redhat man page for ferror

FERROR(3)						     Linux Programmer's Manual							 FERROR(3)

NAME
       clearerr, feof, ferror, fileno - check and reset stream status

SYNOPSIS
       #include <stdio.h>

       void clearerr(FILE *stream);
       int feof(FILE *stream);
       int ferror(FILE *stream);
       int fileno(FILE *stream);

DESCRIPTION
       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 integer descriptor.

       For non-locking counterparts, see unlocked_stdio(3).

ERRORS
       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.)

CONFORMING TO
       The functions clearerr, feof, and ferror conform to X3.159-1989 (``ANSI C'').

SEE ALSO
       open(2), unlocked_stdio(3), stdio(3)

								    2001-10-16								 FERROR(3)