C-为什么我在尝试读取包含反斜杠的字符时遇到段错误？

Question

I'm trying to read a file line by line and my code looking for backslashes, but when it finds one, it exits with segfault. I'm using gcc on Ubuntu linux 19.04 and C11.

void test(char **array) {
    boolean a = *array[0] == '\\';
    boolean b = *array[2] == '\\';
    boolean c = *array[1] == '\\';  //I get segfault here.
}

int main() {
    FILE *messages = fopen("messages.json", "r");
    char *array = NULL;
    size_t size;
    getline(&array, &size, messages);
    test(&array);  //array contains "{\n" string here.
}

Answer 1

You're treating array as if it points directly to an array, which it doesn't. It points to a pointer which points to an array. You can fix it by changing *array[i] to (*array)[i] :

void test(char **array) {
  boolean a = (*array)[0] == '\\';
  boolean b = (*array)[2] == '\\';
  boolean c = (*array)[1] == '\\';
}