Linux Terminal Command: free

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

Concept & Explanation

The free command displays system RAM and Swap usage, including cache, buffers, and available memory.

Common Options & Syntax

free [options] [arguments]

Here are the most common flags used with free:

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
free -h

What it does: Displays system memory usage in human-readable units.

2. Power-User Example (Advanced)

For scripting and advanced diagnostics, use this configuration:

# Advanced
free -hs 5

What it does: Displays memory statistics in human-readable form, refreshing the output every 5 seconds (-s 5).

⚙️ Warning & Common Pitfalls

[!WARNING] Do not judge available memory based on the ‘free’ column alone. Linux uses unused memory for caching (buff/cache). Refer to the ‘available’ column for actual memory capacity.

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

df : Report file system disk space usage.
du : Estimate file space usage.
uname : Print system information.