Find ProcessID - pidof not working

I need to try and find the ProcessId of a process. Initially I was doing: application="/home/user/apps/appName.app" appPid=$(pidof -x $application) This worked fine. However, it now turns out that the applictaion could run from a variety of locations, such as: /home/user/apps/appName.app /home/user/desktop/appName.app /home/user/desktop/link to apps/appName.app So I tried to simply do application="appName.app" appPid=$(pidof -x $application) But this didn't find any matches. I assume that pidof requires a full path to match. How else can I get the ProcessId? - - - I think I need to further explain. If I do ps aux | grep application.app I get two results. user 29912 . . . . /home/user/apps/application.app user 12345 . . . . grep application.app If I then do var1=pgrep application.app echo $var1 the result is blank. It should be 29912.