KbdCharIn

This call returns a character data record from the keyboard.

KbdCharIn

(CharData, IOWait, KbdHandle)

CharData (PKBDKEYINFO) - output

Address of the character data structure:

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. The scan code received from the keyboard is translated to the ASCII character code.
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.
1
0 = Scan code is a character.

1 = Scan code is not a character; 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.
IOWait (USHORT) - input
Wait if a character is not available.

Value

Definition
0
Requestor waits for a character if one is not available.
1
Requestor gets an immediate return if no character is available.
KbdHandle (HKBD) - input
Default keyboard or the logical keyboard.
rc (USHORT) - return
Return code descriptions are:
• NO_ERROR 375
  ERROR_KBD_INVALID_IOWAIT
  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 to 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 KbdCharIn when coding in 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 40H
  o
  KbdHandle is ignored.

  ---

  [Back: Keyboard Function Calls]
  [Next: KbdClose]