use Inline::Files; $h{$a[1]} = $a[0] while @a = split /\s|$/, ; exists $h{$_} and print "$h{$_}\n" while chomp($_ = ); __TABLE__ xanmn_chr09_0114-xanmn_chr09_0114 3346 xanmn_chr09_0129-xanmn_chr09_0129 3358 xanmn_chr09_0116-xanmn_chr09_0116 3348 xanmn_chr09_0127-xanmn_chr09_0127 3354 __VALUES__ 3346 1933 1371 1448 2762 1395