(Mnemonic: underline is understood in certain operations.)
+=back
+
+=over 8
+
=item $<I<digit>>
Contains the subpattern from the corresponding set of parentheses in
=item $.
-The current input line number of the last filehandle that was read. An
-explicit close on the filehandle resets the line number. Since
+The current input line number for the last file handle from
+which you read (or performed a C<seek> or <tell> on). An
+explicit close on a filehandle resets the line number. Since
"C<E<lt>E<gt>>" never does an explicit close, line numbers increase
across ARGV files (but see examples under eof()). Localizing C<$.> has
the effect of also localizing Perl's notion of "the last read
=item $|
If set to nonzero, forces a flush after every write or print on the
-currently selected output channel. Default is 0. Note that STDOUT
-will typically be line buffered if output is to the terminal and block
-buffered otherwise. Setting this variable is useful primarily when you
-are outputting to a pipe, such as when you are running a Perl script
-under rsh and want to see the output as it's happening. This has no
-effect on input buffering.
+currently selected output channel. Default is 0 (regardless of whether
+the channel is actually buffered by the system or not; C<$|> only tells
+you whether you've asked Perl to explicitly flush after each write).
+Note that STDOUT will typically be line buffered if output is to the
+terminal and block buffered otherwise. Setting this variable is useful
+primarily when you are outputting to a pipe, such as when you are running
+a Perl script under rsh and want to see the output as it's happening. This
+has no effect on input buffering.
(Mnemonic: when you want your pipes to be piping hot.)
=item output_field_separator HANDLE EXPR
The output format for printed numbers. This variable is a half-hearted
attempt to emulate B<awk>'s OFMT variable. There are times, however,
when B<awk> and Perl have differing notions of what is in fact
-numeric. Also, the initial value is %.20g rather than %.6g, so you
-need to set "C<$#>" explicitly to get B<awk>'s value. (Mnemonic: # is the
-number sign.)
+numeric. The initial value is %.I<n>g, where I<n> is the value
+of the macro DBL_DIG from your system's F<float.h>. This is different from
+B<awk>'s default OFMT setting of %.6g, so you need to set "C<$#>"
+explicitly to get B<awk>'s value. (Mnemonic: # is the number sign.)
Use of "C<$#>" is deprecated in Perl 5.
status of a file descriptor will be decided according to the value of
C<$^F> at the time of the open, not the time of the exec.
+=item $^H
+
+The current set of syntax checks enabled by C<use strict>. See the
+documentation of C<strict> for more details.
+
=item $INPLACE_EDIT
=item $^I
inplace editing. (Mnemonic: value of B<-i> switch.)
=item $OSNAME
+
=item $^O
The name of the operating system under which this copy of Perl was
The array @INC contains the list of places to look for Perl scripts to
be evaluated by the C<do EXPR>, C<require>, or C<use> constructs. It
initially consists of the arguments to any B<-I> command line switches,
-followed by the default Perl library, probably "/usr/local/lib/perl",
+followed by the default Perl library, probably F</usr/local/lib/perl>,
followed by ".", to represent the current directory. If you need to
modify this at runtime, you should use the C<use lib> pragma in order
to also get the machine-dependent library properly loaded:
can die from a __DIE__ handler. Similarly for __WARN__.
=back
-
projects / p5sagit/p5-mst-13.2.git / blobdiff