Comparing the freshly inputted text to a list of available commands in asm

how do i compare the string in the buffer with a command like '--help' how would you compare the freshly inputted text in the buffer with a command here is my code

xor  ax, ax
mov  ds, ax
mov  es, ax
cld
;bg
MOV AH, 06h   
XOR AL, AL    
XOR CX, CX    
MOV DX, 184FH  
MOV BH, 1Eh  
INT 10H
;cursor
mov dh, 1
mov dl, 30
mov bh, 0
mov ah, 2
int 10h
;text
  mov  si, msg     
  mov  bh, 0      
  lodsb
More:
  mov  ah, 0Eh     ; BIOS.Teletype
  int  10h
  lodsb            
  cmp  al, 0
  jnz  More
;cursor
mov dh, 3
mov dl, 2
mov bh, 0
mov ah, 2
int 10h
;commandline

Key:
    mov  di, buf   
Next:
    mov  ah, 00h   ;GetKeyboardKey
    int  16h       
    stosb          
    mov  bh, 0     
    mov  ah, 0Eh   ; BIOS.Teletype
    int  10h
    cmp  al, 13
    jne  Next      
    mov  al, 10   
    int  10h


buf  db '........'
help db '--help'
msg  db 'WELCOME TO DARSHOS', 0
times 510-($-$$) db 0
dw 0xAA55```

Solution

help db '--help'

It's not clear why you have prefixed this command with those '--'.

For a practical approach to the task, consider next list of available commands:

list  db  'cls', 13
      db  'help', 13
      db  'date', 13
      db  13

Below is one method of searching through this list of CarriageReturn-terminated ASCII strings where no string has more than 7 text characters plus a terminating byte (13). That's 8 in total since that was the limit we chose on inputting the command that we're trying to locate.

The snippet uses a couple of string instructions:

The lodsb string instruction loads the byte at DS:SI into the AL register. This will automatically advance the pointer. If the direction flag DF is clear it will increment by one.
The scasb string instruction will compare the AL register with the byte at ES:DI. This will modify flags that we can interrogate and it will also automatically advance the pointer.

  cld
  mov  si, list
NextItemOnList:
  mov  di, buf          ; Contains the command we want to find (terminated by 13)
NextChar:
  lodsb
  scasb
  jne  NotThisOne
  cmp  al, 13
  jne  NextChar
Found:
  ...
NotThisOne:
  dec  si               ; Back to where the mismatch occured
SkipRemainder:
  lodsb                 ; Skip remainder of this list item
  cmp  al, 13
  jne  SkipRemainder
  cmp  byte [si], 13    ; EndOfList ?
  jne  NextItemOnList   ; No
NotFound:
  ...

With the above code we can find out if the command is on the list, but which was it?

We can choose to associate an index with each command on the list, like in:

  cld
  xor  cx, cx           ; cls=0, help=1, date=2
  mov  si, list
NextItemOnList:
  mov  di, buf          ; Contains the command we want to find (terminated by 13)
NextChar:
  lodsb
  scasb
  jne  NotThisOne
  cmp  al, 13
  jne  NextChar
Found:
  ...
NotThisOne:
  dec  si               ; Back to where the mismatch occured
SkipRemainder:
  lodsb                 ; Skip remainder of this list item
  cmp  al, 13
  jne  SkipRemainder
  inc  cx               ; Next index
  cmp  byte [si], 13    ; EndOfList ?
  jne  NextItemOnList   ; No
NotFound:
  ...

Or we can add to the list the actual addresses where the commands are going to get processed, like in:

list  dw  xCls
      db  'cls', 13
      dw  xHelp
      db  'help', 13
      dw  xDate
      db  'date', 13
      dw  xFail
  ...

  cld
  mov  si, list
NextItemOnList:
  lodsw                 ; Address of command's execution
  mov  bx, ax
  mov  di, buf          ; Contains the command we want to find (terminated by 13)
NextChar:
  lodsb
  scasb
  jne  NotThisOne
  cmp  al, 13
  jne  NextChar
Found:
  ...
NotThisOne:
  dec  si               ; Back to where the mismatch occured
SkipRemainder:
  lodsb                 ; Skip remainder of this list item
  cmp  al, 13
  jne  SkipRemainder
  cmp  word [si], xFail ; EndOfList ?
  jne  NextItemOnList   ; No
NotFound:
  ...