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Perl uses an internal type called a typeglob to hold an entire symbol table entry. The type prefix of a typeglob is a *, because it represents all types. This used to be the preferred way to pass arrays and hashes by reference into a function, but now that we have real references, this is seldom needed. It also used to be the preferred way to pass filehandles into a function, but now that we have the *foo{THING} notation it isn't often needed for that, either. It is still needed to pass new filehandles into functions
(*HANDLE{IO} only works if
HANDLE has already been used).
If you need to use a typeglob to save away a filehandle, do it this way:
$fh = *STDOUT;
or perhaps as a real reference, like this:
$fh = \*STDOUT;
This is also a way to create a local filehandle. For example:
sub newopen {
my $path = shift;
local *FH; # not my!
open (FH, $path) || return undef;
return *FH;
}
$fh = newopen('/etc/passwd');
Another way to create local filehandles is with IO::Handle and its ilk, see
the bottom of open().
See the perlref manpage, the perlsub manpage, and Symbol Tables for more discussion on typeglobs.
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