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 >= 1 || _XOPEN_SOURCE || _POSIX_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 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 integer descriptor.
For non-locking 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.)
CONFORMING TO The functions clearerr(), feof(), and ferror() conform to C89 and C99.
SEE ALSO open(2), fdopen(3), stdio(3), unlocked_stdio(3)
COLOPHON This page is part of release 3.22 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.