Script to add a single line to middle of text file.

progkcp · May 12, 2008, 1:54pm

I've got a configuration file that is filled with xml text statements for example:

<...../>
<...../>
<...../>
<data id="java-options" value="-server -Djava.security.policy..../>
<...../>
<...../>
<...../>

I want to write a korn shell script that will go to this specific line and add a certain parameter as follows:

I'm thinking that I can do this with head and tail but I'm not sure how to do it. Any help help would be appreciated.

era · May 12, 2008, 2:14pm

head and tail cannot add any information on their own. For easy string replacements, you probably want sed.

sed -e '/<data /s/-server/& -My_Parameter/' file >file.new

This will search for "<data" and perform a substitution ("s") of "-server" with "-server -MyParameter" (the & is magical and means "whatever we are substituting") on that line. Other lines are printed unchanged.

progkcp · May 12, 2008, 2:44pm

era:

head and tail cannot add any information on their own. For easy string replacements, you probably want sed.
sed -e '/<data /s/-server/& -My_Parameter/' file >file.new
This will search for "<data" and perform a substitution ("s") of "-server" with "-server -MyParameter" (the & is magical and means "whatever we are substituting") on that line. Other lines are printed unchanged.

This works perfectly, thank you!