| .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later |
| ``int ioctl(fd, CA_SEND_MSG, struct ca_msg *msg)`` |
| File descriptor returned by a previous call to :c:func:`open()`. |
| Pointer to struct :c:type:`ca_msg`. |
| Sends a message via a CI CA module. |
| Please notice that, on most drivers, this is done by writing |
| to the /dev/adapter?/ca? device node. |
| On success 0 is returned. |
| On error -1 is returned, and the ``errno`` variable is set |
| Generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |