#How to use blast from command-line, on Mac OS X.
Download executables (binary) of blast-commands for Mac OS X.
$ curl -O ftp://ftp.ncbi.nih.gov/blast/executables/blast+/2.2.28/ncbi-blast-2.2.28+.dmg
or
$ wget ftp://ftp.ncbi.nih.gov/blast/executables/blast+/2.2.28/ncbi-blast-2.2.28+.dmg