FERROR(3) Library Functions Manual FERROR(3)

clearerr, clearerr_unlocked, feof, feof_unlocked, ferror, ferror_unlocked, fileno, fileno_unlockedcheck and reset stream status

Standard C Library (libc, -lc)

#include <stdio.h>

void
clearerr(FILE *stream);

void
clearerr_unlocked(FILE *stream);

int
feof(FILE *stream);

int
feof_unlocked(FILE *stream);

int
ferror(FILE *stream);

int
ferror_unlocked(FILE *stream);

int
fileno(FILE *stream);

int
fileno_unlocked(FILE *stream);

The function () clears the end-of-file and error indicators for the stream pointed to by stream.

The function () 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 may be cleared by explicitly calling clearerr(), or as a side-effect of other operations, e.g. ().

The function () tests the error indicator for the stream pointed to by stream, returning non-zero if it is set.

The function () examines the argument stream and returns its integer descriptor.

The (), (), (), and () functions are equivalent to clearerr(), feof(), ferror(), and fileno() respectively, except that the caller is responsible for locking the stream with flockfile(3) before calling them. These functions may be used to avoid the overhead of locking the stream and to prevent races when multiple threads are operating on the same stream.

These functions should not fail and do not set the external variable errno.

open(2), fdopen(3), flockfile(3), stdio(3)

The functions clearerr(), feof(), and ferror() conform to ISO/IEC 9899:1990 (“ISO C90”).

January 28, 2009 Mac OS X 12