Removing the escape characters from GNU Screen's screenlog.%n

Question

Is it possible to remove the ESC sequences in GNU Screen's output file? Things such as colours, tabs and other escape characters make their way into the log files and become difficult to decipher.

I've tried Dr. Google & Co. as well as reading the manual, but haven't been able to find anything suitable...

Perhaps I've overlooked something?

Solution 1

Try this piece of Perl magic:

perl -ne 's/\x1b[[()=][;?0-9]*[0-9A-Za-z]?//g;s/\r//g;s/\007//g;print' < screenlog.0

Solution 2

Also try the -r or -R option of less.

less -r screenlog.0

Solution 3

Use ansifilter.

ansifilter screenlog.txt > screenlog.txt.clean

Solution 4

Once you capture your session in screenlog.n , you can cat the file to the terminal and then use screen's hardcopy command to dump the cat's output to a file . The result will provide you with clean output that does not have any escape sequences.

The only 'gotcha' seems to be to make sure that hardcopy captures eveyrthing in the scrollback buffer and that the scrollback buffer contains only what you want to capture.

1. $ screen
2. $ cd /path/to/screenlog.n directory/
3. $ wc -l screenlog.n 
4. $ screen -X scrollback 245 # 245 is the number of lines found from your wc command + 5 
5. $ cat screenlog.n
6. $ screen -X hardcopy -h screenlog.n.cleaned 

Note that -h ensures that you capture the entire scrollback history and not just whats in immediate view

The screenlog.n.cleaned file will now contain a hardcopy of the cat output and won't include any escape sequences

Solution 5

I use the strings command to make a screen log readable. Under Debian it is part of the binutils package.

As its man page says:

strings - find the printable strings in a object, or other binary, file

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Comments

[shaond]

Thanks for that - that's AWESOME! It still has the ^G and ^M characters in there, but its a lot more readable...

[whitequark]

Added that to the expression.

[John T]

I wonder how many ASCII faces are in that one liner. I stopped counting around 20.

[whitequark]

Of course I can write another one-liner that will count them.

[Thalys]

is that something in every linux system or something that needs to be installed?

[Simon Sheehan]

@JourneymanGeek it's not even in the Ubuntu repos, so I'd say its not exactly popular. Looks like you have to get it yourself from the project page, and run/compile yourself. Wouldnt exactly call it a popular program ansifilter.sourceforge.net

[thekingoftruth]

I'm on OSX and used brew install ansifilter and it worked like a charm.

[dmh]

I don't know how this has changed since the 2012 comments about distribution, but I found this in the repo for the current release of Fedora (22).