Modify Struct/Union/Struct in Called Function

[CJason]

How do I pass and use a Struct/Union/Struct into a function, and modify the elements? For example, say I have the following:

struct thestuff {
union {
struct {
char s1[16];
char s2[64];
}s;
char buffer[80];
}u;
}stuff;

How do I pass 'stuff' into a function to be modified?

Thanks so much in advance!!!!

 

[Salem]

Please use [code][/code] tags when posting code.

The better way is to pass a pointer to the structure, like so

// call this with foo( &stuff );
void foo ( struct thestuff *p ) {
  // here do p->member where you would do stuff.member
}

--
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.

 

[CJason]

Sorry, I'll do the "code" thing from now on.

Salem, I have previously tried what you suggested, but I kept getting errors. Can you show me a quick example, using my struct, that you know works? For example, in void foo, show the members being set. I get errors trying to do something like:

strcpy(p->u->s->s1,"HELLO");

Am I accessing the structure incorrectly?

 

[Salem]

Yeah, you only need "->" for the first level.
Everything inside the struct/union is "."

--
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.

 

[CJason]

Sweet! Thank you SO much, Salem! I've been trying to figure that out for a LONG time...and "thought" I had tried every combination of "->" and ".". Apparently, I missed this one.

Thanks again!