OS/2 Shareware BBS: 8 Other/08-Other.zip/KEYWAIT.ZIP/KEYWAIT.OS2

Text File | 1989-09-11 | 6KB | 257 lines

;-------------------------------------------------------------------------------
;
;                keywait.asm
;                ===========
;
;    Waits a few seconds for a keystroke.  If ESC is pressed then sets
;    errorlevel to 27.  If a function key F1-F10 is pressed then sets
;    errorlevel to a value in the range 1-10 corresponding to the function
;    key.  If time expires or any other key is pressed then errorlevel
;    is set to zero.  Can be useful in .CMD files.
;
;    A public domain program by Jon Saxton.  Please distribute source
;    code and not just the object code.
;
;-------------------------------------------------------------------------------

    include os2.inc

COLON    equ    ':'
CR    equ    0Dh
LF    equ    0Ah
ETX    equ    03h
ESCk    equ    1Bh
SPACE    equ    ' '
TAB    equ    9
F1    equ    59
F10    equ    68

THREAD_STACK_SIZE   equ     512
THREAD_STACK_OFFSET equ     THREAD_STACK_SIZE-2

    .model    small

    .data

keyData    KBDKEYINFO    <>

ticks    dw    10            ;Default number of seconds
stkPtr    dd    ?
    org    stkPtr
stkOff    dw    ?
stkSeg    dw    ?
tid    dw    ?
kid    dw    ?

keyboardInput    dd    ?        ; Keyboard input semaphore
timeExpired    dd    ?        ; Timer semaphore

semaphoreList    dw    2        ; Number of elements
        dw    0
        dw    offset keyboardInput
        dw    seg keyboardInput
        dw    0
        dw    offset timeExpired
        dw    seg timeExpired

key        dw    0
blankRet    db    CR
blanks        db    '    '
timerHandle    dd    ?
timerSemHandle    dd    ?
timerSemName    db    '\SEM\TICKER',0
eventNumber    dw    -1
kiMessage    db    'Key pressed: exit code '
toMessage    db    'Timed out:   exit code '
msgLen        equ    $-toMessage
pointers    dw    kiMessage,toMessage

    .code
    .286C

start:
    mov    es,ax            ; Point at environment segment
    mov    di,bx            ; Point at command name
    xor    ax,ax
    repne    scasb            ; Skip to end of command name
    mov    cx,0
skipLeadingBlanks:
    mov    al,es:[di]        ; Get command-line character
    inc    di            ; Point at the next one
    or    al,al            ; Check if anything there
    jz    setTicks
    cmp    al,SPACE        ; Skip leading white space
    je    skipLeadingBlanks
    cmp    al,TAB
    je    skipLeadingBlanks
convertNumber:
    xor    ah,ah
    cmp    al,'0'
    jb    setTicks
    cmp    al,'9'
    ja    setTicks
    sub    al,'0'
    add    cx,cx            ;*2
    mov    dx,cx
    add    cx,cx            ;*4
    add    cx,cx            ;*8
    add    cx,dx            ;*10
    add    cx,ax
    mov    al,es:[di]
    inc    di
    jmp    convertNumber
setTicks:
    mov    ax,cx
    or    ax,ax
    jz    default
    cmp    ax,100
    ja    default
    mov    ticks,ax
default:

; At this point we have analysed the command line and interpreted a single
; number as the number of seconds to wait for a keystroke.  If the number
; of seconds was not specified or is unreasonably large then it has been
; forced to a value of 10.
;
; The next step is to initiate the timer and keyboard threads.    This is
; real OS/2 stuff.

    @DosSemSet    keyboardInput    ; Set the semaphores which are going
    @DosSemSet    timeExpired    ; to be used by the two threads

    @DosAllocSeg    THREAD_STACK_SIZE,stkSeg,0    ; Get a stack
    or        ax,ax            ; Check that it worked
    jz        first
    jmp        error100
first:
    mov        ax,THREAD_STACK_OFFSET    ; Create the timer thread
    mov        stkOff,ax
    @DosCreateThread ticker,tid,[stkPtr]

    @DosAllocSeg    THREAD_STACK_SIZE,stkSeg,0    ; Get a stack
    or        ax,ax            ; Check that it worked
    jz        second
    jmp        error100
second:
    @DosCreateThread keyin,kid,[stkPtr]    ; Create the keyin thread

; Now wait for one of the two threads to signal an event

    @DosMuxSemWait    eventNumber,semaphoreList,-1
    mov        bx,eventNumber
    add        bx,bx
    mov        ax,pointers[bx]
    push        ds
    push        ax
    push        msgLen
    push        0
    call far ptr VioWrtTTy
    mov        si,offset blanks
    mov        ax,'  '
    mov        [si],ax
    mov        ax,key
    call        decimal
    @VioWrtTTy    blanks,3,0
    @DosExit    1,[key]

error100:
    @DosExit    1,100

;-----------------------------------------------------------------------------
;
;    Keyboard input handler.  Waits for a keystroke and returns a value
;    in the range 1-10 if a function key was pressed, 27 if the ESC key
;    was pressed, 0 if anything else was pressed.
;
;-----------------------------------------------------------------------------

keyin    proc

    @KbdCharIn    keyData,0,0        ; Get character
    mov        al,keyData.kbci_chChar
    or        al,al            ; Extended key code?
    jnz        simple            ; No, check for ESC etc
    mov        al,keyData.kbci_chScan    ; Fetch second byte
    cmp        al,F1            ; Check for F1 - F10
    jb        sig0
    cmp        al,F10
    ja        sig0
    sub        al,F1-1
    jmp        sig
simple:
    cmp        al,ESCk            ; ESC causes return value
    jz        sig            ;  to be set to 27
sig0:
    xor        al,al
sig:
    mov        byte ptr key,al
    @DosSemClear    keyboardInput
    @DosExit    0,0

keyin    endp

;------------------------------------------------------------------------------
;
;    Countdown timer.  Displays the number of ticks remaining.  Stops
;    at zero.
;
;------------------------------------------------------------------------------

ticker    proc

    @DosCreateSem    1,timerSemHandle,timerSemName
    @DosSemSet    [timerSemHandle]
    @DosTimerStart    1000,[timerSemHandle],timerHandle
tick:
    @DosSemWait    [timerSemHandle],-1
    @DosSemSet    [timerSemHandle]
    mov        si,offset blankRet+1
    mov        ax,'  '
    mov        word ptr [si],ax
    mov        ax,ticks
    dec        ax
    mov        ticks,ax
    pushf
    call        decimal     ;  seconds remaining
    @VioWrtTTY    blankRet,4,0
    popf
    jnz        tick
    @DosSemClear    timeExpired
;    @DosTimerStop    [timerHandle]
    @DosExit    0,0

ticker    endp

;-----------------------------------------------------------------------------
;
;    DECIMAL
;
;    Converts an unsigned decimal number from AX into ASCII in the
;    buffer addressed by SI.
;
;    Destroys contents of AX, CX, DX
;
;-----------------------------------------------------------------------------

decimal    proc
    xor    dx,dx        ; Clear high-order 16 bits of dividend
    mov    cx,10        ; Load divisor
    div    cx        ; Quotient to AX, remainder to DX
    or    ax,ax        ; Test quotient
    jz    remain        ; If zero then just display the remainder
    push    dx        ; Otherwise save the remainder while we
    call    decimal        ;  deal with the quotient
    pop    dx        ; Recover the remainder
remain:
    add    dl,'0'        ; Convert remainder to a decimal digit
    mov    [si],dl
    inc    si
    ret

decimal    endp

    .stack    160

    end    start