fclose(3) — Linux manual page

fclose(3)                Library Functions Manual               fclose(3)

NAME         top

       fclose - close a stream

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <stdio.h>

       int fclose(FILE *stream);

DESCRIPTION         top

       The fclose() function flushes the stream pointed to by stream
       (writing any buffered output data using fflush(3)) and closes the
       underlying file descriptor.

RETURN VALUE         top

       Upon successful completion, 0 is returned.  Otherwise, EOF is
       returned and errno is set to indicate the error.  In either case,
       any further access (including another call to fclose()) to the
       stream results in undefined behavior.

ERRORS         top

       EBADF  The file descriptor underlying stream is not valid.

       The fclose() function may also fail and set errno for any of the
       errors specified for the routines close(2), write(2), or
       fflush(3).

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                            │ Attribute     │ Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │ fclose()                             │ Thread safety │ MT-Safe │
       └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS         top

       C11, POSIX.1-2008.

HISTORY         top

       C89, POSIX.1-2001.

NOTES         top

       Note that fclose() flushes only the user-space buffers provided by
       the C library.  To ensure that the data is physically stored on
       disk the kernel buffers must be flushed too, for example, with
       sync(2) or fsync(2).

SEE ALSO         top

       close(2), fcloseall(3), fflush(3), fileno(3), fopen(3), setbuf(3)

COLOPHON         top

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Linux man-pages 6.15            2025-05-17                      fclose(3)

Pages that refer to this page: close(2),  abort(3),  fcloseall(3),  fflush(3),  FILE(3type),  fileno(3),  fmemopen(3),  fopen(3),  fopencookie(3),  getmntent(3),  open_memstream(3),  popen(3),  setbuf(3),  stdio(3),  xdr(3)

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