What's the regular way of assertion in C?

Question

I'm using NSAssert macro for Objective-C assertion, and it's the regular way to do this. But it's not work in C functions. What do I should use for this?

Answer 1

#include <assert.h>

...

assert(<expression>);

(reference)

Answer 2

void assert(int expression); 

If expression evaluates to 0 (false), then the expression, source code filename, 
and line number are sent to the standard error, and then calls the abort 
function. 

If the identifier NDEBUG ("no debug") is defined with #define NDEBUG then the 
macro assert does nothing.

Example:

assert(x != 0);

note: Include assert.h

Answer 3

NSCAssert() (and also NSCAssert1(), ... up to NSCAssert5() )