Function fcntl

#[unsafe(no_mangle)]pub unsafe extern "C" fn fcntl(
    fildes: c_int,
    cmd: c_int,
    ...
) -> c_int

Expand description

Performs the operation specified by cmd on open files pointed to by the file descriptor fildes.

The return value depends on the value of cmd:

F_DUPFD: A new file descriptor.
F_DUPFD_CLOEXEC: A new file descriptor.
F_DUPFD_CLOFORK: A new file descriptor.
F_GETFD: Value of flags. The return value shall not be negative.
F_SETFD: Value other than -1.
F_GETFL: Value of file status flags and access modes. The return value shall not be negative.
F_SETFL: Value other than -1.
F_GETLK: Value other than -1.
F_SETLK: Value other than -1.
F_SETLKW: Value other than -1.
F_OFD_GETLK: Value other than -1.
F_OFD_SETLK: Value other than -1.
F_OFD_SETLKW: Value other than -1.
F_GETOWN: Value of the socket owner process or process group; this shall not be -1.
F_SETOWN: Value other than -1.
F_GETOWN_EX: Value other than -1.
F_SETOWN_EX: Value other than -1.

Otherwise, -1 shall be returned and errno set to indicate the error.

fcntl