Best way to programatically check for existence of header file?

Question

Is it just to test compile a simple program, with that header file #included in it?

To better understand the compilation process I'm writing my own "configure", which tests for the existence of a few header and library files.

Answer 1

Yes, use the compiler to compile your simple test program. That's the best and easiest way to see if the compiler can find the header. If you hard code #include search paths you'll always have to modify and adapt for different compilers.

Answer 2

The GNU Autoconf suite checks for headers by running test compilations. Just testing for the existence of a file 'filename.h' is fairly simple:

#include <filename.h>
int main(void){return 0;}

You might prefer quotes instead of angle brackets.