RAII in C (close a file)

close_raii.c

#include <stdio.h>
/* #include <stdlib.h> */

static inline void fclosep(FILE **fp) { if (*fp) fclose(*fp); *fp=NULL; }
#define _cleanup_fclose_ __attribute__((cleanup(fclosep)))

void example_usage(void)
{
    _cleanup_fclose_ FILE *logfile = fopen("logfile.txt", "w+");
    fputs("hello logfile!", logfile);
}

int main()
{   
    example_usage();
    return 0;
}