How to remove ^L control characters from text files?

bashari · 09-12-2012, 07:55 AM

Hi All,

When i try to edit the file i m getting this symbol : ^L

its related to clear the screen and redraw so its not letting me to grep any pattern .

1. I want to remove this Symbol : ^L

Thanks in advance.

Regards
Basha G

colucix · 09-12-2012, 08:29 AM

Hi and welcome to LinuxQuestions!

Ctrl-L is a hidden control character that stats for Form Feed or New Paper sheet. You can find it in the ASCII table at position 12, or better:

Code:

Dec  Hex  Oct  Char  Description
12   C    014  FF    NP Form Feed, new page

You can reproduce it in a terminal using this sequence of keystrokes

Code:

Ctrl-V Ctrl-L

where the first Ctrl-V summons the shell to display a control character. To remove it from a text file, you can either use this sequence of keystrokes or his octal/hex/decimal code taken from the ASCII table.

For example using sed you can do something like this (by typing Ctrl-V and Ctrl-L):

Code:

sed 's/^L//' file

or by means of the octal code:

Code:

sed 's/\o14//' file

Take in mind that to actually change the content of a file using sed, you have to use the -i option. Without -i the output is sent to the terminal (standard output) which is useful for testing the command until it gives the desired result. Hope this helps.

David the H. · 09-12-2012, 11:36 AM

To be more specific, ^L is the caret notation for that non-printing ascii character.

tr is usually the most efficient solution for simple character removal jobs, although you have to work through at temporary file to do it.

Code:

tr -d '\014' <infile.txt >outfile.txt