#!/usr/bin/env perl
use Modern::Perl;

my %seqs;

$/ = '>';                      # break lines on this instead of newline
while(my $line = <DATA>){
    chomp $line;               # remove any trailing >
    next unless $line;         # skip leading blank record before first >
    my($id, $seq) = split /\s+/, $line, 2;
    $seq =~ s/[\r\n]//g;       # strip newlines and/or carriage returns from sequence
    unless($seqs{$id} and length($seqs{$id}) > length($seq)){
        $seqs{$id} = $seq;     # save it if it's a new ID or a longer sequence
    }
}

say ">$_ $seqs{$_}" for keys %seqs;
__DATA__
>ENSG00000010072
MDDDLMLALRLQEEWNLQEAERDHAQESLSLVDASWELVDPTPDLQALFVQFNDQFFWGQ
LEAVEVKWSVRMTLCAGICSYEGKGGMCSIRLSEPLLKLRPRKDLVEVYHTFHDEVDEYR
RHWWRCNGPCQHRPPYYGYVKRATNREPSAHDYWWAEHQKTCGGTYIKIKEPENYSKKGK
GKAKLGKEPVLAAENKGTFVYILLIFM*
>ENSG00000067082
Sequence unavailable
>ENSG00000147724
MSEIQGTVEFSVELHKFYNVDLFQRGYYQIRVTLKVSSRIPHRLSASIAGQTESSSLHSA
CVHDSTVHSRVFQILYRNEEVPINDAVVFRVHLLLGGERMEDALSEVDFQLKVDLHFTDS
EQQLRDVAGAPMVSSRTLGLHFHPRNGLHHQVP
>ENSG00000010072
MDDDLMLALRLQEEWNLQEAERDHAQESLSLVDASWELVDPTPDLQALFVQFNDQFFWGQ
LEAVEVKWSVRMTLCAGICSYEGKGGMCSIRLSEPLLKLRPRKDLVETLLHEMIHAYLFV
TNNDKDREGHGPEFCKHMHRINSLTGANITVYHTFHDEVDEYRRHWWRCNGPCQHRPPYY
GYVKRATNREPSAHDYWWAEHQKTCGGTYIKIKEPENYSKKGKGKAKLGKEPVLAAENKD
KPNRGEAQLVIPFSGKGYVLGETSNLPSPGKLITSHAINKTQDLLNQNHSANAVRPNSKI
KVKFEQNGSSKNSHLVSPAVSNSHQNVLSNYFPRVSFANQKAFRGVNGSPRISVTVGNIP
KNSVSSSSQRRVSSSKISLRNSSKVTESASVMPSQDVSGSEDTFPNKRPRLEDKTVFDNF
FIKKEQIKSSGNDPKYSTTTAQNSSSSSSQSKMVNCPVCQNEVLESQINEHLDWCLEGDS
IKVKSEESL*