This is a valid C code but not a valid C++ code?

Question

In some library I'm using (written in C) its

StorePGM(image, width, height, filename)
char *image;
int width, height;
char *filename;
{
  // something something
}

All functions are defined this way. I never seen such function definitions in my life. They seem to be valid to MSVC but when I compile it as C++ it gives errors.

What is it? some kind of old version C?

Answer 1

Yes. K&R, pre-standard C. Avoid using it.

Answer 2

Yep, it's K&R-Style. (Kernigham & Ritchie are the inventors of C) See also http://www.lysator.liu.se/c/bwk-tutor.html for examples of this pre-ANSI style.