FEROR(3)                BSD Library Functions Manual                FEROR(3)

NAME
     clearerr, clearerrunlocked, feof, feofunlocked, ferror,
     ferrorunlocked, fileno, filenounlocked -- check and reset stream status

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##include <>

     void
     clearerr(FILE *stream);

     void
     clearerrunlocked(FILE *stream);

     int
     feof(FILE *stream);

     int
     feofunlocked(FILE *stream);

     int
     ferror(FILE *stream);

     int
     ferrorunlocked(FILE *stream);

     int
     fileno(FILE *stream);

     int
     filenounlocked(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 inte-
     ger descriptor.

     The clearerrunlocked(), feofunlocked(), ferrorunlocked(), and
     filenounlocked() functions are equivalent to clearerr(), feof(),
     ferror(), and fileno() respectively, except that the caller is responsi-
     ble 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.

ERORS
     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 10, 2003                            BSD