exit main( @ARGV );
{
    my $sub;
    BEGIN {
        $sub= sub {
            # ...
        };
    }
    sub GlobalRoutine {
        &$sub( ... );
    }
}
sub main {
    # ...
}
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It is easy to put this in places where the BEGIN block becomes necessary. Some are much more subtle than this. Without the BEGIN block, $sub is declared and GlobalRoutine is compiled before $sub is initialized so it then becomes possible for GlobalRoutine to be called while $sub is still undef.

I'm sorry that Perl doesn't have real static variables such that I have to resort to an extra empty block and doing the initialization in a BEGIN block. Note that this trick won't work if you are using mod_perl.

FYI, since I didn't use any local variables in the anonymous subroutine, it isn't a closure in my book.

Thank you. This has helped a lot.

It works fine from my tests without the BEGIN block since $sub is initialized befor the compiler will get to GlobalRoutine.

Since $sub goes out of scope, but there is still a pointer to it which can only be accessed via GlobalRoutine, I would consider it a closure, although possibly not by the true sense of the definition. However, $sub could itself use lexical, and meet the 'definition'. I'll call it a pseudo-closure, you can call it a 'closing' if you like.

Cheers,
KM

It works fine from my tests without the BEGIN block since $sub is initialized before the compiler will get to GlobalRoutine.

Then I guess you missed my addition last time. Here:

#!/usr/bin/perl -w
use strict;

exit main( @ARGV );

{
    my $sub;
    ## BEGIN {
        $sub= sub {
            warn "Called local sub: @_\n";
        };
    ## }
    sub GlobalRoutine {
        &$sub( "Test" );
    }
}

sub main {
    GlobalRoutine("hi");
    return 0;
}
__END__
This produces the following:
Use of uninitialized value in subroutine entry at localsub.pl line 14.
Can't use string ("") as a subroutine ref while "strict refs" in use a
+t localsub.pl line 14.
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        - tye (but my friends call me "Tye")