I want to the specified disk file input string, but don't know where so write wrong, please everybody teach

CodePudding user response:

The fopen function, the first parameter to the rightness pointer variable address seems wrong, if the second parameter with double quotes the name of the file is called "filename",

CodePudding user response:

Fopen_s first parameter is the secondary pointer, with secondary pointer modification level pointer pointing to, no problem

This warning is nothing but to say fp might mean empty, since you have been judging err above the case, or err does not include the situation, or compiler to check does not reach the designated position

CodePudding user response:

Want to remove the warning is simple, the following judgment again can

CodePudding user response:

Now that you have use errno_t checked, no problem, but the compiler warning, close test solution: the if (fp& & ! Err);
Solve the words of praise