screen -c /root/monitor.scr
 

• Send an update to /var/log/messages:

# logger "This is a test"
​

• To scroll back on the top window use CTRL+a, release, then press TAB.
• Enter copy mode, use CTRL+a, release, then press [.
• When in copy mode you can use j for up and k for down or use the up/down arrow keys.
• Use CTRL+a then press TAB to toggle back to the command line screen.
• To exit screen, use CTRL+a, release, then type :quit.
• Create a copy of the /etc/ssh/sshd_config file.
• Make a change to it
• See how diff can find differences between files:

# cp /etc/ssh/sshd_config /root/mysshd_config
# vim /root/mysshd_config
 

LogLevel DEBUG
Port 2222
 

# diff /etc/ssh/sshd_config /root/mysshd_config
 

• Create a screen RC file called /root/monitor_sshd.scr , this will start a test instance of SSHD when you start screen:

# screen -t "SSHD Monitor" 1 /usr/sbin/sshd -De -f
/root/mysshd_config
screen -t "Command Window" 2 bash
split
select 1
focus
select 2
startup_message off
 

• Start the split screen SSHD monitor:

# screen -c /root/monitor_sshd.scr
 

• SSH into the test SSHD instance from the bottom screen:

# ssh localhost -p 2222