;---------------------------------------------------------------- ; CMDLINE.INC ; JIM TUCKER ; Last modified: 20 August 1994 ; LANGUAGE: A86 ; This processes the command line for switches, drives and filenames. ; It uses about 240 bytes. You could do it in less but I have put ; emphasis on readability. To encourage beginners I have commented ; more than usual. - JT ; 1) Just returns if cmdline is empty ; 2) Makes cmdline ASCIIZ caps ; 3) Puts switches in a buffer and blanks them on the cmdline ; 4) Stores drive chars in a list and blanks them on the cmdline ; 5) Keeps filenames on cmdline as ASCIIZ with pointers in a list ; DOS command: FOOBAR/sw1/sw2 a: file1/sw3 file2 ; 81h after caps: /SW1/SW2 A: FILE1/SW2 FILE2 <0> ; 81h after switches: A: FILE1 FILE2 <0> ; 81h after drives: FILE1 FILE2 <0> ; 81h after filenames: FILE1<0> FILE2<0><0> ; Switch buffer: /SW1/SW2/SW3<0> ; USAGE: call cmdline ; lea si,switch_buffer ; Scan ASCIIZ string for switches ; mov al,drive1 ; AL contains drive *char* ; mov dx,filename1 ; DX contains address of string ; mov dx,filename2... etc ;---------------------------------------------------------------- SWITCH_BUFFER db 64 dup 0 ;will be ASCIIZ string of switches SWB_SIZE = ($-OFFSET switch_buffer)-1 ;-1 preserves zero byte DRIVE1 db 0 ;will be drive char in caps DRIVE2 db 0 ; in order found on cmd line DRIVE3 db 0 DRIVE4 db 0 MAX_DRIVES = $-OFFSET drive1 FILENAME1 dw 0 ;will point to ASCIIZ *strings* FILENAME2 dw 0 ; in order found on cmd line. FILENAME3 dw 0 FILENAME4 dw 0 ;you may add more if you need them MAX_FILES = ($-OFFSET filename1)/2 ;---------------------------------------------------------------- ; Procedure begins here. The command line (tail) CS:80h = # chars ; on cmdline including ALL blanks (eg the first n after a filename) ; but not including the terminating return (0Dh). The first char is ; at 81h and may be "/" as in "FOOBAR/SWITCH". Redirection <>| is ; not saved and cannot be read here. CMDLINE: test B[80h] ;anybody home? jz ret ;no (but it will be NZ even ;if blanks and no data) ; These calls must be performed in the following order call cmd_caps call cmd_switches call cmd_drives call cmd_files ret ;---------------------------------------------------------------- CMD_CAPS: mov bx,81h ;zero the cr at end of cmdline add bl,[bx-1]B ;bx -> cr mov B[bx],bh ;bh is zero mov si,81h ;where to get mov di,si ;where to put L1: lodsb ;get or al,al ;zero is end of cmdline jz ret ;A86 will find an address cmp al,'a' ;little a? jb >l2 ;too small cmp al,'z' ;little z? ja >l2 ;too big and al,5Fh ;mask out lower case bit L2: stosb ;put jmp l1 ;do more ;---------------------------------------------------------------- ; Switch "/" and following chars put in our buffer until a space or ; zero byte found. This reads multiple switches such as /aaaa/bb... ; as well as switches separated by a space. NOTE: When you process ; the buffer, a switch is terminated by "/" (another switch) or ; a zero byte (end of buffer). CMD_SWITCHES: mov si,81h ;where get lea di,switch_buffer ;where put mov cl,swb_size ;buffer size L1: lodsb ;get or al,al ;end of cmdline? jz ret ;yes, done cmp al,'/' ;switch char? jne l1 ;no L2: or cl,cl ;buffer full? jz >l3 ;yes stosb ;put it in buffer dec cl ;one less buffer byte available L3: mov B[si-1],' ' ;blank char on command line lodsb ;get next cmp al,' ' ;end of it? ja l2 ;no, must be a char je l1 ;space, keep scanning cmdline ret ;must be a zero byte so done ;---------------------------------------------------------------- ; Drives are the char before ':' when ':' is followed by space or zero ; "/DRIVE=x:" has been removed by the switch routine. "A:FILENAME" is ; not a drive because a char follows ":" "A:/SWITCH" is a drive because ; "/SWITCH" is now blank (by the switch routine). CMD_DRIVES: mov si,81h ;where get lea di,drive1 ;where put mov cl,max_drives ;number allowed L1: lodsb ;get or al,al ;end of it? jz ret ;yes cmp al,':' ;possible drive? jne l1 ;no mov dl,[si] ;peek next char (don't bump si) cmp dl,' ' ;space? ja l1 ;bigger, must be a char mov al,[si-2] ;get the drive letter mov W[si-2],2020h ;blank "x:" or cl,cl ;room for more? jz l1 ;no, don't save (table full) stosb ;save it (bumps di) dec cl ;one less jmp l1 ;---------------------------------------------------------------- ; Search for filenames inserting the pointer into table and ; terminating each with ASCIIZ. You may change the number of file ; names you expect in the table. Maximum is the entire command line ; allowing one char and a space for each filename! CMD_FILES: mov si,81h ;where get lea bx,filename1 ;where put mov cl,max_files ;how many L1: mov B[si-1],0 ;done on entry, but no harm L2: lodsb ;get cmp al,' ' ;space? je l2 ;yes, ignore leading spaces jb ret ;below " " so zero byte, exit or cl,cl ;a char, empty table entry left? jz >l3 ;no, don't save but do cmdline mov [bx],si ;save pointer dec W[bx] ; but si pointed one too far add bx,2 ;bx -> next filename dec cl ;one less L3: lodsb ;now look for end of filename cmp al,' ' ;space? ja l3 ;char so keep going je l1 ;space, insert zero byte ret ;must be zero so cmd line done ; END CMDLINE.INC