in reply to Use of uninitialized value in concatenation

if i understand your problem right, this could be the solution.
use strict;
use warnings;
my %words = map { $_ => 1 } qw($Word $name $test);
my $line = '$Word $ $ $ $test';
$line =~ s/(\$\w*)/exists $words{$1} ? $1 : " dollar "/eg;
print "$line\n\n";

[download]
will produce
$Word dollar dollar dollar $test

UPDATE
thanks AnomalousMonk, actually i misunderstood the problem :)
this could do it

$line =~ s/(\$(\w*))/exists $words{$1} ? $1 : "dollar$2"/eg;

[download]
Vivek
-- In accordance with the prarabdha of each, the One whose function it is to ordain makes each to act. What will not happen will never happen, whatever effort one may put forth. And what will happen will not fail to happen, however much one may seek to prevent it. This is certain. The part of wisdom therefore is to stay quiet.

Replies are listed 'Best First'.
Re^2: Use of uninitialized value in concatenation
by AnomalousMonk (Archbishop) on Jun 11, 2009 at 06:07 UTC 
    >perl -wMstrict -le
"my %words = map { $_ => 1 } qw($Word $name);
 my $line = '$Word $ $foo';
 $line =~ s/(\$\w*)/exists $words{$1} ? $1 : qq{ dollar }/eg;
 print $line;
"
$Word  dollar   dollar

    [download]
    I think the OPer wants '$foo' to be replaced by 'dollarfoo'. And what's with the extra spaces?
[reply]
[d/l]
[select]
      #!/usr/bin/perl -w
use strict;
my %words = map { $_ => 1 } qw($Word $name);
 my $line = '$Word $ $foo';
 $line =~ s/(\$\w*)/exists $words{$1} ? $1 : qq{ dollar }/eg;
 print $line;

      [download]
      For $foo it prints dollar and not dollarfoo. But still gets a warning message
[reply]
[d/l]
[reply]
[d/l]
[select]

In Section Seekers of Perl Wisdom