=item $^S
-Current state of the interpreter. Undefined if parsing of the current
-module/eval is not finished (may happen in $SIG{__DIE__} and
-$SIG{__WARN__} handlers). True if inside an eval(), otherwise false.
+Current state of the interpreter.
+
+ $^S State
+ --------- -------------------
+ undef Parsing module/eval
+ true (1) Executing an eval
+ false (0) Otherwise
+
+The first state may happen in $SIG{__DIE__} and $SIG{__WARN__} handlers.
=item $BASETIME
Reflects if taint mode is on or off. 1 for on (the program was run with
B<-T>), 0 for off, -1 when only taint warnings are enabled (i.e. with
-B<-t> or B<-TU>).
+B<-t> or B<-TU>). This variable is read-only.
+
+=item ${^UNICODE}
+
+Reflects certain Unicode settings of Perl. See L<perlrun>
+documentation for the C<-C> switch for more information about
+the possible values. This variable is set during Perl startup
+and is thereafter read-only.
=item $PERL_VERSION
The current set of warning checks enabled by the C<use warnings> pragma.
See the documentation of C<warnings> for more details.
-=item ${^WIDE_SYSTEM_CALLS}
-
-Global flag that enables system calls made by Perl to use wide character
-APIs native to the system, if available. This is currently only implemented
-on the Windows platform.
-
-This can also be enabled from the command line using the C<-C> switch.
-
-The initial value is typically C<0> for compatibility with Perl versions
-earlier than 5.6, but may be automatically set to C<1> by Perl if the system
-provides a user-settable default (e.g., C<$ENV{LC_CTYPE}>).
-
-The C<bytes> pragma always overrides the effect of this flag in the current
-lexical scope. See L<bytes>.
-
=item $EXECUTABLE_NAME
=item $^X
See L<POSIX>.
+The delivery policy of signals changed in Perl 5.8.0 from immediate
+(also known as "unsafe") to deferred, also known as "safe signals".
+See L<perlipc> for more information.
+
Certain internal hooks can be also set using the %SIG hash. The
routine indicated by C<$SIG{__WARN__}> is called when a warning message is
about to be printed. The warning message is passed as the first
ENV STDIN
INC STDOUT
ARGV STDERR
- ARGVOUT
+ ARGVOUT _
SIG
In particular, the new special C<${^_XYZ}> variables are always taken