Try this...

#!/usr/bin/perl

use strict;

my %hash;

my $raw_file_1 = <<FILE_1;
file1:
TST_01  sp|123|fts
TST_02  sp|3438|rvs
TST_03  sp|2744|rtp
TST_04  sp|0123|not_here
FILE_1

my $raw_file_2 = <<FILE_2;
file2:
sp|123|fts  checked_proved
sp|3438|rvs  proven_right
sp|2744|rtp  un_proved
sp|0000|bogus bogus
FILE_2

open( my $file_1, "<", \$raw_file_1 ) or die "Couldn't open \$raw_file
+_1\n";
while (<$file_1>) {
    next if /^file/;
    my ($val, $key) = split;
    $hash{$key} = $val;
}

open( my $file_2, "<", \$raw_file_2 ) or die "Couldn't open \$raw_file
+_2\n";
while (<$file_2>) {
    next if /^file/;
    my ($key, $val) = split;
    print "$hash{$key}\t$key\t$val\n" if ( defined($hash{$key}) );
}
[download]