FERROR(3) Linux Programmer's Manual FERROR(3)
clearerr, feof, ferror, fileno - check and reset stream status
void clearerr(FILE *stream);
int feof(FILE *stream);
int ferror(FILE *stream);
int fileno(FILE *stream);
The function clearerr clears the end-of-file and error indicators for
the stream pointed to by stream.
The function feof tests the end-of-file indicator for the stream
pointed to by stream, returning non-zero if it is set. The end-of-file
indicator can only be cleared by the function clearerr.
The function ferror tests the error indicator for the stream pointed to
by stream, returning non-zero if it is set. The error indicator can
only be reset by the clearerr function.
The function fileno examines the argument stream and returns its inte-
For non-locking counterparts, see unlocked_stdio(3).
These functions should not fail and do not set the external variable
errno. (However, in case fileno detects that its argument is not a
valid stream, it must return -1 and set errno to EBADF.)
The functions clearerr, feof, and ferror conform to X3.159-1989 (``ANSI
open(2), unlocked_stdio(3), stdio(3)