Good catch!
Actually, the only problem with his code as given was the missing join character as the first argument to join. Inserting a null string:   $pw = join('',@chars[map{rand @chars} (1..17)]; This works, because map{rand @chars} (1..17) does indeed generate a list of 17 indices, each in the proper range for the @chars array. (They're floating point, but they get intified when used as indices.)
That said, it's not how I would have done it. I would have written   $pw = join '', map { $chars[ rand @chars ] } 1..17;

jdporter
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