You can simplify the check on the binary number:

unless( $binary=~/^[01]*$/) die "A binary number contains 1's and 0's! only";

^ is the beginning of the string
[01] is a character class matching 0 and 1 only
$is the end of the string

In reply to Re: perl do's and don'ts by mirod
in thread perl do's and don'ts by Anonymous Monk

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