Set the pid of a searched running process (ps -ea | grep }) in shell -

I am creating a shell script, where I run a process and I like this process as ps -ea Searching for Grep & lt; Search_term & gt; And I can get this process okay, but I want to set the PIN of that process in a variable in my shell script, then wait till the end of that process. I like this type of thing:

  pid = ("ps -ea | grep