Yeah - perfect example: The following text, taken from Simon Singh's Code Challenge:

K Q O W E F V J P U J U U N U K G L M E K J I N M W U X F Q M K J B G W R L F N F G H U D W U U M B S V L P S N C M U E K Q C T E S W R E E K O Y S S I W C T U A X Y O T A P X P L W P N T C G O J B G F Q H T D W X I Z A Y G F F N S X C S E Y N C T S S P N T U J N Y T G G W Z G R W U U N E J U U Q E A P Y M E K Q H U I D U X F P G U Y T S M T F F S H N U O C Z G M R U W E Y T R G K M E E D C T V R E C F B D J Q C U S W V B P N L G O Y L S K M T E F V J J T W W M F M W P N M E M T M H R S P X F S S K F F S T N U O C Z G M D O E O Y E E K C P J R G P M U R S K H F R S E I U E V G O Y C W X I Z A Y G O S A A N Y D O E O Y J L W U N H A M E B F E L X Y V L W N O J N S I O F R W U C C E S W K V I D G M U C G O C R U W G N M A A F F V N S I U D E K Q H C E U C P F C M P V S U D G A V E M N Y M A M V L F M A O Y F N T Q C U A F V F J N X K L N E I W C W O D C C U L W R I F T W G M U S W O V M A T N Y B U H T C O C W F Y T N M G Y T Q M K B B N L G F B T W O J F T W G N T E J K N E E D C L D H W T V B U V G F B I J G Y Y I D G M V R D G M P L S W G J L A G O E E K J O F E K N Y N O L R I V R W V U H E I W U U R W G M U T J C D B N K G M B I D G M E E Y G U O T D G G Q E U J Y O T V G G B R U J Y S

... fails miserably, but if I save it as "trajan" and run the following:

$ cat trajan | perl -pe 's/\W|\s//gm' | perl babbage.pl

It works like a champ. But this treatment can also foil my "best guess" as to the key length:

$ tail -12 vigenere.pl | perl -pe 's/\W|\s//gm' \ | perl vigenere.pl - | perl babbage.pl

... the "key" found is "vrgpn", and the plaintext is then shown as "tyekipelepetiehnrinmwebnsxmcaqlvcwio..."

All of which makes me think I need to do some refactoring to look out for these kinds of problems, or at the very least add some interactivity along the lines of the posted solution to the code challenge mentioned above.



--chargrill
$,=42;for(34,0,-3,9,-11,11,-17,7,-5){$*.=pack'c'=>$,+=$_}for(reverse s +plit//=>$* ){$%++?$ %%2?push@C,$_,$":push@c,$_,$":(push@C,$_,$")&&push@c,$"}$C[$# +C]=$/;($#C >$#c)?($ c=\@C)&&($ C=\@c):($ c=\@c)&&($C=\@C);$%=$|;for(@$c){print$_^ +$$C[$%++]}

In reply to Re^4: Breaking the indecipherable cipher, courtesy Charles Babbage. by chargrill
in thread Breaking the indecipherable cipher, courtesy Charles Babbage. by chargrill

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