use strict;
use warnings;

my $path = '/tmp/allfiles';
my $outpath = '/tmp/nonemptyfiles';
opendir my $dh, $path or die $!;
my @files = grep /\.log$/ && -f "$path/$_" && !-z "$path/$_", readdir $dh;
closedir $dh;

for my $fn (@files){
   open my $fr, '<', "$path/$fn" or die "IN: $fn $!";
   open my $fw, '>', "$outpath/$fn" or die "OUT: $fn $!";;
   while( <$fr> ) {
      printf $fw "$1 $2\n" if /(\S+)\s+(\S+)/
   }
}