v4.0/src/MAPPER/QHANDTYP.ASM

   1 ;
   2 page 60,132
   3 ;
   4 title CP/DOS  DOSQhandtype  mapper
   5 ;
   6 dosxxx  segment byte public 'dos'
   7         assume  cs:dosxxx,ds:nothing,es:nothing,ss:nothing
   8 ;
   9 ; ************************************************************************* *
  10 ; *
  11 ; *      MODULE: DosQhandtype
  12 ; *
  13 ; *      FILE NAME: DosQhandtype
  14 ; *
  15 ; *      FUNCTION: Determine whether a handle is file or device
  16 ; *
  17 ; *      CALLING SEQUENCE:
  18 ; *
  19 ; *             push    handle          ; file handle
  20 ; *             push@   handtype        ; handle type
  21 ; *             push@   flagword        ; device descriptor word
  22 ; *             call    dosqhandtype
  23 ; *
  24 ; *      RETURN SEQUENCE:
  25 ; *
  26 ; *             handle type:   0  - if a file
  27 ; *                            1  - if a device
  28 ; *      MODULES CALLED:
  29 ; *
  30 ; *
  31 ; *************************************************************************
  32
  33         public  dosqhandtype
  34         .sall
  35         .xlist
  36         include macros.inc
  37         .list
  38
  39
  40 str     struc
  41 old_bp          dw    ?
  42 return          dd    ?
  43 AttributePtr    dd    ?      ; Device descriptor word returned if device
  44 HandleTypePtr   dd    ?      ; handle type; 0 = file handle, 1 = device handle
  45 Handle          dw    ?      ; file handle
  46 str     ends
  47
  48
  49 dosqhandtype proc   far
  50
  51         Enter   dosqhandtype            ; push registers
  52
  53         mov     bx,[bp].Handle          ; get file handle
  54         mov     ax,4400h
  55         int     21h                     ; get handle type
  56
  57         lds     si,[bp].AttributePtr    ; setup area for attribute return
  58         mov     ds:[si],dx
  59
  60         lds     si,[bp].HandleTypePtr
  61         mov     ds:word ptr [si],0      ; assume it is a file
  62
  63         test    dx,00080h               ; test for file
  64         jz      ItIsAFile               ; jump if true
  65
  66         mov     ds:word ptr [si],1      ; else, it is a device, set flag
  67
  68 ItIsAFile:
  69         Mexit                           ; pop registers
  70         ret     size str - 6            ; return
  71
  72 dosqhandtype  endp
  73
  74 dosxxx  ends
  75
  76         end