# [−][src]Macro nix::ioctl_write_ptr

    macro_rules! ioctl_write_ptr {
        ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr, $ty:ty) => { ... };
    }

Generates a wrapper function for an ioctl that writes data through a pointer to the kernel.

The arguments to this macro are:

- The function name
- The ioctl identifier
- The ioctl sequence number
- The data type passed by this ioctl

The generated function has the following signature:

ⓘThis example is not tested

    pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: *const DATA_TYPE) -> Result<libc::c_int>

For a more in-depth explanation of ioctls, see `::sys::ioctl`.

# Example

    ioctl_write_ptr!(s_audio, b'V', 34, v4l2_audio);

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