Did not use 'wait' yet.
How I understand by now the wait works only for child processes, started background.

Is there any other way to watch completion of any, not related process (at least, a process, owned by the same user?)

I need to start a background process, witch will be waiting for completion of the parent script.

Thank you
Alex

There are many approaches to finding out about the execution and/or completion [assumed complete if not running] of another process.

1) Have the other program write a file as it starts, and delete it upon its exit. Then, you just need to check if the file exists.
2) By checking for parameters with the 'grep' at the end of a
>ps -ef | grep ___
3) By checking for the existence of specific files [assuming you can run lsof - which may need to be installed]. lsof does a list of open files.
>lsof | grep ___

Thank you for answering, but it is not what I am looking for.
The 'ps ..' with grep is what I am using now, but meeting the 'wait..' command I see, that use such comand would remove big portion of codding and processing time

About the 'isof', it seems, you have once mentioned it to me, and I replay that we do not have it and I could not find any references to that on internet, and I have no ability to install anything.

All other methods I would use, if nothing else is available.

But I am looking for optimal way to perform an action.

So, by your answer I should assume that there is no in UNIX analogical command for waiting a completion of not child processes?