NAME
clearerr,
feof,
ferror,
fileno —
check and reset stream
status
LIBRARY
Standard C Library (libc, -lc)
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.
ERRORS
The functions
clearerr(),
feof(), and
ferror() should neither fail nor set the external variable
errno. However, the function
fileno()
may fail and return -1 in case the argument
stream is
not associated with a valid file descriptor. (In this case the
NetBSD implementation does not follow the optional
POSIX recommendation to set the
errno variable to
EBADF
.)
SEE ALSO
open(2),
stdio(3)
STANDARDS
The functions
clearerr(),
feof(), and
ferror() conform to
ANSI X3.159-1989
(“ANSI C89”). The function
fileno()
conforms to
IEEE Std 1003.1-1990
(“POSIX.1”).