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

int main(int argc, char* argv[]) {
    // if the file does not exist, read mode will
    // return NULL, which will often lead to seg faults
    // in write code
    // if the file does exist, read mode just won't
    // write the data to the file
    FILE* file = fopen("abc.txt", "r");

    printf("%p\n", (void*)file);

    fputc('a', file);

    fclose(file);
    return EXIT_SUCCESS;
}
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