I'm on the perl faq-a-day mailing list and the faq for today 'How can I expand variables in text strings?' has me a bit puzzled.

I understand the first example using symrefs and globals, but the second example with lexicals and /e-evals tripped me up.

They suggest the following for expanding lexicals $foo and $bar: 

$text = 'this has a $foo in it and a $bar';
$text =~ s/(\$\w+)/$1/eeg;   # needs /ee, not /e

[download]
Its that double /ee that gets me. I did some testing and they are correct, a single /e wont work. In fact, a single /e doesn't seem to modify the default behaviour at all.
#!/usr/bin/perl -wT
use strict;
no strict 'refs';

my $foo = 'switch';
my $bar = 'button';
my $text1 = my $text2 = my $text3 = 'this has a $foo in it and a $bar'
+;

$text1 =~ s/(\$\w+)/$1/g;
$text2 =~ s/(\$\w+)/$1/ge;
$text3 =~ s/(\$\w+)/$1/gee;

print "T1 /g   : $text1\n";
print "T2 /ge  : $text2\n";
print "T3 /gee : $text3\n";

=OUTPUT
T1 /g   : this has a $foo in it and a $bar
T2 /ge  : this has a $foo in it and a $bar
T3 /gee : this has a switch in it and a button

[download]
Why do /g and /ge above produce the same string? Is it doing an eval '$1' instead of a eval "$1"?

-Blake

In reply to /ee regex modifier by blakem

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