; $Id: kRxa.asm,v 1.1 2000-06-03 03:50:45 bird Exp $ ; ; kRxa - Small rexx script interpreter. ; ; Assembly edition. ; ; Copyright (c) 2000 knut st. osmundsen (knut.stange.osmundsen@pmsc.no) ; ; Project Odin Software License can be found in LICENSE.TXT ; .386p .model flat .stack 10000h ;DEBUG EQU 1 ; ; External Functions ; extrn DosWrite:PROC extrn RexxStart:PROC ; ; Defined Constants And Macros ; MAX_ARG_LENGTH EQU 1000h ; ; Structures and Typedefs ; RXSTRING STRUC cb dd ? pach dd ? RXSTRING ENDS DATA32 segment dword public 'DATA' use32 ; ; Global Variables ; ifdef DEBUG ;Debug stuff szMsgDebug1 db "Debug1",13,10,0 szMsgDebug2 db "Debug2",13,10,0 szMsgDebug3 db "Debug3",13,10,0 endif ;Error messages. szMsgScriptnameTooLong db "Fatal error: The scriptname is too long.",13,10,0 szMsgArgumentsTooLong db "Fatal error: The arguments are too long.",13,10,0 szMsgRexxStartFailed db "Fatal error: RexxStart failed.",13,10,0 ;Rexx argument string rxstrArgs RXSTRING <0, offset szArgs> ;Command env. name - RexxStart param - dont't know what it is used for... szEnv db "hmm", 0 ;Some uninitialized buffers szScriptname db 260d dup (?) szArgs db MAX_ARG_LENGTH dup (?) DATA32 ends CODE32 segment dword public 'CODE' use32 ;; ; Exe Entry Point. ; @returns ; @param eax = eax = ebx = ecx = esi = edi = ebp = 0 ; @param [esp + 00h] Return address. (32-bit flat) ; @param [esp + 04h] Module handle for program module. ; @param [esp + 08h] Reserved ; @param [esp + 0ch] Environment data object address. ; @param [esp + 10h] Command line linear address in environemnt data object. ; @uses ; @equiv ; @time ; @sketch ; @status ; @author knut st. osmundsen (knut.stange.osmundsen@pmsc.no) ; @remark main PROC NEAR hModule EQU [ebp + 08h] pEnvironment EQU [ebp + 10h] pCommandline EQU [ebp + 14h] LOCAL sRexxRc:word LOCAL cbActual:dword ; ; Find the arguments ; mov eax, pCommandline call strlen add eax, pCommandline ; ; The script name is the first argument to this program ; The script arguments are following, so we'll have to find them.. ; ; ; Copy the script name. ; mov ecx, 260 ; Max length. xchg esi, eax ; esi <- Pointer to the arguments (script name) (-1). mov edi, offset szScriptname ; edi <- Target string buffer for the script name. mov ah, ' ' ; terminator is ' ' or '\0' skiploop1: ; skip spaces inc esi ; next char (initially at terminator of exe name). mov al, byte ptr [esi] ; Get first char to determin terminator type. cmp al, ah jz skiploop1 cmp al, '"' ; if not '"' then goto copy loop. jne loop1 mov al, '"' ; terminator is '"' or '\0' inc eax ; skip '"'. loop1: or al, al ; zero terminator? jz endloop1 cmp al, ah ; the other terminator? jz endloop1 stosb ; copy the byte ; next char inc esi ; next dec ecx ; check that we haven't reached the max length. jz Scriptname_Too_Long mov al, byte ptr [esi] ; read (next) byte jmp loop1 endloop1: mov byte ptr [edi], 0 ; terminate scriptname. ; more arguments? or al, al ; stopped at null terminator, then no more args. jz callrexx inc esi ; skip terminator. ; ; skip spaces between the scriptname and the first argument. loop2: mov al, byte ptr [esi] cmp al, ' ' jne endloop2 inc esi jmp loop2 endloop2: ; ; Copy arguments, we'll copy till '\0' ; mov eax, esi call strlen ; get argument length mov ecx, eax ; ecx <- number of bytes to copy (argument length). mov rxstrArgs.cb, ecx ; Set length of rexx argument string. cmp ecx, MAX_ARG_LENGTH jae Arguments_Too_Long ; Overflow detected. mov edi, offset szArgs ; edi <- Target argument buffer. repnz movsb ; memcpy(edi, esi, ecx); ; Not sure if it copies the '\0', but that ; don't matter while the memory is initialized ; to zero by the OS! callrexx: ; init return string. xor ebx, ebx ; ebx <- 0 push ebx ; NULL - Rexx program return string. lea eax, sRexxRc push eax ; Rexx program return code. push ebx ; NULL - EXIT (FIXME?) push ebx ; RXCOMMAND (0) - Program called as Command. push offset szEnv ; Command env. name. What is this???? push ebx ; NULL - Pointer to INSTORE? Not used. push offset szScriptname ; Name of REXX script. push offset rxstrArgs ; Pointer to argument array (rexx strings) - 1 element. push 1 ; Number of arguments - one. call RexxStart sub esp, DWORD * 9 ;Check return value from RexxStart or eax, eax jnz RexxStartFailed ; ; return rexx error code. ; mov ax, sRexxRc ret ; ; errors ; Scriptname_Too_Long: mov eax, offset szMsgScriptnameTooLong jmp PrintError Arguments_Too_Long: mov eax, offset szMsgArgumentsTooLong jmp PrintError RexxStartFailed: mov eax, offset szMsgRexxStartFailed jmp PrintError PrintError: lea ebx, cbActual push ebx ; cbActual - last arg for DosWrite mov ebx, eax ; ebx <- string pointer call strlen push eax ; Bytes to write push ebx ; Pointer to string. push 1 ; stderr call DosWrite sub esp, DWORD * 4 ; clean stack. mov eax, -10002 ret main ENDP ;; ; String length function. ; @cproto int _Optlink strlen(const char *) ; @returns eax = string length. ; @param eax pointer to string. ; @uses ecx, edx strlen PROC NEAR push edi xor ecx, ecx dec ecx ; ecx <- 0ffffffffh mov edi, eax ; esi <- string pointer xor eax, eax ; scan until null terminator is found. repnz scasb ; the actual scan. neg ecx ; ecx is ffffffffh - string length ; negate it to get the string length. mov eax, ecx ; mov string length into eax (return value) sub eax, 2 ; addjust it. pop edi ret strlen ENDP ifdef DEBUG ;; ; Write debug string to stdout. ; ; @param eax Pointer to string. ; @uses ; @equiv ; @time ; @sketch ; @status ; @author knut st. osmundsen (knut.stange.osmundsen@pmsc.no) ; @remark debugwrite PROC NEAR LOCAL cbActual:dword push ebx push esi push edi ; ; Write the arguments to stdout. ; push ebx lea ebx, cbActual push ebx ; cbActual - last arg for DosWrite mov ebx, eax call strlen push eax ; Bytes to write push ebx ; Pointer to string. push 1 ; stdout call DosWrite sub esp, DWORD * 4 ; clean stack. pop edi pop esi pop ebx ret debugwrite ENDP endif CODE32 ENDS END main