如何在 perl5 的格式语句中使用子程序参数？

Question

I want to be able to do something like:

sub prline {
        format STDOUT =
@<<<< @>>>>>> @>>>>>>
@_
.
write;
}

prline("EPIC", "BUY", "SELL");

but it doesn't work. What's the fix?

Update 1:

I find the format statement still to be completely mystifying. How comes the following outputs a blank line?

my ( $epic, $buy, $sell ) = qw( EPIC BUY SELL );
write();

format STDOUT =
@<<<< @>>>>>> @>>>>>>
$epic, $buy, $sell
.

Answer 1

You define the format (as you have done), fill in package variables, then use write to make it happen. I have something close to what you want in an article I wrote for The Effective Perler . You still have to use package vars, but you can localize them:

foreach my $record ( @cats ) {
    local( $id, $name, $food ) = @$record;
    write( $fh );
    }

Learning Perl used to have a whole chapter on formats during the Perl 4 days, and I've reproduced that in Formats on the book's website.