Afaik it really is a glob. Just one that doesn't live in the package namespace (and thus it has no name) but an anonymous one just like the rest of the lexically scoped vars.

Partly true. With open my $foo, $file, $foo is a reference to a glob, and the glob is not anonymous, because globs can only be in a package. The glob reference $foo can be dereferenced in a normal fashion: *$foo. With *$foo, you'll have a normal glob, like all others. Globs have a string representation that happens to be an asterisk, followed by namespace :: name.

Consider:

#!/usr/bin/perl -l
{
    open my $foo, '>', $$ or die $!;
    print $foo;                        # GLOB(0x...)
    print ref $foo;                    # GLOB
    print *$foo;                       # *main::$foo
    print $foo "Test";                 # Test > $$
}

# The scope has ended. Because the lexical dies, the file is closed.
# The (normally unreachable because of its invalid name) glob
# *main::$foo still exists, because globals just don't die.

# And they lived happily ev^U
[download]

{
    open my $foo, '>', $$ or die $!;
    print $foo;                        # GLOB(0x...)
    print ref $foo;                    # GLOB
    print *$foo;                       # *main::$foo
    print $foo "Test";                 # Test > $$
    {
        open my $foo, '>',"$$.z" or die $!;
        print $foo;                        # GLOB(0x...)
        print ref $foo;                    # GLOB
        print *$foo;                       # *main::$foo   <-- !!!!!
        print $foo "Test";                 # Test > $$
    }
}
[download]

U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

the glob is not anonymous, because globs can only be in a package

Actually, as you hint at later, local makes this so that it isn't strictly true. You have to create a glob in a package namespace (at least when writing Perl, probably not so when writing C imbedded in perl), which also gives it a name, but it doesn't have to stay there. I don't know if open also temporarilly creates *{'$foo'} and then moves it out of the symbol table, but the end result is similar to that of:   my $foo= do { local *{'$foo'}; \*{'$foo'}; }; so that none of your *$foos are in any symbol table, and so none of them are the same as *{'$foo'}.

        - tye (but my friends call me "Tye")