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:

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**Output:

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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:

Display Command Line Arguments

-a option

**Output:

Display Command Line Arguments

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:

Display PIDs

-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

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

Sort Processes by PID

**5. Show User/Owner of Processes (-u)

To display the owner of each process:

Show User/Owner of Processes

Show User/Owner of Processes

**6. Highlight Current Process (-h)

To highlight the current process and its ancestors:

Highlight Current Process

Highlight Current Process

**7. Show Process Group IDs (-g)

To display process group IDs:

Show 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

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

Display Version Information

**Output:

Output

Output