Black Perl
en.wikipedia.org
en.wikipedia.org
#!/usr/bin/perl -s
@x=qw/e n d/;if(
$kg){$e=13;$_="setrand(@{[int((rand)*90)]})
;K=vector(2,g,nextprime(random(10^$s)));e=$e;n=K[1]*
K[2];d=e^-1%((K[1]-1)*(K[2]-1));";s/\s//sg;for(
`echo "$_ e\nn\nd\n"|gp -q`){print$x[$j++]
,"=",`echo "10i16o$_ p"|dc`}exit}$t=
unpack'H*',join'',<>;$l=length$n;$y
=$e?$l-2:$l;$i="16dio";while (){$M=
($e&&1+int(rand 8)).(substr $t,$p
,$y or last);$i.="\U$M $k $n\E|
pc";$p+=$y}for(reverse
`echo "$i"|dc`){chop
;$d&&s/^(.)//||($_=
sprintf"%0${l}s"
,$_); $f
.=$_}#
print
pack
'H*'
,$f
My personal best was this "zombie" code: http://www.joelesko.com/cgi-bin/obfu.pl?obfuID=5
Take a look at the first issues of The Perl Journal as well.
v6 would fix everything that I find irksome on v5.
I like the Ruby language a lot; the whole method_missing system beats AUTOLOAD hacks and I like Ruby's standard classes and core libraries. The Smalltalk influence is nice too; I like when an "OO language" feels object-oriented all the way down.
Fun to hack around, but then you have to maintain someone else's Perl, or write a large application in it, and the endless facepalming begins.
Perl lit is awesome and erudite: the best idioms are described in the Cookbook. Programming Perl is a joy to read, Best Practices could be used as a standards guide.
I agree that v5 has some problematic constructs, but, all in all, what Larry Wall & Co did was awesome.
I would be delighted to see you cause a segfault in Haskell without taking advantage of an implementation bug.
The point isn't that you can or cannot write bad code in any language, it's not that simple. It's a matter of how difficult a language's semantics, type-checking, logical structures, and faculties make it to traverse the spectrum towards bad code.
Python has clean indentation baked in at the implementation. All major interpreted languages don't allow you to muck around with pointers.
Functional languages strongly discourage mutability. Object oriented languages are really just a foil for context scoping in various ways combined with somewhat sanitary code-reuse that is less likely to introduce type or memory sharing bugs.
It really bothers me when people say, "you can write bad code in any language". Of course you can, but that ejects the subtlety and reality of the matter into vacuum. You cannot disregard the effect of the programming environment on the code, and the supposed canard of Perl's write-once read-never is not false but rather, a tendency that it facilitates.
I mean, have you seen the number of operators in Perl?
http://tinyurl.com/badvbx (large 300 dpi jpg, Period Table of Operators in Perl)
While this makes Perl the king of golfing, the mental context it consumes to remember all the operators someone else may use in their code (but that you do not) makes reading their code a non-trivial task.
This is precisely the thing people complain about when comparing (unfavourably) C++ to C. There's just too much syntax and too many complicated interactions that make it nearly impossible to reason about what the code does, let alone any degree of referential transparency.
Potentially one of Lisp's most powerful attributes is as you may have heard, the lack of syntax. The one ever-present syntactic feature in Lisp (paren) is widely mocked as well by detractors!
Perl is awesome. It's erudite. It's a fantastic means of parsing and manipulating text (I vastly prefer Perl to awk/sed abuse except for in-line commands.) Perl documentation is really good too.
All the meta of what makes a languages pleasant to use, is mostly there for Perl, but the language itself is a syringe of heroin and rat poison, just begging you to abuse the power.
And don't mention CPAN. People who accuse Python libraries of being written by amateurs haven't seen the manifest horrors that exist in CPAN. Rubyists have it good by comparison.
Can we please drop the "you can write bad code in any language" line now?
> I would be delighted to see you cause a segfault in Haskell without taking advantage of an implementation bug.
import Foreign
main = peek nullPtr
import Data.Typeable
import Data.ByteString
data Wrap a = Wrap a
deriving (Show)
instance Typeable (Wrap a) where
typeOf _ = typeOf ()
main = let Just (Wrap bad) = cast $ Wrap () in print (bad :: ByteString)
>>> import ctypes as c
>>> c.string_at(0)
Segmentation faultI mean really, kind of missing the point don't you think?
It's not even like Haskell makes it trivial to mutate the pointers in a natively Von Neumann-esque manner.
Monads don't count either.
Example: how often have you seen unsafe C# code (pointers) used in a production web app?
Counterpart to the above: How often do you see pointers used in C? All the time
Presenting the pathological case isn't refuting what I'm saying, it's just affirming it by showing how far you have to go out of your way to abuse your memory access, whereas in C, it's just a part of how you code. (Functors, for example.)
> It's not even like Haskell makes it trivial to mutate the pointers in a natively Von Neumann-esque manner.
Haskell has a module specifically for manipulating pointers[1]. There's no inherent safety in using Haskell rather than C for pointer based code.
> Monads don't count either.
This sentence makes no sense, and makes me think you've never (or seldom) used Haskell before.
> Example: how often have you seen unsafe C# code (pointers) used in a production web app?
Somewhat often -- pointers are used in database adapter, template engines, graphics rendering, and any code which needs to call into foreign libraries.
> Counterpart to the above: How often do you see pointers used in C? All the time
That's because C is used in code where performance is absolutely critical, which demands having control over memory layout and management. Pointers aren't a symptom of using C -- using C is a result of needing pointers.
[1] http://haskell.org/ghc/docs/latest/html/libraries/base-4.2.0...
I think that making calls to functions implemented in C via the FFI would be more productive. I've never heard of anyone using pointers in Python for anything.
>This sentence makes no sense, and makes me think you've never (or seldom) used Haskell before.
Sure it does, performing an arbitrary mutation on an already known variable (location in memory) in Haskell is very intentionally non-trivial due to striving for purity as a functional language. (Copy rather than overwrite behavior as a default.)
>That's because C is used in code where performance is absolutely critical, which demands having control over memory layout and management. Pointers aren't a symptom of using C -- using C is a result of needing pointers.
Uh, the whole, "C only uses pointers for speed" thing is completely incorrect. All the experienced C programmers I know use pointers simply because they're the most direct and portable means of writing terse code that is still performant in spite of the brevity. I mentioned functors for a reason.
This is more pedantic than some of the conversations I've witnessed in ##C on Freenode, come on.
You're missing the point by a greater distance than Christopher Columbus missed the West Indies in the late 15th century.
This paragraph 1) has nothing to do with monads and 2) is incorrect. Monads exist to enforce in which order computations are performed. And there's nothing difficult about mutating memory in Haskell; aside from a lack of built-in syntax, it's a close equivalent to C.
import Foreign
main = do
p <- malloc -- p = malloc(sizeof(char))
poke p 'a' -- *p = 'a'
peek p >>= print -- printf("'%c'\n", *p)
poke p 'b' -- *p = 'b'
peek p >>= print -- printf("'%c'\n", *p)
free p -- free(p)As has been said before, it's not important what a language makes possible, so much as what it makes easy -- and, I'd like to add, what it makes hard.
So, sure, you make a great, fun technical point, but at the same time Haskell as a language and a community has very, very carefully worked to make sure people don't make segfaults — actually, they tried to make sure people don't even write ugly code with polluted namespaces and odd global state.
Perl, C, Java just haven't (as much).
You mean a different kind of "bad code" than the comment to which you replied.
Ruby, Python, Haskell, Prolog, ML, CL -- none of these languages prevent malicious or inexperienced coders from choosing poor identifiers, violating encapsulation, abusing or ignoring language-specific idioms, or designing a big ball of mud.
> I mean, have you seen the number of operators in Perl?
That's Perl 6, not Perl 5, and it's out of date.
Also, from my personal experience, in general the average quality of Perl code I've seen, whether it's CPAN libraries or code at I see at work, is much less than the average quality Python and Ruby code I see, which is more of a community problem than a language one, although Perl being the way it is seems to attract a certain class of developers I would rather not have to work with.
Turns out the problem is that I don't know Ruby.
I am downloading Perl 3 and am just going to run the thing.
Edit: OK, yacc is too new, make is too new, the C compiler can't understand 1989 C, etc... so I have lost interest.
Depending on who you ask, this decision was either for convenience ("this book teaches Perl 4" is easier to say than "this book teaches Perl 3.numbers.here") or marketing ("look--Perl 4 came out!"), the latter sort of like Slackware's increment of version numbers from 4 to 7.
That was done because all of the other distros at the time had higher version numbers and people were looking at Slackware with a, "Well, it's only version 4. RedHat/Mandrake/etc are already on version 7!" attitude. I remember there being a written (web) justification for it.
It's a thorny problem, really. In many cases, we have to preserve hardware required to decode information--think u-matic tape players, 5.25" floppies, Iomega zip drives, etc.--as well as software to decode the information on the files.