That function isn't very graceful, especially with that repetitive shifting and data duplication. Here's how you could rewrite it:
process($data_ref, \@set_up, $template, $fd_out);
sub process
{
my ($data, $set_up, $template, $fd_out) = @_;
foreach my $record (@$data)
{
# ...
}
}
Maybe it's just me, but I find reading function arguments with
shift is usually pointless since you can just declare the works in a single line. It's also nice to have the function argument declaration in a similar format to how you call it, so you can see if things match up.
As of Perl 5.6 or thereabouts, you can open a filehandle that is put into a scalar (glob reference) using the
open function:
my $fd_out;
open($fd_out, $what_file);
while (<$fd_out>) { # ... }
Or, of course, there is always
IO::File:
my $fd_out = IO::File->new($what_file, 'r');
while (<$fd_out>) { # ... }
These filehandles are a lot easier to pass back and forth than the regular globs. If you're even thinking about using them as function arguments, don't use globs.
As a note:
${$foo} and
$$foo are equivalent. It's often simpler to just leave off the extra braces since they don't serve any practical purpose. There are occasions like
${$foo->{bar}} where they more appropriate.