7.6.2. Solution

use Symbol qw(qualify_to_ref);

sub my_eof (*) {
  my $handle = shift;
  $handle = qualify_to_ref($handle, caller( ));
  # use $handle
}

7.6.3. Discussion

The * prototype tells Perl that the function expects a bareword filehandle as its argument. This lets you call the function like so:

my_eof(HANDLE);

This works even when use strict 'subs' is in effect. The function receives a string as its argument, though. To safely use the argument as a filehandle, you need the Symbol module to turn it into a reference to a typeglob. And since typeglob refs can be used wherever you'd use named filehandles, store that reference in a scalar variable and use the variable as an indirect filehandle within your subroutine.

If you pass in a filehandle that is already a reference to a typeglob, like those autovivified by open, Perl and qualify_to_ref still do the right thing:

open(my $fh, "<", $filename) or die;
my_eof($fh);

7.6.4. See Also