How to build a 16 bit CLI for my Kernel using the Assembly language. Like MS-DOS

SkiMask11,

Do you prefer line-oriented or block-oriented CLI language?

Pseudoly, you'd want to parse keyboard input "after" a <enter> then branch from there.

Smiddy

I know how a command line works, but I don't know how to put it into Assembly code. I know how to add characters when the user types on the keyboard, but I don't know how to make the machine know what's a command

Baldr

What's the difference between line and blocked? Doesn't line oriented involve python?

Did you search for keyboard input?

I searched Keyboard input Assembly and I got so many helpful resources, thank you so much Smiddy. I feel that the Internet isn't so vast when it comes to OS development, is their a better way to learn about OS development?

Other than your own research? Take a course...

Assuming you want use the BIOS then int 0x16 ah=0x00 will get you the key strokes (blocking), returning the ASCII code in al. Otherwise trap IRQ1 and decode than scancodes on the PS2 ports (0x60 and 0x64). Then just store/parse accordingly.

Are you kidding or what? There is way more than enough.
The OSDev wiki alone is a trove for amateur OS developers.
There are also many (literally in the hundreds!) amateur open-source systems written both in pure assembly as well as assembly and C. DexOS and KolibriOS come to mind.
If you're unwilling or unable to read the source of much bigger systems like Linux or the *BSDs, you still can check the source of earlier versions of MINIX or Linux 0.0.1.

It's all there. All you need is patience and the willingness to learn, try things, fail and retry.

I wrote a 2k Dos clone in fasm that may help you.