combinediff Command in Linux

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Combinediff is a command line utility in Linux that belongs to the patchutils package. This command is used to combine various unified diffs into a single patch. It creates a cumulative unified patch from multiple incremental patches. This command is particularly useful when there are multiple patches for the same file that need to be combined in sequence.

Table of Contents

This tutorial is a step-by-step guide on installing and using the combinediff command in Linux.

• How to Install combinediff Command in Linux?
• How to Use combinediff Command in Linux?
• Examples of combinediff Command in Linux

How to Install combinediff Command in Linux?

The combinediff command is part of the patchutils package, which is not typically pre-installed on most Linux distributions. Therefore, you generally need to install it manually. Different Linux distributions use different package managers to install packages like patchutils.

We can install combinediff command on Debian-based systems using the apt package manager, as follows −

sudo apt install patchutils

To install, this command on CentOS or RHEL, we can use the yum package manager, as follows −

sudo yum install patchutils

Similarly, we can use the dnf package manager to install the patchutils package on Fedora −

sudo dnf install patchutils

The pacman package can be used to install the combinediff command on Arch Linux −

sudo pacman -S patchutils

Step 1: Install combinediff Command

Here, we are using Ubuntu 24.04, and we will use the apt package manager to install patchutils on our system −

sudo apt install patchutils

The patchutils package including the combinediff command has been successfully installed on our system −

Step 2: Verify combinediff Installation

We can verify the combinediff installation by checking its version as follows −

combinediff --version

The output shows that we are using ptachutils version 0.4.2 on our system −

Step 3: Access combinediff Manual Page

After successfully installing the patchutils package on your system, you can access the manual page for the combinediff command to learn more about it −

man combinediff

Alternatively, you can also access the help page of this command to explore its basic usage and valid options −

combinediff -h

How to Use combinediff Command in Linux?

combinediff creates a unified diff that merges two diffs. The diff files must be listed in the order they are to be applied and should have at least three lines of context for best results. The combinediff cannot inspect the original files, therefore, it has stricter input format requirements than patch(1). GNU diff output is acceptable, but hand-edited patches may need adjustments using recountdiff(1).

Note: The patches must be in strict incremental order, meaning the second patch should be relative to the state after applying the first patch. While the input diffs can be in context format, the output will always be in unified format.

Basic Syntax of combinediff Command

To use the combinediff command in Linux, you must execute the below-mentioned syntax −

combinediff [Options] patch1 patch2

Here, [Options] represents the optional flags or arguments that are used to customize the functionality of the combinediff command. patch1 and patch2 represent the patch files that need to be combined.

combinediff Command Options

Combinediff command supports several options, some of which are listed in the following table along with their description −

Examples of combinediff Command in Linux

Let’s go through the following examples to learn how the combinediff command works in Linux −

• combinediff Command Basic Usage
• Combine Two Patches and Pipe Them to a File
• Combine Two Diffs and Show Output on Terminal

combinediff Command Basic Usage

Suppose we have two patch files “diffFile.patch” and “fileDiff.patch”. To combine these patch files, we can run the combinediff command as follows −

combinediff diffFile.diff fileDiff.diff > combinedDiff.diff

The combinediff command combines the diffFile.patch and fileDiff.patch files and redirects the output to the combineDiff.patch file.

Combine Two Patches and Pipe Them to a File

We can use the combinediff command to combine two patches and apply them to a file, as follows −

combinediff diffFile.diff fileDiff.diff | patch -p1 exampleFile.txt

This command will combine the diffFile and fileDiff and apply the changes to the exampleFile.txt.

Combine Two Diffs and Show Output on Terminal

We can view the output of the combined diff directly on the terminal. For this purpose, we must use the following syntax −

combinediff diffFile.diff fileDiff.diff | less

Similarly, you can use different options with the combinediff command to combine and manage patch files efficiently in Linux systems.

Conclusion

combinediff is a useful command-line utility in Linux that is a part of the patchutils package. It is designed to merge multiple unified diffs into a single patch file. It serves as a crucial tool for integrating incremental changes across files efficiently.

In this tutorial, we explored how to install and utilize combinediff commands efficiently in Linux. We started by installing patchutils on various Linux distributions, such as Ubuntu, CentOS, Fedora, and Arch Linux, using their respective package managers. After installation, we verified its presence and accessed the manual pages for detailed usage instructions. Finally, we discussed the usage of the combinediff command using some practical examples.