use CGI qw(:all);

my @files = <../data/texts/*.txt>;
my %labels = (
    map { $_ => +( m!([^/]+)\z! ) } @files
);

print popup_menu(
    -name   => 'select',
    -values => \@files,
    -labels => \%labels
);

__END__
<select name="select">
<option value="../data/texts/foo.txt">foo.txt</option>
<option value="../data/texts/bar.txt">bar.txt</option>
</select>