compare two columns of the same excel sheet using perl.

[rumiya]

I have two columns in my excel sheet one is for gene id and other for the length of the gene. now I need to find out the largest length of among various transcript id of the same geneid. and need to display the distinct geneid with largest length in perl language.

[Luuk]

You say you have two columns:
1) 'gene id'
2) length of 'gene id'

This part in your question i do not understand, probably because my knowledge of English language: '... of among various transcript id ...'

How does 'transcript id' relate to 'gene id'?

Why do you want to solve this in Perl, (or why will you not solve this in Excel)