=item $ARG
=item $_
+X<$_> X<$ARG>
The default input and pattern-searching space. The following pairs are
equivalent:
=item $a
=item $b
+X<$a> X<$b>
Special package variables when using sort(), see L<perlfunc/sort>.
Because of this specialness $a and $b don't need to be declared
=over 8
=item $<I<digits>>
+X<$1> X<$2> X<$3>
Contains the subpattern from the corresponding set of capturing
parentheses from the last pattern match, not counting patterns
=item $MATCH
=item $&
+X<$&> X<$MATCH>
The string matched by the last successful pattern match (not counting
any matches hidden within a BLOCK or eval() enclosed by the current
The use of this variable anywhere in a program imposes a considerable
performance penalty on all regular expression matches. See L</BUGS>.
+See L</@-> for a replacement.
+
=item $PREMATCH
=item $`
+X<$`> X<$PREMATCH>
The string preceding whatever was matched by the last successful
pattern match (not counting any matches hidden within a BLOCK or eval
The use of this variable anywhere in a program imposes a considerable
performance penalty on all regular expression matches. See L</BUGS>.
+See L</@-> for a replacement.
+
=item $POSTMATCH
=item $'
+X<$'> X<$POSTMATCH>
The string following whatever was matched by the last successful
pattern match (not counting any matches hidden within a BLOCK or eval()
The use of this variable anywhere in a program imposes a considerable
performance penalty on all regular expression matches. See L</BUGS>.
+See L</@-> for a replacement.
+
=item $LAST_PAREN_MATCH
=item $+
+X<$+> X<$LAST_PAREN_MATCH>
The text matched by the last bracket of the last successful search pattern.
This is useful if you don't know which one of a set of alternative patterns
This variable is read-only and dynamically scoped to the current BLOCK.
=item $^N
+X<$^N>
The text matched by the used group most-recently closed (i.e. the group
with the rightmost closing parenthesis) of the last successful search
=item @LAST_MATCH_END
=item @+
+X<@+> X<@LAST_MATCH_END>
This array holds the offsets of the ends of the last successful
submatches in the currently active dynamic scope. C<$+[0]> is
=item $NR
=item $.
+X<$.> X<$NR> X<$INPUT_LINE_NUMBER> X<line number>
Current line number for the last filehandle accessed.
=item $RS
=item $/
+X<$/> X<$RS> X<$INPUT_RECORD_SEPARATOR>
The input record separator, newline by default. This
influences Perl's idea of what a "line" is. Works like B<awk>'s RS
=item $OUTPUT_AUTOFLUSH
=item $|
+X<$|> X<autoflush> X<flush> X<$OUTPUT_AUTOFLUSH>
If set to nonzero, forces a flush right away and after every write
or print on the currently selected output channel. Default is 0
=item $OFS
=item $,
+X<$,> X<$OFS> X<$OUTPUT_FIELD_SEPARATOR>
The output field separator for the print operator. If defined, this
value is printed between each of print's arguments. Default is C<undef>.
=item $ORS
=item $\
+X<$\> X<$ORS> X<$OUTPUT_RECORD_SEPARATOR>
The output record separator for the print operator. If defined, this
value is printed after the last of print's arguments. Default is C<undef>.
=item $LIST_SEPARATOR
=item $"
+X<$"> X<$LIST_SEPARATOR>
This is like C<$,> except that it applies to array and slice values
interpolated into a double-quoted string (or similar interpreted
=item $SUBSEP
=item $;
+X<$;> X<$SUBSEP> X<SUBSCRIPT_SEPARATOR>
The subscript separator for multidimensional array emulation. If you
refer to a hash element as
=item $FORMAT_PAGE_NUMBER
=item $%
+X<$%> X<$FORMAT_PAGE_NUMBER>
The current page number of the currently selected output channel.
Used with formats.
=item $FORMAT_LINES_PER_PAGE
=item $=
+X<$=> X<$FORMAT_LINES_PER_PAGE>
The current page length (printable lines) of the currently selected
output channel. Default is 60.
=item $FORMAT_LINES_LEFT
=item $-
+X<$-> X<$FORMAT_LINES_LEFT>
The number of lines left on the page of the currently selected output
channel.
=item @LAST_MATCH_START
=item @-
+X<@-> X<@LAST_MATCH_START>
$-[0] is the offset of the start of the last successful match.
C<$-[>I<n>C<]> is the offset of the start of the substring matched by
=item $FORMAT_NAME
=item $~
+X<$~> X<$FORMAT_NAME>
The name of the current report format for the currently selected output
channel. Default is the name of the filehandle. (Mnemonic: brother to
=item $FORMAT_TOP_NAME
=item $^
+X<$^> X<$FORMAT_TOP_NAME>
The name of the current top-of-page format for the currently selected
output channel. Default is the name of the filehandle with _TOP
=item $FORMAT_LINE_BREAK_CHARACTERS
=item $:
+X<$:> X<FORMAT_LINE_BREAK_CHARACTERS>
The current set of characters after which a string may be broken to
fill continuation fields (starting with ^) in a format. Default is
=item $FORMAT_FORMFEED
=item $^L
+X<$^L> X<$FORMAT_FORMFEED>
What formats output as a form feed. Default is \f.
=item $ACCUMULATOR
=item $^A
+X<$^A> X<$ACCUMULATOR>
The current value of the write() accumulator for format() lines. A format
contains formline() calls that put their result into C<$^A>. After
=item $CHILD_ERROR
=item $?
+X<$?> X<$CHILD_ERROR>
The status returned by the last pipe close, backtick (C<``>) command,
successful call to wait() or waitpid(), or from the system()
Also see L<Error Indicators>.
=item ${^CHILD_ERROR_NATIVE}
+X<$^CHILD_ERROR_NATIVE>
The native status returned by the last pipe close, backtick (C<``>)
command, successful call to wait() or waitpid(), or from the system()
as $? when the pragma C<use vmsish 'status'> is in effect.
=item ${^ENCODING}
+X<$^ENCODING>
The I<object reference> to the Encode object that is used to convert
the source code to Unicode. Thanks to this variable your perl script
=item $ERRNO
=item $!
+X<$!> X<$ERRNO> X<$OS_ERROR>
If used numerically, yields the current value of the C C<errno>
variable, or in other words, if a system or library call fails, it
Also see L<Error Indicators>.
=item %!
+X<%!>
Each element of C<%!> has a true value only if C<$!> is set to that
value. For example, C<$!{ENOENT}> is true if and only if the current
=item $EXTENDED_OS_ERROR
=item $^E
+X<$^E> X<$EXTENDED_OS_ERROR>
Error information specific to the current operating system. At
the moment, this differs from C<$!> under only VMS, OS/2, and Win32
=item $EVAL_ERROR
=item $@
+X<$@> X<$EVAL_ERROR>
The Perl syntax error message from the last eval() operator.
If $@ is the null string, the last eval() parsed and executed
=item $PID
=item $$
+X<$$> X<$PID> X<$PROCESS_ID>
The process number of the Perl running this script. You should
consider this variable read-only, although it will be altered
=item $UID
=item $<
+X<< $< >> X<$UID> X<$REAL_USER_ID>
The real uid of this process. (Mnemonic: it's the uid you came I<from>,
if you're running setuid.) You can change both the real uid and
=item $EUID
=item $>
+X<< $> >> X<$EUID> X<$EFFECTIVE_USER_ID>
The effective uid of this process. Example:
=item $GID
=item $(
+X<$(> X<$GID> X<$REAL_GROUP_ID>
The real gid of this process. If you are on a machine that supports
membership in multiple groups simultaneously, gives a space separated
=item $EGID
=item $)
+X<$)> X<$EGID> X<$EFFECTIVE_GROUP_ID>
The effective gid of this process. If you are on a machine that
supports membership in multiple groups simultaneously, gives a space
=item $PROGRAM_NAME
=item $0
+X<$0> X<$PROGRAM_NAME>
Contains the name of the program being executed.
have their own copies of it.
=item $[
+X<$[>
The index of the first element in an array, and of the first character
in a substring. Default is 0, but you could theoretically set it
lexical block.
=item $]
+X<$]>
The version + patchlevel / 1000 of the Perl interpreter. This variable
can be used to determine whether the Perl interpreter executing a
=item $COMPILING
=item $^C
+X<$^C> X<$COMPILING>
The current value of the flag associated with the B<-c> switch.
Mainly of use with B<-MO=...> to allow code to alter its behavior
=item $DEBUGGING
=item $^D
+X<$^D> X<$DEBUGGING>
The current value of the debugging flags. (Mnemonic: value of B<-D>
switch.) May be read or set. Like its command-line equivalent, you can use
=item $SYSTEM_FD_MAX
=item $^F
+X<$^F> X<$SYSTEM_FD_MAX>
The maximum system file descriptor, ordinarily 2. System file
descriptors are passed to exec()ed processes, while higher file
=item $INPLACE_EDIT
=item $^I
+X<$^I> X<$INPLACE_EDIT>
The current value of the inplace-edit extension. Use C<undef> to disable
inplace editing. (Mnemonic: value of B<-i> switch.)
=item $^M
+X<$^M>
By default, running out of memory is an untrappable, fatal error.
However, if suitably built, Perl can use the contents of C<$^M>
=item $OSNAME
=item $^O
+X<$^O> X<$OSNAME>
The name of the operating system under which this copy of Perl was
built, as determined during the configuration process. The value
=item $PERLDB
=item $^P
+X<$^P> X<$PERLDB>
The internal variable for debugging support. The meanings of the
various bits are subject to change, but currently indicate:
=item $LAST_REGEXP_CODE_RESULT
=item $^R
+X<$^R> X<$LAST_REGEXP_CODE_RESULT>
The result of evaluation of the last successful C<(?{ code })>
regular expression assertion (see L<perlre>). May be written to.
=item $EXCEPTIONS_BEING_CAUGHT
=item $^S
+X<$^S> X<$EXCEPTIONS_BEING_CAUGHT>
Current state of the interpreter.
=item $BASETIME
=item $^T
+X<$^T> X<$BASETIME>
The time at which the program began running, in seconds since the
epoch (beginning of 1970). The values returned by the B<-M>, B<-A>,
=item $PERL_VERSION
=item $^V
+X<$^V> X<$PERL_VERSION>
The revision, version, and subversion of the Perl interpreter, represented
as a string composed of characters with those ordinals. Thus in Perl v5.6.0
=item $WARNING
=item $^W
+X<$^W> X<$WARNING>
The current value of the warning switch, initially true if B<-w>
was used, false otherwise, but directly modifiable. (Mnemonic:
=item $EXECUTABLE_NAME
=item $^X
+X<$^X> X<$EXECUTABLE_NAME>
The name used to execute the current copy of Perl, from C's
C<argv[0]> or (where supported) F</proc/self/exe>.
unless $secure_perl_path =~ m/$Config{_exe}$/i;}
=item ARGV
+X<ARGV>
The special filehandle that iterates over command-line filenames in
C<@ARGV>. Usually written as the null filehandle in the angle operator
files in C<@ARGV>.
=item $ARGV
+X<$ARGV>
contains the name of the current file when reading from <>.
=item @ARGV
+X<@ARGV>
The array @ARGV contains the command-line arguments intended for
the script. C<$#ARGV> is generally the number of arguments minus
command name itself. See C<$0> for the command name.
=item ARGVOUT
+X<ARGVOUT>
The special filehandle that points to the currently open output file
when doing edit-in-place processing with B<-i>. Useful when you have
L<perlrun> for the B<-i> switch.
=item @F
+X<@F>
The array @F contains the fields of each line read in when autosplit
mode is turned on. See L<perlrun> for the B<-a> switch. This array
if not in package main when running under C<strict 'vars'>.
=item @INC
+X<@INC>
The array @INC contains the list of places that the C<do EXPR>,
C<require>, or C<use> constructs look for their library files. It
=item @ARG
=item @_
+X<@_> X<@ARG>
Within a subroutine the array @_ contains the parameters passed to that
subroutine. See L<perlsub>.
=item %INC
+X<%INC>
The hash %INC contains entries for each filename included via the
C<do>, C<require>, or C<use> operators. The key is the filename
=item %ENV
=item $ENV{expr}
+X<%ENV>
The hash %ENV contains your current environment. Setting a
value in C<ENV> changes the environment for any child processes
=item %SIG
=item $SIG{expr}
+X<%SIG>
The hash %SIG contains signal handlers for signals. For example:
=back
=head2 Error Indicators
+X<error> X<exception>
The variables C<$@>, C<$!>, C<$^E>, and C<$?> contain information
about different types of error conditions that may appear during
English> in libraries is strongly discouraged. See the
Devel::SawAmpersand module documentation from CPAN
( http://www.cpan.org/modules/by-module/Devel/ )
-for more information.
+for more information. Writing C<use English '-no_match_vars';>
+avoids the performance penalty.
Having to even think about the C<$^S> variable in your exception
handlers is simply wrong. C<$SIG{__DIE__}> as currently implemented
projects / p5sagit/p5-mst-13.2.git / commitdiff