=item B<-C [I<number/list>]>
X<-C>
-The C<-C> flag controls some Unicode of the Perl Unicode features.
+The C<-C> flag controls some of the Perl Unicode features.
As of 5.8.1, the C<-C> can be followed either by a number or a list
of option letters. The letters, their numeric values, and effects
512 r Regular expression parsing and execution
1024 x Syntax tree dump
2048 u Tainting checks
- 4096 (Obsolete, previously used for LEAKTEST)
+ 4096 U Unofficial, User hacking (reserved for private, unreleased use)
8192 H Hash dump -- usurps values()
16384 X Scratchpad allocation
32768 D Cleaning up
X<-P>
B<NOTE: Use of -P is strongly discouraged because of its inherent
-problems, including poor portability.>
+problems, including poor portability. It is deprecated and will be
+removed in a future version of Perl.>
This option causes your program to be run through the C preprocessor before
compilation by Perl. Because both comments and B<cpp> directives begin
operator instead. Note: availability of B<undump> is platform
specific and may not be available for a specific port of Perl.
-This switch has been superseded in favor of the new Perl code
-generator backends to the compiler. See L<B> and L<B::Bytecode>
-for details.
-
=item B<-U>
X<-U>
=item B<-x>
X<-x>
-=item B<-x> I<directory>
+=item B<-x>I<directory>
tells Perl that the program is embedded in a larger chunk of unrelated
ASCII text, such as in a mail message. Leading garbage will be
can process any or all of the trailing garbage via the DATA filehandle
if desired).
+The directory, if specified, must appear immedately following the B<-x>
+with no intervening whitespace.
+
=back
=head1 ENVIRONMENT
=item PERL_HASH_SEED
X<PERL_HASH_SEED>
-(Since Perl 5.8.1.) Used to randomise Perl's internal hash function.
+(Since Perl 5.8.1.) Used to randomise perl's internal hash function.
To emulate the pre-5.8.1 behaviour, set to an integer (zero means
exactly the same order as 5.8.0). "Pre-5.8.1" means, among other
-things, that hash keys will be ordered the same between different runs
-of Perl.
+things, that hash keys will always have the same ordering between
+different runs of perl.
+
+Most hashes return elements in the same order as Perl 5.8.0 by default.
+On a hash by hash basis, if pathological data is detected during a hash
+key insertion, then that hash will switch to an alternative random hash
+seed.
The default behaviour is to randomise unless the PERL_HASH_SEED is set.
-If Perl has been compiled with C<-DUSE_HASH_SEED_EXPLICIT>, the default
+If perl has been compiled with C<-DUSE_HASH_SEED_EXPLICIT>, the default
behaviour is B<not> to randomise unless the PERL_HASH_SEED is set.
-If PERL_HASH_SEED is unset or set to a non-numeric string, Perl uses
+If PERL_HASH_SEED is unset or set to a non-numeric string, perl uses
the pseudorandom seed supplied by the operating system and libraries.
-This means that each different run of Perl will have a different
-ordering of the results of keys(), values(), and each().
B<Please note that the hash seed is sensitive information>. Hashes are
randomized to protect against local and remote attacks against Perl