Binary printf formats aren't supported in earlier versions. From v5.6.0 perldoc perldelta:

"Binary numbers supported

 Binary numbers are now supported as literals, in s?printf formats, and `oct()':

     $answer = 0b101010;
     printf "The answer is: %b\n", oct("0b101010");"

Update: forgot to put in the meat.
As a string:

$ perl -e '$c = 12;print reverse map {vec $c,$_,1}  0..8*length($c)-1;
+'
0011001000110001

[download]

As a number:

$ perl -e '$c = 12;print reverse map {$c&1<<$_?1:0}  0..8;'
000001100

[download]

After Compline,
Zaxo

In reply to Re: bit string by Zaxo
in thread bit string by kiseok7

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