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symbol(3pm) [osx man page]

Symbol(3pm)						 Perl Programmers Reference Guide					       Symbol(3pm)

NAME

       Symbol - manipulate Perl symbols and their names

SYNOPSIS

	   use Symbol;

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

	   ungensym $sym;      # no effect

	   # replace *FOO{IO} handle but not $FOO, %FOO, etc.
	   *FOO = geniosym;

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

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

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

DESCRIPTION

       "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::geniosym" creates an anonymous IO handle.  This can be assigned into an existing glob without affecting the non-IO portions of the
       glob.

       "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.

BUGS

       "Symbol::delete_package" is a bit too powerful. It undefines every symbol that lives in the specified package. Since perl, for performance
       reasons, does not perform a symbol table lookup each time a function is called or a global variable is accessed, some code that has already
       been loaded and that makes use of symbols in package "Foo" may stop working after you delete "Foo", even if you reload the "Foo" module
       afterwards.

perl v5.16.2							    2012-08-26							       Symbol(3pm)

Check Out this Related Man Page

Sub::Exporter::GlobExporter(3pm)			User Contributed Perl Documentation			  Sub::Exporter::GlobExporter(3pm)

NAME

       Sub::Exporter::GlobExporter - export shared globs with Sub::Exporter collectors

VERSION

       version 0.002

SYNOPSIS

       First, you write something that exports globs:

	 package Shared::Symbol;

	 use Sub::Exporter;
	 use Sub::Exporter::GlobExport qw(glob_exporter);

	 use Sub::Exporter -setup => {
	   ...
	   collectors => { '$Symbol' => glob_exporter(Symbol => '_shared_globref') },
	 };

	 sub _shared_globref { return *Common }

       Now other code can import $Symbol and get their *Symbol made an alias to *Shared::Symbol::Symbol.

       If you don't know what this means or why you'd want to do it, you may want to stop reading now.

       The other class can do something like this:

	 use Shared::Symbol '$Symbol';

	 print $Symbol; # prints the scalar entry of *Shared::Symbol::Symbol

       ...or...

	 use Shared::Symbol '$Symbol' => { -as => 'SharedSymbol' };

	 print $SharedSymbol; # prints the scalar entry of *Shared::Symbol::Symbol

OVERVIEW

       Sub::Exporter::GlobExporter provides only one routine, "glob_exporter", which may be called either by its full name or may be imported on
       request.

	 my $exporter = glob_exporter( $default_name, $globref_locator );

       The routine returns a collection validator that will export a glob into the importing package.  It will export it under the name
       $default_name, unless an alternate name is given (as shown above).  The glob that is installed is specified by the $globref_locator, which
       can be either the globref itself, or a reference to a string which will be called on the exporter

       For an example, see the "SYNOPSIS", in which a method is defined to produce the globref to share.  This allows the glob-exporting package
       to be subclassed, for for the subclass to choose to re-use the same glob when exporting or to export a new one.

       If there are entries in the arguments to the globref-exporting collector other than those beginning with a dash, a hashref of them will be
       passed to the globref locator.  In other words, if we were to write this:

	 use Shared::Symbol '$Symbol' => { arg => 1, -as => 2 };

       It would result in a call like the following:

	 my $globref = Shared::Symbol->_shared_globref({ arg => 1 });

AUTHOR

       Ricardo Signes <rjbs@cpan.org>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2010 by Ricardo Signes.

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

perl v5.10.1							    2010-11-23					  Sub::Exporter::GlobExporter(3pm)
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