http://www.perlmonks.org?node_id=261346


in reply to How can I use $1 in an assigned string

A more robust way to do this would be something like this,
that uses a reusable generic function for the actual replacements.
Especially if your template string is going to be dynamic.

#!/usr/local/bin/perl use strict; my $filter = q{user ([^\s]+) has ([^\n\r]+)$}; my $log_string = q{user bob has logged on}; my $template = q{user $1 has accessed the system and is $2}; if ( $log_string =~ /$filter/ ) { # would be better to use something else rather # than '$1' as a replacement mark my %vars = ( '$1' => $1, '$2' => $2, ); my $t = interpolate( $template, \%vars ); print qq{LINE: [$t]\n}; } sub interpolate { my ( $text, $vars ) = @_; study $text; $text =~ s/\Q$_\E/$vars->{$_}/g for ( keys %{$vars} ); return $text; } # END interpolate
Wonko