Linux Tutorial

Linux File/Directory Management

Linux Packaging And Compression

Vim Text Editor

Linux Text Processing

Linux Software Installation

Linux User/User Group Management

Linux Permission Management

Linux Filesystem Management

Linux Advanced Filesystem Management

Linux System Management

Linux Backup and Recovery

Linux System Service Management

Linux System Log Management

Linux Boot Management

LAMP/LNMP Environment

SELinux Management

Linux pstree Command: Display Process Tree

The pstree command in Linux is a useful tool for displaying a tree-like structure of running processes, showing parent-child relationships among them. This tutorial will introduce you to the pstree command, its usage, and some practical examples.

Installing pstree

Before using pstree, ensure it's installed on your system. To install pstree, use the appropriate command for your Linux distribution:

sudo apt install psmisc       # Debian/Ubuntu-based distributions
sudo yum install psmisc       # CentOS/RHEL-based distributions
sudo dnf install psmisc       # Fedora-based distributions
sudo pacman -S psmisc         # Arch-based distributions

Basic Usage

The basic syntax for the pstree command is as follows:

pstree [options]

By default, pstree displays a tree-like structure of all running processes on the system, showing process hierarchy.

Options

The pstree command supports a variety of options to control the output and appearance of the process tree. Here are some commonly used options:

-p: Show PIDs in the tree output
-u: Show the process owner (user)
-n: Sort processes by PID
-a: Show command line arguments of processes
-P: Highlight a specific process by PID
-U: Use Unicode characters for tree drawing

Examples

Here are some practical examples of using the pstree command:

Display a process tree with PIDs:
```
pstree -p
```
Display a process tree with process owners:
```
pstree -u
```
Display a process tree sorted by PIDs:
```
pstree -n
```
Display a process tree with command line arguments:
```
pstree -a
```
Display a process tree, highlighting a specific process by PID (e.g., 12345):
```
pstree -P 12345
```
Display a process tree using Unicode characters for tree drawing:
```
pstree -U
```

Displaying Process Subtrees

You can display a subtree of processes by specifying a user or PID as an argument to the pstree command:

Display the process subtree for a specific user (e.g., john):
```
pstree john
```
Display the process subtree for a specific PID (e.g., 12345):
```
pstree 12345
```

In conclusion, the pstree command is a handy tool for visualizing the parent-child relationships of processes in a Linux system. By using the available options and filters, you can efficiently monitor and analyze the process hierarchy on your system.

How to use pstree to display process hierarchy: The pstree command displays the process hierarchy in a tree-like structure. To view the process tree:
```
pstree
```
Viewing process tree in Linux with pstree: Use pstree to visualize the process hierarchy. For example, to display the process tree for a specific user:
```
pstree -u username
```
Advanced options for the pstree command in Linux: pstree has various options for customizing output. For instance, to display only the processes related to a specific command:
```
pstree -ap | grep process_name
```
Visualizing process hierarchy with pstree in Unix-like systems: Visualize the process hierarchy using pstree. For example, to display the process tree with full command-line arguments:
```
pstree -a
```
pstree vs ps: differences in process listing tools: While ps provides a flat list of processes, pstree displays the process hierarchy in a tree structure. For example:
```
ps aux | grep process_name
pstree -p | grep process_name
```
Customizing output format with pstree in Linux: Customize the output format of pstree using options like -n to display process IDs:
```
pstree -n
```
Monitoring system processes and dependencies with pstree: Use pstree to monitor system processes and their dependencies. For example, to display the process tree with highlighted changes:
```
watch -n 1 pstree
```