#include <stdio.h>
#include <assert.h>

int mystrlen (char * pszStr){
    assert(pszStr!=NULL);

    printf("alles ok");
    return 0;
}

int main(void){
  char * p = {"Hallo"};
  mystrlen(NULL);
  return 0;
}


// assertion "pszStr!=NULL" failed: file "assert.c", line 6, function: mystrlen
// Aborted (core dumped)

// assert ausschalten mit -DNDEBUG für release-version