China DOS Union

I want to write a batch file. It takes several parameters; some of them are standalone items, while some others must be run only after UCDOS is running. That creates a problem: if I put
\ucdos\rd16
\ucdos\knl
at the front, then those items that don't need UCDOS will also have to be run only after UCDOS is running, which is annoying. If I don't put UCDOS at the front, then those programs that must run under UCDOS will each need to have \ucdos\rd16 ; \ucdos\knl added to them. That's somewhat repetitive and cumbersome. And those items will end up starting UCDOS repeatedly, even though starting UCDOS once is enough.
Is there any good way to solve this?
Can I make a check in the batch file to determine whether UCDOS is already running?

Although I'm not very good at batch files, I can give you some programming ideas. You can create a temporary file as a marker when it runs, and then do a conditional check where needed so that different actions are carried out.

Re daiddcc:

What you're asking isn't very clear. From what I understand, you want to mix together program items that don't need UCDOS and ones that do, but you find the frequent switching of UCDOS on and off troublesome.

First, let's analyze the problem. To avoid the code redundancy caused by frequently switching UCDOS on and off, you can write the UCDOS startup/shutdown code as a separate batch file, then use call directly before and after program items that need UCDOS. If you want to avoid redundancy in the execution process, then it depends on the specific situation. First separate the program items that need UCDOS from those that don't, then put them into two large modules. In the UCDOS module, start UCDOS first, then according to the parameter switch jump to the specific module that needs to be executed.

Also, to determine whether UCDOS is already running, you can register an environment variable, which is usually a bit better than creating a temporary file:

::ucdos.bat
@echo off
\ucdos\rd16
\ucdos\knl
set ucdos=load

::application
@echo off
if "%ucdos%"=="" call ucdos.bat
if "%ucdos%"=="load" goto program that needs UCDOS or UCDOS unload label

The method from the poster above is very practical!

That's a good method!

Many thanks! I originally thought there wouldn't be any good method, but it looks like my understanding of batch files is still far from enough.