fe-read-status.rst 1.4 KB

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  1. .. -*- coding: utf-8; mode: rst -*-
  2. .. _FE_READ_STATUS:
  3. ********************
  4. ioctl FE_READ_STATUS
  5. ********************
  6. Name
  7. ====
  8. FE_READ_STATUS - Returns status information about the front-end. This call only requires - read-only access to the device
  9. Synopsis
  10. ========
  11. .. c:function:: int ioctl( int fd, FE_READ_STATUS, unsigned int *status )
  12. :name: FE_READ_STATUS
  13. Arguments
  14. =========
  15. ``fd``
  16. File descriptor returned by :ref:`open() <frontend_f_open>`.
  17. ``status``
  18. pointer to a bitmask integer filled with the values defined by enum
  19. :c:type:`fe_status`.
  20. Description
  21. ===========
  22. All Digital TV frontend devices support the ``FE_READ_STATUS`` ioctl. It is
  23. used to check about the locking status of the frontend after being
  24. tuned. The ioctl takes a pointer to an integer where the status will be
  25. written.
  26. .. note::
  27. The size of status is actually sizeof(enum fe_status), with
  28. varies according with the architecture. This needs to be fixed in the
  29. future.
  30. int fe_status
  31. =============
  32. The fe_status parameter is used to indicate the current state and/or
  33. state changes of the frontend hardware. It is produced using the enum
  34. :c:type:`fe_status` values on a bitmask
  35. Return Value
  36. ============
  37. On success 0 is returned.
  38. On error -1 is returned, and the ``errno`` variable is set
  39. appropriately.
  40. Generic error codes are described at the
  41. :ref:`Generic Error Codes <gen-errors>` chapter.