open( my $testfile, "+>> $file" ) $!\n";
if ( -z "$testfile" ) ---> checking for empty file
##</code><code>##

open my $testfile,'+>>',$file or die "Can't open '$file': $!";
my $pos=tell $testfile;
($pos!=-1) or die "tell failed for '$file': $!";
if ($pos==0) {
    # file is empty
} else {
    # file has some content
}