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Assembly Source File | 1990-10-07 | 120KB | 3,972 lines

page 66,132 ;============================================================================ ; BAT2EXEC.COM - a batch file compiler ; ; Syntax: ; BAT2EXEC filename ; ; Revision History: ; ; Version 1.0 Initial Release PC Magazine Vol 9 Num 14 ; Version 1.1 Bug Fixes July 19, 1990 ; Version 1.2 Bug Fixes July 28, 1990 ; Added ability to read large BAT files. ; Version 1.3 PATH cmd fix. Oct. 3, 1990 ; Echo cmd fix ; Other small bug fixes. ; ;============================================================================ code segment assume cs:code org 2ch local_environment dw ? ;Word containing the segment ; of the program's env. block. org 80h command_tail db ? ;Offset of the command tail. org 100h main: jmp initialize program db 13,10,"BAT2EXEC 1.3 " copyright db "(c) 1990 Ziff Communications Co.",10,13 author db "PC Magazine ",254," Douglas Boling" db 10,13,"$",1Ah ;---------------------------------------------------------------------------- ;Equates used to find data offsets in the compiled program. ;---------------------------------------------------------------------------- BUFF_SIZE equ 255 ;Size of runtime buffers std_data_size equ offset data_end - data_start code_start_ptr equ [bp + offset code_start - offset data_start] com_stack_ptr equ [bp + offset stack_ptr - offset data_start] com_prog_size equ [bp + offset prog_segsize - offset data_start] com_label_start equ [bp + offset label_list_strt - offset data_start] parse_buff equ [bp + offset prse_buff_ptr - offset data_start] parse2_buff equ [bp + offset prs2_buff_ptr - offset data_start] exec_buff equ [bp + offset exec_buff_ptr - offset data_start] forloop_buff equ [bp + offset for_buff_ptr - offset data_start] forloop_ptr equ [bp + offset floop_ptr - offset data_start] stdout_hdl equ [bp + offset file_handle1 - offset data_start] outfile_hdl equ [bp + offset file_handle2 - offset data_start] stdin_hdl equ [bp + offset file_handle3 - offset data_start] infile_hdl equ [bp + offset file_handle4 - offset data_start] environment_seg equ [bp + offset master_env - offset data_start] dos_version equ [bp + offset version_num - offset data_start] process_rc equ [bp + offset proc_rc - offset data_start] shift_count equ [bp + offset shift_cnt - offset data_start] code_call_size equ offset code_call_end - offset code_call code_jmp_size equ offset code_jmp_end - offset code_jmp code_jc_size equ offset code_jc_end - offset code_jc code_jnc_size equ offset code_jnc_end - offset code_jnc code_jmpdis_size equ offset code_jmpdis_end - offset code_jmpdis code_leasi_size equ offset code_leasi_end - offset code_leasi code_movsi_size equ offset code_movsi_end - offset code_movsi code_movsiim_size equ offset code_movsiim_end - offset code_movsiim code_leadi_size equ offset code_leadi_end - offset code_leadi code_movdi_size equ offset code_movdi_end - offset code_movdi code_movdiim_size equ offset code_movdiim_end - offset code_movdiim ;============================================================================ ;Compiler data ;============================================================================ command_table db "IF",0 ;Commands processed by db "REM",0 ; compiler db "FOR",0 db "ECHO",0 db "GOTO",0 db "EXIT",0 db "PAUSE",0 db "SHIFT",0 db "SET",0 db "CALL",0 db "PATH",0 db "PROMPT",0 db "CD",0 ;DOS commands internal to db "MD",0 ; command.com. db "RD",0 db "CLS",0 db "DIR",0 db "DEL",0 db "REN",0 db "VER",0 db "VOL",0 db "CTTY",0 db "CHCP",0 db "TYPE",0 db "COPY",0 db "DATE",0 db "TIME",0 db "ERASE",0 db "CHDIR",0 db "MKDIR",0 db "RMDIR",0 db "BREAK",0 db "RENAME",0 db "DELETE",0 db "VERIFY",0 db "COMMAND",0,0 batcmd_jmptbl dw if_cmd ;if command dw rem_cmd ;rem command dw for_cmd ;for command dw echo_cmd ;echo command dw goto_cmd ;goto command dw rem_cmd ;exit command dw pause_cmd ;pause command dw shift_cmd ;shift command dw set_cmd ;set command dw internal_cmd ;call command dw path_cmd ;Path command dw prompt_cmd ;Prompt command dw internal_cmd ;DOS internal command dw external_cmd ;DOS program dw label_cmd ;Process BAT label batcmd_jmptbl1 = $ ifstr1 db "ERRORLEVEL" ifstr2 db "EXIST" internal_cmdsw db "/C " ;Switch for transient commands for_active_flag db 0 ;Set if parsing a FOR loop goto_active db 0 ;Set if goto parsed goto_data_ptr dw 0 ;Data offset of last goto temp1 dw 0 ;Temp data storage. cmd_switches db ? ;Used if command line switches cmd_switch_end = $ ; needed. last_routine dw offset init_code_next ;Last canned routine used. codebuff_start dw 0 ;Buffer to construct the code codebuff_ptr dd 0 ; image of the COM file. databuff_start dw ? ;Buffer to hold the data databuff_end dw ? ; image of the COM file. firstlabel dw -1 ;Ptr to 1st label in COM file outbuff_ptr dd 0 ;Buffer to hold the final outbuff_end dw 0 ; image of the COM file. quote_flag db 0 ;Disable translate flag redirect_in db 0 ;Input redirection flag redirect_out db 0 ;Output redirection flag pipe_toggle db 0 ;Piping file flag pipein_file dw 0 pipein_flag db 0 pipeout_file dw 0 pipeout_flag db 0 pipe1_file dw 0 db "T^M^P_$1.!!!",0 ;Name of piping file 1 pipe2_file dw 0 db "T^M^P_$2.!!!",0 ;Name of piping file 2 inbuff_ptr dw offset end_of_code+512 ;Buffer for BAT file inbuff_size dw 1024 ;Size of input buffer file_handle dw -1 ;Handle of BAT file file_linecount dw 0 ;Line number being processed. com_string db ".COM",0 ;Extension for output file outfile_name db 13 dup (" ") ;Name of output file. filemsg1 db 13,10,"Error in line $" ;File identification message. errmsg0 db "Need DOS 2.0 or greater$" errmsg1 db 13,10,"Syntax: BAT2EXEC filename.ext",13,10,"$" errmsg2 db "Can",39,"t find input file$" errmsg3 db "Not enough memory$" errmsg4 db "No input file specified$" errmsg5 db "COM file size too big$" errmsg6 db "Syntax error$" errmsg7 db "Compiler data buffer full$" errmsg8 db "Label defined more than once$" errmsg9 db "Label " errmsg9labl db 8 dup (" ") db "not found$" errmsg10 db "Illegal disk specified$" errmsg11 db "FOR loops cannot be nested$" endmsg db 13,10,"$" ;---------------------------------------------------------------------------- ; Start of compiler code. ;---------------------------------------------------------------------------- initialize proc near assume cs:code,ds:code,es:code mov dx,offset program ;Display copyright message. mov ah,9 int 21h cld ;Set string operations 'up.' mov ah,30h ;Get DOS version, run only int 21h ; if 2.0 or greater. xchg al,ah ;Swap major, minor numbers mov dx,offset errmsg0 ;Bad DOS version cmp ah,2 jb jmp_disp_error mov sp,offset end_of_code + 512 ;Move stack mov ah,4ah ;Reduce memory mov bx,1000h ; allocation to 64K int 21h mov ax,inbuff_ptr ;Compute start of buffer for add ax,inbuff_size ; COM file data. mov databuff_start,ax mov ah,48h ;Allocate memory block for mov bx,1000h ; intermediate buffer. int 21h mov dx,offset errmsg3 ;Not enough memory msg jc jmp_disp_error mov word ptr codebuff_ptr[2],ax ;Save segment. mov ah,48h ;Allocate memory block for mov bx,1000h ; output file buffer. int 21h jc jmp_disp_error mov word ptr outbuff_ptr[2],ax ;Save segment. ; ;Parse the command line for switches. ; mov si,offset command_tail xor cx,cx or cl,[si] ;Get command line length je init_0 ;If zero, report no filename inc si parse_cmdline_l1: xor bl,bl ;Search for the next call scan4char ; non-space character. jnc init_1 ;If zero, report no filename init_0: mov dx,offset errmsg1 jmp short jmp_disp_error ;If none, report no filename init_1: mov al,[si] cmp al,"/" ;See if command switch je parse_error call loadbatfile ;Load input BAT file jc jmp_disp_error jmp short parse_cmdline_end parse_error: mov dx,offset errmsg2 jmp_disp_error: jmp disp_error parse_cmdline_end: ; ;Compile BAT file line by line. ; mov si,inbuff_ptr ;SI points to input BAT file mov di,databuff_start ;DI points to COM file data. add di,std_data_size ;Make room for std data set. new_line: inc file_linecount ;Inc line number new_line1: xor bl,bl ;Look for 1st character call scan4char ;If nothing on line, check jc comp_endcheck ; for EOF call redirect_check cmp byte ptr [si],'@' ;See if non echo prefix jne comp_1 inc si ;Move past @ comp_1: call parse ;Parse 1st word in the line. jc jmp_disp_error jmp short new_line comp_endcheck: cmp al,13 ;See if carrage return, if so je new_line ; continue. cmp file_handle,-1 ;If at end of buffer, check je comp_end ; to see if any more of the call loadbatfile ; file to read. jc jmp_disp_error mov si,inbuff_ptr ;Reset SI to start of buffer. jmp short new_line1 comp_end: ; ;Inline code complete, append terminate code. ; call redirect_close mov databuff_end,di ;Save ptr to end of data. les di,codebuff_ptr assume es:nothing mov si,offset end_code ;Append terminate code mov cx,offset end_code_end-offset end_code rep movsb mov word ptr codebuff_ptr,di ;Save ptr to end of COM code. ; ;File processed. Assemble data and code into one routine. Start by ;stringing the canned routines together using the links set by the ;INCLUDE routine. ; les di,outbuff_ptr ;Get ptr to output buffer mov si,offset init_code_next ; for COM file. file_1: mov cx,[si-2] ;Get size of routine push [si] ;Save pointer to next routine add si,4 ;Skip past number of links rep movsb ;Copy routine to COM file. pop si or si,si ;See if last routine jne file_1 ;No, loop back. ; ;Save starting offset of data to be used by the COM program. ; mov bp,offset data_start_ptr-offset init_code mov ax,100h ;AX = end pointer add ax,di ;Add length of canned routines. mov es:[bp],ax ;Save data start pointer mov bp,di ;Use BP as starting data offset mov si,databuff_start ;Compute length of COM data mov cx,databuff_end ; plus the canned routines. sub cx,si add ax,cx ;Add data length to end ptr ; ;Now that we have the length of the canned routines and the data, we can ;compute the starting offset of the inline code. Use this number to adjust ;the jump table entries in the label list. While fixing offsets check to ;see that all labels have code offsets, if not, print no label error msg. ;When complete, append data to file. ; mov bx,offset firstlabel ;Get pointer to the first label mov dx,[bx] ;Get offset to 1st label entry add dx,bx ;Add in BX to get absolute off file_11: cmp word ptr [bx],-1 ;See if at end of label list. je file_13 add bx,[bx] ;Get next in list cmp word ptr [bx+2],-1 ;See if label ptr to code je file_12 ; initialized. No, error. add [bx+2],ax ;Add starting offset of code jmp short file_11 file_12: mov si,bx ;Label not defined as a add si,5 ; destination. Print error xor cx,cx ; message inc lost label. mov cl,[bx+4] ;Get size of label push cs pop es mov di,offset errmsg9labl rep movsb mov dx,offset errmsg9 ;Label not found msg jmp disp_error file_13: rep movsb ;Append data to COM file. sub dx,databuff_start ;Set pointer to 1st label list mov es:com_label_start,dx ;Initialize pointer. ; ;Append the inline code to the program. ; mov ax,100h add ax,di mov es:code_start_ptr,ax ;Save offset of main code. mov cx,word ptr codebuff_ptr mov si,codebuff_start ;Get pointer to code mov ds,word ptr codebuff_ptr[2] assume ds:nothing sub cx,si ;Get size of code add ax,cx ;Make sure canned routines jnc file_2 ; and data < 64 K bytes. file_too_big: mov dx,offset errmsg5 ;COM file too big msg jmp disp_error file_2: rep movsb ;Append inline code. ; ;Compute the size of the data buffers and the stack used by the COM program. ;Write these numbers to the COM file data area. ; push cs pop ds assume ds:code add ax,512 ;Add room for stack jc file_too_big and ax,0fffeh ;Set stack on even word. mov es:com_stack_ptr,ax ;Save run time stack pointer add ax,2 ;Make room for buff length word mov es:parse_buff,ax ;Save ptr to parsing buffer. add ax,BUFF_SIZE+2 ;Add room for buffer 2 jc file_too_big mov es:parse2_buff,ax ;Save ptr to parsing buffer 2 add ax,BUFF_SIZE+2 ;Add room for buffer jc file_too_big mov es:exec_buff,ax ;Save ptr to exec buffer add ax,BUFF_SIZE+2 ;Add room for buffer jc file_too_big mov es:forloop_buff,ax ;Save ptr to For loop buffer add ax,BUFF_SIZE ;Add room for buffer jc file_too_big mov outbuff_end,di ;Save end pointer to file add ax,15 jc file_3 ;Compute size of COM file mov cl,4 ; in paragraphs. shr ax,cl mov es:com_prog_size,ax ;Save file size mov byte ptr es:shift_count,0 ;Clear shift count mov byte ptr es:process_rc,0 ;Clear return code file_3: ; ;Write file to disk. ; mov ah,3ch ;Create file xor cx,cx ;Normal attributes mov dx,offset outfile_name ;Name of file int 21h mov bx,ax ;Copy handle mov ah,40h ;Write file push ds lds dx,outbuff_ptr ;Get start of buffer mov cx,cs:[outbuff_end] ;Get number of bytes to write sub cx,dx int 21h ;Write file to disk pop ds mov ah,3eh ;Close file int 21h ; ;Compile complete. Clean up and end. ; good_exit: xor al,al ;Return code = 0 exit: push ax ;Save return code mov ah,49h ;Release memory block used mov es,word ptr cs:[codebuff_ptr+2] ; for file buffer. int 21h mov bx,file_handle cmp bx,-1 ;See if input file closed. jne exit_1 ; If not, do so. mov ah,3eh ;Close file. int 21h exit_1: pop ax ;Get back return code mov ah,4Ch ;Terminate int 21h ; ;Display error message. ; disp_error: push cs pop ds assume ds:code cmp file_linecount,0 je disp_error1 ;If processing a file, print push dx ; a message informing the mov dx,offset filemsg1 ; user the line that call printmsg ; contained the error. mov ax,file_linecount call hex2asc mov dx,offset endmsg call printmsg pop dx disp_error1: call printmsgcr ;print string mov al,01 ;Terminate with RC = 1 jmp short exit ;----------------------------------------------------------------------------- ; PARSE Parse a statment. ; Entry: SI - Pointer to string to parse. ; DI - Pointer to end of COM file data. ; Exit: CF - Set if error. ; SI - Updated. ;----------------------------------------------------------------------------- parse proc near mov bx,14 mov al,[si] ;See if label, if so, skip cmp al,":" ; cmd search. je parse_2 mov bx,12 cmp al,"%" ;See if cmd line param or env je parse_2 ; var. If so, internal cmd mov ax,[si+1] ;See if change to default disk cmp al,":" jne parse_1 mov bx, 12 ;Set internal command. cmp ah," " jbe parse_2 parse_1: call capsalpha ;Capitalize batch command push di ;Search list of BAT cmds. mov di,offset command_table call findstr pop di parse_2: push bx ;Scan past command except for cmp bx,8 ; external progs, inter cmds, ja parse_3 ; and labels. mov bl,1 call scan4char jnc parse_3 ;If end of line, back up to dec si ; show CR. parse_3: pop bx shl bx,1 ;Compute offset of routine to add bx,offset batcmd_jmptbl ; call. call [bx] ;Call routine to compile line. ret parse endp ;----------------------------------------------------------------------------- ; FINDSTR determines if a string is in a list. ; Entry: SI - Pointer to ASCII string to find. ; DI - Pointer to list of ASCIIZ strings. ; CX - Size of string ; Exit: CF - Clear if string found ; BX - If CF clear, index into list ;----------------------------------------------------------------------------- findstr proc near push cx push es push cs ;Point ES:DI to table of pop es ; batch commands. xor dx,dx or dx,cx ;Save length of string je finds_3 xor bx,bx ;Zero index counter finds_1: push si mov cx,dx ;Restore command size repe cmpsb ;Compare command pop si je string_found inc bx xor al,al cmp [di-1],al jne finds_2 dec di finds_2: mov cx,10 ;Scan to next zero repne scasb cmp byte ptr [di],0 ;See if second zero. If so jne finds_1 ; end of list. finds_3: mov bx,13 stc ;Indicate string not found findstr_exit: pop es pop cx ret string_found: cmp bx,12 ;If past the BAT commands, jb findstr_3 ; then it is an internal cmd. mov bx,12 findstr_3: clc ;Set string found flag jmp short findstr_exit findstr endp ;----------------------------------------------------------------------------- ; CAPSWORD capitalizes word pointed to by SI ; Entry: SI - Pointer to ASCII word to capitalize ; Exit: CX - Size of word ;----------------------------------------------------------------------------- capsalpha proc near assume ds:nothing,es:nothing push ax xor ax,ax ;Exit on non-alpha chars jmp short capsword_entry2 capsalpha endp ;----------------------------------------------------------------------------- ; CAPSWORD capitalizes word pointed to by SI ; Entry: SI - Pointer to ASCII word to capitalize ; Exit: CX - Size of word ;----------------------------------------------------------------------------- capsword proc near assume ds:nothing,es:nothing push ax mov ah,1 ;Ignore extra characters capsword_entry2: push di push si push es push ds ;Set ES:DI = DS:SI pop es mov di,si xor cx,cx ;Clear byte counter. caps_1: lodsb ;Get character cmp al," " ;Allow any non-space character jbe caps_exit cmp al,"a" ;If between a and z, jb caps_3 ; capitalize it. cmp al,"z" ja caps_exit and al,0DFh caps_2: stosb ;Save character inc cx ;Inc byte counter jmp short caps_1 caps_3: or ah,ah ;See if we should check jne caps_2 ; non-alpha chars. cmp al,'Z' ja caps_exit cmp al,'A' jae caps_2 caps_exit: pop es pop si pop di pop ax ret capsword endp ;----------------------------------------------------------------------------- ; REDIRECT CLOSE post process redirection commands ; Entry: DI - Pointer to end of COM file data. ; Exit: CF - Set if error. ; Batch file line updated to remove any redirection symbols ;----------------------------------------------------------------------------- redirect_close proc near assume cs:code,ds:code cmp redirect_in,0 ;See if redirecton active je redirclose_1 mov redirect_in,0 mov bx,offset redirci_next ;Append close redirect file call include_code ; routine to code. xor cx,cx call inline_code redirclose_1: cmp redirect_out,0 ;See if redirecton active je redirclose_2 mov redirect_out,0 mov bx,offset redirco_next ;Append close redirect file call include_code ; routine to code. xor cx,cx call inline_code redirclose_2: cmp pipein_flag,0 ;See if in pipe curr active je redirclose_3 mov dx,pipein_file ;Get offset of input pipe file mov cx,1 ;Indicate parameter type mov bx,offset redirdel_next ;Delete the piping file call include_code call inline_code mov pipein_flag,0 ;Clear flag redirclose_3: cmp pipeout_flag,0 ;See if out pipe curr active je redirclose_exit mov dx,pipeout_file ;Get offset of input pipe file xor bx,bx ;Add output redirection code xor ax,ax ; to file. call redirect_openi mov pipein_flag,1 ;Set pipe input flag mov pipeout_flag,0 ;Clear pipe output flag mov pipein_file,dx ;Copy pointer to filename redirclose_exit: ret redirect_close endp ;----------------------------------------------------------------------------- ; REDIRECT CHECK process redirection commands ; Entry: SI - Pointer to current BAT file line ; DI - Pointer to end of COM file data. ; Exit: CF - Set if error. ; Batch file line updated to remove any redirection symbols ;----------------------------------------------------------------------------- redirect_check proc near assume cs:code,ds:code push si call redirect_close mov quote_flag,0 redirect_1: mov bp,si ;Save current position lodsb cmp al,'"' ;See if quote jne redirect_2 not quote_flag redirect_2: cmp quote_flag,0 ;Ignore characters in quotes jne redirect_1 ; ; Check for piping ; cmp al,'|' ;Check for piping symbol jne redirect_5 mov byte ptr [si-1],13 ;Replace | with CR mov bx,offset pipe1_file ;Get offset of pipe file to cmp pipe_toggle,0 ; use. Alternate files so jne redirect_3 ; that input and output files mov bx,offset pipe2_file ; don't get mixed up. redirect_3: not pipe_toggle xor dx,dx ;If file not already used, or dx,[bx] ; load the filename into jne redirect_4 ; the COM data buffer. mov dx,di sub dx,databuff_start ;Compute offset of filename mov [bx],dx ;Save pointer to filename lea si,[bx+2] ;Get address of filename mov ah,1 call copy_string ;Copy name to COM data buffer xor al,al ;Terminate filename with zero stosb redirect_4: mov pipeout_file,dx mov pipeout_flag,1 xor bx,bx ;Add output redirection code xor ax,ax ; to file. call redirect_openo jmp short redirect_exit ;Terminate line scan. ; ; Check for output redirection ; redirect_5: cmp al,'>' ;Check for redirect out jne redirect_7 xor bx,bx cmp byte ptr [si],'>' ;Check for append redirect jne redirect_6 lodsb ;Remove 2nd > inc bx redirect_6: push bx ;Save append flag xor bl,bl call scan4char ;Get filename mov dx,di mov ah,1 ;Copy only one word call copy_string xor al,al ;Terminate name with zero stosb sub dx,databuff_start ;Compute offset of filename pop ax call redirect_openo call erase_redirect ;Erase redirect from line. jmp short redirect_1 redirect_7: cmp al,'<' ;Check for redirect in jne redirect_10 xor bl,bl call scan4char ;Get filename mov dx,di mov ah,1 ;Copy only one word call copy_string xor al,al ;Terminate name with zero stosb sub dx,databuff_start ;Compute offset of filename call redirect_openi call erase_redirect ;Erase redirect from line. jmp redirect_1 redirect_10: cmp al,13 je redirect_exit jmp redirect_1 redirect_exit: clc pop si ret redirect_check endp ;----------------------------------------------------------------------------- ; REDIRECT OPENO process redirection commands ; Entry: AX - 1 = append file. ; Entry: DX - Offset from data buffer start of file name ; BX - 0 no translation of filename. ;----------------------------------------------------------------------------- redirect_openo proc near assume cs:code,ds:code push si push ax ;Save append flag mov cx,0031h ;Indicate parameter type or bx,bx ;See if env var or cmd line je redirect_oo1 ; parms. mov bx,offset procstr_next ;Get offset of translate call include_code ; routine. Include if needed. mov bx,offset prse_buff_ptr - offset data_start mov cx,0032h ;Indicate parameter type call inline_code ;Insert translate code. redirect_oo1: mov bx,offset rediroo_next ;Append open redirect file call include_code pop bx ;Restore append flag call inline_code mov redirect_out,1 ;Set redirect active flag pop si ret redirect_openo endp ;----------------------------------------------------------------------------- ; REDIRECT OPENI loads code to open a file for input redirection ; Entry: DX - Offset from data buffer start of file name ; BX - 0 no translation of filename. ;----------------------------------------------------------------------------- redirect_openi proc near assume cs:code,ds:code push si mov cx,1 ;Indicate parameter type or bx,bx ;See if env var or cmd line je redirect_oi1 ; parms. mov bx,offset procstr_next ;Get offset of translate call include_code ; routine. Include if needed. mov bx,offset prse_buff_ptr - offset data_start mov cx,2 ;Indicate parameter type call inline_code ;Insert translate code. redirect_oi1: mov bx,offset rediroi_next ;Append open redirect file call include_code call inline_code mov redirect_in,1 ;Set redirect active flag pop si ret redirect_openi endp ;----------------------------------------------------------------------------- ; ERASE REDIRECT ; Entry: BP - Pointer to redirect character ; SI - Pointer to end of redirect phrase. ;----------------------------------------------------------------------------- erase_redirect proc near assume cs:code,ds:code push di ;Save ptr to data buffer mov al,' ' mov di,bp ;Get start of redirect string dec si erase_1: stosb cmp di,si jb erase_1 pop di ret erase_redirect endp ;----------------------------------------------------------------------------- ; IF CMD compiles an IF command. ; Entry: SI - Pointer to character after the IF command ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- if_cmd proc near assume cs:code,ds:code xor bl,bl ;Find 1st char of next word call scan4char mov cx,si ;Save pointer to test mov dx,di mov bp,0 ;Clear 'NOT' flag ; ;See if NOT prefix is used in test ; lodsw ;Get 1st two chars of test or ax,2020h cmp ax,'on' ;See if 'no' jne if_cmd_chk_cmp lodsw ;Get 2nd and 3rd characters or al,20h ;Convert 3rd char to lower cmp al,'t' ; case. See if last char is jne if_cmd_chk_cmp ; 't' followed by s space cmp ah,' ' ja if_cmd_chk_cmp inc bp xor bl,bl ;Find next word call scan4char mov cx,si ; ;Test for string compare by looking for == signs. ; if_cmd_chk_cmp: mov si,cx ;Restore pointer to condition mov bl,3 ;Find next space or equal sign call scan4char jc if_syntax_jmp xor bl,bl call scan4char ;Find next word cmp word ptr [si],"==" ;See if string compare je if_cmd_cmp1 ;No, check other tests jmp if_cmd_chk_errlev if_cmd_cmp1: inc si ;Move SI past equals signs inc si xor bl,bl ;Find second string call scan4char jnc if_cmd_cmp2 if_syntax_jmp: jmp if_syntax if_cmd_cmp2: push si ;Save pointer to 2nd string mov si,cx ;Restore ptr to 1st string push di ;Save ptr to size byte inc di mov dx,di ;Save ptr to start of string sub dx,databuff_start mov ah,2 ;Copy only one word call copy_string ;Load string into data space xor al,al stosb or bx,bx ;See if translation is needed pop bx ;Restore pointer to size byte mov [bx],cl ;Save length of string mov cl,1 ;Assume LEA parameter call je if_cmd_03 mov bx,offset procstr_next ;Append translate string call include_code ; routine to code. mov bx,offset prs2_buff_ptr - offset data_start mov cx,0021h ;Indicate parameter type call inline_code ;Insert translate code. mov dx,bx ;Copy ptr to buffer. mov cx,2 ;Use MOV parameter type if_cmd_03: pop si ;Restore ptr to 2nd string push dx ;Save pointer to 1st string push cx ;Save parameter type if_cmd_04: push di ;Save ptr to size byte inc di mov dx,di ;Save ptr to start of string sub dx,databuff_start mov ah,2 call copy_string ;Load string into data space xor al,al stosb or bx,bx ;See if translation is needed pop bx mov [bx],cl ;Save length of string mov cx,10h ;Set parameter type je if_cmd_06 mov bx,offset procstr_next ;Append translate string call include_code ; routine to code. mov bx,offset prse_buff_ptr - offset data_start mov cx,0021h ;Indicate parameter type call inline_code ;Insert translate code. mov dx,bx ;Copy ptr to buffer. mov cx,20h ;Use proper parameter type if_cmd_06: mov bx,offset ifequal_next ;Append comparison code call include_code pop bx ;Restore param 1 type and bl,0fh or cl,bl ;Combine parameter types mov bx,dx ;Move parameter 2 pop dx ;Restore parameter 1 call inline_code ;Add call to string compare jmp if_cmd_10 if_syntax: mov dx,offset errmsg6 ;Syntax error. stc jmp if_exit ; ;See if ERRORLEVEL test. ; if_cmd_chk_errlev: mov si,cx ;Restore pointer to 1st string mov bx,cx ;Save pointer to 1st string mov di,offset ifstr1 ;See if ERRORLEVEL test call capsalpha cmp cx,10 jne if_cmd_2 repe cmpsb ;Compare strings jne if_cmd_2 mov bx,offset iferrlev_next ;Save offset of errlev code push bx ; on stack. Use exist code xor bl,bl call scan4char ;Scan to next word. cmp byte ptr [si],'=' jne if_cmd_21 inc si xor bl,bl call scan4char ;Scan to next word. jmp short if_cmd_21 ; to append error code. ; ;See if EXIST test. ; if_cmd_2: mov si,bx ;Restore pointer to 1st string mov di,offset ifstr2 ;See if EXIST test cmp cx,5 ;Check length of string jne if_syntax repe cmpsb ;Compare strings jne if_syntax mov bx,offset ifexist_next ;Save test existance code off push bx xor bl,bl call scan4char ;Scan to next word. if_cmd_21: mov di,dx ;Restore data pointer sub dx,databuff_start mov ah,2 call copy_string xor al,al ;Terminate string with zero. stosb mov cl,21h ;Set parameter type or bx,bx ;See if translation is needed je if_cmd_3 mov bx,offset procstr_next ;Append translate string call include_code ; routine to code. mov bx,offset prse_buff_ptr - offset data_start mov cx,0021h ;Indicate parameter type call inline_code ;Insert translate code. mov dx,bx ;Copy ptr to buffer. mov cl,22h ;Use proper parameter type if_cmd_3: pop bx ;Restore test code offset call include_code mov bx,offset prs2_buff_ptr - offset data_start call inline_code ;Insert exist test call if_cmd_10: mov cx,200h ;Include Jump if carry opcode or bp,bp je if_cmd_12 mov cx,300h ;Change to Jump if not carry if_cmd_12: call inline_code push ax ;Save address of jmp to modify push word ptr codebuff_ptr ;Save current code buff ptr ; ;Compile the remainder of the line as if it were a normal statment. ; xor bl,bl ;Scan for next word call scan4char call parse ;Compile remainder of line. pop cx ;Compute the difference for the pop bx ; jmp opcode. jc if_exit ;If error during parse, exit. push es mov ax,word ptr codebuff_ptr mov es,word ptr codebuff_ptr[2] sub ax,cx mov es:[bx],ax ;Save jmp offset pop es clc if_exit: ret if_cmd endp ;----------------------------------------------------------------------------- ; FOR CMD compiles an FOR command. ; Entry: SI - Pointer to character after the FOR command ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- for_cmd proc near assume cs:code,ds:code cmp for_active_flag,0 je for_cmd_0 mov dx,offset errmsg11 ;No nested FOR loops stc jmp for_exit for_cmd_0: mov goto_active,0 ;Clear goto detect flag inc for_active_flag xor bl,bl ;Find 1st char of next word call scan4char jc jmp_for_syntax mov bp,si ;Save pointer to loop variable mov dx,di sub dx,word ptr databuff_start ; ;Copy the set data to the com file data area. As always, if environment ;variables or command line parameters are in the data, insert a call to ;the translate routine before calling the for loop routine. ; for_cmd_1: lodsb ;Scan until '(' is found cmp al,13 ; indicating the start of the jne for_cmd_2 ; data set. jmp_for_syntax: jmp for_syntax for_cmd_2: cmp al,'(' jne for_cmd_1 mov ah,3 ;Copy until ')' found. call copy_string xor al,al ;Terminate string with zero. stosb mov cx,11h or bx,bx je for_cmd_3 mov bx,offset procstr_next ;Append translate string call include_code ; routine to code. mov bx,offset for_buff_ptr - offset data_start mov cx,0021h ;Indicate parameter type call inline_code ;Insert translate code. mov dx,bx ;Copy ptr to buffer. mov cl,12h ;Use proper parameter type for_cmd_3: push word ptr codebuff_ptr ;Save current code buff ptr mov bx,offset forloop_next call include_code mov bx,di ;Initialize for loop data sub bx,databuff_start ; structure. mov word ptr [di],0 inc di inc di call inline_code ;Insert call to loop code. mov cx,200h ;Include Jump if carry opcode call inline_code push ax ;Save address of jmp to modify push word ptr codebuff_ptr ;Save current code buff ptr ; ;Scan the remainder of the line. Replace all instances of the loop variable ;with a special code that the run time translate routine understands. ; xor bl,bl ;Find DO call scan4char jc for_syntax_1 push si lodsw ;Confirm DO exists and ax,0dfdfh ;Convert to upper case cmp ax,"OD" pop si jne for_syntax_1 mov bl,1 ;Find end of 'DO' call scan4char jc for_syntax_1 xor bl,bl ;Find start of loop command. call scan4char jc for_syntax_1 push si ;Save pointer to command. push di ;Save data buffer pointer. mov di,si mov bl,2 ;Find the end of the line. call scan4char mov dx,si ;Save pointer to end of line for_cmd_4: mov si,bp ;Get ptr to loop variable. mov cx,3 ;Scan the remainder of the repe cmpsb ; line for the loop variable. jne for_cmd_5 ; When found, replace with dec di ; % followed by 7f7fh. This dec di ; flag tells the runtime mov ax,7f7fh ; xlate routine to sub in stosw ; the loop string. for_cmd_5: cmp di,dx ;See if at the end of the line. jb for_cmd_4 pop di ;Restore data buffer ptr pop si ;Restore ptr to command. ; ;Compile the remainder of the line as if it were a normal statment. ; call parse ;Compile remainder of line. pop cx ;Get code ptr after loop code pop bx ;Get addr of JC pop ax ;Get code ptr to loop code jc for_exit1 mov dx,cx ;DX may have had an error msg sub ax,word ptr codebuff_ptr ;Compute displacment from END sub ax,3 ; of JMP opcode. mov cx,400h ;Insert JMP opcode after code call inline_code ; for statments inside FOR mov ax,word ptr codebuff_ptr; loop. sub ax,dx push es mov es,word ptr codebuff_ptr[2] mov es:[bx],ax pop es ; ; If goto parsed during FOR, place jump for goto after FOR loop ; cmp goto_active,0 je for_exit mov dx,goto_data_ptr mov bx,offset gotodly_next ;Append goto delay call include_code ; routine to code. mov cx,1 call inline_code ;Add code to COM file. for_exit: clc for_exit1: mov for_active_flag,0 ;Clear flag ret for_syntax_1: add sp,6 ;Clean off stack for_syntax: mov dx,offset errmsg6 ;Syntax error stc jmp short for_exit1 for_cmd endp ;----------------------------------------------------------------------------- ; GOTO CMD compiles a goto command. ; Entry: SI - Pointer to first character after the command. ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- goto_cmd proc near assume cs:code,ds:code mov goto_active,1 ;Needed for FOR loop mov bp,di ;Save ptr to start of string. xor bl,bl ;Find the first nonspace char. call scan4char mov dx,offset errmsg6 ;Check for Syntax error jc goto_cmd_error cmp byte ptr [si],':' ;See if leading :. If so, jne goto_c0 ; don't include in label. inc si goto_c0: push si xor ax,ax stosw ;Save word in case FOR loop xor ah,ah ; delay goto. call copy_string ;Copy label to COM data. xor al,al ;Terminate label with zero stosb pop si mov dx,offset errmsg8 ;Check to see if label found. or cx,cx ;If not, error. je goto_cmd_error cmp for_active_flag,0 ;If in for loop, force eval jne goto_c1 ; Jmp must occur after FOR or bx,bx ;See if env var or cmd line je goto_c2 ; parms. If not hard code jmp goto_c1: mov bx,offset procstr_next ;Get offset of translate call include_code ; routine. Include if needed. mov dx,bp ;Get pointer to label. sub dx,databuff_start ;Compute offset. mov goto_data_ptr,dx ;Save offset in case FOR loop add dx,2 ;Move past word ptr mov bx,offset prse_buff_ptr - offset data_start mov cx,0021h ;Indicate parameter type call inline_code ;Insert translate code. mov dx,bx mov cx,32h ;Use proper parameter type mov bx,offset goto_next ;Append goto string call include_code ; routine to code. xor bx,bx cmp for_active_flag,0 ;If in FOR loop delay goto. je goto_c11 ; Pass ptr to word to save mov bx,goto_data_ptr ; destination address. goto_c11: call inline_code ;Add code to COM file. jmp goto_cmd_exit ; ;Since label doesn't use env vars or cmd line params, hard code JMP. ; goto_c2: mov di,bp ;Reset data ptr to ignore label call getlabel ;See if label in list. mov ax,bx ;Copy pointer to label pointer add ax,2 ; to code. sub ax,databuff_start ;Compute offset of pointer mov cx,100h ;Insert JMP opcode. call inline_code goto_cmd_exit: mov bl,2 call scan4char ;Scan to the end of the line. clc goto_cmd_exit1: ret goto_cmd_error: stc jmp short goto_cmd_exit1 goto_cmd endp ;----------------------------------------------------------------------------- ; LABEL CMD processes a label found in the bat file. ; Entry: SI - Pointer to first character of the label ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- label_cmd proc near assume cs:code,ds:code inc si ;Move past ':' call getlabel cmp word ptr [bx+2],-1 ;See if list entry initialized jne label_error ; if so error. mov ax,word ptr codebuff_ptr mov [bx+2],ax ;Save code ptr in COM data mov bl,2 call scan4char ;Scan to the end of the line. clc label_exit: ret label_error: mov dx,offset errmsg8 ;Two identical labels stc jmp short label_exit label_cmd endp ;----------------------------------------------------------------------------- ; GETLABEL searches the label list in the data area. If a matching label entry ; is found it is returned, if not a label entry is created. ; Entry: SI - Pointer to first character of the label ; DI - Pointer to end of compiled data. ; Exit: BX - Points to label entry. ; SI,DI updated. ;----------------------------------------------------------------------------- getlabel proc near assume cs:code,ds:code call capsword ;Convert to caps & get length. cmp cx,8 ;Max length of a label 8 jbe getlabel_1 ; characters to be consistant mov cx,8 ; with DOS. getlabel_1: mov bp,di ;Save data ptr mov di,offset firstlabel ;Get ptr to the 1st label mov bx,di cmp word ptr [di],-1 ;See if any labels defined. je getlabel_2 ;No, skip label list search. push cx ;Save label size add bx,[bx] ;Point to first label call lblsrch_code ;Search label list. pop cx mov di,bp ;Create label entry. jnc getlabel_exit getlabel_2: mov di,bp ;Create label entry. mov ax,-1 stosw ;Clear end of list tag stosw ;Indicate unitialized label mov al,cl stosb ;Save length of label rep movsb ;Copy label into data buffer mov ax,bp sub ax,bx ;Compute offset to new label mov [bx],ax ;Load offset in prev. label mov bx,bp ;Get start of label entry getlabel_exit: clc ret getlabel endp ;----------------------------------------------------------------------------- ; EXTERNAL CMD compiles a routine to exexute a program. ; Entry: SI - Pointer to character after the command ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- external_cmd proc near assume cs:code,ds:code mov dx,di ;Save ptr to filename sub dx,databuff_start ;Compute offset. mov ah,1 call copy_string ;Copy filename to COM data. mov temp1,bx ;Save translate flag dec si ;Back up one char xor al,al ;Terminate filename with zero stosb inc di push di ;Save ptr to command line tail xor ah,ah call copy_string ;Copy command line tail. mov ax,000dh ;Append CR and zero stosw pop bp ;Save length of cmd line tail. inc cl ; Adjust for the CR since mov [bp-1],cl ; ProcStr will add CR to the sub bp,databuff_start ; count. Exec prog fixes mov cx,11h ; this at run time. or bx,bx ;See if translation code needed je externalcmd_1 ; ;See if we need translation for command line tail. ; push dx mov dx,bp ;Get pointer to cmd line tail mov bx,offset procstr_next ;Get offset of translate call include_code ; routine. mov bx,offset prse_buff_ptr - offset data_start mov cx,21h ;Indicate parameter type call inline_code ;Insert translate code. mov cx,21h ;Use proper parameter type mov bp,bx pop dx externalcmd_1: ; ;See if we need translation for param. ; mov ax,temp1 ;Get translate flag for cmd or ax,ax ;See if extern cmd needs je externalcmd_2 ; translation. mov bx,offset procstr_next ;Get offset of translate call include_code ; routine. mov bx,offset prs2_buff_ptr - offset data_start push cx mov cx,21h ;Indicate parameter type call inline_code ;Insert translate code. pop cx and cl,0f0h ;Use proper parameter type or cl,02h ; retain the prev param type mov dx,bx ; for cmd line tail. externalcmd_2: mov bx,offset external_next ;Append prog launch code call include_code mov bx,bp ;Get ptr to filename call inline_code ;Add code to COM file. clc ret external_cmd endp ;----------------------------------------------------------------------------- ; INTERNAL CMD compiles a command internal to command.com ; Entry: SI - Pointer to character after the command ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- internal_cmd proc near assume cs:code,ds:code inc di ;Make room for string size. push di ;Save ptr to internal command. push si mov si,offset internal_cmdsw movsw ;Copy /C switch to tell movsb ; COMMAND.COM to execute and pop si ; terminate. xor ah,ah call copy_string ;Copy internal command mov ax,000dh ;Append CR and zero stosw pop bp add cl,3 ;Add length of /c switch mov [bp-1],cl ;Save length of command line mov dx,bp ;Get pointer to internal cmd sub dx,databuff_start ;Compute offset. mov cx,1 or bx,bx ;See if translation code needed je internalcmd_1 mov bx,offset procstr_next ;Get offset of translate call include_code ; routine. mov bx,offset prse_buff_ptr - offset data_start mov cx,0021h ;Indicate parameter type call inline_code ;Insert translate code. mov cx,2 ;Use proper parameter type mov dx,bx ;Get input from str1 buffer internalcmd_1: mov bx,offset intcmd_next ;Append internal cmd routine call include_code ; to code. call inline_code ;Add code to COM file. clc ret internal_cmd endp ;----------------------------------------------------------------------------- ; PATH CMD compiles a path command ; Entry: Same as SET command ;----------------------------------------------------------------------------- path_cmd proc near assume cs:code,ds:code mov bp,2 push si add si,4 ;Move past path cmd xor bx,bx ;Find the first nonspace char. call scan4char ;If no characters, set flag pop si jnc set_entry1 ; to print path string. mov bp,3 jmp short set_entry1 path_cmd endp ;----------------------------------------------------------------------------- ; PROMPT CMD compiles a path command ; Entry: Same as SET command ;----------------------------------------------------------------------------- prompt_cmd proc near assume cs:code,ds:code mov bp,1 jmp short set_entry1 prompt_cmd endp ;----------------------------------------------------------------------------- ; SET CMD compiles a command to change variables in the environment ; Entry: SI - Pointer to character after the command ; DI - Pointer to end of compiled data. ; Exit: CF - Set if error ; DX - Offset to error message if CF set. ; SI,DI updated. ;----------------------------------------------------------------------------- set_cmd proc near assume cs:code,ds:code mov bp,0 ;Assume not PATH or PROMPT set_entry1: push bp xor bx,bx ;Find the first nonspace char. call scan4char mov dx,di ;Save ptr to set command. jc setcmd_0 xor ah,ah call copy_string ;Copy string to COM data setcmd_0: xor al,al ;Append zero stosb sub dx,databuff_start ;Compute offset of data. mov cx,31h or bx,bx ;See if translation code needed je setcmd_1 mov bx,offset procstr_next ;Get offset of translate call include_code ; routine. mov bx,offset prse_buff_ptr - offset data_start mov cx,21h ;Indicate parameter type call inline_code ;Insert translate code. mov cx,32h ;Use proper parameter type mov dx,bx ;Get input from str1 buffer setcmd_1: mov bx,offset setenv_next ;Append set routine to code. call include_code pop bx ;Get PATH/PROMPT flag call inline_code ;Add code to COM file. clc ret set_cmd endp ;----------------------------------------------------------------------------- ; ECHO CMD compiles an ECHO command. ; Entry: SI - Pointer to character after the ECHO command ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- echo_cmd proc near assume cs:code,ds:code mov dx,si ;Save pointer to string start inc dx ;Move pointer past 1st space xor bl,bl ;Echo can either echo a call scan4char ; string to the keyboard or jc echo_c01 ; toggle the echo flag. or al,20h ;Check for on or off keyword cmp al,"o" ; to indicate what type of jne echo_c0 ; Echo this is. mov ax,[si+1] ;Get next two characters or al,20h ;Make lower case mov bl,1 cmp al,"n" ;Check for echo on je echo_c00 or ah,20h ;Make lower case cmp ax,"ff" ;Check for echo off jne echo_c0 dec bl mov ah,[si+3] ;Get character past word echo_c00: cmp ah," " ;Make sure not just the start ja echo_c0 ; of another word. mov bl,2 call scan4char ;Find end of line. jmp short echo_exit ; ;Echo ASCII line, Include code in COM file to echo string. ; echo_c01: mov si,dx ;Restore data pointer cmp byte ptr [si-2],'.' ;See if Echo. jne echo_exit mov dx,di jmp short echo_c1 echo_c0: mov si,dx ;Restore data pointer mov dx,di xor ah,ah call copy_string ;Copy string to COM data. echo_c1: mov ax,0d0ah ;Terminate line with CRLF stosw xor al,al ;Append zero byte stosb mov cx,1 ;Append runtime routines. sub dx,databuff_start or bx,bx ;Check translate flag, if set je echo_c21 ; append translate code 1st. mov bx,offset procstr_next ;Append translate string call include_code ; routine to code. mov bx,offset prse_buff_ptr - offset data_start mov cx,0021h ;Indicate parameter type call inline_code ;Insert translate code. mov dx,bx mov cx,2 ;Use proper parameter type echo_c21: mov bx,offset echo_msg_next ;Append echo string call include_code ; routine to code. echo_c3: call inline_code ;Add code to COM file. echo_cstatus: echo_exit: clc echo_cmd_exit: ret echo_cmd endp ;----------------------------------------------------------------------------- ; PAUSE CMD compiles a PAUSE command. ; Entry: SI - Pointer to character after the PAUSE command ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- pause_cmd proc near assume cs:code,ds:code ;Append routine if necessary mov bx,offset pause_next ;Append PAUSE routine if call include_code ; necessary. mov cx,0 ;Add inline code with 0 params call inline_code ; to call pause routine. mov bl,2 ;Scan to end of line call scan4char clc pause_cmd_exit: ret pause_cmd endp ;----------------------------------------------------------------------------- ; SHIFT CMD compiles a SHIFT command. ; Entry: SI - Pointer to character after the SHIFT command ; DI - Pointer to end of compiled data. ; Exit: AL - Error code if CF set ; CF - Set if error ; SI,DI updated. ;----------------------------------------------------------------------------- shift_cmd proc near assume cs:code,ds:code mov bx,offset shift_next ;Append shift routine if call include_code ; necessary. mov cx,0 ;Add inline code with 0 params call inline_code ; to call pause routine. mov bl,2 ;Scan to end of line call scan4char clc ret shift_cmd endp ;----------------------------------------------------------------------------- ; REM CMD Processes remark lines in batch file. ; Entry: SI - pointer to line in BAT file ;----------------------------------------------------------------------------- rem_cmd proc near assume cs:code,ds:code dec si ;Back up to make sure we don't rem_c1: lodsb ; miss a carrage return. cmp al,1ah ;Loop until end of line or end je rem_exit ; of file. cmp al,13 jne rem_c1 rem_exit: clc ret rem_cmd endp ;----------------------------------------------------------------------------- ; COPY STRING copies a string to the com file data buffer. ; Entry: SI - Pointer to 1st character of the string. ; DI - Pointer to end of compiled data. ; AH - 0 = copy until end of line ; 1 = copy only one word ; 2 = copy only one word, break on / ; 3 = copy until ')' ; Exit: BX - 0 if no environment variables or command line parameters. ; CX - Size of string. ; SI,DI updated. ;----------------------------------------------------------------------------- copy_string proc near assume cs:code,ds:code push dx mov dx,di ;Copy pointer to string xor bx,bx ;Clear param/env flag xor cx,cx ;Clear count copystr_1: lodsb ;Get byte cmp al,13 ;See if carrage return je copystr_exit ;Yes, quit. cmp al,1ah ;See if EOF je copystr_exit copystr_2: cmp ah,3 ;See if set copy jne copystr_3 ;No, skip next test. cmp al,')' ;See if end of set je copystr_exit ;Yes, quit. jmp short copystr_4 copystr_3: or ah,ah ;See if phrase or word copy je copystr_4 ;Phase, skip next test. cmp al,' ' ;See if end of word. jbe copystr_exit ;Yes, quit. cmp al,'=' ;Equal sign indicates end of je copystr_exit ; word. cmp ah,2 je copystr_4 cmp al,'/' ;/ indicates end of word. je copystr_exit copystr_4: inc cx cmp al,'%' ;See if translation needed. jne copystr_6 inc bh or bl,bl ;See if already set. mov bl,0 ;Clear flag jne copystr_6 ;If set, this must be the cmp byte ptr [si],7fh ;Check for For loop var. If jne copystr_5 ; found, copy it removing stosb ; the extra 7f. lodsb inc si jmp short copystr_6 copystr_5: cmp byte ptr [si],'9' ; trailing % of an env var. jbe copystr_6 call capsword ;Env var, capitialize it. inc bl copystr_6: stosb ;Save byte jmp short copystr_1 ;Loop back. copystr_exit: pop dx ret copy_string endp ;----------------------------------------------------------------------------- ; INLINE CODE Adds the necessary inline code to call a canned ; routine. ; Entry: AX - Offset of canned routine. ; CL - (low nibble) Method to pass parameter one ; CL - (high nibble) Method to pass parameter two ; CH - (low nibble) Call/Jump method ; DX - Parameter one ; BX - Parameter two ;----------------------------------------------------------------------------- inline_code proc near push bp push si ;Save pointer to input buffer. push di push es les di,codebuff_ptr ;Point ES:DI to buffer mov bp,cx and cl,0fh ;Look only at SI code nibble cmp cl,1 ;Check for LEA SI jne inline_1 mov si,offset code_leasi mov [si+2],dx ;Load paramter one mov cx,code_leasi_size rep movsb ;Copy routine into COM file. jmp short inline_10 inline_1: cmp cl,2 ;Check for MOV SI jne inline_2 mov si,offset code_movsi mov [si+2],dx ;Load parameter one mov cx,code_movsi_size rep movsb ;Copy routine into COM file. jmp short inline_10 inline_2: cmp cl,3 ;Check for MOV SI Immediate jne inline_10 mov si,offset code_movsiim mov [si+1],dx ;Load parameter one mov cx,code_movsiim_size rep movsb ;Copy routine into COM file. inline_10: mov cx,bp ;Get back code and cl,0f0h cmp cl,10h ;Check for LEA DI jne inline_11 mov si,offset code_leadi mov [si+2],bx ;Load paramter two mov cx,code_leadi_size rep movsb ;Copy routine into COM file. jmp short inline_13 inline_11: cmp cl,20h ;Check for MOV DI jne inline_12 mov si,offset code_movdi mov [si+2],bx ;Load parameter two mov cx,code_movdi_size rep movsb ;Copy routine into COM file. jmp short inline_13 inline_12: cmp cl,30h ;Check for MOV immed DI jne inline_13 mov si,offset code_movdiim mov [si+1],bx ;Load parameter two mov cx,code_movdiim_size rep movsb ;Copy routine into COM file. inline_13: mov cx,bp and ch,0fh jne inline_20 mov si,offset code_call ;Code to call the canned mov cx,code_call_size ; routine. mov [si+1],ax ;Insert the destination offset. rep movsb ;Copy routine into COM file. jmp short inline_30 inline_20: cmp ch,01 ;Check for jmp jne inline_21 mov si,offset code_jmp ;Code to jmp to destination. mov cx,code_jmp_size mov [si+2],ax ;Insert the destination offset. rep movsb ;Copy routine into COM file. jmp short inline_30 inline_21: cmp ch,02 ;Check for jc jne inline_22 mov si,offset code_jc ;Code to jc to destination. mov cx,code_jc_size lea ax,[di+3] ;Save offset of JMP to mod rep movsb ;Copy routine into COM file. jmp short inline_30 inline_22: cmp ch,03 ;Check for jnc jne inline_23 mov si,offset code_jnc ;Code to jnc to destination. mov cx,code_jnc_size lea ax,[di+3] ;Save offset of JMP to mod rep movsb ;Copy routine into COM file. jmp short inline_30 inline_23: cmp ch,04 ;Check for jmp displacment jne inline_30 mov si,offset code_jmpdis ;Code to jmp IP relative. mov [si+1],ax mov cx,code_jmpdis_size rep movsb ;Copy routine into COM file. inline_30: mov word ptr cs:codebuff_ptr,di pop es pop di pop si pop bp ret inline_code endp ;----------------------------------------------------------------------------- ; INCLUDE CODE - Appends the routine to the append list if necessary and ; returns the offset of the routine in the compiled program. ; Entry: BX - Pointer to header of canned routine to append. ; Exit: AX - Offset of canned routine in COM file. ;----------------------------------------------------------------------------- include_code proc near assume ds:code,es:nothing push cx push dx mov ax,[bx-4] ;Get COM file offset or ax,ax ;If zero, routine has not jne include_exit ; been appended. mov cx,bx ;Save pointer to new routine ; ;Address the prevous 'last' routine header. Update that header, then use ;information in that header to compute the offset of the new routine. ; xchg bx,last_routine mov [bx],cx ;Add code to chain. mov ax,[bx-2] ;Compute offset of new routine add ax,[bx-4] ; by adding the offset of the sub ax,[bx+2] ; prevous routine to its size. mov bx,cx mov cx,[bx+2] ;Get number of called routines. add ax,cx mov [bx-4],ax ;Set offset of code. jcxz include_exit shr cx,1 ;If this routine needs other add bx,4 ; routines, include them in push ax ; the COM file. include_1: push cx push bx mov bx,[bx] call include_code pop bx mov [bx],ax add bx,2 pop cx loop include_1 pop ax include_exit: pop dx pop cx ret include_code endp ;----------------------------------------------------------------------------- ; PRINTMSG prints the message pointed to by DX to the screen. ; Entry: DX - pointer to ASCII message terminated by $ ;----------------------------------------------------------------------------- printmsg proc near assume ds:nothing,es:nothing push ds push cs pop ds assume ds:code mov ah,9 ;Print message int 21h pop ds ret printmsg endp ;----------------------------------------------------------------------------- ; PRINTMSGCR calls PRINTMSG, then appends a carriage return to the message. ; Entry: DX - pointer to ASCII message terminated by $ ;----------------------------------------------------------------------------- printmsgcr proc near assume ds:nothing,es:nothing push dx call printmsg mov dx,offset endmsg call printmsg pop dx ret printmsgcr endp ;----------------------------------------------------------------------------- ; HEX2ASC converts a binary number to ASCII and prints it to the screen. ; Entry: AX - binary number ;----------------------------------------------------------------------------- hex2asc proc near assume ds:nothing,es:nothing push bx mov cx,5 ;Allow max of five digits hex_loop1: xor dx,dx ;Clear high word mov bx,10 ;Load number base div bx ;Divide by base (10) add dl,30h ;Convert to ascii push dx ;Save digit on stack loop hex_loop1 mov cx,5 ;Allow max of five digits mov bl,"0" ;Set leading zero indicator hex_loop2: pop dx ;Get digit off stack or bl,dl ;Don't print leading zeros. cmp bl,"0" ;The first non zero will je hex_1 ; change bl to non-zero. mov ah,2 ;DOS character output int 21h hex_1: loop hex_loop2 hex_exit: pop bx ret hex2asc endp ;----------------------------------------------------------------------------- ; LOADBATFILE loads the input BAT file. ; Entry: DS:SI - pointer to the name of the file to open ; Exit: CF - clear if successful ; ; Support for BAT files larger than 16 K is not currently implimented. ;----------------------------------------------------------------------------- loadbatfile proc near assume cs:code,ds:code push di push si mov bx,file_handle cmp bx,-1 jne loadfile_3 mov dx,si ;Save filename pointer mov di,offset outfile_name ;Point DI to buffer to hold mov cx,8 ; the output file name. loadfile_1: lodsb ;Copy the name until the cmp al,' ' ; extension is reached. je loadfile_2 cmp al,'.' je loadfile_2 stosb loop loadfile_1 loadfile_2: mov si,offset com_string ;Append COM extension to movsb ; output file name. movsw movsw mov si,dx ;Get back filename pointer mov bl,1 ;Find end of filename call scan4char dec si mov byte ptr [si],0 ;Make filename ASCIIZ. mov ax,3d00h ;Open file (Read only) int 21h jc loadfile_error mov bx,ax ;Copy file handle ; ;Read contents into file buffer. ; loadfile_3: mov file_handle,-1 ;Assume file completely read. mov ah,3fh ;Read input BAT file into mov dx,inbuff_ptr ; memory above stack space mov cx,inbuff_size ;Get size of buffer sub cx,4 int 21h mov di,dx ;Point DI to end of the file add di,ax cmp ax,cx ;Check if complete file read. jb loadfile_4 std ;If there is more of the file push dx ; to read, scan backwards to mov dx,ax ; the end of the last line. mov cx,ax ;Get file length mov al,13 ;Scan for last CR repne scasb cld ;Reset string flag add di,3 add cx,3 xchg cx,dx ;Compute the number of bytes sub dx,cx ; to back up the file pointer mov cx,0 ; The filepointer is a 32 jz loadfile_31 ; bit number in CX,DX. dec cx loadfile_31: mov ax,4201h ;Move file pointer backwards int 21h mov file_handle,bx pop dx loadfile_4: mov ax,1a1ah stosw ;Append EOF bytes. stosw cmp file_handle,-1 jne loadfile_exit mov ah,3eh ;Close file. int 21h loadfile_exit: clc loadfile_exit1: pop si pop di ret loadfile_error: stc mov dx,offset errmsg2 ;Bad filename specified. jmp short loadfile_exit1 loadbatfile endp ;----------------------------------------------------------------------------- ; SCAN4CHAR scans a string to find the first character. ; Entry: SI - pointer to ASCII string ; BL - 0 = find next char, ; 1 = find next space, ; 2 = find end of line, ; 3 = find next space or =. ; Exit: AL - matching character ; SI - pointer to matching character ; CF - set if carriage return or EOF found ;----------------------------------------------------------------------------- scan4char proc near assume ds:nothing,es:nothing scan4loop: lodsb cmp al,13 ;Check for carriage return. je scan4_eol cmp al,1ah ;Check for end of file char. jne scan4_1 scan4_eol: stc jmp short scan4_exit1 scan4_1: cmp bl,3 je scan4_equal cmp bl,1 ;Check if searching for space, je scan4_space ; character, or end of line. ja scan4loop cmp al," " ;Check for space or other jbe scan4loop ; 'white' characters. jmp short scan4_exit scan4_equal: cmp al,"=" ;Check for exit je scan4_exit scan4_space: cmp al," " ;Check for characters. ja scan4loop scan4_exit: dec si ;Back up before character clc scan4_exit1: ret scan4char endp ;============================================================================ ;Routines used by compiled program. ;============================================================================ ;!!-------------------------------------------------------------------------- ;Code fragments used to call canned routines. ;---------------------------------------------------------------------------- code_call proc near mov ax,1234h ;Set address to call routine. call ax ;Call canned routine. code_call_end = $ code_call endp code_jmp proc near mov ax,[bp+1234h] ;Set address to call routine. jmp ax ;Jump to new offset. code_jmp_end = $ code_jmp endp code_jc proc near jnc code_jc_end ;Jump over long jmp jmp initialize ;This jmp will be modified code_jc_end = $ code_jc endp code_jnc proc near jc code_jnc_end ;Skip over long jmp jmp initialize ;This jmp will be modified code_jnc_end = $ code_jnc endp code_jmpdis proc near jmp initialize ;This jmp will be modified code_jmpdis_end = $ code_jmpdis endp code_leasi proc near lea si,[bp+1234h] ;Load address of data code_leasi_end = $ code_leasi endp code_movsi proc near mov si,[bp+1234h] ;Load data code_movsi_end = $ code_movsi endp code_movsiim proc near mov si,1234h ;Load immediate data code_movsiim_end = $ code_movsiim endp code_leadi proc near lea di,[bp+1234h] ;Load address of data code_leadi_end = $ code_leadi endp code_movdi proc near mov di,[bp+1234h] ;Load data code_movdi_end = $ code_movdi endp code_movdiim proc near mov di,1234h ;Load immediate data code_movdiim_end = $ code_movdiim endp ;---------------------------------------------------------------------------- ;Predefined data needed for all compiled programs. ;---------------------------------------------------------------------------- data_start = $ code_start dw ? ;Offset of main code routine stack_ptr dw ? ;Offset of end of code + stack prog_segsize dw ? ;Size of COM prog in paragraphs prse_buff_ptr dw ? ;Buffer for parsing strings prs2_buff_ptr dw ? ;Buffer for parsing strings exec_buff_ptr dw ? ;Buffer for exec function for_buff_ptr dw ? ;Buffer for For loop variables floop_ptr dw ? ;Pointer to for loop string file_handle1 dw ? ;Saved handle of std output file_handle2 dw ? ;Handle of output file file_handle3 dw ? ;Saved handle of std input file_handle4 dw ? ;Handle of input file label_list_strt dw ? ;Offset into data of 1st label. master_env dw ? ;Segment of environment blk version_num dw ? ;DOS version number proc_rc db ? ;Return code of last program. shift_cnt db ? ;Count of shift parameter data_end = $ ;---------------------------------------------------------------------------- ;INIT CODE Routine at the start of all compiled programs. ;---------------------------------------------------------------------------- init_code_off dw 100h ;Pointer to offset in COM file init_code_size dw offset init_code_end-offset init_code_start init_code_next dw 0 ;Ptr to next routine to append init_code_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called init_code_start = $ init_code proc near assume cs:code,ds:code,es:code,ss:code cld mov bp,ds:[offset data_start_ptr - offset init_code + 100h] mov bp,[bp] mov sp,com_stack_ptr ;Move stack pointer mov bx,com_prog_size ;Reduce memory allocation mov ah,4ah ;Resize memory block int 21h mov ax,ds:[2ch] ;Get program environment seg mov environment_seg,ax ; use unless SET cmd used. mov bx,code_start_ptr ;Get starting code offset jmp bx ;Jump to start of code. data_start_ptr dw ? ;Offset of data area. init_code endp init_code_end = $ ;---------------------------------------------------------------------------- ;END CODE Routine appended at the end of all compiled programs. ;---------------------------------------------------------------------------- end_code_off dw 0 ;Pointer to offset in COM file end_code_size dw offset end_code_end-offset end_code_start end_code_next dw 0 ;Ptr to next routine to append end_code_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called end_code_start = $ end_code proc near assume cs:code,ds:code mov ax,4c00h ;Terminate program int 21h end_code endp end_code_end = $ ;---------------------------------------------------------------------------- ;ECHO MSG CODE Routine used print a string to the standard output device ; Entry: DS:SI - offset of string to print. ;---------------------------------------------------------------------------- echo_msg_off dw 0 ;Pointer to offset in COM file echo_msg_size dw offset echo_msg_end-offset echo_msg_start echo_msg_next dw 0 ;Ptr to next routine to append echo_msg_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called echo_msg_start = $ echo_msg_code proc near assume cs:code,ds:code mov dl,[si] ;Get character inc si or dl,dl je echo_msg_1 mov ah,2 ;Print character int 21h jmp short echo_msg_code echo_msg_1: ret echo_msg_code endp echo_msg_end = $ ;---------------------------------------------------------------------------- ;ECHO STATUS CODE Routine used to report the status of the echo flag. ; Entry: AL - Echo flag. ;---------------------------------------------------------------------------- echo_stat_ptr dw 0 ;Pointer to offset in COM file echo_stat_size dw offset echo_stat_end-offset echo_stat_start echo_stat_next dw 0 ;Ptr to next routine to append echo_stat_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called echo_stat_start = $ echo_stat_code proc near assume cs:code,ds:code call echo_stat_1 ;Push IP on stack echo_msg db "ECHO is $" echo_on db "on",10,13,"$" echo_off db "off",10,13,"$" echo_stat_1: pop dx ;Pop offset of echo message push ax ;Save status of echo flag mov ah,9 int 21h add dx,offset echo_on-offset echo_msg ;Point to 'on' msg pop ax or al,al ;Check status of echo flag je echo_report_1 add dx,offset echo_off-offset echo_on ;Point to 'off' msg add dx,5 ;Point to off message. echo_report_1: mov ah,9 ;Print last part of echo stat int 21h ret echo_stat_code endp echo_stat_end = $ ;---------------------------------------------------------------------------- ;PAUSE CODE Routine used pause execution of the COM file. ;---------------------------------------------------------------------------- pause_ptr dw 0 ;Pointer to offset in COM file pause_size dw offset pause_end-offset pause_start pause_next dw 0 ;Ptr to next routine to append pause_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called pause_start = $ pause_code proc near assume cs:code,ds:code call pause_1 ;Push IP on stack pause_msg db "Strike any key when ready...",13,10,"$" pause_1: pop dx ;Pop offset of message mov ah,9 ;Print message. int 21h mov ah,7 ;Keyboard unfiltered input int 21h ; without echo. ret pause_code endp pause_end = $ ;---------------------------------------------------------------------------- ;SHIFT CODE Routine used shift the input parameters by one. ;---------------------------------------------------------------------------- shift_ptr dw 0 ;Pointer to offset in COM file shift_size dw offset shift_end-offset shift_start shift_next dw 0 ;Ptr to next routine to append shift_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called shift_start = $ shift_code proc near assume cs:code,ds:code inc byte ptr shift_count ;Inc shift count. ret shift_code endp shift_end = $ ;----------------------------------------------------------------------------- ; SCAN_CHAR scans a string to find the first character. ; Entry: SI - pointer to ASCII string ; DL - 0 = find next char, 1 = find next space ; CX - file length ; Exit: AL - first nonspace character ; CF - set if carriage return found ;----------------------------------------------------------------------------- scan4_off dw 0 ;Pointer to offset in COM file scan4_size dw offset scan4_end - offset scan4_start scan4_next dw 0 ;Ptr to next routine to append scan4_lnks dw 0 scan4_start = $ scan_char proc near assume ds:nothing,es:nothing scan_loop: lodsb cmp al,9 ;See if char is tab je scan_space ;If before, end of line cmp al," " ;See if char is space. jb scan_eol ;If before, end of line je scan_space or dl,dl ;Not space, if looking jne scan_loop ; for space continue. jmp short scan_exit scan_space: or dl,dl ;Space found, see if looking je scan_loop ; for one. scan_exit: clc ret scan_eol: stc ret scan_char endp scan4_end = $ ;----------------------------------------------------------------------------- ; GETMEMBER returns a pointer to the Nth word in a line. ; Entry: SI - pointer to line of words ; DH - number of the word to return ; Exit: SI - pointer to word ; CF - Set if word not in line. ;----------------------------------------------------------------------------- getmember_scan4 equ [bx-6] getmember_off dw 0 ;Pointer to offset in COM file getmember_size dw offset getmember_end - offset getmember_start getmember_next dw 0 ;Ptr to next routine to append getmember_lnks dw 2 ;Bytes in the dependancy header getmember_start = $ dw offset scan4_next ;Offset of called routine. getmember proc near assume cs:code,ds:code,es:code,ss:code push bx call getmember_0 getmember_0: pop bx getmember_1: xor dl,dl call getmember_scan4 ;Find next word jc getmember_notfound dec dh ;Dec parameter count jle getmember_2 inc dl call getmember_scan4 ;Find next space jc getmember_exit jmp short getmember_1 ;If not done, loop back. getmember_2: dec si ;Backup to 1st char in word. clc getmember_exit: pop bx ret getmember_notfound: stc jmp short getmember_exit getmember endp getmember_end = $ ;----------------------------------------------------------------------------- ; PROCSTRING processes a string to convert any environment variables or ; command line variables. ; Entry: DS:SI - ASCIIZ string to process ; ES:DI - pointer to output buffer. ; Exit: DS:SI - pointer to beginning of new ASCIIZ string. ; [SI-1] - Length of new string. ;----------------------------------------------------------------------------- procstr_cmdl equ [bx-8] procstr_env equ [bx-6] procstr_off dw 0 ;Pointer to offset in COM file procstr_size dw offset procstr_end - offset procstr_start procstr_next dw 0 ;Ptr to next routine to append procstr_lnks dw 4 ;Bytes in the dependancy header procstr_start = $ dw offset subparm_next ;Offset of called routines. dw offset subenv_next procstr_code proc near assume cs:code,ds:code,es:code push bx call procstr_0 procstr_0: pop bx push di push si mov ah,BUFF_SIZE ;Set size of buffer procstr_1: lodsb ;Get byte from string or al,al ;Check for end of string je procstr_exit cmp al,"%" ;See if special character procstr_jmp: je procstr_3 ;Yes, process special char. procstr_2: stosb ;Store byte from string dec ah jne procstr_1 procstr_exit: xor al,al ;Force zero byte end. stosb pop si pop di mov bl,BUFF_SIZE sub bl,ah mov ds:[di-1],bl ;Store length of string pop bx ret ; ;A percent sign has been found indicating a 'soft' parameter. Three types of ;soft parameters are allowed; command line parameter, environment variable, ;and for loop parameter. ; procstr_3: lodsb ;Get next character dec cx cmp al,"%" ;If double %, include one je procstr_2 ; in string. cmp al,7fh ;See if for loop var jne procstr_32 push si mov si,forloop_ptr ;Get ptr to for loop string procstr_30: lodsb cmp al,0 ;If zero, end of string je procstr_31 stosb dec ah ;Dec buffer size counter jne procstr_30 ;If buffer not full, continue procstr_31: pop si ;Get back source string pointer jmp short procstr_4 procstr_32: mov dh,al ;Copy and check to see if sub dh,"0" ; the next char is a number. jb procstr_5 ; If so, assume a line cmp dh,9 ; parameter. ja procstr_5 call procstr_cmdl ;Call cmd line param routine procstr_4: or ah,ah jne procstr_1 jmp short procstr_exit ;If at end of string, done procstr_5: dec si ;Backup to 1st character inc cx call procstr_env jmp short procstr_4 procstr_code endp procstr_end = $ ;----------------------------------------------------------------------------- ; SUBLINEPARAM substitutes a parameter from the command line. ; Entry: ES:DI - pointer to buffer to copy the line parameter ; DH - binary number of the line parameter ; AH - size of buffer ; Exit: ES:DI - pointer to byte after the parameter in the buffer ; CX - remaining length of the buffer ;----------------------------------------------------------------------------- subparm_getmem equ [bx-6] subparm_off dw 0 ;Pointer to offset in COM file subparm_size dw offset subparm_end - offset subparm_start subparm_next dw 0 ;Ptr to next routine to append subparm_lnks dw 2 ;Bytes in the dependancy header subparm_start = $ dw offset getmember_next ;Offset of called routine. sublineparam proc near assume cs:code,ds:code,es:code,ss:code push bx call sublineparam_1 db "DOS2X",0 ;Dummy %0 parameter for DOS 2x sublineparam_1: pop bx push cx push si push ds mov si,80h ;Get ptr to cmd line xor cx,cx mov cl,[si] ;Get number of chars in buffer. inc si ;Point to data add dh,ds:shift_count ;Add in shift count. or dh,dh ;Check count of param to find. jnz sublineparam_12 ; ;For parameter 0, attempt to look in the env block for the name of the prog. ; push ax ;Save buffer size in AH mov ah,30h ;Get DOS version int 21h ;If DOS 2.x, program nane not cmp al,2 ; in the env segment. Use pop ax ja sublineparam_10 ; dunny name instead. lea si,[bx] ;Point to dummy parameter jmp short sublineparam_2 sublineparam_10: push es push di mov es,ds:[2ch] ;Get segment of local env xor al,al xor di,di mov cx,8000h sublineparam_11: repne scasb ;Find double zero scasb jne sublineparam_11 scasw ;Scan to name mov si,di ;Copy pointer to name pop di pop es mov ds,ds:[2ch] jmp short sublineparam_2 sublineparam_12: call subparm_getmem ;Get pointer to proper word. jc sublineparam_exit sublineparam_2: lodsb ;Get character from parameter cmp al," " ;If space, parameter done jbe sublineparam_exit stosb dec ah ;Dec buffer size counter jnz sublineparam_2 sublineparam_exit: pop ds pop si pop cx pop bx ret sublineparam endp subparm_end = $ ;----------------------------------------------------------------------------- ; SUBENVVAR substitutes a parameter from the program environment block. ; Entry: DS:SI - pointer to enviroment variable. ; ES:DI - pointer to buffer. ; AH - size of buffer. ; Exit: ES:DI - pointer to byte after the parameter in the buffer ; DS:SI - pointer to the character after the line parameter number ; CX - remaining free bytes in the buffer. ;----------------------------------------------------------------------------- subenv_srchenv equ [bx-6] subenv_off dw 0 ;Pointer to offset in COM file subenv_size dw offset subenv_end-offset subenv_start subenv_next dw 0 ;Ptr to next routine to append subenv_lnks dw 2 ;Bytes in the dependancy header subenv_start = $ dw offset searchenv_next ;Call to search environment blk subenvvar proc near assume cs:code,ds:code,es:code,ss:code push bx call subenvvar_0 subenvvar_0: pop bx push ds ; ;Compute the length of the variable name. ; mov cx,255 push di ;Save pointer to internal buff mov di,si ;Compute the length of the mov dx,cx ; environment variable by mov al,"%" ; searching for the trailing repne scasb ; % sign. sub dx,cx ;Compute length of variable. dec dx ;Subtract % byte from length. mov cx,di pop di push cx ;Save ptr to end of var call subenv_srchenv ;Search environment block. jc short subenvvar_exit ;CF set, variable not found. ; ;Environment variable found. Substitute into string. ; subenvvar_1: lodsb ;Get env var character or al,al ;Check for end of string je subenvvar_exit stosb ;Save character in string dec ah ;Dec buffer size count. jne subenvvar_1 ;If buffer not full, continue subenvvar_exit: pop si ;Restore string pointer pop ds ;Restore segment register pop bx ret subenvvar endp subenv_end = $ ;----------------------------------------------------------------------------- ; SEARCH_ENV scans the environment block for a string. ; Entry: DS:SI - pointer to ASCII string ; DX - length of string ; Exit: DS:SI - points to first character of environment string ; CF - clear if string found ;----------------------------------------------------------------------------- searchenv_off dw 0 ;Pointer to offset in COM file searchenv_size dw offset searchenv_end - offset searchenv_start searchenv_next dw 0 ;Ptr to next routine to append searchenv_lnks dw 0 searchenv_start = $ search_env proc near assume ds:nothing,es:nothing push bx push cx push di push es mov es,environment_seg ;Get seg of environment blk xor di,di ;Point ES:DI to environment. mov bx,si ;Save pointer to var name search_env_1: mov si,bx ;Get back ptr to var name. mov cx,dx ;Compare env var to var in repe cmpsb ; string. je search_env_2 ;Variable found, exit loop xor al,al ;Find next environment var. mov cx,-1 ;Scan the entire segment. repne scasb cmp byte ptr es:[di],0 ;If double zero, end of env jne search_env_1 ; block. else, loop back. search_env_not_found: mov si,di ;Point SI to end of env data push es pop ds stc jmp short search_env_exit search_env_2: ; ;Environment variable found. Point DS:SI to the string. ; mov si,di push es ;DS:SI points to env string pop ds search_env_3: lodsb ;Move environment pointer past cmp al,"=" ; the equals sign. jne search_env_3 cmp byte ptr [si],0 je search_env_not_found search_env_4: lodsb ;Move pointer to first or al,al ; non-space character. jb search_env_5 cmp al," " jb search_env_4 search_env_5: dec si clc search_env_exit: pop es pop di pop cx pop bx ret search_env endp searchenv_end = $ ;---------------------------------------------------------------------------- ;EXTERNAL CMD Routine used to launch programs from the COM file. ; Entry DS:SI - Pointer to the ASCIIZ program name ; ES:DI - Pointer to the ASCIIZ command line tail ;---------------------------------------------------------------------------- extern_intcmd equ [bx-14] extern_echomsg equ [bx-12] extern_parspath equ [bx-10] extern_launch equ [bx-8] extern_ifexits equ [bx-6] extern_pathcnt equ [bx] extern_path_var equ [bx+1] extern_file_ext equ [bx+6] extern_filename equ [bx+15] extern_filetail equ [bx+17] extern_lostmsg equ [bx+19] extern_cmdparm equ [bx+46] extern_pathflag equ [bx+49] external_ptr dw 0 ;Pointer to offset in COM file external_size dw offset external_end - offset external_start external_next dw 0 ;Ptr to next routine to append external_lnks dw 10 ;Bytes in the dependancy header ;Number of routines called external_start = $ dw intcmd_next ;Call to launch COMMAND.COM dw echo_msg_next ;Call to display string dw parsepath_next ;Call to get part of path dw launch_next ;Call execute file dw ifexist_next ;Call to find file external_code proc near assume cs:code,ds:code push bx call external_0 db 0 ;Cnt to track path search. db "PATH=" db "COMEXEBAT" dw 0 ;Pointer to filename dw 0 ;Pointer to command line tail db "Bad command or file name",13,10,0 db "/C " db 0 ;Flag for path search external_0: pop bx ;Get pointer to local vars. mov extern_filename,si ;Save ptr to file name mov extern_filetail,di ;Save ptr to command line tail mov dx,exec_buff ;Get pointer to free buffer. add dx,4 ;Make room for /C if needed. mov byte ptr extern_pathflag,0 mov byte ptr extern_pathcnt,0 ;Parse path to generate filename. external_1: mov di,dx ;Get ptr to start of buffer xor cx,cx ;Check to see if we need to or cl,extern_pathcnt ; check the directorys in jne external_19 ; the path. ;The first time through, parse the name without using the path. push dx push si xor dx,dx ;Assume default drive cmp byte ptr [si+1],':' ;See if drive specified jne external_11 mov dl,[si] and dl,0dfh ;Set to upper case sub dl,'@' ;Convert ASCII to number movsw ;Copy drive letter add word ptr extern_filename,2 ;Don't use drive in path external_11: cmp byte ptr [si],'\' ;See if starting at root. je external_110 mov al,'\' ;Start at root dir stosb push si mov si,di ;Get pointer to buffer. mov ah,47h ;Get current directory int 21h pop si xor al,al mov cx,64 repne scasb ;Find end of directory string dec di cmp byte ptr [di-1],'\' ;Unless at root dir, add je external_110 mov al,'\' stosb external_110: xor ax,ax external_12: lodsb ;Get a byte cmp ax,2e2eh ;See if we need to back up jne external_13 ; one directory. std mov al,'\' ;Scan backwards to erase mov cx,18 ; last directory. repne scasb repne scasb cld inc di jmp short external_12 external_13: stosb mov ah,al ;Copy last character. cmp al,'\' ;See if name specifies a path jne external_14 inc byte ptr extern_pathflag external_14: cmp al,0 jne external_12 external_15: dec di ;Since DOS does not let the mov dx,di ; user specify the file ext. std ; scan back to make sure one mov cx,5 ; is not attached. mov al,'.' repne scasb cld jne external_16 inc di mov dx,di external_16: mov di,dx pop si pop dx jmp short external_4 ;Parse the path string to search remaining directorys. external_19: cmp byte ptr extern_pathflag,0 ;If a complete path was jne external_badcmd ; specified, don't search mov si,extern_filename ; the path. call extern_parspath jnc external_2 ;If we have checked all external_badcmd: lea si,extern_lostmsg ; directories in the path, call extern_echomsg ; display file not found msg. jmp short external_exit ;Append filename to the end of the path. external_2: mov cx,73 ;Max length of filename external_3: lodsb cmp al,' ' ;See if end of word jbe external_4 cmp al,'.' ;See if end of filename je external_4 stosb loop external_3 external_4: mov al,'.' ;Append '.' to filename stosb lea si,extern_file_ext ;Get pointer to extensions mov cx,3 ;3 extension types COM EXE BAT external_5: movsw ;Append extension to filename movsb xor al,al ;Termainate with zero stosb push dx push si push cx mov si,dx ;Get ptr to start of name call extern_ifexits ;Search for file pop cx pop si pop dx jnc external_6 sub di,4 ;Backup to file extension loop external_5 inc byte ptr extern_pathcnt ;Look in the next path str jmp external_1 external_6: cmp cx,1 ;See if BAT extension jne external_8 lea si,extern_cmdparm ;Get pointer to /C sub dx,3 mov di,dx ;Get ptr to string buffer movsw ;Copy /C param movsb xor al,al mov cx,252 repne scasb ;Find end of filename mov byte ptr [di-1],' ' ;Fill in zero with space mov si,extern_filetail ;Get ptr to command line tail cmp [si-1],cl ja external_7 mov cl,[si-1] ;Get length of cmd line tail external_7: rep movsb mov byte ptr [di],13 ;Append CR to cmd line. mov si,dx ;Get pointer to BAT filename mov ax,di ;Compute length of cmd line. sub ax,dx mov [si-1],al call extern_intcmd ;Launch COMMAND.COM jmp short external_exit external_8: mov di,extern_filetail ;Get ptr to command line tail dec di ;Back up to buffer length dec byte ptr [di] ;Sub CR from length push di mov si,dx ;Get ptr to start of name call extern_launch ;Execute program pop di inc byte ptr [di] ;Restore cmd line length external_exit: pop bx ret external_code endp external_end = $ ;----------------------------------------------------------------------------- ; PARSEPATH Parses the PATH and returns a qualified directory from the path. ; Entry: ES:DI - pointer to destination buffer. ; CX - index into the path variable. (zero based.) ; Exit: ES:DI - pointer to ASCIIZ destination filename. ; CF - Set if past end of the path ;----------------------------------------------------------------------------- parsepath_srenv equ [bx-6] parsepath_off dw 0 ;Pointer to offset in COM file parsepath_size dw offset parsepath_end - offset parsepath_start parsepath_next dw 0 ;Ptr to next routine to append parsepath_lnks dw 2 parsepath_start = $ dw offset searchenv_next ;Call to search env block parsepath proc near assume cs:code,ds:code,es:code,ss:code push bx call parsepath_1 db "PATH" parsepath_1: pop bx push dx push si push ds mov dx,4 ;Length of PATH string mov si,bx ;Point SI to PATH string call getcom_srchenv ;PATH var ptr return in DS:SI parsepath_2: dec cx ;Dec path segment count jcxz parsepath_4 parsepath_3: lodsb ;Get character or al,al ;See if end of path string je parsepath_notfound cmp al,';' ;See if end of path segment jne parsepath_3 jmp short parsepath_2 parsepath_4: lodsb cmp al,';' ;See if end of path segment je parsepath_5 or al,al ;See if end of path je parsepath_5 stosb jmp short parsepath_4 parsepath_5: push cs pop ds cmp byte ptr es:[di-1],'\' ;Append \ if necessary. je parsepath_6 mov al,'\' stosb parsepath_6: clc parsepath_exit: pop ds pop si pop dx pop bx ret parsepath_notfound: stc jmp short parsepath_exit parsepath endp parsepath_end = $ ;----------------------------------------------------------------------------- ; INTCMD Launches the shell ,usually COMMAND.COM, to run an internal command. ; Entry DS:SI - pointer to the ASCIIZ internal command to run. ;----------------------------------------------------------------------------- intcmd_launch equ [bx-8] intcmd_getcom equ [bx-6] intcmd_off dw 0 ;Pointer to offset in COM file intcmd_size dw offset intcmd_end - offset intcmd_start intcmd_next dw 0 ;Ptr to next routine to append intcmd_lnks dw 4 intcmd_start = $ dw offset launch_next ;Call to load and run program. dw offset getcom_next ;Call to find shell name. intcommand proc near assume cs:code,ds:code,es:code,ss:code push bx call intcmd_1 intcmd_1: pop bx ;Get pointer to sub calls. mov di,si ;Copy ptr to command dec di ;Back up to cmd line size. mov al,process_rc ;Get and save return code push ds push ax call intcmd_getcom ;Get comspec string. call cs:intcmd_launch ;Run program. pop ax pop ds mov process_rc,al ;Restore return code pop bx ret intcommand endp intcmd_end = $ ;----------------------------------------------------------------------------- ; GETCOMSPEC Gets the name of the shell program running ; Exit: DS:SI - pointer to the ASCIIZ name of the shell porgram. ;----------------------------------------------------------------------------- getcom_srchenv equ [bx-6] getcom_off dw 0 ;Pointer to offset in COM file getcom_size dw offset getcom_end - offset getcom_start getcom_next dw 0 ;Ptr to next routine to append getcom_lnks dw 2 getcom_start = $ dw offset searchenv_next ;Call to search environment blk getcomspec proc near assume cs:code,ds:code,es:code,ss:code push bx call getcom_1 getcom_str db "COMSPEC" getcom_1: pop bx mov dx,offset getcom_1 - offset getcom_str mov si,bx call getcom_srchenv ;Get pointer to comspec string pop bx ret getcomspec endp getcom_end = $ ;---------------------------------------------------------------------------- ;LAUNCH PROG Routine used to load and run programs. ; Entry DS:SI - pointer to the program name to run. ; ES:DI - pointer to the command line tail. ; Exit return code variable set. ;---------------------------------------------------------------------------- launch_fcb1 equ [bx] launch_fcb2 equ [bx+16] launch_ptr dw 0 ;Pointer to offset in COM file launch_size dw offset launch_end - offset launch_start launch_next dw 0 ;Ptr to next routine to append launch_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called launch_start = $ launch_code proc near assume cs:code,ss:code push bx call launch_1 ;Push IP on stack db 0 ;Dummy FCB for program db "DUMMY FCB" db 0,0,0,0 db 0 ;Dummy FCB for program db "DUMMY FCB" db 0,0,0,0 launch_1: pop bx ;Get pointer to local vars. push ds push es ;Save stack ptr since it is not mov com_stack_ptr,sp ; saved under DOS 2.x. ;Parse first two parameters into FCBs. push di ;Save ptr to tail push si ;Save ptr to name mov si,di ;Copy ptr to cmd line inc si ;Skip size byte lea di,launch_fcb1 mov ax,2903h ;Parse FCB int 21h lea di,launch_fcb2 mov ax,2903h int 21h pop si pop di push cs ;Create Parameter block on lea dx,launch_fcb2 ; the stack. Start with 2nd push dx ; FCB. push cs lea dx,launch_fcb1 push dx push cs ;Push ptr to command line tail. push di mov ax,cs:[environment_seg] ;Use env block set by prog. push ax mov bx,sp ;Copy pointer to parameter blk mov ax,4b00h ;DOS EXEC program. mov dx,si ;Get pointer to filename int 21h mov bp,offset data_start_ptr - offset init_code + 100h mov bp,cs:[bp] mov bx,cs ;Reload BP to access local data cli mov ss,bx ;Restore stack mov sp,com_stack_ptr sti cld ;Restore default direction pop es pop ds ;Get return code mov ah,4dh ;Get return code int 21h mov process_rc,al ;Save pop bx ret launch_code endp launch_end = $ ;---------------------------------------------------------------------------- ;GOTO Routine to jump to a label pointed to by a cmd line parameter or ; environment variable. ; Entry DS:SI - pointer to label to find. ; DI - Wait flag/ptr. If <> 0, put goto address at pointer. ; Exit This routine does not return unless the label is not found. ;---------------------------------------------------------------------------- goto_echomsg equ [bx-7] goto_lblsrch equ [bx-5] goto_ptr dw 0 ;Pointer to offset in COM file goto_size dw offset goto_end - offset goto_start goto_next dw 0 ;Ptr to next routine to append goto_lnks dw 4 ;Bytes in the dependancy header ;Number of routines called goto_start = $ dw echo_msg_next ;Used to print error msg dw lblsrch_next ;Used to find label goto_code proc near assume cs:code,ds:code call goto_1 db 8 dup (" ") db " Label not found",13,10,0 goto_1: pop bx push di ;Save wait flag/pointer mov di,bx ;Load label into error msg xor dx,dx ;Get size of label as it is mov cx,8 ; copied into error msg. goto_2: lodsb cmp al," " jbe goto_4 cmp al,'a' jb goto_3 and al,0dfh ;Capitalize label cmp al,'Z' ja goto_4 goto_3: stosb inc dx loop goto_2 goto_4: mov cx,dx ;Get size of label mov si,bx ;Get pointer to label mov di,com_label_start ;Get ptr to start of label list add di,bp ;Add offset of data push bx ;Save ptr to msg call goto_lblsrch ;Call search routine pop dx ;Restore ptr to message pop si ;Restore Wait flag/pointer jc goto_5 ;CF set, label not found. mov ax,[bx+2] ;Get destination ptr or si,si ;See if delay flag <> 0 je goto_41 ;If 0, no delay mov [bp+si],ax ;Save ret addr at pointer ret goto_41: pop ax ;Remove return address push [bx+2] ;Push new return address goto_exit: ret goto_5: mov bx,dx ;Set addressability to call call goto_echomsg ;Print error message. ret goto_code endp goto_end = $ ;---------------------------------------------------------------------------- ;GOTO DLY Routine used if goto statment is inside a FOR loop. Since a for ; loop cannot be exited before it ends, this routine checks to see if ; the GOTO statment was ever executed. If so, we now can jump. ; Entry DS:SI - pointer to destination pointer. 0 = no jump. ; Exit This routine does not return unless the ptr = 0 ;---------------------------------------------------------------------------- gotodly_ptr dw 0 ;Pointer to offset in COM file gotodly_size dw offset gotodly_end - offset gotodly_start gotodly_next dw 0 ;Ptr to next routine to append gotodly_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called gotodly_start = $ gotodly_code proc near assume cs:code,ds:code xor ax,ax ;Get pointer, test if zero. or ax,[si] ;If zero, return. If not je gotodly_exit ; push the new destination pop bx ; on the stack and return. push ax gotodly_exit: ret gotodly_code endp gotodly_end = $ ;---------------------------------------------------------------------------- ;LABEL SEARCH Routine to search list of labels to determine goto destination. ; Entry ES:DI - pointer to the first entry in the list. (Assume ES = DS) ; DS:SI - pointer to label to find. ; CX - Length of label ; Exit BX - pointer to matching list entry, or last entry if not found. ; CF - Set if label not found. ;---------------------------------------------------------------------------- lblsrch_ptr dw 0 ;Pointer to offset in COM file lblsrch_size dw offset lblsrch_end - offset lblsrch_start lblsrch_next dw 0 ;Ptr to next routine to append lblsrch_lnks dw 0 ;Bytes in the dependancy header ;Number of routines called lblsrch_start = $ lblsrch_code proc near assume cs:code,ds:code push si mov dx,si ;Save ptr to label mov ax,cx ;Save label length mov bx,di ;Get ptr to list lblsrch_1: mov di,bx add di,4 ;Move to label string mov si,dx ;Get ptr to new label mov cx,ax ;Get length of label cmp [di],cl ;Compare lengths of the labels jne lblsrch_2 inc di ;Skip past length byte repe cmpsb ;Compare labels. je lblsrch_4 lblsrch_2: cmp word ptr [bx],-1 ;See if at end of list je lblsrch_3 add bx,[bx] ;Point to next label jmp short lblsrch_1 lblsrch_3: stc ;No label found. jmp short lblsrch_exit lblsrch_4: clc ;Label found lblsrch_exit: pop si ret lblsrch_code endp lblsrch_end = $ ;----------------------------------------------------------------------------- ; IFEQUAL Compares two strings. ; Entry: DS:SI - Pointer to first ASCIIZ String ; ES:DI - Pointer to second ASCIIZ String ; CX - Length of strings. ; Exit: CF - Clear if equal ;----------------------------------------------------------------------------- ifequal_off dw 0 ;Pointer to offset in COM file ifequal_size dw offset ifequal_end - offset ifequal_start ifequal_next dw 0 ;Ptr to next routine to append ifequal_lnks dw 0 ifequal_start = $ ifequal proc near assume cs:code,ds:code,es:code,ss:code xor cx,cx mov cl,[si-1] ;Get size of string cmp cl,[di-1] ;Compare sizes of strings jne ifequal_notequal rep cmpsb ;Compare strings jne ifequal_notequal clc ret ifequal_notequal: stc ret ifequal endp ifequal_end = $ ;----------------------------------------------------------------------------- ; IFEXIST Determines if a file exists. ; Entry: DS:SI - Pointer to ASCIIZ filename. ; DI - Pointer to buffer for disk transfer area. ; Exit: CF - Clear if file exists ; DI - IF file exists, points to filename. ;----------------------------------------------------------------------------- ifexist_off dw 0 ;Pointer to offset in COM file ifexist_size dw offset ifexist_end - offset ifexist_start ifexist_next dw 0 ;Ptr to next routine to append ifexist_lnks dw 0 ifexist_start = $ ifexist proc near assume cs:code,ds:code,es:code,ss:code mov dx,di mov ah,1ah ;Set DTA int 21h mov dx,si ;Copy pointer to filename xor cx,cx ;Normal attributes mov ah,4eh ;DOS Find First int 21h jc ifexist_exit add di,1eh ;Point DI to filename in DTA clc ifexist_exit: ret ifexist endp ifexist_end = $ ;----------------------------------------------------------------------------- ; IFERRLEV Compares the value passed with the return code of the last ; program executed. ; Entry: SI - Pointer to ASCIIZ Error level. ; Exit: CF - Clear if process error level above or equal to SI ;----------------------------------------------------------------------------- iferrlev_off dw 0 ;Pointer to offset in COM file iferrlev_size dw offset iferrlev_end - offset iferrlev_start iferrlev_next dw 0 ;Ptr to next routine to append iferrlev_lnks dw 0 iferrlev_start = $ iferrlev proc near assume cs:code,ds:code,es:code,ss:code xor ax,ax ;Convert ASCIIZ number into mov bx,ax ; decimal iferrlev_1: mov bl,[si] ;Convert error level number sub bl,'0' ; from ASCII to decimal. jb iferrlev_2 cmp bl,9 ja iferrlev_2 mov dx,10 mul dx jc iferrlev_2 add ax,bx ;Add in digit inc si jmp short iferrlev_1 iferrlev_2: cmp process_rc,al ;Compare to last program ret iferrlev endp iferrlev_end = $ ;----------------------------------------------------------------------------- ; FORLOOP Processes commands in a FOR loop. ; Entry: SI - Pointer to ASCIIZ set of parameters. ; DI - Pointer loop structure in data area ; LoopCnt db 0 Member of the set to use ; FirstFlag db 0 Indicates Find first/next ; Exit: CF - Set if FOR loop complete. ;----------------------------------------------------------------------------- forloop_getmem equ [bx-6] forloop_savchr equ [bx] forloop_eptr equ [bx+1] forloop_dta equ [bx+3] forloop_off dw 0 ;Pointer to offset in COM file forloop_size dw offset forloop_end - offset forloop_start forloop_next dw 0 ;Ptr to next routine to append forloop_lnks dw 2 forloop_start = $ dw getmember_next forloop proc near assume cs:code,ds:code,es:code,ss:code push bx call forloop_0 db 0 ;Saved termaination character dw 0 ;Ptr to term character address db 43 dup (0) ;Used for DTA forloop_0: pop bx push si mov si,forloop_eptr or si,si je forloop_01 mov al,forloop_savchr mov byte ptr [si-1],al ;Remove zero terminator forloop_01: pop si ; ;Set DTA. If 2nd time or later time looping on a member, use find next to ;determine the string for this time through the loop. ; lea dx,forloop_dta mov ah,1ah ;Set DTA int 21h cmp byte ptr [di+1],0 ;See if first time for member je forloop_1 mov ah,4fh ;Find next file int 21h jc forloop_1 ;Not found, go to next member lea dx,[bx+21h] ;Point to filename in DTA jmp short forloop_notdone ;Execute loop body ; ;First time with this member of the set, if wildcards are in the member, ;use DOS find first to get the loop string. ; forloop_1: mov byte ptr [di+1],0 ;Clear first/next flag inc byte ptr [di] ;Look at next member of the set mov dh,[di] ;Get loop count call forloop_getmem ;Get member of set. If no jc forloop_done ; more members, loop done. mov dx,si ;Save pointer to member xor ah,ah ;Clear wildcard flag forloop_2: lodsb ;Scan set member to check for cmp al,' ' ; any wildcard chars. jbe forloop_4 cmp al,'?' jne forloop_3 inc ah ;Set wildcard found flag forloop_3: cmp al,'*' jne forloop_2 inc ah ;Set wildcard found flag jmp short forloop_2 forloop_4: xor al,al xchg byte ptr [si-1],al ;Set zero terminator. mov forloop_savchr,al ;Save char over written or ah,ah ;If no wildcards, execute je forloop_notdone ;Execute loop body mov byte ptr [di+1],1 ;Set first/next flag xor cx,cx ;Normal attributes mov ah,4eh ;DOS find first int 21h jc forloop_1 ;If not found, get next member lea dx,[bx+1eh] ;Set ptr to filename in DTA forloop_notdone: mov forloop_ptr,dx ;Set loop data ptr mov forloop_eptr,si clc forloop_exit: pop bx ret forloop_done: mov word ptr [di],0 ;Clear loop variables mov word ptr forloop_eptr,0 stc jmp short forloop_exit forloop endp forloop_end = $ ;----------------------------------------------------------------------------- ; FINDENV Finds the master environment block. ; Exit: Variable Environment_seg set with segment of master environment. ;----------------------------------------------------------------------------- findenv_dosver equ [bx+7] findenv_cmdname equ [bx] findenv_off dw 0 ;Pointer to offset in COM file findenv_size dw offset findenv_end - offset findenv_start findenv_next dw 0 ;Ptr to next routine to append findenv_lnks dw 0 findenv_start = $ findenv proc near assume cs:code,ds:code,es:code,ss:code push bx call findenv_0 db "COMMAND" dw 0 findenv_0: pop bx push es mov ax,ds:[2ch] ;Get default env cmp environment_seg,ax ;Check to see if already jne findenv_jmp_exit ; found. push bx ;Ver changes BX mov ah,30h ;Get dos Version int 21h xchg al,ah mov findenv_dosver,ax mov ah,52h ;get address of first MCB int 21h mov ax,es:[bx-2] ;point ES to MCB mov cx,20 ;Allow only 20 loops. pop bx findenv_1: mov es,ax cmp byte ptr es:[0],"M" ;check for mcb signature jne short findenv_exit inc ax ;point AX to memory block cmp ax,es:[1] ;See if this is a PSP block je findenv_4 findenv_2: add ax,es:[3] ;Get size of memory block loop findenv_1 findenv_jmp_exit: jmp short findenv_exit findenv_4: cmp word ptr findenv_dosver,0a00h ;If OS/2, use DOS 3.3 method. jae findenv_5 cmp word ptr findenv_dosver,0400h;If DOS 4.00 or greater, jb findenv_5 ; COMMAND.COM may not be the push ds ; first program loaded. Look lea si,findenv_cmdname ; at the name of the program mov di,8 ; stored in the last 8 bytes mov cx,7 ; of the memory control repe cmpsb ; block. If the string pop ds ; "COMMAND" isn't found, jne findenv_2 ; keep looking. findenv_5: mov dx,ax ;Save PSP seg of command.com mov es,ax mov bx,es:[2ch] ;Get seg of prog environment mov ax,bx dec bx mov es,bx cmp byte ptr es:[0],"M" ;See if valid memory block je findenv_found mov ax,dx ;Get back cmd.com segment dec ax ;Point back to mcb mov es,ax findenv_6: add ax,es:[3] ;If master env segment not inc ax ; saved at 2Ch of the PSP, mov es,ax ; scan the memory blocks cmp es:[1],dx ; for first segment je findenv_7 ; owned by command.com. loop findenv_6 jmp short findenv_exit ;Master env not found. findenv_7: inc ax ;Point AX to env segment findenv_found: mov environment_seg,ax ;Save pointer to master env findenv_exit: pop es pop bx ret findenv endp findenv_end = $ ;----------------------------------------------------------------------------- ; SET_ENV Sets/resets environment variables. ; Entry: DS:SI - pointer to ASCII string containing the environment variable ; and, optionally, the string to assign. ; If no string specified, the environment is dumped to the ; screen. ; DI - Flag to indicate setting of PATH and PROMPT vars ; 0 = Normal Env var, 1 = PROMPT var, 2 = PATH var. ;----------------------------------------------------------------------------- setenv_findenv equ [bx-10] setenv_echo equ [bx-8] setenv_serchenv equ [bx-6] setenv_pathflag equ [bx] setenv_varlen equ [bx+1] setenv_fullmsg equ [bx+2] setenv_crmsg equ [bx+29] setenv_nopath equ [bx+32] setenv_off dw 0 ;Pointer to offset in COM file setenv_size dw offset setenv_end - offset setenv_start setenv_next dw 0 ;Ptr to next routine to append setenv_lnks dw 6 setenv_start = $ dw offset findenv_next ;Call to find the master env dw offset echo_msg_next ;Call to print line. dw offset searchenv_next ;Call to search environment blk set_env proc near assume ds:nothing,es:nothing push bx call setenv_1 db 0 ;PATH/PROMPT flag storage db 0 ;Var length. db "Out of environment space",13,10,0 db 13,10,0 db "No Path",0 setenv_1: pop bx ;Set up local addressing mov ax,di xchg al,ah mov setenv_pathflag,ah push ax call setenv_findenv ;Find master env block pop ax push bp push es ;See if we need to simply print the PATH statment. cmp ah,3 jne setenv_19 mov dx,4 call setenv_serchenv ;Get pointer to variable jnc setenv_11 lea si,setenv_nopath ;If path string not found, push cs ; print no path msg. pop ds jmp short setenv_12 setenv_11: sub si,5 ;Back up to start of PATH setenv_12: call cs:setenv_echo ;Print string push cs pop ds lea si,setenv_crmsg ;Append CR. call setenv_echo jmp setenv_8 setenv_19: mov cx,BUFF_SIZE xor dx,dx push si ;Save ptr to new env var mov di,si setenv_2: lodsb or ah,ah ;See if PATH or PROMPT je setenv_23 cmp al," " ;If PATH or PROMPT statments, jne setenv_23 ; remove any spaces between mov al,"=" ; variable and assignment. push di stosb setenv_20: lodsb ;Scan past equal sign cmp al," " je setenv_20 cmp al,"=" je setenv_20 setenv_21: stosb or al,al je setenv_22 lodsb ;Remove spaces in set string. jmp short setenv_21 setenv_22: pop di jmp short setenv_4 setenv_23: or al,al je setenv_4 cmp al,"=" ;Scan until end of variable je setenv_4 ; found. cmp al,'a' jb setenv_3 cmp al,'z' ja setenv_3 and al,0dfh ;Capitalize variable setenv_3: cmp al," " ;Keep a count of non-space jbe setenv_31 ; characters. inc dh setenv_31: stosb inc dl ;Var length count. loop setenv_2 setenv_4: pop si ; ;If no characters after SET, dump env vars to screen. ; mov setenv_varlen,dl ;Save length of env var. mov al,dh xor dh,dh or dh,dh ;See if path or prompt jne setenv_40 setenv_40: or al,al ;If second Zero, end of vars. jne setenv_48 push ds mov ds,cs:[environment_seg] ;Get segment of environment xor si,si lea di,setenv_crmsg ;Get address of CR string mov cx,cs setenv_41: call cs:setenv_echo ;Print var push ds push si mov ds,cx mov si,di call cs:setenv_echo ;Print CR pop si pop ds cmp byte ptr ds:[si],0 ;If next char 0, end of block jne setenv_41 pop ds jmp setenv_8 ; ;Set or Clear env var. ; setenv_48: mov ax,si inc di cmp byte ptr cs:[di]," " ;If nothing past '=' then jae setenv_49 ; simply erase var from env. xor ax,ax setenv_49: push ax ;Save set/erase flag call setenv_serchenv ;Get pointer to variable pop dx push ds ;ES = env segment pop es mov di,si ;Copy pointer to variable jc setenv_61 xor al,al ;Scan backwards to find start std ; of var name mov cx,256 repne scasb inc di inc di push di cld ;Scan forward to find end of mov cx,256 ; variable. repne scasb mov si,di pop di xor ah,ah setenv_5: lodsb ;Move byte from past var to stosb ; cover up current assignment or ah,al ;If two zeros in a row then je setenv_6 ; end of env vars. mov ah,al jmp short setenv_5 setenv_6: dec di ;Back up before last zero setenv_61: push cs pop ds mov si,dx ;Get back ptr to env var or si,si ;See if var assignment je setenv_8 push es ;Get size of the environment mov ax,es ; block by reading the size dec ax ; in the memory control block. mov es,ax mov bp,es:[3] mov cl,4 shl bp,cl ;Convert to bytes. dec bp dec bp pop es xor ax,ax ;See if there is room in the mov al,setenv_varlen ; env block for the var name. inc al ; If not, don't even start. add ax,di ; If room for name, copy as cmp ax,bp ; much of the var as possible jae setenv_72 mov ah,setenv_pathflag ;Get pathflag byte setenv_7: cmp di,bp ;Check for end of env block. jae setenv_72 lodsb ;Copy new env var cmp ah,2 jne setenv_71 ;If PATH var, make upper case. cmp al,'a' jb setenv_71 cmp al,'z' ja setenv_71 and al,0dfh setenv_71: stosb or al,al ;Check for end of variable. jne setenv_7 stosb jmp short setenv_8 setenv_72: xor al,al stosb push cs pop es lea si,setenv_fullmsg ;If environment block full, call setenv_echo ; print message. setenv_8: pop es pop bp pop bx ret set_env endp setenv_end = $ ;----------------------------------------------------------------------------- ; REDIROO Opens a file for output redirection. ; Entry: DS:SI - pointer to ASCII filename to open. ; DI - 0 open new file, 1 append to existing file. ;----------------------------------------------------------------------------- rediroo_off dw 0 ;Pointer to offset in COM file rediroo_size dw offset rediroo_end - offset rediroo_start rediroo_next dw 0 ;Ptr to next routine to append rediroo_lnks dw 0 rediroo_start = $ rediroo proc near assume ds:nothing,es:nothing mov word ptr stdout_hdl,-1 ;Clear handle mov dx,si ;Get ptr to outfile file xor cx,cx ;Normal attributes mov ax,3c02h ;Create file or di,di ;See if append or new file je rediroo_2 inc ah ;Open file rediroo_2: int 21h jc rediroo_exit mov bx,ax ;Copy file handle or di,di je rediroo_3 mov ax,4202h ;Move file ptr to end of file xor dx,dx mov cx,dx int 21h jc rediroo_exit rediroo_3: mov outfile_hdl,bx ;Save output file handle push bx mov ah,45h ;Duplicate output handle mov bx,1 ;Std output handle int 21h mov stdout_hdl,ax ;Save dup std output handle mov cx,1 pop bx mov ah,46h ;Force dup file handle int 21h rediroo_exit: ret rediroo endp rediroo_end = $ ;----------------------------------------------------------------------------- ; REDIRCO Closes a file used for output redirection. ;----------------------------------------------------------------------------- redirco_off dw 0 ;Pointer to offset in COM file redirco_size dw offset redirco_end - offset redirco_start redirco_next dw 0 ;Ptr to next routine to append redirco_lnks dw 0 redirco_start = $ redirco proc near assume ds:nothing,es:nothing cmp word ptr stdout_hdl,-1 ;If error on redirect, skip je redirco_exit ; restore. mov ah,46h ;Force restore of std out mov bx,stdout_hdl mov cx,1 int 21h mov ah,3eh ;Close file mov bx,outfile_hdl ;Get output file handle int 21h redirco_exit: ret redirco endp redirco_end = $ ;----------------------------------------------------------------------------- ; REDIROI Opens a file for input redirection. ; Entry: DS:SI - pointer to ASCII filename to open. ; DI - 0 open new file, 1 append to existing file. ;----------------------------------------------------------------------------- rediroi_off dw 0 ;Pointer to offset in COM file rediroi_size dw offset rediroi_end - offset rediroi_start rediroi_next dw 0 ;Ptr to next routine to append rediroi_lnks dw 0 rediroi_start = $ rediroi proc near assume ds:nothing,es:nothing mov word ptr stdin_hdl,-1 ;Clear handle mov dx,si ;Get ptr to outfile file mov ax,3d00h ;Open file, Read only int 21h jc rediroi_exit mov infile_hdl,ax ;Save input file handle push ax mov ah,45h ;Duplicate input handle xor bx,bx int 21h mov stdin_hdl,ax ;Save dup std input handle xor cx,cx pop bx mov ah,46h ;Force dup file handle int 21h rediroi_exit: ret rediroi endp rediroi_end = $ ;----------------------------------------------------------------------------- ; REDIRCI Closes a file used for input redirection. ;----------------------------------------------------------------------------- redirci_off dw 0 ;Pointer to offset in COM file redirci_size dw offset redirci_end - offset redirci_start redirci_next dw 0 ;Ptr to next routine to append redirci_lnks dw 0 redirci_start = $ redirci proc near assume ds:nothing,es:nothing cmp word ptr stdin_hdl,-1 ;If error on redirect, skip je redirci_exit ; restore. mov ah,46h ;Force restore of std in hdl xor cx,cx mov bx,stdin_hdl int 21h mov ah,3eh ;Close file mov bx,infile_hdl ;Get input file handle int 21h redirci_exit: ret redirci endp redirci_end = $ ;----------------------------------------------------------------------------- ; REDIRDEL Deletes piping file. ; Entry: DS:SI - pointer to ASCII filename to delete. ;----------------------------------------------------------------------------- redirdel_off dw 0 ;Pointer to offset in COM file redirdel_size dw offset redirdel_end - offset redirdel_start redirdel_next dw 0 ;Ptr to next routine to append redirdel_lnks dw 0 redirdel_start = $ redirdel proc near assume ds:nothing,es:nothing mov dx,si ;Copy pointer to filename mov ah,41h ;Delete file int 21h ret redirdel endp redirdel_end = $ initialize endp even ;compiler stack on word boundry end_of_code = $ code ends end main e. cmp al,'a' jb setenv_71 cmp al,'z' ja setenv_71 and al,0dfh setenv_71: stosb