KbdPeek

Bindings:  C, MASM 

This call returns any available character data record from the keyboard 
without removing it from the buffer. 

 KbdPeek    (CharData, KbdHandle) 
 

 CharData (PKBDKEYINFO) - output 
    Address of the character data information: 

    asciicharcode (UCHAR) 
       ASCII character code. The scan code received from the keyboard is 
       translated to the ASCII character code. 

    scancode (UCHAR) 
       Code received from the keyboard hardware. 

    status (UCHAR) 
       State of the keystroke event: 

       Bit       Description 

       7-6       00 = Undefined. 

                 01 = Final character, interim character flag off. 

                 10 = Interim character. 

                 11 = Final character, interim character flag on. 

       5         1 = Immediate conversion requested. 

       4-2       Reserved, set to zero. 

       1         0 = Scan code is a character. 

                 1 = Scan code is not a character; it is an extended key 
                 code from the keyboard. 

       0         1 = Shift status returned without character. 

    reserved (UCHAR) 
       NLS shift status.  Reserved, set to zero. 

    shiftkeystat (USHORT) 
       Shift key status. 

       Bit       Description 
       15        SysReq key down 
       14        CapsLock key down 
       13        NumLock key down 
       12        ScrollLock key down 
       11        Right Alt key down 
       10        Right Ctrl key down 
       9         Left Alt key down 
       8         Left Ctrl key down 
       7         Insert on 
       6         CapsLock on 
       5         NumLock on 
       4         ScrollLock on 
       3         Either Alt key down 
       2         Either Ctrl key down 
       1         Left Shift key down 
       0         Right Shift key down 

    time (ULONG) 
       Time stamp indicating when a key was pressed.  It is specified in 
       milliseconds from the time the system was started. 

 KbdHandle (HKBD) - input 
    Default keyboard or the logical keyboard. 

 rc (USHORT) - return 
    Return code descriptions are: 

    0         NO_ERROR 
    439       ERROR_KBD_INVALID_HANDLE 
    445       ERROR_KBD_FOCUS_REQUIRED 
    447       ERROR_KBD_KEYBOARD_BUSY 
    464       ERROR_KBD_DETACHED 
    504       ERROR_KBD_EXTENDED_SG 
 
 Remarks 

 On an enhanced keyboard, the secondary enter key returns the normal 
 character 0DH and a scan code of E0H. 

 Double-byte character codes (DBCS) require two function calls to obtain 
 the entire code. 

 If shift report is set with KbdSetStatus the CharData record returned, 
 reflects changed shift information only. 

 Extended ASCII codes are identified with the status byte, bit 1 on and 
 the ASCII character code being either 00H or E0H. Both conditions must be 
 satisfied for the character to be an extended keystroke.  For extended 
 ASCII codes, the scan code byte returned is the second code (extended 
 code). Usually the extended ASCII code is the scan code of the primary 
 key that was pressed. 

 A thread in the foreground session that repeatedly polls the keyboard 
 with KbdCharIn (with no wait), can prevent all regular priority class 
 threads from executing.  If polling must be used and a minimal amount of 
 other processing is being performed, the thread should periodically yield 
 the CPU by issuing a DosSleep call for an interval of at least 5 
 milliseconds. 

 
 Family API Considerations 

 Some options operate differently in the DOS mode than in the OS/2 mode. 
  Therefore, the following restrictions apply to KbdPeek when coding for 
 the DOS mode: 

 o The CharData structure includes everything except the time stamp. 
 o Interim character is not supported. 
 o Status can be 0 or 1. 
 o KbdHandle is ignored.