# What is PPID on Linux? > Parent Process IDentifier A process ID is the number assigned to an application by the operating system. This serves to identify the application uniquely while it is running. This number changes for each copy of a program running. And it is different each time an application opens and closes. By the nature of the system, further applications are spawned by the original process that is loaded when the operating system is loaded. So all processes have a parent and child relationship with the process that spawned them. Therefore, the parent process identifier is the process ID of the parent where "parent" is the process that spawned the process we are looking at. This information can be used in troubleshooting tools to show groups of related processes. For example, in Process Explorer, you can see a Web browser process grouped with all its helper subprocesses or child processes. On Windows, is is possible to find the parent process. But I don't remember having the parent process ID readily available. On Linux, it seems like the PPID is more readily available. For example, in the XFCE Task Manager, the option to show PPID is given equal prominence with more common statistics like memory usage and user ID. ## PowerShell I was able to generate this crude listing. Note that some of the parent process IDs were not available. I don't have an explanation for that. But XFCE Task Manager correctly associates the orphans from PowerShell (ex "Web Content") with their parents (ex Firefox). I've edited the output for length. ``` PowerShell Get-Process | Select-Object @{name='Parent'; expr={$_.Parent.Id}}, Id, Name | Sort-Object Parent, Id Parent Id Name ------ -- ---- 105455 Web Content 1 2617 firefox 1 135731 code --no-sandbox --force-user-env --unity-launch --enable-crashpad 1284 1362 Thunar 1370 127909 thunderbird 1667 1688 pwsh 1688 11884 vim ``` ## References => https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer Process Explorer | Microsoft Docs => https://docs.xfce.org/apps/xfce4-taskmanager/start Task Manager | XFCE Docs => https://linuxhandbook.com/find-process-id/ How to Find Process ID (PID and PPID) in Linux => https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_calculated_properties Calculated Properties | Microsoft Docs => https://github.com/PowerShell/PowerShell/issues/17541 Parent Process Object is Missing | GitHub Created: Sunday, June 19, 2022 Updated: Sunday, June 19, 2022