The basic format of a BLAST search:

$ blastn -query il2.seq -db /idata/appdata/blastdb/refseq_rna -out il2.blastn

To limit the number of one line descriptions and alignments that are shown (limited here to 10 each):

$ blastn -query il2.seq -db /idata/appdata/blastdb/refseq_rna -num_descriptions 10 -num_alignments 10 -out il2.blastn