fe-read-snr.rst 831 B

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  1. .. -*- coding: utf-8; mode: rst -*-
  2. .. _FE_READ_SNR:
  3. ***********
  4. FE_READ_SNR
  5. ***********
  6. Name
  7. ====
  8. FE_READ_SNR
  9. .. attention:: This ioctl is deprecated.
  10. Synopsis
  11. ========
  12. .. c:function:: int ioctl(int fd, FE_READ_SNR, int16_t *snr)
  13. :name: FE_READ_SNR
  14. Arguments
  15. =========
  16. ``fd``
  17. File descriptor returned by :c:func:`open() <dvb-fe-open>`.
  18. ``snr``
  19. The signal-to-noise ratio is stored into \*snr.
  20. Description
  21. ===========
  22. This ioctl call returns the signal-to-noise ratio for the signal
  23. currently received by the front-end. For this command, read-only access
  24. to the device is sufficient.
  25. Return Value
  26. ============
  27. On success 0 is returned.
  28. On error -1 is returned, and the ``errno`` variable is set
  29. appropriately.
  30. Generic error codes are described at the
  31. :ref:`Generic Error Codes <gen-errors>` chapter.