Linux Terminal Command: pgrep

The pgrep command is an essential tool in Process & Job Control. In this tutorial, we will explore what pgrep does, look at everyday examples, and cover advanced options to supercharge your command-line workflow.

Concept & Explanation

The pgrep command searches active system processes and lists the PIDs matching the search criteria.

Common Options & Syntax

pgrep [options] [arguments]

Here are the most common flags used with pgrep:

Simple Usage: Basic default commands.
Detailed View: Shows diagnostic information.
Advanced Actions: Can chain parameters for scripting.

1. Interactive Example (Simple)

Here is how most people run the command:

# Example
pgrep sshd

What it does: Prints the process IDs of all running SSH daemons.

2. Power-User Example (Advanced)

For scripting and advanced diagnostics, use this configuration:

# Advanced
pgrep -l -u root,www-data -f gunicorn

What it does: Lists both the PID and process name (-l) of all Gunicorn processes running under ‘root’ or ‘www-data’ users.

⚙️ Warning & Common Pitfalls

[!WARNING] By default, pgrep only matches the first 15 characters of process names. Use the -f flag to match against the full command line path.

Here are some related posts on cli_tty1 you might want to check out:

ps : Report a snapshot of the current processes.
top : Display Linux processes in real time.
htop : Interactive process viewer.