Hi, In a text file, if there are any listed structures, the start and end will be marked by <bl>..</bl>. All the lines between these elements should be tagged as <listitem>..</listitem>. I wrote a code as below: 

    if (m|<bl>| .. m|</bl>|)
    {
        s/^(?!<bl>)|(?<=<bl>)/<listitem>/g;
        s-(?=</bl>)|(?<!</bl>)(?=\n)-<\/listitem>-g;
    }

[download]

This is working fine if the structure is plain like below: 

<bl>List item 1
List item 2
List item 3</bl>

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But, I also encounter instances where <bl> appears within a <bl> like below: 

<bl>List item 1
List item 2
<bl>List item a
List item b
List item c</bl>
List item 3</bl>

[download]
If I run the above text with my code, the conversion fails. I intend to get the output as follows 
<listitem>List item 1</listitem>
<listitem>List item 2</listitem>
<listitem>List item a</listitem>
<listitem>List item b</listitem>
<listitem>List item c</listitem></listitem>
<listitem>List item 3</listitem>

[download]

All the entires of the sublist should be tagged and later the end tag of item 2 should be inserted. Also after finishing the sublist, tagging for the main list should continue until </bl> for the main list is encountered. I could not derive a structure to the script for this. Could someone help me on this?

In reply to Help in using Regular Expressions by rsriram

Title:
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