foreach my $filename (<*.seq>)
{
    print "$filename\n";
}
[download]

Update: (as per Abigail-II's comments below)

while (my $filename = <*.seq>)
{
    print "$filename\n";
}
[download]

Method 2:

use IO::Dir;

my $dh = IO::Dir->new('.');
while (defined(my $filename = $dh->read))
{
    next unless $filename =~ /\.seq$/;
    print "$filename\n";
}
[download]

And, there's at least 3-4 others people could come up with, depending on your exact needs.