For this problem the answer and analysis

CodePudding user response:

D, r is single quotes, not right

CodePudding user response:

Should be in double quotes,

CodePudding user response:

D, it is recommended that check the fopen prototype;

 FILE * fopen (const char * path, const char * mode). 

CodePudding user response:

I hope it can help you: https://blog.csdn.net/it_xiangqiang/category_10581430.html
I hope it can help you: https://blog.csdn.net/it_xiangqiang/category_10768339.html