Things that I didn't know you could do with GNU C

scoping.c

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

#define nil NULL
#define ScopedFile FILE * __attribute__((cleanup(fclosep)))
#define ScopedMemory void * __attribute__((cleanup(freep)))

void fclosep(FILE **f){
    if (*f){
        fclose(*f);
    }
}

void freep(void **p){
    if (*p){
        free(*p);
        *p = nil;
    }
}

int main(){
    ScopedFile f = nil;
    ScopedMemory ptr = malloc(sizeof(long long));
    
    if ((f = fopen("/tmp/foo.txt", "w"))  != nil){
        fprintf(f, "foo\n");
    }
    return 0;
}