| .. -*- coding: utf-8; mode: rst -*- |
| |
| .. _lirc-write: |
| |
| ************ |
| LIRC write() |
| ************ |
| |
| Name |
| ==== |
| |
| lirc-write - Write to a LIRC device |
| |
| |
| Synopsis |
| ======== |
| |
| .. code-block:: c |
| |
| #include <unistd.h> |
| |
| |
| .. c:function:: ssize_t write( int fd, void *buf, size_t count ) |
| :name: lirc-write |
| |
| Arguments |
| ========= |
| |
| ``fd`` |
| File descriptor returned by ``open()``. |
| |
| ``buf`` |
| Buffer with data to be written |
| |
| ``count`` |
| Number of bytes at the buffer |
| |
| Description |
| =========== |
| |
| :ref:`write() <lirc-write>` writes up to ``count`` bytes to the device |
| referenced by the file descriptor ``fd`` from the buffer starting at |
| ``buf``. |
| |
| The exact format of the data depends on what mode a driver uses, use |
| :ref:`lirc_get_features` to get the supported mode. |
| |
| When in :ref:`LIRC_MODE_PULSE <lirc-mode-PULSE>` mode, the data written to |
| the chardev is a pulse/space sequence of integer values. Pulses and spaces |
| are only marked implicitly by their position. The data must start and end |
| with a pulse, therefore, the data must always include an uneven number of |
| samples. The write function must block until the data has been transmitted |
| by the hardware. If more data is provided than the hardware can send, the |
| driver returns ``EINVAL``. |
| |
| Return Value |
| ============ |
| |
| On success, the number of bytes read is returned. It is not an error if |
| this number is smaller than the number of bytes requested, or the amount |
| of data required for one frame. On error, -1 is returned, and the ``errno`` |
| variable is set appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
