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/ IRIX Base Documentation 2001 May / SGI IRIX Base Documentation 2001 May.iso / usr / share / catman / p_man / catD / iocblk.z / iocblk
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Text File  |  1998-10-30  |  8.3 KB  |  133 lines
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  4. iiiiooooccccbbbbllllkkkk((((DDDD4444))))                                                          iiiiooooccccbbbbllllkkkk((((DDDD4444))))
  5.  
  6.  
  7.  
  8. NNNNAAAAMMMMEEEE
  9.      _iiii_oooo_cccc_bbbb_llll_kkkk - STREAMS _iiii_oooo_cccc_tttt_llll structure
  10.  
  11. SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
  12.      _####_iiii_nnnn_cccc_llll_uuuu_dddd_eeee _<<<<_ssss_yyyy_ssss_////_ssss_tttt_rrrr_eeee_aaaa_mmmm_...._hhhh_>>>>
  13.      _####_iiii_nnnn_cccc_llll_uuuu_dddd_eeee _<<<<_ssss_yyyy_ssss_////_dddd_dddd_iiii_...._hhhh_>>>>
  14.  
  15. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  16.      The _iiii_oooo_cccc_bbbb_llll_kkkk structure describes a user's _iiii_oooo_cccc_tttt_llll(2) request.
  17.  
  18. UUUUSSSSAAAAGGGGEEEE
  19.      The _iiii_oooo_cccc_bbbb_llll_kkkk structure is used in _MMMM______IIII_OOOO_CCCC_TTTT_LLLL, _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK, and _MMMM______IIII_OOOO_CCCC_NNNN_AAAA_KKKK messages.
  20.      Modules and drivers usually convert _MMMM______IIII_OOOO_CCCC_TTTT_LLLL messages into _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK or
  21.      _MMMM______IIII_OOOO_CCCC_NNNN_AAAA_KKKK messages by changing the type and updating the relevant fields
  22.      in the _iiii_oooo_cccc_bbbb_llll_kkkk structure.
  23.  
  24.      Data cannot be copied to the user's buffer with an _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK message if
  25.      the _iiii_oooo_cccc_tttt_llll is transparent.
  26.  
  27.      No data can be copied to the user's buffer with an _MMMM______IIII_OOOO_CCCC_NNNN_AAAA_KKKK message.
  28.  
  29.      When processing a transparent _iiii_oooo_cccc_tttt_llll, the _iiii_oooo_cccc_bbbb_llll_kkkk structure is usually
  30.      overlaid with a _cccc_oooo_pppp_yyyy_rrrr_eeee_qqqq(D4) structure.  The stream head guarantees that
  31.      the message is large enough to contain either structure.
  32.  
  33.    SSSSttttrrrruuuuccccttttuuuurrrreeee DDDDeeeeffffiiiinnnniiiittttiiiioooonnnnssss
  34.      The _iiii_oooo_cccc_bbbb_llll_kkkk structure contains the following members:
  35.  
  36.      _iiii_nnnn_tttt     _iiii_oooo_cccc______cccc_mmmm_dddd_;;;;    _////_**** _iiii_oooo_cccc_tttt_llll _cccc_oooo_mmmm_mmmm_aaaa_nnnn_dddd _****_////
  37.      _cccc_rrrr_eeee_dddd______tttt  _****_iiii_oooo_cccc______cccc_rrrr_;;;;    _////_**** _uuuu_ssss_eeee_rrrr _cccc_rrrr_eeee_dddd_eeee_nnnn_tttt_iiii_aaaa_llll_ssss _****_////
  38.      _uuuu_iiii_nnnn_tttt______tttt  _iiii_oooo_cccc______iiii_dddd_;;;;     _////_**** _iiii_oooo_cccc_tttt_llll _IIII_DDDD _****_////
  39.      _uuuu_iiii_nnnn_tttt______tttt  _iiii_oooo_cccc______cccc_oooo_uuuu_nnnn_tttt_;;;;  _////_**** _nnnn_uuuu_mmmm_bbbb_eeee_rrrr _oooo_ffff _bbbb_yyyy_tttt_eeee_ssss _oooo_ffff _dddd_aaaa_tttt_aaaa _****_////
  40.      _iiii_nnnn_tttt     _iiii_oooo_cccc______eeee_rrrr_rrrr_oooo_rrrr_;;;;  _////_**** _eeee_rrrr_rrrr_oooo_rrrr _cccc_oooo_dddd_eeee _ffff_oooo_rrrr _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK _oooo_rrrr _MMMM______IIII_OOOO_CCCC_NNNN_AAAA_KKKK _****_////
  41.      _iiii_nnnn_tttt     _iiii_oooo_cccc______rrrr_vvvv_aaaa_llll_;;;;   _////_**** _rrrr_eeee_tttt_uuuu_rrrr_nnnn _vvvv_aaaa_llll_uuuu_eeee _ffff_oooo_rrrr _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK _****_////
  42.      The _iiii_oooo_cccc______cccc_mmmm_dddd field is the _iiii_oooo_cccc_tttt_llll command request specified by the user.
  43.  
  44.      The _iiii_oooo_cccc______cccc_rrrr field contains a pointer to the user credentials.
  45.  
  46.      The _iiii_oooo_cccc______iiii_dddd field is the _iiii_oooo_cccc_tttt_llll ID, used to uniquely identify the _iiii_oooo_cccc_tttt_llll
  47.      request in the stream.
  48.  
  49.      The _iiii_oooo_cccc______cccc_oooo_uuuu_nnnn_tttt field specifies the amount of user data contained in the
  50.      _MMMM______IIII_OOOO_CCCC_TTTT_LLLL message.  User data will appear in _MMMM______DDDD_AAAA_TTTT_AAAA message blocks linked
  51.      to the _MMMM______IIII_OOOO_CCCC_TTTT_LLLL message block.  If _iiii_oooo_cccc______cccc_oooo_uuuu_nnnn_tttt is set to the special value
  52.      _TTTT_RRRR_AAAA_NNNN_SSSS_PPPP_AAAA_RRRR_EEEE_NNNN_TTTT, then the _iiii_oooo_cccc_tttt_llll request is ``transparent.''  This means that
  53.      the user did not use the _IIII______SSSS_TTTT_RRRR format of STREAMS _iiii_oooo_cccc_tttt_lllls and the module or
  54.      driver will have to obtain any user data with _MMMM______CCCC_OOOO_PPPP_YYYY_IIII_NNNN messages, and
  55.      change any user data with _MMMM______CCCC_OOOO_PPPP_YYYY_OOOO_UUUU_TTTT messages.  In this case, the _MMMM______DDDD_AAAA_TTTT_AAAA
  56.      message block linked to the _MMMM______IIII_OOOO_CCCC_TTTT_LLLL message block contains the value of
  57.      the _a_r_g parameter in the _iiii_oooo_cccc_tttt_llll system call.  For an _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK message, the
  58.      _iiii_oooo_cccc______cccc_oooo_uuuu_nnnn_tttt field specifies the amount of data to copy back to the user's
  59.      buffer.
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. iiiiooooccccbbbbllllkkkk((((DDDD4444))))                                                          iiiiooooccccbbbbllllkkkk((((DDDD4444))))
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  73.  
  74.      The _iiii_oooo_cccc______eeee_rrrr_rrrr_oooo_rrrr field can be used to set an error for either an _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK or
  75.      an _MMMM______IIII_OOOO_CCCC_NNNN_AAAA_KKKK message.
  76.  
  77.      The _iiii_oooo_cccc______rrrr_vvvv_aaaa_llll field can be used to set the return value in an _MMMM______IIII_OOOO_CCCC_AAAA_CCCC_KKKK
  78.      message.  This will be returned to the user as the return value for the
  79.      _iiii_oooo_cccc_tttt_llll system call that generated the request.
  80.  
  81. RRRREEEEFFFFEEEERRRREEEENNNNCCCCEEEESSSS
  82.      _cccc_oooo_pppp_yyyy_rrrr_eeee_qqqq(D4), _cccc_oooo_pppp_yyyy_rrrr_eeee_ssss_pppp(D4), _dddd_aaaa_tttt_aaaa_bbbb(D4), _mmmm_eeee_ssss_ssss_aaaa_gggg_eeee_ssss(D5), _mmmm_ssss_gggg_bbbb(D4)
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  129.                                                                         PPPPaaaaggggeeee 2222
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