For the following code: 
my $test = shift;  # we want a binary "tape" of 1s and 0s as the arg

unless ( $test and $test =~ /^[01]+$/ ) {
    die "Your input was: $test\nGive a string (tape) of zeros and ones
+ only!\n";
}
my @test_queue = split '', $test; # turn string into queue/array

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We get the following behavior even though a single zero should pass the regexp test. A single one does pass, BTW.

Anyone know why? Gracias. 

c:\Documents and Settings\1\My Documents\perl\dfa\simple>code.pl 0
code.pl 0
Your input was: 0
Give a string (tape) of zeros and ones only!

[download]

In reply to regexp - character class containing zero does not find zero by princepawn

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