F_GETFL(2const) - Linux manual page (original) (raw)

FGETFL(2const) FGETFL(2const)

NAME top

   F_GETFL, F_SETFL - get/set file status flags

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#include <fcntl.h>**

   **int fcntl(int** _fd_**, F_GETFL);**
   **int fcntl(int** _fd_**, F_SETFL, int** _arg_**);**

DESCRIPTION top

   Each open file description has certain associated status flags,
   initialized by [open(2)](../man2/open.2.html) and possibly modified by [fcntl(2)](../man2/fcntl.2.html).
   Duplicated file descriptors (made with [dup(2)](../man2/dup.2.html), [F_DUPFD(2const)](../man2/F%5FDUPFD.2const.html),
   [fork(2)](../man2/fork.2.html), etc.) refer to the same open file description, and thus
   share the same file status flags.

   The file status flags and their semantics are described in
   [open(2)](../man2/open.2.html).

   **F_GETFL**
          Return (as the function result) the file access mode and
          the file status flags; _arg_ is ignored.

   **F_SETFL**
          Set the file status flags to the value specified by _arg_.
          File access mode (**O_RDONLY**, **O_WRONLY**, **O_RDWR**) and file
          creation flags (i.e., **O_CREAT**, **O_EXCL**, **O_NOCTTY**, **O_TRUNC**)
          in _arg_ are ignored.  On Linux, this operation can change
          only the **O_APPEND**, **O_ASYNC**, **O_DIRECT**, **O_NOATIME**, and
          **O_NONBLOCK** flags.  It is not possible to change the **O_DSYNC**
          and **O_SYNC** flags; see BUGS, below.

RETURN VALUE top

   **F_GETFL**
          Value of file status flags.

   **F_SETFL**
          Zero.

   On error, -1 is returned, and _[errno](../man3/errno.3.html)_ is set to indicate the error.

ERRORS top

   See [fcntl(2)](../man2/fcntl.2.html).

   **EPERM** Attempted to clear the **O_APPEND** flag on a file that has the
          append-only attribute set.

STANDARDS top

   POSIX.1-2008.

HISTORY top

   SVr4, 4.3BSD, POSIX.1-2001.

BUGS top

F_SETFL It is not possible to use F_SETFL to change the state of the O_DSYNC and O_SYNC flags. Attempts to change the state of these flags are silently ignored.

SEE ALSO top

   [fcntl(2)](../man2/fcntl.2.html), [open(2)](../man2/open.2.html)

COLOPHON top

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Linux man-pages 6.15 2025-07-20 FGETFL(2const)

Pages that refer to this page:fcntl(2), F_GETSIG(2const)