
        Usage:

        /Users/pbucher/bin/make_chro_idx.nstorage.pl <chr_NC_gi> <chr_size> <chro_idx.nstorage>

        Combines text files <chr_NC_gi> and <chr_size> in a single binary file named chro_idx.nstorage.
        chr_NC_gi maps sequence identifiers to chromosome namas whereas chr_size informs programs
        about the size of the chromosomes. C programs of the ChIP-Seq tools use the text files
        chr_NC_gi and chr_size whereas Perl scripts the binary file chro_idx.nstorage. Note that the
        filenames are hard-coded in the programs, which read these file. However, this script takes the
        names of these files from the command line. The filenames are thus freee.
        
