Manpages

Symbol

NAME

SYNOPSIS

    use Symbol;

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

    ungensym $sym;      # no effect

    print qualify("x"), "\n";              # "Test::x"
    print qualify("x", "FOO"), "\n"        # "FOO::x"
    print qualify("BAR::x"), "\n";         # "BAR::x"
    print qualify("BAR::x", "FOO"), "\n";  # "BAR::x"
    print qualify("STDOUT", "FOO"), "\n";  # "main::STDOUT" (global)
    print qualify(\*x), "\n";              # returns \*x
    print qualify(\*x, "FOO"), "\n";       # returns \*x

    use strict refs;
    print { qualify_to_ref $fh } "foo!\n";
    $ref = qualify_to_ref $name, $pkg;

    use Symbol qw(delete_package);
    delete_package('Foo::Bar');
    print "deleted\n" unless exists $Foo::{'Bar::'};

DESCRIPTION

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 qualified 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.

Index

NAME

SYNOPSIS

DESCRIPTION