批处理脚本以并行运行文件中的命令

Question

I need to use a cmd tool that is very inneficient. It usually takes a lot to return the prompt, or it hangs.

I want to automate this process by making aa new batch file that takes the commands from an input.txt file and makes parallel calls to this batch to not waste time, and log everything in a log file.

This is as far as I got

@echo off
for /f "tokens=*" %%a in (input.txt) do (
  START %%a >> result.txt
  TIMEOUT /T 60
)
PAUSE

But I get the error:

The process cannot access the file because it is being used by another process.

which I presume it's referring to the redirection to results.txt, because the previous command is still running.

Besides that it fills my PC with CMDs.

Can anyone please help me with this?

Answer 1

That's a bit confusing. You want your commands to be executed in parallel but you don't want them to be executed in different CMD windows? You should try to add /B:

START /B %%a

This will make the CMDs spawn "invisible" - means in background. To avoid access violation errors, you could move the redirection from your bat file to the txt file by appending the redirection to each line. Say your txt looks like this:

...
ping 127.0.0.1
copy C:\xyz.txt d:\xyz.txt
...

The modified file will look like this:

...
ping 127.0.0.1>>result.txt
copy C:\xyz.txt d:\xyz.txt>>result.txt
...

This looks similar but there is a big difference. START "ping 127.0.0.1" >> result.txt means write the result of START ... into your text file while START "ping 127.0.0.1>>result.txt" means write the result of the ping command into the file.