For more information on regular expressions, see Section 4.6 later in this chapter.
$
digit
Contains the text matched by the corresponding
set of parentheses in the last pattern matched. For example,
$1
matches whatever was
contained in the first set of parentheses in the previous
regular expression.
$&
$MATCH
$`
$PREMATCH
The string preceding whatever was matched by the last successful pattern match.
$`
$POSTMATCH
The string following whatever was matched by the last successful pattern match.
$+
$LAST_PAREN_MATCH
The last bracket matched by the last search pattern. This is useful if you don’t know which of a set of alternative patterns was matched. For example:
/Version: (.*)|Revision: (.*)/ && ($rev = $+);
$^N
The string matched by the most recently closed group.
This is most useful inside (?{
. . . })
blocks for examining matched
text. If you have multiple matches denoted by parentheses,
$^N
can be used in lieu of
$1
, $2
, $3
, etc., so you don’t have to
manually count the number of sets of parentheses that denote
your matches. For example:
#!/usr/local/bin/perl -w $words = "person|here"; $words =~ /(w+)|(w+)/; print $^N; # Prints 'here'
3.135.247.181