fscanf - How to know if EOF means end of file or reading/another error?

Question

I have a question about I/O in C language, how can I make a difference to know if the lecture of my file has ended or if the data can't be read (or has a problem) as in the both cases, fscanf returns EOF ?

Answer 1

Don´t rely only on the return value of fscanf(), rely beside this one on feof() and ferror() after the call to fscanf():

FILE* file;
if((file == fopen("file.txt","r")) == NULL)
{
    fprintf(stderr, "File could not be opened!");
    return EXIT_FAILURE;
}

char buf;

/******************************************************************************/

while(fscanf(file,"%c",buf) == 1) {     // checks if an error was happen, else 
                                        // iterate to catching characters.
   /* handling of read character */
}

if(ferror(file))                        // checks if an I/O error occurred.
{
   // I/O error handling
   fprintf(stderr,"Input/Output error at reading file!");
   clearerr(file);
   // Further actions
}
else if(feof(file))                     // checks if the end of the file is reached.       
{
   // end of file handling
   fprintf(stderr,"Reached End of File!");
   clearerr(file);
   // Further actions
}

/******************************************************************************/

if(fclose(file) != 0)
{
    fprintf(stderr, "File could not be closed properly!");
    return EXIT_FAILURE;
}