fileno(3) [freebsd man page]

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

FERROR(3)                                                    Linux Programmer's Manual                                                   FERROR(3)

NAME

       clearerr, feof, ferror, fileno - check and reset stream status

SYNOPSIS

       #include <stdio.h>

       void clearerr(FILE *stream);

       int feof(FILE *stream);

       int ferror(FILE *stream);

       int fileno(FILE *stream);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       fileno(): _POSIX_C_SOURCE

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 nonzero if it is set.  The end-of-file
       indicator can be cleared only by the function clearerr().

       The function ferror() tests the error indicator for the stream pointed to by stream, returning nonzero if it is set.  The  error  indicator
       can be reset only by the clearerr() function.

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

       For nonlocking counterparts, see unlocked_stdio(3).

ERRORS

       These  functions should not fail and do not set the external variable errno.  (However, in case fileno() detects that its argument is not a
       valid stream, it must return -1 and set errno to EBADF.)

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +--------------------+---------------+---------+
       |Interface           | Attribute     | Value   |
       +--------------------+---------------+---------+
       |clearerr(), feof(), | Thread safety | MT-Safe |
       |ferror(), fileno()  |               |         |
       +--------------------+---------------+---------+
CONFORMING TO

       The functions clearerr(), feof(), and ferror() conform to C89, C99, POSIX.1-2001, and POSIX.1-2008.

       The function fileno() conforms to POSIX.1-2001 and POSIX.1-2008.

SEE ALSO

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

COLOPHON

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

                                                                    2017-09-15                                                           FERROR(3)