FERROR(3)						   BSD 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 func-
     tions may be used to avoid the overhead of locking the stream and to prevent races when multiple threads are operating on the same stream.

ERRORS

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

SEE ALSO

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

STANDARDS

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

BSD
								 January 28, 2009							       BSD