Perl in a Nutshell, 2nd Edition

English

Provides aliases for the Perl built-in special variables. Everything else about the variables and their use remains the same. Be aware, though, that using the English module significantly slows down a program for regular expressions.

Some of the Perl variables match some awk built-in variables. For those cases, you’ll find two English names: a short version (which is the awk name) and a longer version. For example, you can use either $ERRNO (the awk name) or $OS_ERROR to refer to the Perl variable $!.

Here is the list of variables and their English alternatives:

Perl	English	Perl	English
@_	@ARG	$?	$CHILD_ERROR
$_	$ARG	$!	$OS_ERROR
$%	$MATCH	$!	$ERRNO
$'	$PREMATCH	$@	$EVAL_ERROR
$'	$POSTMATCH	$$	$PROCESS_ID
$+	$LAST_PAREN_MATCH	$$	$PID
$.	$INPUT_LINE_NUMBER	$<	$REAL_USER_ID
$.	$NR	$<	$UID
$/	$INPUT_RECORD_SEPARATOR	$>	$EFFECTIVE_USER_ID
$/	$RS	$>	$EUID
$|	$OUTPUT_AUTOFLUSH	$(	$REAL_GROUP_ID
$,	$OUTPUT_FIELD_SEPARATOR	$(	$GID
$,	$OFS	$)	$EFFECTIVE_GROUP_ID
$\	$OUTPUT_RECORD_SEPARATOR	$)	$EGID
$\	$ORS	$0	$PROGRAM_NAME
$"	$LIST_SEPARATOR	$]	$PERL_VERSION
$;	$SUBSCRIPT_SEPARATOR	$^A	$ACCUMULATOR
$;	$SUBSEP	$^D	$DEBUGGING
$%	$FORMAT_PAGE_NUMBER	$^F	$SYSTEM_FD_MAX
$=	$FORMAT_LINES_PER_PAGE	$^I	$INPLACE_EDIT
$-	$FORMAT_LINES_LEFT	$^P	$PERLDB
$~	$FORMAT_NAME	$^T	$BASETIME
$^	$FORMAT_TOP_NAME	$^W	$WARNING
$:	$FORMAT_LINE_BREAK_CHARACTERS	$^X	$EXECUTABLE_NAME
$^L	$FORMAT_LINEFEED	$^O	$OSNAME