## Fast download BLAST databases from NCBI

Database files (volumes) are downloaded in parallel: number of threads to use
is determined automatically. MD5 checksum is verified and the database volume
extracted upon download.  Database volumes are not downloaded in a particular
order. The volumes are updated if a newer version is available on the server,
or re-downloaded if corrupt. Aborted downloads are safely resumed.

`ncbi-blast-dbs` is faster than NCBI's `update_blastdb.pl`. But unlike
`update_blastdb.pl`, which is a pure Perl script, `ncbi-blast-dbs` delegates
download and checksum verification to `wget` and `md5sum` and is thus not as
universal.

### Installation

    gem install ncbi-blast-dbs

### Usage

#### List available BLAST databases

    ncbi-blast-dbs

#### Download all volumes of a BLAST database

    ncbi-blast-dbs nt nr

Databases are downloaded one after the other while volumes of each database
are downloaded in parallel.

    ncbi-blast-dbs nt nr

NCBI expects users to submit their email address when downloading data from
their FTP server. To comply with that, download as:

    email="my email address here" ncbi-blast-dbs nr