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FERROR(3) FreeBSD Library Functions Manual FERROR(3)
NAME
clearerr, clearerr_unlocked, feof, feof_unlocked, ferror,
ferror_unlocked, fileno, fileno_unlocked - check and reset stream status
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#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);
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 may be cleared by explicitly calling clearerr(), or as a side-
effect of other operations, e.g. fseek().
The function ferror() tests the error indicator for the stream pointed to
by stream, returning non-zero if it is set.
The function fileno() examines the argument stream and returns its
integer descriptor.
The clearerr_unlocked(), feof_unlocked(), ferror_unlocked(), and
fileno_unlocked() 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.
STANDARDS
The functions clearerr(), feof(), and ferror() conform to ISO/IEC
9899:1990 ("ISO C90").
HISTORY
The functions clearerr(), feof(), ferror(), and fileno() first appeared
in Version 7 AT&T UNIX.
FreeBSD 14.0-RELEASE-p6 April 2, 2022 FreeBSD 14.0-RELEASE-p6