Microsoft Programmer's Library 1.3

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Assembly Source File | 1988-12-12 | 27.9 KB | 715 lines

title SNAP -- Sample OS/2 Device Monitor page 55,132 .286 ; ; SNAP.ASM ; ; A sample OS/2 device monitor that captures the current display into ; the file SNAPxx.IMG, where xx is the session number. SNAP works in ; character mode only and may not be used in a PM window. The ; following keys are defined as defaults: ; ; Alt-F10 hot key to capture a screen ; Ctrl-F10 hot key to deinstall SNAP.EXE ; ; Assemble with: C> masm snap.asm; ; Link with: C> link snap,,,os2,snap ; ; Usage is: C> snap ; ; Copyright (C) 1988 Ray Duncan ; cr equ 0dh ; ASCII character codes lf equ 0ah ; hot key definitions: snapkey equ 71h ; snapshot Alt-F10 exitkey equ 67h ; exit Ctrl-F10 stksize equ 2048 ; stack size for threads extrn DosAllocSeg:far extrn DosBeep:far extrn DosBufReset:far extrn DosClose:far extrn DosCloseSem:far extrn DosCreateSem:far extrn DosCreateThread:far extrn DosExecPgm:far extrn DosExit:far extrn DosGetInfoSeg:far extrn DosOpenSem:far extrn DosMonClose:far extrn DosMonOpen:far extrn DosMonRead:far extrn DosMonReg:far extrn DosMonWrite:far extrn DosOpen:far extrn DosSemClear:far extrn DosSemSet:far extrn DosSemWait:far extrn DosSetPrty:far extrn DosSleep:far extrn DosSuspendThread:far extrn DosWrite:far extrn VioEndPopUp:far extrn VioGetMode:far extrn VioPopUp:far extrn VioReadCharStr:far extrn VioWrtCharStr:far jerr macro p1,p2,p3 ;; Macro to test return code local zero ;; in AX and jump if nonzero or ax,ax ;; Uses JMP DISP16 to avoid jz zero ;; branch out of range errors mov dx,offset DGROUP:p2 ;; p2 = message address mov cx,p3 ;; p3 = message length jmp p1 ;; routine p1 displays message zero: endm DGROUP group _DATA _DATA segment word public 'DATA' exitsem dd 0 ; semaphore for final exit snapsem dd 0 ; semaphore for 'snap' thread sname db '\SEM\SNAP' ; system semaphore name sname1 db 'nn.LCK',0 shandle dd 0 ; system semaphore handle pflags dw 0 ; VioPopUp flags wlen dw ? ; receives length written action dw ? ; receives DosOpen action watchID dw ? ; keyboard thread ID snapID dw ? ; snapshot thread ID sel dw ? ; selector from DosAllocSeg kname db 'KBD$',0 ; keyboard device name khandle dw 0 ; keyboard monitor handle fname db '\SNAP' ; name of snapshot file fname1 db 'nn.IMG',0 fhandle dw 0 ; handle for snapshot file scrbuf db 80 dup (0) ; receives screen data slen dw $-scrbuf ; length of screen buffer newline db cr,lf ; carriage return-linefeed nl_len equ $-newline gseg dw ? ; global info segment selector lseg dw ? ; local info segment selector obuff db 64 dup (0) ; receives name of dynlink obuff_len equ $-obuff ; causing DosExecPgm to fail kbdin dw 128,64 dup (0) ; input and output buffers kbdout dw 128,64 dup (0) ; for keyboard monitor kbdpkt db 128 dup (0) ; keyboard data packet kpktlen dw ? ; length of buffer/packet pname db 'SNAP.EXE',0 ; child process name retcode dd 0 ; child process info vioinfo label byte ; receives display mode dw 8 ; length of structure db 0 ; display mode type db 0 ; colors cols dw 0 ; number of columns rows dw 0 ; number of rows msg1 db 'SNAP utility installed!' msg1_len equ $-msg1 msg2 db 'Alt-F10 to capture screen into file SNAP.IMG,' msg2_len equ $-msg2 msg3 db 'Ctrl-F10 to shut down SNAP.' msg3_len equ $-msg3 msg4 db 'SNAP utility deactivated.' msg4_len equ $-msg4 msg5 db 'Error detected during SNAP installation:' msg5_len equ $-msg5 msg6 db 'Can''t create SNAP system semaphore.' msg6_len equ $-msg6 msg7 db 'Can''t start child copy of SNAP.' msg7_len equ $-msg7 msg8 db 'SNAP is already loaded.' msg8_len equ $-msg8 msg9 db 'Can''t open KBD$ monitor connection.' msg9_len equ $-msg9 msg10 db 'Can''t register as KBD$ monitor.' msg10_len equ $-msg10 msg11 db 'Can''t allocate thread stack.' msg11_len equ $-msg11 msg12 db 'Can''t create keyboard thread.' msg12_len equ $-msg12 msg13 db 'Can''t create snapshot thread.' msg13_len equ $-msg13 msg14 db 'Can''t create snapshot file.' msg14_len equ $-msg14 divider db 79 dup ('-'),cr,lf divider_len equ $-divider _DATA ends _TEXT segment word public 'CODE' assume cs:_TEXT,ds:DGROUP main proc far ; entry point from OS/2 ; get info segment selectors push ds ; receives global info selector push offset DGROUP:gseg push ds ; receives local info selector push offset DGROUP:lseg call DosGetInfoSeg ; transfer to OS/2 ; build system semaphore ; and snapshot file names mov es,gseg ; get foreground screen group mov al,es:[0018h] aam ; convert to ASCII add ax,'00' xchg ah,al mov word ptr fname1,ax ; store into filename mov word ptr sname1,ax ; store into semaphore name ; does SNAPxx.LCK exist? push ds ; receives semaphore handle push offset DGROUP:shandle push ds push offset DGROUP:sname ; semaphore name call DosOpenSem ; transfer to OS/2 or ax,ax ; was open successful? jz main1 ; jump, we're child SNAP ; we're the parent SNAP, ; create system semaphore push 1 ; make it nonexclusive push ds ; receives semaphore handle push offset DGROUP:shandle push ds ; system semaphore name push offset DGROUP:sname call DosCreateSem ; transfer to OS/2 jerr error,msg6,msg6_len ; jump if create failed ; set the semaphore... push word ptr shandle+2 ; semaphore handle push word ptr shandle call DosSemSet ; transfer to OS/2 ; launch child SNAP... push ds ; object name buffer push offset DGROUP:obuff ; receives failed dynlink push obuff_len ; length of buffer push 4 ; child detached push 0 ; NULL argument pointer push 0 push 0 ; NULL environment pointer push 0 push ds ; receives child info push offset DGROUP:retcode push ds ; pathname for child push offset DGROUP:pname call DosExecPgm ; request launch of child jerr error,msg7,msg7_len ; jump if launch failed ; wait for child to load push word ptr shandle+2 ; semaphore handle push word ptr shandle push -1 ; timeout = indefinite push -1 call DosSemWait ; transfer to OS/2 ; close the semaphore... push word ptr shandle+2 ; semaphore handle push word ptr shandle call DosCloseSem ; transfer to OS/2 jmp main3 ; now exit main1: ; come here if child SNAP... ; check if already resident push word ptr shandle+2 ; semaphore handle push word ptr shandle push 0 ; timeout = 0 push 0 call DosSemWait ; transfer to OS/2 or ax,ax ; is semaphore clear? jnz main2 ; no, proceed ; yes, don't load again mov dx,offset DGROUP:msg8 ; address of warning message mov cx,msg8_len ; length of message jmp error ; display message and exit main2: ; initialize semaphores... push ds ; address of exit semaphore push offset DGROUP:exitsem call DosSemSet ; transfer to OS/2 push ds ; address of snapshot semaphore push offset DGROUP:snapsem call DosSemSet ; transfer to OS/2 ; open monitor connection ... push ds ; address of device name push offset DGROUP:kname push ds ; receives monitor handle push offset DGROUP:khandle call DosMonOpen ; transfer to OS/2 jerr error,msg9,msg9_len ; jump if open failed ; register as keyboard monitor push khandle ; handle from DosMonOpen push ds ; monitor input buffer address push offset DGROUP:kbdin push ds ; monitor output buffer address push offset DGROUP:kbdout push 1 ; position = front of list mov es,gseg ; foreground session number mov al,byte ptr es:[0018h] ; from global info segment xor ah,ah push ax call DosMonReg ; transfer to OS/2 jerr error,msg10,msg10_len ; jump if register failed push stksize ; allocate stack for WATCH thread push ds ; variable to receive selector push offset DGROUP:sel push 0 ; not shareable call DosAllocSeg ; transfer to OS/2 jerr error,msg11,msg11_len ; jump, can't allocate stack ; create keyboard thread push cs ; initial execution address push offset _TEXT:watch push ds ; receives thread ID push offset DGROUP:watchID push sel ; address of thread's stack push stksize call DosCreateThread ; transfer to OS/2 jerr error,msg12,msg12_len ; jump, can't create thread ; promote keyboard thread push 2 ; scope = single thread push 3 ; class = time critical push 0 ; delta = 0 push watchID ; thread ID call DosSetPrty ; transfer to OS/2 push stksize ; allocate stack for SNAP thread push ds ; variable to receive selector push offset DGROUP:sel push 0 ; not shareable call DosAllocSeg ; transfer to OS/2 jerr error,msg11,msg11_len ; jump, can't allocate stack ; create snapshot thread push cs ; initial execution address push offset _TEXT:snap push ds ; receives thread ID push offset DGROUP:snapID push sel ; address of thread's stack push stksize call DosCreateThread ; transfer to OS/2 jerr error,msg13,msg13_len ; jump, can't create thread call signon ; announce installation ; tell parent we are running push word ptr shandle+2 ; semaphore handle push word ptr shandle call DosSemClear ; transfer to OS/2 ; block on exit semaphore... push ds ; semaphore handle push offset DGROUP:exitsem push -1 ; timeout = indefinite push -1 call DosSemWait ; transfer to OS/2 push watchID ; suspend keyboard thread call DosSuspendThread ; transfer to OS/2 push snapID ; suspend snapshot thread call DosSuspendThread ; transfer to OS/2 ; close monitor connection push khandle ; monitor handle call DosMonClose ; transfer to OS/2 ; close system semaphore push word ptr shandle+2 ; semaphore handle push word ptr shandle call DosCloseSem ; transfer to OS/2 ; close snapshot file push fhandle ; file handle call DosClose ; transfer to OS/2 call signoff ; announce deinstallation main3: push 1 ; terminate all threads push 0 ; return success code call DosExit ; final exit to OS/2 main endp error proc near ; fatal error encountered ; DS:DX = message, CX = length test khandle,-1 ; monitor active? jz error1 ; no, jump ; yes, shut it down push khandle ; monitor handle call DosMonClose ; transfer to OS/2 error1: mov ax,word ptr shandle ; system semaphore open? or ax,word ptr shandle+2 jz error2 ; no, jump ; clear semaphore, in case ; we're the child SNAP push word ptr shandle+2 ; semaphore handle push word ptr shandle call DosSemClear ; transfer to OS/2 ; close the semaphore push word ptr shandle+2 ; semaphore handle push word ptr shandle call DosCloseSem ; transfer to OS/2 error2: mov ax,1 ; get popup window call popup ; display title... push ds ; message address push offset DGROUP:msg5 push msg5_len ; message length push 10 ; Y push (80-msg5_len)/2 ; X (center it) push 0 ; Vio handle call VioWrtCharStr ; transfer to OS/2 ; display error message... push ds ; message address push dx push cx ; message length push 12 ; Y mov ax,80 ; X (center it) sub ax,cx shr ax,1 push ax push 0 ; Vio handle call VioWrtCharStr ; transfer to OS/2 push 0 ; pause for 3 seconds push 3000 call DosSleep ; transfer to OS/2 call unpop ; release popup window push 1 ; terminate all threads push 1 ; return error code call DosExit ; exit program error endp watch proc far ; keyboard thread, monitors ; for snapshot or exit hot keys mov kpktlen,kpktlen-kbdpkt ; max buffer length for read ; get keyboard data packet... push ds ; monitor input buffer address push offset DGROUP:kbdin push 0 ; wait until data available push ds push offset DGROUP:kbdpkt ; receives keyboard data packet push ds push offset DGROUP:kpktlen ; contains/receives length call DosMonRead ; transfer to OS/2 cmp kbdpkt+2,0 ; is this extended code? jnz watch1 ; no, pass it on cmp kbdpkt+3,exitkey ; is it exit hot key? jz watch2 ; jump if exit key cmp kbdpkt+3,snapkey ; is it snapshot hot key? jnz watch1 ; no, jump cmp word ptr kbdpkt+12,0 ; is it break packet? jnz watch ; yes, ignore it ; snapshot hot key detected ; clear snapshot semaphore... push ds ; semaphore handle push offset DGROUP:snapsem call DosSemClear ; transfer to OS/2 jmp watch ; discard this hot key watch1: ; not hot key, pass character push ds ; monitor output buffer address push offset DGROUP:kbdout push ds ; keyboard data packet address push offset DGROUP:kbdpkt push kpktlen ; length of data packet call DosMonWrite ; transfer to OS/2 jmp watch ; get another packet watch2: ; exit hot key detected... cmp word ptr kbdpkt+12,0 ; is it break packet? jnz watch ; yes, ignore it ; clear exit semaphore... push ds ; semaphore handle push offset DGROUP:exitsem call DosSemClear ; transfer to OS/2 jmp watch ; let thread 1 shut down watch endp snap proc far ; This thread blocks on the ; snapshot semaphore, then ; dumps the screen contents ; to the file SNAPxx.IMG. ; open/create snapshot file push ds ; address of filename push offset DGROUP:fname push ds ; variable to receive file handle push offset DGROUP:fhandle push ds ; variable to receive action taken push offset DGROUP:action push 0 ; initial file size push 0 push 0 ; normal file attribute push 12h ; create or replace file push 21h ; write access, deny write push 0 ; DWORD reserved push 0 call DosOpen ; transfer to OS/2 jerr error,msg14,msg14_len ; jump if can't create snap1: ; write divider line push fhandle ; file handle push ds ; address of divider string push offset DGROUP:divider push divider_len ; length of string push ds ; receives bytes written push offset DGROUP:wlen call DosWrite ; transfer to OS/2 ; force disk update... push fhandle ; file handle call DosBufReset ; transfer to OS/2 ; wait on snapshot semaphore push ds ; semaphore handle push offset DGROUP:snapsem push -1 ; timeout = indefinite push -1 call DosSemWait ; transfer to OS/2 mov ax,3 ; pop-up in transparent mode call popup ; to read screen contents ; get screen dimensions... push ds ; receives video mode info push offset DGROUP:vioinfo push 0 ; Vio handle call VioGetMode ; transfer to OS/2 mov bx,0 ; BX := initial screen row snap2: ; read line from screen... mov ax,cols ; width to read mov slen,ax push ds ; address of screen buffer push offset DGROUP:scrbuf push ds ; contains/receives length push offset DGROUP:slen push bx ; screen row push 0 ; screen column push 0 ; Vio handle call VioReadCharStr ; transfer to OS/2 push ds ; scan backwards from end pop es ; of line to find last mov cx,slen ; nonblank character mov di,offset DGROUP:scrbuf add di,slen dec di mov al,20h std repe scasb cld jz snap3 ; if Z = True, line was empty inc cx ; otherwise correct the length snap3: ; write line to file... push fhandle ; file handle push ds ; address of data push offset DGROUP:scrbuf push cx ; clipped line length push ds ; receives bytes written push offset DGROUP:wlen call DosWrite ; transfer to OS/2 ; write newline (CR-LF) push fhandle ; file handle push ds push offset DGROUP:newline ; address of newline push nl_len ; length of newline push ds ; receives bytes written push offset DGROUP:wlen call DosWrite ; transfer to OS/2 inc bx ; bump screen row counter cmp bx,rows ; whole screen done yet? jne snap2 ; no, write another push 440 ; reward user with some push 200 ; audible feedback call DosBeep ; transfer to OS/2 call unpop ; release the screen ; done with screen capture, ; reset snapshot semaphore push ds ; semaphore handle push offset DGROUP:snapsem call DosSemSet ; transfer to OS/2 jmp snap1 ; go wait on semaphore snap endp signon proc near ; announce installation, ; display help message mov ax,1 ; put up popup window call popup ; mode = wait, nontransparent push ds ; message address push offset DGROUP:msg1 push msg1_len ; message length push 10 ; Y push (80-msg1_len)/2 ; X (center it) push 0 ; Vio handle call VioWrtCharStr ; transfer to OS/2 push ds ; message address push offset DGROUP:msg2 push msg2_len ; message length push 13 ; Y push (80-msg2_len)/2 ; X (center it) push 0 ; Vio handle call VioWrtCharStr ; transfer to OS/2 push ds ; message address push offset DGROUP:msg3 push msg3_len ; message length push 15 ; Y push (80-msg3_len)/2 ; X (center it) push 0 ; Vio handle call VioWrtCharStr ; transfer to OS/2 push 0 ; pause for 4 seconds push 4000 ; so user can read message call DosSleep ; transfer to OS/2 call unpop ; take down popup window ret ; back to caller signon endp signoff proc near ; announce deinstallation mov ax,1 ; put up popup window call popup ; mode = wait, nontransparent push ds ; message address push offset DGROUP:msg4 push msg4_len ; message length push 12 ; Y push (80-msg4_len)/2 ; X (center it) push 0 ; VIO handle call VioWrtCharStr push 0 ; pause for 2 seconds push 2000 ; so user can read message call DosSleep ; transfer to OS/2 call unpop ; take down popup window ret signoff endp popup proc near ; put up popup window ; AX = VioPopUp flags ; bit 0 = 0 no wait ; 1 wait for pop-up ; bit 1 = 0 nontransparent ; 1 transparent mov pflags,ax ; set pop-up mode push ds ; address of popup flags push offset DGROUP:pflags push 0 ; Vio handle call VioPopUp ; transfer to OS/2 ret ; back to caller popup endp unpop proc near ; take down popup window push 0 ; Vio handle call VioEndPopUp ; transfer to OS/2 ret ; back to caller unpop endp _TEXT ends end main