Open Source Software

clearerr(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 4.09 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/.

                              2016-03-15                         FERROR(3)



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