Linux Terminal Command: patch

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

Concept & Explanation

The patch command applies modifications generated by the diff command to an original source file.

Common Options & Syntax

patch [options] [arguments]

Here are the most common flags used with patch:

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
patch original.txt < patch.diff

What it does: Applies changes listed in ‘patch.diff’ to ‘original.txt’.

2. Power-User Example (Advanced)

For scripting and advanced diagnostics, use this configuration:

# Advanced
patch -R original.txt < patch.diff

What it does: Reverses the patch (-R), reverting ‘original.txt’ back to its state before the patch was applied.

⚙️ Warning & Common Pitfalls

[!WARNING] If the original file was modified after the diff was created, patch can fail or create temporary rejection files (.rej).

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

diff : Compare files line by line.