Insert using sed

ZAMO · 01-15-2009, 02:27 AM

Hi all,

Am trying to insert # to the beginning of lines in a file using sed 's/^/#/' and it is working good. How can I avoid inserting # for some lines, say from 25-50 in a file on modifying the same command.

Code:

sed 's/^/#/' filename

Thanks

rizwanrafique · 01-15-2009, 05:44 AM

Wrong solution so removed.

GazL · 01-15-2009, 06:03 AM

Quote:

Originally Posted by rizwanrafique

sed doesn't know about line numbers.

Really?

Code:

bash-3.1$ cat testing
one
two   
three
four
five
six
seven
bash-3.1$ sed '3,6s/^/#/' testing
one
two   
#three
#four
#five
#six
seven
bash-3.1$

Quote:

Originally Posted by ZAMO

How can I avoid inserting # for some lines, say from 25-50 in a file on modifying the same command.

Code:

sed 's/^/#/' filename

Thanks

You can negate the address range, which may suit what you're looking for. Zamo.

Code:

bash-3.1$ sed '3,6!s/^/#/' testing
#one
#two   
three
four
five
six
#seven

homey · 01-15-2009, 06:14 AM

Maybe this will work for you

Code:

sed -i.bak '{1,24s/.*/# &/; 51,$s/.*/# &/}' file.txt

rizwanrafique · 01-15-2009, 08:48 AM

My mistake. It knows and works well. :-)

jschiwal · 01-15-2009, 08:52 AM

You can negate a line range as well:
sed '25-50!s/^/# /' file

This will add # to all lines except for lines 25-50.

ZAMO · 01-15-2009, 11:05 PM

Thanks to All your replies..