pstree Command in Linux with Examples (original) (raw)
Last Updated : 31 Oct, 2025
The pstree command in Linux is a powerful tool that displays running processes as a tree structure. This visual representation makes it easier to understand the hierarchy of processes, providing a more intuitive view of how processes are related to each other. The root of the tree is either the `init` process or a process with a specified PID. While pstree comes pre-installed on most Linux distributions, it can also be installed on other Unix-like systems.
Basic Pstree Example
To display the basic process tree, simply run the **pstree command without any options:

**Output:

This output shows the hierarchical relationship between processes, with child processes indented under their parent processes.
Syntax
pstree [options] [pid or username]
Key Options of the pstree Command
| Option | Description |
|---|---|
| -a | Show command line arguments |
| -p | Show PIDs |
| -c | Disable compaction of identical subtrees |
| -n | Sort processes with the same parent by PID |
| -u | Show uid transitions |
| -h | Highlight current process and its ancestors |
| -g | Show PGID numbers |
| -V | Display version information |
**1. Display Command Line Arguments (-a)
To include command line arguments in the output:

-a option
**Output:

output
This output shows more detailed information about each process, including the command line arguments used to start them.
**2. Display PIDs (-p)
To show Process IDs (PIDs) for each process:

-p option
**3. Disable Compaction of Identical Subtrees (-c)
By default, `****pstree**` compacts identical branches. Use the `****-c**` option to expand all subtrees:

Disable Compaction of Identical Subtrees
**4. Sort Processes by PID (-n)
To sort processes with the same parent by PID instead of by name:

Sort Processes by PID
**5. Show User/Owner of Processes (-u)
To display the owner of each process:

Show User/Owner of Processes
**6. Highlight Current Process (-h)
To highlight the current process and its ancestors:

Highlight Current Process
**7. Show Process Group IDs (-g)
To display process group IDs:

Show Process Group IDs
Advanced Usages of pstree Command
**1. Display Process Tree for a Specific User
To show all process trees rooted at processes owned by a specific user:

Display Process Tree for a Specific User
Replace `****username**` with the actual username you want to investigate.
**2. Display Version Information
To check the version of `****pstree**` installed on your system:

Display Version Information
**Output:

Output