C:\Daten\perl>cat nostrict2.pl
sub abcdefghiklcafkasgf { blaubart }

$b = abcdefghiklcafkasgf;
print "b = $b\n";
$html = abc;
$b =~ s/$html/cdef/g;
print $b;

C:\Daten\perl>nostrict2.pl
b = blaubart
blaubart