THIS FAILS .... Sorry ... How to make closures in C

closure_example.c

#include <stdio.h>

void (*greeter(char greeting[]))(char[])
{
  int intern_position = 1;
  
  void result(char name[])
  {
    if(intern_position) return;
    printf("%s, %s!\n", greeting, name);
  }
  
  result(""); // without this function call
              // the function wouldnt exist
              // and throw an segmentation
              // fault.
  
  intern_position = 0;
  
  return result;
}

int main()
{
  void (*g)(char[]);
  
  g = greeter("Hallo");
  g("Welt");
  
  // after some notes and comments another test
  g("hackernews"); // THIS FAILS - segmentation error.
  
  return 0;
}

test.c:6:1: warning: ISO C forbids nested functions [-pedantic]

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after testing i found out, that this wouldnt work! See on line 31.