GNU Screen Tips

Taking a break from the OSPF workbook to write up a brief summary of my favorite GNU screen hotkeys.

Basic hotkeys

Ctrl+a Ctrl+a = Return to your last terminal

Ctrl+a p and Ctrl+a n will move you to the previous and next terminals, respectively.

Ctrl+a d = Detach from your current session

From any command prompt, type screen -ls to list your open screen sessions.

[531][charlie] ~ $ screen -ls

There are screens on:
        29333.pts-2.champion    (03/20/2010 07:04:40 PM)        (Detached)
        26943.pts-3.champion    (03/20/2010 06:16:20 PM)        (Detached)

2 Sockets in /var/run/screen/S-charlie.

If you only have one session open, just type screen -r to rejoin.

If you have multiple sessions, type screen -r 123 where 123 is the socket number from the list command.

Tip: You only need to type enough characters to make the number unique.

So in the example above, you could type screen -r 26 to rejoin the second session.

Writing to multiple screens

Another great time saver is writing to multiple screens at once.

Here is how I use it with my Dynamips lab.

First, I want to make sure I’m no longer in configuration mode.

At the screen command prompt (Ctrl+a : ) enter
at \# stuff end\015
which will send "end" to all your terminals. Now you can "write mem" to all your devices simultaneously.  Again, at the screen command prompt enter  
at \# stuff wr\015
At this point I will quickly rotate through the devices to make sure things are saved, return to dynamips and issue a save /all or export /all.
Tada, all my configs are now saved.  Of course, you could use one line but I prefer to use two to ensure there is no lag between the two commands.

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You’re currently reading “GNU Screen Tips,” an entry on Cisco Fun

Published:: March 21, 2010 / 4:47 am

Category:: Uncategorized

Tags:: Tips and tricks

About

Hi, my name is Charlie and I started studying for my Cisco certifications in 2007. At the time, I worked as a MIS administration doing pretty mundane, brainless tasks (think Windows XP/2003 server environments).

My company sent me to a networking class and I fell in love with the material. A week after the class I knew the direction I wanted to take my career.

This blog will chronicle my journey through the Cisco networking certification world. The current focus is the CCIE (R&S). I passed the lab in December, 2010.

Adnan Hassan 12.3.10 / 12am

Thanks for the info.

I am using the Alt-W to save my configs using the following command. Edit /etc/screenrc and paste this line.

bindkey ^[w at \# stuff 15151515end1515151515en151231515wr15

it will first enter end, en and 123(for password of switches on tty)command to make sure all routers/switches in priv mode.

finally it will do wr on all the switches/routers.

so within 1 sec you have saved your config just by pressing alt-w.

charliec 12.3.10 / 12am

That’s an awesome awesome awesome tip, thanks! Will try it out.

hmm dont know what happened to my slashes in the previous post.
lets try one more time.
bindkey ^[w at \# stuff 15151515end1515151515en151231515\wr15

Adnan Hassan 12.3.10 / 1am

Uploaded a screenrc file for you so you can use it as a reference.
http://www.4shared.com/file/VF1_UUjL/screenrc.html?

The config features

1) Alt-x (alt+1,alt+2 etc to switch b/w windows)
2)Change of Escape Character C-A to C-` (Cisco IOS C-A is so useful, you dont wanna waste that shortcut with the escape of screen.)
3) Alt Left and Alt right to go to next and previous window.

if you wanna know whats the exact code for the bindkey

do the following on “screen”.

cat > /dev/null

and type your combination to get the code.

sam 12.5.11 / 7pm

Can you please post your screenrc file again. It is deleted at 4shared.

Thanks,

The Story « Cisco Fun 12.17.10 / 1am

[...] you use are planning to use Linux, check out this post on tips with Screen and make sure to read the comments. There is a valuable script provided by [...]

fortable1999 (@Menguras) 10.26.11 / 6am

nice.

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GNU Screen Tips

Basic hotkeys

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