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)