ferror(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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

NAME         top

       clearerr, feof, ferror - check and reset stream status

SYNOPSIS         top

       #include <stdio.h>

       void clearerr(FILE *stream);
       int feof(FILE *stream);
       int ferror(FILE *stream);

DESCRIPTION         top

       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.

       For nonlocking counterparts, see unlocked_stdio(3).

RETURN VALUE         top

       The feof() function returns nonzero if the end-of-file indicator
       is set for stream; otherwise, it returns zero.

       The feof() function returns nonzero if the error indicator is set
       for stream; otherwise, it returns zero.

ERRORS         top

       These functions should not fail and do not set errno.

ATTRIBUTES         top

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

       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │Interface                             Attribute     Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │clearerr(), feof(), ferror()          │ Thread safety │ MT-Safe │
       └──────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO         top

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

NOTES         top

       POSIX.1-2008 specifies that these functions shall not change the
       value of errno if stream is valid.

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 5.11 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/.

                               2021-03-22                      FERROR(3)

Pages that refer to this page: fgetc(3)fread(3)fseek(3)gets(3)getw(3)puts(3)scanf(3)stdio(3)