About feof () bugs

A few days ago to attend a training, listen to people say use feof () as a sign of the end of the document to be careful. At that time I did not agree, feof, this function I used Ah, did not find any bugs.

But after coming back to write a program a try, there is a bug.

I tried to copy a file using feof as a flag to end the decision file:

while (!feof (FP_RD))

{

Char t = fgetc (FP_RD);

FPUTC (t, FP_WR);

}

But when I open the copied file, the end of the send out a 0xff more.

Check the Internet:

C language feof function is read the contents of the above to determine whether the file is over, and from the above program can be seen, I was first judged and then read the file, it will inevitably lead to write a file when more than a section. Correct it to the following form:

Char t = fgetc (FP_RD);

while (!feof (FP_RD))

{

FPUTC (t, FP_WR);

t = fgetc (FP_RD);

}