prints out the command line parameters.asm

; this sample prints out the command line parameters.
; in dos you simply add this line after an executable, for example:

; paramexe p1 p2 p3

; it is possible to set parameter in emulator 
; by selecting "set command line parameters" from the "file" menu.

name "paramexe"

data segment
    msg db 'no command line parameters!', 0Dh,0Ah, '$'
ends

stack segment
    db  20 dup(0)
ends

code segment
start:
    ; set segment registers:
    mov ax, data    
    mov ds, ax
    
    mov si, 80h      ; cmd parameters offset.
    
    ; copy command line to our buffer:
    xor cx, cx      ; zero cx register.
    mov cl, es:[si] ; get command line size.
    
    cmp cx, 0       ; cx = 0 ?
    jz  no_param    ; then skip the copy.
    
    inc si          ; start printing from second byte.
    next_char:
    mov al, es:[si]
    mov ah, 0eh     ; print out in teletype mode
    int 10h
    inc si
    loop    next_char
    
    jmp exit    ; skip error message.
    
    no_param:
    ; print out the error message:
    lea dx, msg
    mov ah, 09h
    int 21h
    
    
    exit:
    ; wait for any key press...
    mov ah, 0
    int 16h
    
    
    ; return control to the operating system:
    mov ah, 4ch
    int 21h
ends

end start