Question

I have an xml file that I want to configure using a bash script. For example if I had this xml:

<a>

  <b>
    <bb>
        <yyy>
            Bla 
        </yyy>
    </bb>
  </b>

  <c>
    <cc>
      Something
    </cc>
  </c>

  <d>
    bla
  </d>
</a>

(confidential info removed)

I would like to write a bash script that will remove section <b> (or comment it) but keep the rest of the xml intact. I am pretty new the the whole scripting thing. I was wondering if anyone could give me a hint as to what I should look into.

I was thinking that sed could be used except sed is a line editor. I think it would be easy to remove the <b> tags however I am unsure if sed would be able to remove all the text between the <b> tags.

I will also need to write a script to add back the deleted section.

Answer 1

This would not be difficult to do in sed, as sed also works on ranges.

Try this (assuming xml is in a file named foo.xml):

sed -i '/<b>/,/<\/b>/d' foo.xml

-i will write the change into the original file (use -i.bak to keep a backup copy of the original)

This sed command will perform an action d (delete) on all of the lines specified by the range

# all of the lines between a line that matches <b>
# and the next line that matches <\/b>, inclusive
/<b>/,/<\/b>/

So, in plain English, this command will delete all of the lines between and including the line with <b> and the line with </b>

If you’d rather comment out the lines, try one of these:

# block comment
sed -i 's/<b>/<!-- <b>/; s/<\/b>/<\/b> -->/' foo.xml

# comment out every line in the range
sed -i '/<b>/,/<\/b>/s/.*/<!-- & -->/' foo.xml