A background application is one that runs without appearing in the Dock or Force Quit window. It can sometimes be useful to look for a specific background application when troubleshooting. Follow these steps:
- Open the Activity Monitor (/Applications/Utilities/).
Tip: Before Mac OS X 10.3, this utility was named Process Viewer.
- Choose All Processes from the Show pop-up menu.
- Locate the background application (by name or percentage of time being used).
For Activity Monitor, the process' identification number (PID) appears in the main window. If you need the PID when using Process Viewer, follow these steps:
- Select the process from the listing.
- Click the disclosure triangle labeled More Info, which is near the bottom of the window.
- Click the Process ID tab.
Process ID appears in the first line. It should be a whole number that is positive.
Note: Do not confuse the "parent process id" or "process group id", which are different numbers.
The PID is necessary for the terminal commands sample and kill, among others.