C:\Daten\perl>cat nostrict1.pl
$b = abcdefghiklcafkasgf;
print "b = $b\n";
$html = abc;
$b =~ s/$html/cdef/g;
print $b;

sub abcdefghiklcafkasgf { blaubart }

C:\Daten\perl>nostrict1.pl
b = abcdefghiklcafkasgf
cdefdefghiklcafkasgf