Реклама
erid:2VtzqwUcu3z
ООО "Хи-Квадрат", ИНН 7718990614
Symbol - manipulate Perl symbols and their namesSYNOPSIS
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
`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 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.
