pstree

Display the derivation relationship between processes in a tree diagram.

Description

The pstree command displays the derivation relationship between processes in a tree diagram, providing a clear and intuitive view of the process hierarchy.

Syntax

pstree(options)

Options

-a: Display the full command line for each process, including paths, parameters, or resident service markers.
-c: Disable compact notation for identical process subtrees.
-G: Use VT100 terminal line-drawing characters.
-h: Highlight the current process when listing the tree.
-H<PID>: Similar to "-h", but highlights the specified process.
-l: Use long format for displaying the tree.
-n: Sort processes by PID instead of by name.
-p: Display process IDs (PIDs).
-u: Display user names.
-U: Use UTF-8 line-drawing characters.
-V: Display version information.

Examples

Display PIDs for all current processes:

pstree -p

Display detailed information for all processes, using compact notation for identical process names:

pstree -a

Retrieve the PID of an SSH session:

pstree -p | grep ssh

#  |-sshd(1221)-+-sshd(2768)---bash(2770)-+-grep(2810)
#  |            `-sshd(2807)---sshd(2808)

From the output above, you can see the tree diagram of the sshd process and its branches. The main sshd process is sshd(1221), with two branches sshd(2768) and sshd(2807).