not reading from a record-oriented file (or your OS doesn't have
record-oriented files), then you'll likely get a full chunk of data
with every read. If a record is larger than the record size you've
-set, you'll get the record back in pieces.
+set, you'll get the record back in pieces. Trying to set the record
+size to zero or less will cause reading in the (rest of the) whole file.
On VMS, record reads are done with the equivalent of C<sysread>,
so it's best not to mix record and non-record reads on the same
Its use is highly discouraged.
Note that, unlike other compile-time directives (such as L<strict>),
-assignment to $[ can be seen from outer lexical scopes in the same file.
-However, you can use local() on it to strictly bound its value to a
+assignment to C<$[> can be seen from outer lexical scopes in the same file.
+However, you can use local() on it to strictly bind its value to a
lexical block.
=item $]
By default, running out of memory is an untrappable, fatal error.
However, if suitably built, Perl can use the contents of C<$^M>
as an emergency memory pool after die()ing. Suppose that your Perl
-were compiled with -DPERL_EMERGENCY_SBRK and used Perl's malloc.
+were compiled with C<-DPERL_EMERGENCY_SBRK> and used Perl's malloc.
Then
$^M = 'a' x (1 << 16);
would allocate a 64K buffer for use in an emergency. See the
F<INSTALL> file in the Perl distribution for information on how to
-enable this option. To discourage casual use of this advanced
-feature, there is no L<English|English> long name for this variable.
+add custom C compilation flags when compiling perl. To discourage casual
+use of this advanced feature, there is no L<English|English> long name for
+this variable.
=item $OSNAME
the possible values. This variable is set during Perl startup
and is thereafter read-only.
+=item ${^UTF8CACHE}
+
+This variable controls the state of the internal UTF-8 offset caching code.
+1 for on (the default), 0 for off, -1 to debug the caching code by checking
+all its results against linear scans, and panicking on any discrepancy.
+
=item ${^UTF8LOCALE}
This variable indicates whether an UTF-8 locale was detected by perl at
The current set of warning checks enabled by the C<use warnings> pragma.
See the documentation of C<warnings> for more details.
+=item ${^WIN32_SLOPPY_STAT}
+
+If this variable is set to a true value, then stat() on Windows will
+not try to open the file. This means that the link count cannot be
+determined and file attributes may be out of date if additional
+hardlinks to the file exist. On the other hand, not opening the file
+is considerably faster, especially for files on network drives.
+
+This variable could be set in the F<sitecustomize.pl> file to
+configure the local Perl installation to use "sloppy" stat() by
+default. See L<perlrun> for more information about site
+customization.
+
=item $EXECUTABLE_NAME
=item $^X
The name used to execute the current copy of Perl, from C's
-C<argv[0]>.
+C<argv[0]> or (where supported) F</proc/self/exe>.
Depending on the host operating system, the value of $^X may be
a relative or absolute pathname of the perl program file, or may