http://www.perlmonks.org?node_id=1128

lib:Symbol

See the current Perl documentation for lib:Symbol.

Here is our local, out-dated (pre-5.6) version:


Symbol - manipulate Perl symbols and their names



    use Symbol;

    $sym = gensym;
    open($sym, "filename");
    $_ = <$sym>;
    # etc.

    ungensym $sym;      # no effect

    print qualify("x"), "\n";
    

Symbol::gensym creates an anonymous glob and returns a reference to it. Such a glob reference can be used as a file or directory handle.

For backward compatibility with older implementations that didn't support anonymous globs, Symbol::ungensym is also provided. But it doesn't do anything.

Symbol::qualify turns unqualified symbol names into qualified variable names (e.g. ``myvar'' -> ``MyPackage::myvar''). If it is given a second parameter, qualify uses it as the default package; otherwise, it uses the package of its caller. Regardless, global variable names (e.g. ``STDOUT'', ``ENV'', ``SIG'') are always qualfied with ``main::''.

Qualification applies only to symbol names (strings). References are left unchanged under the assumption that they are glob references, which are qualified by their nature.

Symbol::qualify_to_ref is just like Symbol::qualify except that it returns a glob ref rather than a symbol name, so you can use the result even if use strict 'refs' is in effect.

Symbol::delete_package wipes out a whole package namespace. Note this routine is not exported by default--you may want to import it explicitly.