use Inline::Files;

undef $h{$_} while chomp($_ = <CODES>);

while(<FASTA>){
    print if /(^\w{3})/ and exists $h{$1};
}

__CODES__
lus
cel
cfa

__FASTA__
where do you study your perl?
cel-let-7-5-blah blah blah
cfa-miR-761-blah blah blah
cfa-miR-764-blah blah blah
lus-miR167-blah blah blah
other-blah
blah-
123
[download]