/prog/ - Shortest way to segfault on C

Name: Anonymous 2009-10-17 15:47

main(){main();}

Name: Anonymous 2009-10-17 15:51



#define main() m



m { m ;}

Name: Anonymous 2009-10-17 15:54

>>2
It's funny because you're actually writing more.

Name: Anonymous 2009-10-17 16:30

main=58;

Name: Anonymous 2009-10-17 16:34

main=0;

Name: Anonymous 2009-10-17 16:35

$ gcc -x c -Dm='main(){strdup(1);}' -

m

Name: Anonymous 2009-10-17 16:35

main;

Name: Anonymous 2009-10-17 16:41

>>7
It's hard to believe that actually compiles

Name: Anonymous 2009-10-17 16:42

>>8
warning: data definition has no type or storage class warning: type defaults to ‘int’ in declaration of ‘main’ warning: ‘main’ is usually a function

Name: Anonymous 2009-10-17 16:43

>>6
echo -n | cc -x c -nostdlib -

Name: Anonymous 2009-10-17 16:44

>>9
Yes, but who ever listened to warnings

Name: Anonymous 2009-10-17 16:46

>>11
No, they explain what happens:

main; is equivalent to int main;

Name: Anonymous 2009-10-17 19:11

>>4,5
GENIUS!

Name: Anonymous 2009-10-18 7:42

>>12
So what, it's a prototype declaration?
Also, wtf is main=5; doing? Declaring main as an int, assiging 5 and then making libc attempt to call a variable?

Name: Anonymous 2009-10-18 9:45

>>14
So what, it's a prototype declaration?
Variable declaration (without initializing it)... hmm, what are global variables initialized to? They can't very well take on a random value, because they aren't allocated on the stack, right? I know static globals are zeroed.
Also, wtf is main=5; doing? Declaring main as an int, assiging 5 and then making libc attempt to call a variable?
Correct. Calling a variable is equivalent to jumping to its position, then executing the bytes that represent it (and subsequent data).

Name: Anonymous 2009-10-18 10:14

[metatroll:Unix/Cee]% ed maineq5.c

maineq5.c: No such file or directory

a

int main = 5;

.

w

14

q

[metatroll:Unix/Cee]% gcc -o i_am_bleeding maineq5.c 

[metatroll:Unix/Cee]% ./i_am_bleeding 

zsh: bus error  ./i_am_bleeding

[metatroll:Unix/Cee]%

It didn't even warn me or anything. I'm impressed!

Name: Anonymous 2009-10-18 10:30



CL-SHELL> emacs -nw maineq5.lisp

(setq main 5) C-a C-c C-c C-c C-x

CL-SHELL>

It didn't even warn me or anything. I'm impressed!

Name: Anonymous 2009-10-18 10:32



vim maineq5.perl

i#!/usr/bin/perl

return (0);,.;wq

It didn't even warn me or anything. I'm impressed!

Name: >>16-chan 2009-10-18 10:49

>>17-18
（　≖‿≖）

Name: Anonymous 2009-10-18 10:56

>>17
What is this `CL-SHELL'?

Name: Anonymous 2009-10-18 11:04

>>20
Google, 3rd hit.

Name: Anonymous 2009-10-18 12:18

>>17
Did you just invoke emacs to edit a single file? Emacs is a DAEMON!

Name: Anonymous 2009-10-18 12:28

>>22
Is this just your way of saying ``I've read SICP'' ?

Name: Anonymous 2009-10-18 12:42

>>23
Replies on /prog/ keep getting lazier and lazier :(

Name: Anonymous 2009-10-18 13:32

>>24
excuse me?

Name: Anonymous 2009-10-18 13:40

>>25
LIKE DEAD DOGS

Name: Anonymous 2009-10-18 14:58

main=195;
And I failed ;_;

Name: Anonymous 2009-10-18 18:13

>>15
Thanks for the explanation. Tbh, I was expecting flame/trolls, but yeah... thanks

Name: Anonymous 2010-11-13 13:45

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Shortest way to segfault on C

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2 Name: Anonymous 2009-10-17 15:51

3 Name: Anonymous 2009-10-17 15:54

4 Name: Anonymous 2009-10-17 16:30

5 Name: Anonymous 2009-10-17 16:34

6 Name: Anonymous 2009-10-17 16:35

7 Name: Anonymous 2009-10-17 16:35

8 Name: Anonymous 2009-10-17 16:41

9 Name: Anonymous 2009-10-17 16:42

10 Name: Anonymous 2009-10-17 16:43

11 Name: Anonymous 2009-10-17 16:44

12 Name: Anonymous 2009-10-17 16:46

13 Name: Anonymous 2009-10-17 19:11

14 Name: Anonymous 2009-10-18 7:42

15 Name: Anonymous 2009-10-18 9:45

16 Name: Anonymous 2009-10-18 10:14

17 Name: Anonymous 2009-10-18 10:30

18 Name: Anonymous 2009-10-18 10:32

19 Name: >>16-chan 2009-10-18 10:49

20 Name: Anonymous 2009-10-18 10:56

21 Name: Anonymous 2009-10-18 11:04

22 Name: Anonymous 2009-10-18 12:18

23 Name: Anonymous 2009-10-18 12:28

24 Name: Anonymous 2009-10-18 12:42

25 Name: Anonymous 2009-10-18 13:32

26 Name: Anonymous 2009-10-18 13:40

27 Name: Anonymous 2009-10-18 14:58

28 Name: Anonymous 2009-10-18 18:13

29 Name: Anonymous 2010-11-13 13:45

30 Name: Anonymous 2013-02-07 22:59

Name: Anonymous 2009-10-17 15:47

Name: Anonymous 2009-10-17 15:51

Name: Anonymous 2009-10-17 15:54

Name: Anonymous 2009-10-17 16:30

Name: Anonymous 2009-10-17 16:34

Name: Anonymous 2009-10-17 16:35

Name: Anonymous 2009-10-17 16:35

Name: Anonymous 2009-10-17 16:41

Name: Anonymous 2009-10-17 16:42

Name: Anonymous 2009-10-17 16:43

Name: Anonymous 2009-10-17 16:44

Name: Anonymous 2009-10-17 16:46

Name: Anonymous 2009-10-17 19:11

Name: Anonymous 2009-10-18 7:42

Name: Anonymous 2009-10-18 9:45

Name: Anonymous 2009-10-18 10:14

Name: Anonymous 2009-10-18 10:30

Name: Anonymous 2009-10-18 10:32

Name: >>16-chan 2009-10-18 10:49

Name: Anonymous 2009-10-18 10:56

Name: Anonymous 2009-10-18 11:04

Name: Anonymous 2009-10-18 12:18

Name: Anonymous 2009-10-18 12:28

Name: Anonymous 2009-10-18 12:42

Name: Anonymous 2009-10-18 13:32

Name: Anonymous 2009-10-18 13:40

Name: Anonymous 2009-10-18 14:58

Name: Anonymous 2009-10-18 18:13

Name: Anonymous 2010-11-13 13:45

Name: Anonymous 2013-02-07 22:59