Thanks once again. Yes, it is working but it is getting the wrong input and hence prints out incorrectly. 
/protein_id="NP_12312"
/db_xref="GI:7546536"

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Here. in order to get the GI number, I use this matching expression elsif ( /^\s*protein_id\S*\n\s*\Sdb_xref="GI:(\d+)/ ) but it is not matching. Am I doing some fundamental mistake with the matching operators?

In reply to Re^4: Read, match string and print by sophix
in thread Read, match string and print by sophix

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