Hacker News Reader

Comment by usrbinbash | Hacker News Reader

Nothing beats

    #define TRUE (__LINE__ % 10 != 0)

View on HN

What about adding "echo sleep 0.01 >> ~/.bashrc" to their .bashrc (or whichever shell config file is used)?

I don't get it. What's so bad/annoying about sleeping for 10 milliseconds whenever a new shell is opened? I don't think anyone would notice. "sleep 1000", on the other hand...

EDIT: I misunderstood it as executing

   echo sleep 0.01 >> ~/.bashrc

once instead of adding that line to .bashrc – even though that's exactly what you wrote...

Wouldn't it add another ten Ms every time you opened a new terminal session?

yeah its windows 95 simulator :)

The idea is to add the 'echo ..' to the .bashrc, not just run the command once.

Ah, now I get it. Thanks! That's evil, indeed.

It appends another sleep each time you start a new shell, so it subtly slows down over time.

wouldn't it do so exponentially?

The first time it does it once, the second time the statement is there twice so it does it twice, then 4, 8, 16, etc. ?

No, the entire statement isn't added each time, only the sleep portion.

the third time the statement is there three times ..

No, because;

    echo sleep 0.01 >> ~/.bashrc

adds this to .bashrc;

    sleep 0.01

It doesn't add itself, so the sleep tie grows linear by 0.01sec each time a shell is opened.

The real evil comes from putting it in ~/.bash_logout or equivalent so it doesn't get as much visibility as a bashrc might.

That's truly evil.

echo "README: No such file or directory" > README

Back when security was less of a thing and the default $PATH usually included the current directory: echo 'echo ls: command not found' >ls; chmod 755 ls

Haha nice, so maybe:

    notfound() { echo "$1: $2: No such file or directory"; }
    f_cat() { notfound cat "$1"; }
    f_ls() { notfound ls "$1"; }
    alias cat=f_cat
    alias ls=f_ls

And then why not obfuscate ;)

    . <(cat <<'EOF' | base64 -d
    bm90Zm91bmQoKSB7IGVjaG8gIiQxOiAkMjogTm8gc3VjaCBmaWxlIG9yIGRpcmVjdG9yeSI7IH0K
    Zl9jYXQoKSB7IG5vdGZvdW5kIGNhdCAiJDEiOyB9CmZfbHMoKSB7IG5vdGZvdW5kIGxzICIkMSI7
    IH0KYWxpYXMgY2F0PWZfY2F0CmFsaWFzIGxzPWZfbHMK
    EOF
    )

A friend of mine was doing a CTF that puts you into a chroot jail. He could see the flag.txt, but trying to `cat flag.txt` was saying "cat: flag.txt: No such file or directory."

He was absolutely stumped. I just said, "what if 'cat: flag.txt [...]' is the flag?"

Sure enough. That was actually the flag.

hexdump -C flag.txt

The chroot jail did not have access to hexdump.

Or vi.

Or basically anything other than ls and cat.

export EDITOR=rm

That’s pure evil.

I've always liked

    #define else

Oh, that's good. My favorite:

    #define while if

Of course it will fail for programs that make use of do..while

#define while if

Perfect balance of harmless and annoying. I would probably never figure it out. Maybe include a cryptic warning so the person eventually looks at it…

    #define while if
    #warning "loop flow control substituted for conditional"

That fails if you have a do ... while.

May I then suggest...

    #define if while

That fails when you have an else. :)

would that work?

    #define while(x) for(;true;)

It would cause a compile error for do-while loops. And there’s no reason to use `for` here, `while (true)` would do the same (C macros don’t expand recursively in such cases).

I guess i would go with this in a header file that includes rand.h instead, then:

    #define while(cond) while ((cond) && rand() >= somesufficientlysmallnumber)

    #define else

There!

I think I could devise scenarios where that would fail compilation when `else` is used as a macro argument, but other than that it seems quite solid. :)

No put that into some libc .h file on host :)

I'd replace != with ==, so that issue at src.c:380 were unlikely to be reproduced in a reduced case.

I disagree. You want TRUE to be almost always 1. First, if TRUE is almost always 0, the underlying problem will be detected too quickly. Second, this will increase the chance that any seemingly irrelevant change will cause the code to work correctly, making any effort to isolate the bug a frustrating exercise.

If only we'd harness all this creative energy for good, humanity would have transcended to a higher plane of existence.

Maybe the higher place of existence is to find humor in playing subtle pranks on our fellow man. I mean, most fun gods were also pranksters.

Maybe our world is a prank.

>most fun gods were also pranksters.

Eris is 100% the Greek god of putting this kind of thing into your friends and colleague's code. I suspect she also approves of `#define volatile` which could make for a frustrating debugging session.

Better these pranks than using it for more malvertisments

If we used the megagazillions we currently waste by stuffing them into the military-industrial-complex for useful things instead, we could easily end hunger, provide medicine and clean water, give everyone acess to moden technology and high quality education, fund tons of useful research...

...and still have time and money aplenty left for some laughs on the way.

I thought I could mess that up in my mind, and indeed I did. Sorry for the noise!

Reply on news.ycombinator.com