OK for whatever reason I'm having trouble causing a seg fault. I want to produce one so that I can use `gdb` to see how to debug one. I have tried both examples from [the Wikipedia](http://en.wikipedia.org/wiki/Segmentation_fault) article yet neither work.

The first one:

```
char *s = "Hello World!";
*s = 'H';

```

And the second example:

```
int main(void) 
{
    main();
}

```

**EDIT:** I'm using Ubutnu 9.10 and `g++` as my compiler. Can anyone show me some code that is guaranteed to segfault?