Any good idioms for error handling in straight C programs?

Question

Getting back in to some C work.

Many of my functions look like this:

int err = do_something(arg1, arg2, arg3, &result);

With th

Answer 1

One approach which has been taken by OpenGL is to not return errors from functions at all but rather present an error state which can be examined after the function call. One nice thing about this approach is that when you have a function which you actually want to return something other than an error code, you can handle errors in the same way. Another thing which is nice about this is that if a user wants to call a number of functions and only succeed if all of them were successful, you can check for errors after the x amount of calls.

/* call a number of functions which may error.. */
glMatrixMode(GL_MODELVIEW);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glEnable(GL_TEXTURE_2D);

/* ...check for errors */
if ((error = glGetError()) != GL_NO_ERROR) {
    if (error == GL_INVALID_VALUE)
        printf("error: invalid value creating view");
    else if (error == GL_INVALID_OPERATION)
        printf("error: invalid operation creating view");
    else if (error == GL_OUT_OF_MEMORY)
        printf("error: out of memory creating view");
}