if ($str2 =~ /\Q$str1\E/) #\Q...\E means like qr
                           #don't interpret characters
                           #like '(' within $str1
                           #use them verbatim
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To avoid misunderstanding, you might also consider removing "like qr" from the foregoing comment, or possibly changing to something like "means,as when used in qr, to avoid interpreting characters like ...".