Bash diff usage. This blog post will provide a .
Bash diff usage. When the diff command is run on regular files, and when it compares text files in different directories, the diff command tells which lines must be changed in the files so that they match. Continue reading for more detailed information, advanced usage scenarios, and tips to master this essential command. 'diff' tries to match each line against each regular expression, starting with the last one given. txt, and the output indicates that ‘World!’ in the first file differs from ‘Planet!’ in the second file. It is a powerful tool that Aug 3, 2025 · This blog post will explore the fundamental concepts of Linux directory diff, its usage methods, common practices, and best practices to help you efficiently compare directories and manage changes. The names old and new should not contain any slashes. > I need to get the dog detailed. g. We look at a few ways we can use the diff command to do this. In other words, for each non-ignorable change, 'diff' prints the complete set of changes in its vicinity, including the ignorable ones. But the ‘diff’ command in Linux has much more to offer. Whether you're a developer tracking changes in source code, a system administrator monitoring configuration file updates, or just someone who wants to know what has changed between two versions of a text document, the `diff` command is an invaluable tool. This concise guide unveils essential commands for efficient file comparison. Pro Vim users go for vimdiff. In the first part of this diff command tutorial series, we discussed the basics of the command, including how it works and how the output it produces can be comprehended. txt’ and ‘file2. This Linux tutorial explains how to use the Linux diff command with syntax and arguments. , ls to list files). Change the color of the output to enhance readability. Dec 28, 2010 · I want to compare file1 with file2 and generate a file3 which contains the lines in file1 which are not present in file2. The diff command compares two files line by line and displays the differences between them. Oct 25, 2023 · In this article, you will learn to use the diff command with its different options to compare differences in files and directory structures. Oct 15, 2023 · Here learn how to use the Linux diff command to compare two files. One powerful tool that facilitates this process is the diff command. This guide covers basic usage, options for ignoring whitespace, side-by-side comparisons, and more, helping you track changes with ease. Aug 30, 2023 · The diff command in Linux is a utility tool that allows you to compare files from the command line. If this config variable is set, diff generation is not performed using the internal diff machinery, but using the given command. I need an analogue of this for the case, when changes are between two Apr 26, 2024 · Instead, you must download the security patch, apply it to the source code, and then recompile the software. Mar 21, 2021 · Learn to use the diff utility in Linux for file comparison and patch creation. Think of it as Git’s way of answering the question, “What’s changed?” When Explore the Linux diff command, a powerful tool for comparing and analyzing text files. `diff` stands for difference, and its primary function is to compare two files or directories and show the differences between them. Through git diff command usage, developers gain clarity about their code modifications before they become permanent parts of the commit history. It comes in very handy when you would like to check if there May 21, 2025 · What is the diff Command and Why Should You Care? The diff command is a core utility in Linux and Unix-like operating systems that compares files line by line and reports the differences between them. It identifies the differences between two files and outputs these changes in a format that can be used to patch one file to become identical to the other. It is. The diff command performs a line-by-line comparison of two files or directories and outputs the differences between them. It can compare single files or the contents of directories. Discover how to expertly compare files using bash diff two files. Discover how to leverage the powerful diff command in Linux to compare files, track changes, and identify differences between text-based documents and directories. Jan 23, 2019 · diff is a mightly command line tool found in most of Unix and Unix-like operating systems. When using hexdumps and text diff to compare binary files, especially xxd, the additions and removals of bytes become shifts in addressing which might make it difficult to see. git difftool is a frontend to git diff and accepts the same options and arguments. Aug 9, 2025 · The Linux diff tool is a versatile and powerful utility for comparing files and directories. This command-line utility lists changes you must apply to make the files identical. How to Use the diff Command The syntax for the diff command is as follows: Discover the powerful tools `diff` and `patch` for file comparison and patching on Linux. This guide provides a detailed introduction to the diff command, covering basic to advanced techniques to help you get the most out of it. Aug 8, 2022 · But there is an easier, hassle-free method to compare files using the Linux command line. It is used to compare files and directories by highlighting the differences between them. In this article, we'll be looking into these interesting and versatile commands to see how to use them. This blog post will delve into the The full documentation for diff is maintained as a Texinfo manual. There will be some notable differences, though, due to the short-sightedness of the diff programmers. Understand the basic syntax, options, and practical examples for comparing files and directories. Mar 18, 2024 · In Bash scripting, understanding the difference between $* and $@ is crucial for handling command-line arguments correctly. diff helps you to find differences between files and directories. txt and the output will be: 2,4c2,4 < I need to run the laundry. < I need to get the car detailed. You can also run the git diff <branch_name1> <branch_name2> command to compare the changes from the first branch with changes from the second branch. Mar 29, 2022 · 4 Diff Comparisons You Need to Know You can run the git diff HEAD command to compare the both staged and unstaged changes with your last commit. Apr 2, 2020 · The command diff from the package diffutils compares files line by line. This guide also covers practical examples and the optimal use scenarios for each tool, serving as a valuable resource for system Jun 2, 2011 · I'm looking to run a Linux command that will recursively compare two directories and output only the file names of what is different. diff compares the files and patch applies the output to other files. Apr 6, 2012 · 6 The best way I found, aside of using a dedicated commit GUI, is to use git difftool -d - This opens your diff tool in directory comparison mode, comparing HEAD with current dirty folder. Can be overridden with the GIT_EXTERNAL_DIFF environment variable. Command substitution `…` substitutes the output of the command into the command line, so diff sees the list of files in both directories as arguments. Arrows show how each diff command lets you see changes between these different stages of your repository. Normally, to compare two files in Linux, we use the diff – a simple and original Unix command-line tool that shows you the difference between two computer files; compares files line by line and it is May 11, 2021 · In this article, we will go through 15 Popular diff command examples in Linux. Bash is like a robot assistant for your computer. Jul 11, 2024 · Some of the most convenient ‘tricks’ on Linux depend on the use of a handful of special characters. Continue reading for more detailed information and advanced usage scenarios. I'd like to merge two files by doing the following: Output the diff of the two files into a temp file and Manually select the lines I want to copy/save. This article will show you how to use it, with some examples of common usage. git diff --cached compares the Index and HEAD (staged but uncommitted changes). Master different modes and streamline file management tasks. The Linux operating system is based on a robust set of command line tools that allow users to easily manage and control the system. This guide provides step-by-step instructions on using `diff` to compare files line by line and `patch` to apply changes, streamlining the management of code and configuration file updates. It is made using the diff command and applied using the patch command. txt file2. In this article, I will explain the frequent uses of the diff command with practical examples. This article explains how to create and apply the diff and patch commands. Widely used to get differences between original files and updated, let's learn how. May 17, 2025 · Conclusion Understanding what is git diff transforms your approach to version control. Apr 19, 2025 · Learn how to effectively use the diff command to compare files and directories in Linux. You will need to understand the symbols and options to use this command. What is the Usage of the diff Command Utility in Linux? To understand the usage of the diff command, three different files are already created in which two files, “myfile1” and “myfile2”, are identical, and “myfile3” is different. For example, consider: File 1 abcde abc abcccd File 2 abcde ab abccc Using diff -u I get: @@ -1,3 +1,3 @@ git difftool is a Git command that allows you to compare and edit files between revisions using common diff tools. If the patch should communicate file timestamps as well as file Aug 5, 2025 · Linux binary diff is a powerful technique that can be used in a variety of scenarios, from software development to system administration. Let's run a simple test case where we will try Jul 24, 2023 · There are several file comparison and diff tools that you can use on Linux, and in this review, we shall look at some of the best CLI and GUI-based diff tools. This blog post will take you on a journey through the fundamental Learn how to use the diff command to compare files line by line in Linux, with examples and options. Mar 14, 2025 · The manual page for the command "git diff". By understanding the fundamental concepts and using the right tools and practices, users can efficiently identify differences between binary files. Here’s a code snippet demonstrating its usage: diff file1. This is a basic way to use the ‘diff’ command in Linux, but there’s much more to learn about this versatile tool. This includes anything that is present in one directory and not Feb 21, 2002 · This manual is for GNU Diffutils (version 3. Options for the diff command in Linux: -y used to display differences in files side by side -s Make sure you have the #!/bin/bash shebang line for your script if you use double brackets. It outputs the differences between two files, making it […] Jul 23, 2025 · Bash scripting is a great way to automate different types of tasks in a system. By showcasing what has changed Jul 18, 2024 · The Linux diff command compares two files line by line and displays the differences. Jan 24, 2013 · 62 If you prefer the diff output style from git diff, you can use it with the --no-index flag to compare files not in a git repository: git diff --no-index a. 5 days ago · The grep command is one of the most useful tools in Linux and Unix systems. It displays the result on your terminal and provides several instructions to modify a file from the command line. Jan 10, 2025 · The diff command in Linux is a powerful utility used to compare files line by line. It can also compare the contents of directories. In this article, we'll cover the basics of this command along with some easy-to-understand examples. Oct 8, 2025 · git diff compares changes between the Working Tree and Index (unstaged changes). patch and diff are found in Linux and other Unix-Like operating systems, such as macOS. We use both variables to represent the command-line arguments passed to a script or function, but they can behave differently. It can bring out the distinction between various versions of commits history and therefore a powerful tool to use in monitoring the project progress. They play a crucial role in version control, code review, and software maintenance. $ man meld Basic Usage of Meld If you have used the Linux diff command previously then you will appreciate Meld once you get started using it. GNU diffUtils Package Oct 5, 2024 · Conclusion The diff command is an essential tool for comparing files and directories in Linux. This command reveals the heart of Git’s power: precise tracking of every character changed across your codebase. Linux Diff Command Instead of directly jumping on to Mar 14, 2020 · Wondering how to use the diff command in Linux and want to know what the Linux diff command is? This article will help you understand the command well and answer the question about the usage of the diff command. I have two text files and want to find the differences between them using Windows Powershell. This article explains how to create a patch for a single file or for a whole directory using diff and how to apply this patch after. This blog post will provide a Jul 19, 2024 · Learn how to use the diff --color command to customize the output colors in Linux programming. git diff HEAD compares the Working Tree to the HEAD commit (all local changes). This comprehensive guide from a Linux expert will teach you how to truly master the diff command through actionable insights and real-world use case walkthroughs. This tool is invaluable for developers and system administrators, offering insights into changes made between versions of scripts, codebases, text files, and configurations. Assuming that Jun 3, 2024 · In this tutorial, you will learn how you can use the diff command on your Linux system to easily compare files within the terminal. Jul 12, 2024 · In the world of Linux, managing and comparing files is a common task for system administrators and developers alike. If you don't know how diff works and are looking for a quick tutorial to get you started, you've come to the right place. See also Bash FAQ - "What is the difference between test, [ and [ [ ?" Bash Practices - Bash Tests Server Fault - What is the difference between double and single brackets in bash? Jul 15, 2015 · The output of diff -u command is formatted a bit differently (so called "unified diff" format). The diff command is used to compare files line by line. txt and file2. This tutorial explains Linux “diff” command, options and its usage with examples. Whether you’re working with configuration files, source code, or text files, diff helps you identify changes and differences with precision. Multiple single letter options (unless they take an argument) can be combined into a single command line word: -ac is equivalent to Jul 31, 2025 · In the world of Linux, file management and version control are crucial aspects of system administration and software development. Nov 5, 2023 · Sometimes in Linux, we wish to compare text. Run man meld to familiarize yourself with all the available options. txt Understanding the Basics of Bash Diff What is Bash Diff? `bash diff` is a powerful command-line utility found in Unix-like operating systems that allows users to compare the content of files. See git-diff [1]. One of the most powerful and widely used command line utilities is the "diff" command. The command will output the differences between these two files, line by line. txt Using a couple of files with around 200k file name strings in each, I benchmarked (with the built-in time command) this approach vs some of the other answers here: Oct 12, 2017 · then we can use diff to automatically display for us which lines differ between the two files with this command: diff file1. The differences can be stored in a file called a patch file. From the diff manpage: -b, --ignore-space-change ignore changes in the amount of white space -w, --ignore-all-space ignore all white space From this, I infer that the difference betwe Nov 12, 2009 · I'd like to use 'diff' to get a both line difference between and character difference. The diff command examines two different versions of a file and lists the differences between them. This post looks at a number of command operators on Linux and shows how they work. Jul 27, 2025 · In the world of Linux and software development, the `diff` and `patch` utilities are indispensable tools. It is used to search for specific words, phrases, or patterns inside text files, and shows the matching lines on your screen. diff is a part of GNU Project and is freely available on Linux platform. With examples shows how it can list the changes to the standard output. Learn essential Linux file comparison techniques using diff command, explore colorful visualization tools, and master practical file comparison skills for developers and system administrators. If the info and diff programs are properly installed at your site, the command info diff should give you access to the complete manual. It displays the differences between the working directory and the staging area or between two commits, branches, or tags. txt’. diff has an option, -I regexp, which ignores changes that just insert or delete lines that match the given regular expression. It helps you manage configurations, troubleshoot changes, and maintain consistency. < I need to wash the dog. Is there something similar to the Unix diff tool available? Or is there another other way I haven't Sep 15, 2021 · To compliment diff commands, Linux also provides another command to apply changes from one file to another called patch . Mar 5, 2025 · Git diff is your window into the changes happening in your code repository. One of the most powerful and widely used tools for comparing files is the `diff` command. By understanding its fundamental concepts, usage methods, common practices, and best practices, you can efficiently manage file revisions and identify changes. Use the diff command to compare text files. It lets you control your Linux/Unix system by typing commands (e. Basic Usage diff -rq directory1 directory2 -r: Looks through all subdirectories or recursively compares subdirectories. Example of grep Command in Linux grep Command is useful when you need to quickly find certain keywords or phrases in logs or documents. Explore the essential file comparison tools `diff` and `cmp` on Unix systems. Utilizing the diff Command (Via Command Line) With the use of the diff command, examining two directory details is simple. Jan 2, 2024 · This command compares the contents of file1. Learn how to apply diff patch. Jun 1, 2025 · Linux diff command help and information with diff examples, syntax, related commands, and how to use the diff command from the command line. diff is a powerful Bash command that compares two files line by line or two directories This is vastly inefficient as opposed to using cmp instead. Example 1: Search for a word in a file If you have a file Jun 5, 2019 · That's where patch and diff come into play. Oct 30, 2019 · To compare two files in Linux, diff command is used. Jul 23, 2025 · 1. Most options have two equivalent names, one of which is a single letter preceded by ‘ - ’, and the other of which is a long name preceded by ‘ -- ’. The Linux diff package is a command-line tool that is used to find the differences between two files. Oct 16, 2024 · Learn how to use the diff command in Linux with this step-by-step tutorial. The Linux command line is very powerful and provides a file comparison utility within vim to differentiate files side by side. diff Options (Comparing and Merging Files)Below is a summary of all of the options that GNU diff accepts. `diff` offers detailed, line-by-line comparisons for text files, ideal for tracking changes, while `cmp` conducts a byte-by-byte analysis suitable for all file types, including binaries. Developers can avoid doing repetitive tasks using bash scripting. Dec 11, 2023 · In this example, we use the ‘diff’ command to compare the contents of ‘file1. Aug 25, 2021 · Git diff command helps to show a comparison between files, branches, tags and commits that make up a commit-tree. This page provides detailed information about how to use the command, its options, and examples. Aug 31, 2024 · If you are working with data or codes, you may have to compare two files, or the content in two directories. Otherwise, a good method is the command diff -Naur old new where old and new identify the old and new directories. Learn installation tips, basic and advanced usage through practical examples, and explore further resources to Mar 18, 2024 · In this tutorial, we’ll develop a hands-on understanding of file comparison in Linux using the diff command. May 18, 2021 · The diff command is an easy way to compare files or directories from the Linux shell. Learn its syntax, practical examples, and advanced options to effectively manage and process text data. Oct 5, 2023 · The diff command is used to compare two files and display the differences between them, including changes, deletions, and additions. It is also very much possible to use the Meld from the command line interface. Jun 13, 2025 · In the world of Linux, file comparison is a common and essential task. The "diff" command in Linux is used to compare the contents of two files line by line and show the difference between them. Dec 27, 2023 · The built-in ‘diff’ command has been the go-to differencing solution on Linux/Unix systems for decades thanks to its versatility, power and ubiquity. Jan 12, 2025 · The diff command originated in Unix systems and was created by Douglas McIlroy in 1974. It identifies Learn how to compare two files in Linux using the diff command with syntax, options, and practical examples. --- > I need to do the laundry > I need to wash the car. What you want is for diff to see two file names on its command line, and have the contents of these files be the directory listings. On Linux, you can use the diff command to compare two files, but there is a bit of a learning curve with this utility. The output of the diff command includes line numbers and labels to indicate the type of difference (change, deletion, or addition). Mar 13, 2024 · Invoke the Meld application and get ready to use its GUI. Learn to understand the diff command output. COLOPHON top This page is part of the diffutils (GNU diff utilities) project. The ability to compare files line by line is crucial for identifying differences, debugging code, and ensuring the integrity of data. Here diff shows us a single piece of the text, instead of two separate texts. Order does matter when you're comparing branches. The problem here is that diff -u only gives When using a version control system this should be easy; for example, with Git you can use git diff. Dec 17, 2024 · The diff command is a powerful utility prevalent in Unix-based systems, such as Linux and macOS. 2. `diff` is used to compare two files or directories and identify the differences between them, while `patch` is used to apply those differences to a target file or set of files. txt b. Jul 21, 2023 · In an earlier article, we reviewed 9 best file comparison and difference (Diff) tools for Linux and in this article, we will describe how to find the difference between two directories in Linux. While there's definitely a bit of learning curve involved with this command line utility, it's worth learning especially if your daily work involves performing file-related tasks on a CLI-only Linux machines. Nov 25, 2019 · diff is a command-line utility that allows you to compare two files line by line. Dec 5, 2024 · The Linux diff command is a crucial tool for comparing files and directories. Jun 8, 2023 · The commands diff and patch form a powerful combination. It looks through files in the directories and folders for any changes and highlights them. It uses the longest common subsequence algorithm to identify differences between files. With options to ignore white space, display changes side by side, or provide unified context, it offers flexibility for both simple and complex comparisons The `diff` command in Bash is used to compare two files line by line and output the differences between them. Mar 19, 2020 · What is the difference between using [[ condition ]] and [ condition ] or (( condition )) and ( condition )? In what scenario do we need to use either of these? (( 10 > 9 )) works but (( 10 -gt Jul 23, 2025 · The git diff command is the most straightforward way to see the differences between the two branches. At its core, it’s a command that shows you the differences between various states of your files — whether that’s comparing your current work against what you’ve already staged or comparing changes between branches and commits. But its output could be overwhelming to you. diff is a much slower and more expensive tool, and you only need to use it when you want to know exactly what the difference is, not whether there is one or not. Oct 10, 2024 · In Linux, there are several powerful file comparison and difference tools available, ranging from command-line utilities to graphical applications that provide visual representations of changes. Dec 27, 2016 · diff is the Linux command line tool that is used for creating patches (sometimes called diffs) and requires that you have two copies of the code: one with your changes and one without. The main usage of the diff command is to find the difference between two files in Linux. Aug 23, 2025 · Want to see the difference between two files? Normal users use diff command. Learn about git diff and how it helps with saving changes. You can specify more than one regular expression for lines to ignore by using more than one '-I' option. A patch file contains the differences between two versions of the same file or source code. Information about the project can be found at May 1, 2025 · This detailed guide explains how to compare files and directories in Linux using the diff command with practical examples. Learn more about the diff command, its syntax, options, and use-case examples. Why would you want to compare files or directories? May 21, 2025 · Use diff and patch tools to compare and change files. 12, 12 January 2025), and documents the GNU diff, diff3, sdiff, and cmp commands for showing the differences between files and the GNU patch command for using their output to update files. The diff command is most commonly used to create a patch containing the differences between one or more files that can be applied using the patch command. There are various options available for using the diff command, such as displaying a brief statement about file differences, side Aug 30, 2022 · Using only bash, diff, tput, and less, we can closely approximate the output of git diff. It is a part of the GNU Core Utilities and is available on most Linux distributions. Git diff is a multi-use Git command that when executed runs a diff function on Git data sources. jl9jki ldlfw rwcm qo77pay we7czsaxn mwke tqcmyda7 mdfy5w abin8 z0fpnq