仅在程序启动后才继续批处理脚本

Question

I have a batch script (yes I know batch is awful, no I don't care) that checks my VM's on the local machine to the ones stored on my USB, if they're out of date, it updates them, then boots them. I use multiple machines at uni, so this makes it easier to ensure the VM I'm working on are always the latest.

When I open them like this;
PATH "%PROGRAMFILES%\\VMware\\VMware Workstation\\"
START vmware.exe -x "%USERPROFILE%\\Desktop\\VMs\\VM1\\VM1.vmx"
START vmware.exe -x "%USERPROFILE%\\Desktop\\VMs\\VM2\\VM2.vmx"
START vmware.exe -x "%USERPROFILE%\\Desktop\\VMs\\VM3\\VM3.vmx"
It causes the VM's to open in separate windows, rather than tabs of the same window for easy switching.

The workaround I came up with is to boot the VMware program first, then when I open the .VMXs, they all open as tabs in the same window.
The problem is that the VMware program sometimes takes a long time to open. Similar to Photoshop's loading splashscreen, but instead with no visual indicator, VMware opens up to 20 seconds after the icon has been clicked, or it has been summoned with a script.

So finally, here is my question.
Is there a way to make a batch that waits for the program to open before continuing? I know by omitting START I can stop the batch until the program closes, but obviously this is useless for my purposes.

If all else fails, I may just have to include a 30 second timeout and hope it's enough.

Answer 1

I don't think there's any reliable way to do this.

If you have a program that you need to open and then wait for a certain state to change in the program before doing something else, that state could be set by any arbitrary operation running on any thread spawned by the application. There would be no way to know when the application had set that state unless you were able to somehow communicate with the program to query or be notified of its state.

Theoretically if you knew enough about what the program was doing internally you could monitor the thread count or file system accesses or something to determine roughly when it had changed to the desired state, but just using a timer would be much much simpler.