Add perlvar.pod, a (temporary?) place to document magical variables.

Author: pmichaud

lib/perlvar.pod

@@ -0,0 +1,40 @@
+=begin pod
+
+=head1 perlvar - list of known magical variables
+
+=head2 Compile-time "constants"
+
+    $?FILE      Which file am I in?
+    $?LINE      Which line am I at?
+    &?ROUTINE   Which routine am I in?
+    &?BLOCK     Which block am I in?
+    %?LANG      What is the current set of interwoven languages?
+
+Other compile-time constants:
+
+    $?KERNEL    Which kernel am I compiled for?
+    $?DISTRO    Which OS distribution am I compiling under
+    $?VM        Which virtual machine am I compiling under
+    $?XVM       Which virtual machine am I cross-compiling for
+    $?PERL      Which Perl am I compiled for?
+    $?SCOPE     Which lexical scope am I in?
+    $?PACKAGE   Which package am I in?
+    $?MODULE    Which module am I in?
+    $?CLASS     Which class am I in? (as variable)
+    $?ROLE      Which role am I in? (as variable)
+    $?GRAMMAR   Which grammar am I in?
+    $?TABSTOP   ???
+    $?USAGE
+
+=head2 Dynamic variables
+
+    $*ARGFILES  Magic command-line input handle
+    @*ARGS      Arguments from the command line
+    $*IN        Standard input filehandle
+    $*OUT       Standard output filehandle
+    $*ERR       Standard error filehandle
+    $*TZ
+    $*FATAL
+    $*CWD
+    
+=end pod