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Text File | 1989-09-11 | 5.9 KB | 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