removing empty tags

Shell Programming and Scripting
1

Hi,

I have a file as shown below.
<crown:clinicalData>
<crown:alb date="2008-07-10" lowValue="3.50" method="BCG" value="3.50"/>
<crown:cre date="2008-07-10" value="9.5"></crown:cre>
<crown:ktvHdAd>
</crown:ktvHdAd>
<crown:ktvPdAd>
</crown:ktvPdAd>
</crown:clinicalData>

I want to remove the empty tags. i.e I want to remove

&lt;crown:ktvHdAd&gt;
&lt;/crown:ktvHdAd&gt;

and

&lt;crown:ktvPdAd&gt;
&lt;/crown:ktvPdAd&gt;

If it happens to have records in between the tags, then I do not want to delete.

Can any of you know good approaches to it?

Thanks
Vijay

2 
perl -i.bak -0777 -pe's|\n*<\S*?>\s*</\S*?>||g' filename