fclose（） 以 “Segmentation fault （core dumped）” 结尾

问：

我没有在互联网上找到答案，如果有的话，请链接它......

#include <stdio.h>

int main(){
    FILE*fp;
    char arr[4];
    printf("Opening...\n");
    fp=fopen("slide.txt", "r");
    printf("Opened\n");
    if(fp==NULL){
        printf("No such file\n");
        return 1;
    }
    fscanf(fp, "%s", arr);
    printf("Printing...\n");
    printf("%s\n", arr);
    printf("Printed\n");
    printf("Closing...\n");
    fclose(fp);
    printf("Closed\n");
    return 0;
}

文件内容：

ciao

我有的输出：

Opening...
Opened
Printing...
ciao
Printed
Closing...
Segmentation fault (core dumped)