fgetc(): Is it enough to just check EOF?

Question

In various examples found on the web fgetc() is used like this:

FILE *fp = fopen(PATH, \"r\");

if (fp == NULL) {
    perror(\"main\");
    exit         


        

Answer 1

You can check it with ferror(3), right after the while:

while (EOF != (ch = fgetc(fp)))
   // do something

if (ferror(fp) != 0)
   // error handling

ferror returns a non-zero if an error occured.

If you want use fp after an error occured, you'll need to clear the error flag with clearerr:

clearerr(fp);