I'm trying to develop a script to annotate a VCF file with functional predictions and scores from dbNSFP. dbNSFP is distributed as large tab de-limited files with information for each non synonymous variant locus. https://sites.google.com/site/jpopgen/dbNSFP
I thought it might be most efficient to index these files and use the Tabix perl API to query these files for each variant in my VCF file. I searched for any working examples or documentation for the tabix perl API without any luck and I'd like to know if there is something available that might be easier than looking into the source code.
So, while I can see the desire in wanting to do this yourself I should point out that there already exists a widely used tool in the genomics community that will annotate a VCF file with dbNSFP annotations, and has recently been updated so it works using TABIX, making it much quicker than it was before.
snpSIFT which is part of the snpEff package, can do this. Since snpSIFT is published, snpEff is pretty widely used for annotating VCF files, etc, you might want to just use this program rather than trying to reinvent the wheel.