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How to Check OS Version in Linux

How to Check OS Version in Linux
Hostman Team
Technical writer
Linux
05.03.2024
Reading time: 11 min
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The popularity of the powerful and versatile Linux operating system lies in the variety of available versions. From Ubuntu to Red Hat, from Mint to Fedora, each Linux version offers users unique features and benefits. Hostman offers a reliable managed Linux VPS. It is important to check Linux OS version for compatibility, as varied versions have different software requirements.

Using an older version may not allow you to install and run the latest software updates. Some hardware components may not be supported by certain Linux versions. Knowing your OS version can help you troubleshoot any compatibility issues. Therefore, it is important to check the Linux OS version and know which one you're using.

Knowing your OS version in Linux is obligatory for security reasons. All operating systems release updates to address security vulnerabilities, and Linux is no exception. If you know your OS version, you can be sure that the necessary security updates are installed. This is especially important for businesses and organizations dealing with confidential information and requiring strong security control.

Another reason for checking Linux OS version is for support purposes. Various versions differentiate by support lifecycles. They have limited time to receive updates and support from developers. Knowing your OS version gives you an idea of ​​when it needs to be updated. An unsupported Linux version can leave your system vulnerable to security threats and compatibility issues.

What is a Linux Version

A Linux version, commonly termed a distro or distribution, is a customized version of the Linux operating system. It comes with a tailored mix of software, desktop environments, and functionalities. These distributions are custom-made to meet the varied needs and desires of their users. This comprises everything from individual PC users to huge corporations. Linux's open-source nature and flexibility enable various people and organizations to create and modify these distributions to meet specific needs.

For example:

  • Distributions such as Ubuntu, Debian, and Linux Mint are pretty useful for beginners because they offer user-friendly interfaces, extensive documentation, and a strong community network.

  • Advanced distributions like Arch Linux grant unparalleled customization and autonomy, ideal for users who prefer crafting their systems from the ground up.

  • Server-oriented distributions like CentOS and Red Hat Enterprise Linux (RHEL) are engineered for reliability, security, and top-tier performance, making them perfect for enterprise environments and critical applications.

  • Specialized distributions like Kali Linux for security testing and Tails for anonymity are designed for specific purposes.

A typical Linux distribution includes the Linux kernel (which controls hardware), a package manager (for installing and updating applications), and a set of default applications. The desktop environment (like GNOME, XFCE, or KDE) can be tailored in appearance and functionality to align with user preferences.

Popular Linux distributions and their versions

It’s important to check the Linux OS version as the operating system offers a large selection of distributions, each with its own unique features and characteristics. Common forms include Ubuntu, Debian, Red Hat, CentOS, Fedora and Mint.

Ubuntu is famous for its user-friendly interface and regular updates. Debian is known for its strict adherence to free software principles. Red Hat Enterprise Linux (RHEL) offers a stable and secure platform for businesses. CentOS provides similar features to users for free. Fedora is distinguished by its frequent updates and use of the latest software. Mint features a more traditional desktop environment.

Each version differs in software, desktop environment, and support lifecycle. Each distribution has various versions or releases with different code names and updates. Ubuntu has editions such as Bionic Beaver, Cosmic Cuttlefish and Disco Dingo, while Fedora has editions such as Silverblue and Workstation. They satisfy different needs and preferences of a wide range of users.

Each Linux distribution has its own unique version numbering system, because it is an open-source operating system developed and maintained by a community of developers. Therefore, each distribution has its own set of developers who make decisions about naming and numbering their releases. Users can easily determine which version they are using and what changes have been made since the last update, and developers can track their progress and plan future releases. 

Typically a three-level version numbering system with numbers separated by dots is used. The first number is a major release for updates or changes to the distribution, the second number is a minor release for bug fixes, security updates, and minor feature additions, the third number is a hotfix release for minor bug fixes and updates.

Ubuntu uses a version numbering system in the format 'XX.YY.ZZ', where the first number is a year, the second is a month of release, and the third number is incremented with each new release that month. The system displays the age of release and frequency of updates.

Code names, such as names of animals or cities, are also used to recognize releases of Linux distributions. Fedora uses code names for its releases like 'Bordeaux' and 'Heisenbug' to make it easier for users to navigate the different versions.

There are many ways to find out the version of the Linux operating system and get distribution information about it. We’ll cover the most commonly used. Read on to learn how to check OS version in Linux.

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How to check the Linux OS version through the 'lsb_release' command

You can apply the lsb_release command to check the Linux OS version. You’ll receive detailed information about the distribution, release, and codename of your operating system.

  1. To start, open the terminal;

  2. Type the command:

lsb_release -a

  1. Press Enter to view a list of information displayed in your terminal.

C56d4f7a 2f24 4048 Be0c 67c63857aca6

  • The Distributor ID line is a name of your Linux distribution, for instance, Ubuntu, Fedora, or CentOS.

  • The Description line is a brief description of your Linux distribution with details such as the release number and the codename of your system.

  • The Release line is a display of the specific version of your Linux distribution, such as '18.04' for Ubuntu or a name like 'Bionic Beaver.'

  • The Codename line is your system’s codename assigned to each version of a Linux distribution, such as 'Bionic Beaver' for Ubuntu 18.04.

How to check the OS version in Linux through the 'cat /etc/os-release' command

You can apply the cat /etc/os-release command to check the OS version in Linux. It will help you quickly determine your OS version and show detailed information.

  1. To start, open the terminal; 

  2. Type the command:

cat /etc/os-release

  1. Press Enter to view a list of information displayed on your terminal.

1045c272 3aba 450d 967f 5019a859f72e

  • The ID field is the name of your Linux distribution, such as Ubuntu or CentOS.

  • The VERSION_ID field is the specific version of that distribution, such as Ubuntu 18.04 or CentOS 7.

The cat /etc/os-release command shows other useful information about your operating system, such as the name and version of the operating system kernel, the desktop environment or window manager you are using, and the OS build and release date.

How to check version of OS in Linux through the 'uname -a' command

You can apply the uname -a command to check the Linux OS version. It displays detailed information about your system's kernel version, architecture, processor type, hostname, and even the date and time of the last system boot.

  1. To start, open the terminal; 

  2. Type the command:

uname -a

  1. Press Enter to view a list of information displayed on your terminal.

Uname

The output typically includes the Linux operating system kernel version and system architecture to ensure that you download and install the correct version of the software, avoiding compatibility issues and potential bugs. The command also provides information about the last time the system booted for analyzing system performance and identifying potential problems.

Other ways to check OS version in Linux

  • The hostnamectl command

This is a new way to check the Linux OS version, available on systems using systemd. It provides more detailed data than previous methods, including kernel version, architecture, and hardware platform.

  1. To get the output, open the terminal; 

  2. Type the command:

hostnamectl

  1. Press Enter to view a list of information displayed on your terminal.

C44fdb8b A09a 4a03 A1d4 8d35d06fe483

  • The /etc/os-release file

The /etc directory contains configuration files and scripts used by the system, including the os-release file with information about the OS version

To get the output, open the terminal and enter the command:

cat /etc/os-release

83621b31 F710 4db3 A72a B70fcaee3e61

  • The /etc/issue file

This file with system information is used for login prompts as well as for checking the OS version in Linux.

To get the output, enter the command:

cat /etc/issue

F6085c18 3b4d 49bb B4c5 277389d53352

The name and version of the operating system are displayed here.

  • The version file

Some Linux distributions have a version file in the /etc directory with information about the distribution and version.

To get the output, open the terminal and enter the command:

cat /etc/version

The distribution name and version number are displayed here.

How to Check Linux OS Version Using GUI

This operating system has several ways to check your OS version. We have already explored the common methods through the command line interface. Now let’s learn how to check the Linux OS version without command. This is where the graphical user interface (GUI) comes into play, offering a convenient way to access system information.

You need to access the system settings:

  1. To start, click on the 'Activities' button on the top-left corner of the screen;

  2. Enter 'system' in the search bar;

  3. Navigate to the 'System Settings' window and click the 'Details' option to display the OS name, version, and other system information in a new window.

Checking the OS version in any Linux distribution is similar and differs slightly only in names of the buttons or windows in the search bar:  

  • In Ubuntu click on the 'Activities' button and type 'System Settings' in the search bar, then navigate to the 'Details' tab.

  • In Fedora click on the 'Show Applications' button and type 'Settings' in the search bar, then navigate to the 'About' tab.

  • In CentOS click on the 'Applications' button and navigate to 'System Tools' and then 'Settings', then navigate to the 'System' tab.

Checking the OS Version in Linux FAQ

Let's go over a few frequently asked questions about Linux OS versions.

Why is it vital to check the OS version in Linux?

Verifying the OS version in Linux is essential for ensuring compatibility, maintaining security, and accessing support. Each version has distinct software prerequisites, life cycle durations, and security patches.

How often should I check my Linux OS version?

Consistently verifying your OS version is crucial, especially before adding new software or updates. This practice keeps your system current and secure.

What are some of the widely recognized Linux distributions?

Some widely recognized Linux distributions are Ubuntu, Debian, Kali Linux, Raspberry Pi, CentOS, Fedora, and Linux Mint. Each one boasts unique features designed to cater to the diverse needs of its user base.

Can I check the Linux OS version using a GUI?

Yes, you can check the Linux OS version via the GUI by heading to the system settings and locating the 'Details' or 'About' section, depending on your particular distribution.

Why do various Linux distributions have unique version numbering systems?

Each Linux distribution is developed and maintained by a different community or organization. Consequently, they all have unique version numbering systems to monitor progress and schedule future releases. For instance, Ubuntu's version number format is 'XX.YY.ZZ', where 'XX' denotes the year, 'YY' indicates the month of release, and 'ZZ' increments with each new release within that month.

Conclusion

Linux OS versions vary in underlying architecture, package management system, desktop environment, security features, compatibility, and release cycles. Each version has its own unique set of features and benefits, so users can choose the one that best suits their needs and preferences. Understanding your Linux OS version helps you in troubleshooting and solving problems, providing a better insight into the system's capabilities and limitations, allowing you to make informed decisions when it comes to upgrading or modifying the system.

Now you have learned the different methods on how to check OS version in Linux through special commands or using GUI. Choose the best way for yourself and use it. Regularly checking and updating your Linux OS version is a good practice to ensure productive and hassle-free operation of your computer. This ensures that the system is running the latest version and all necessary security protocols are installed.

Linux
05.03.2024
Reading time: 11 min
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Bash Regular Expressions

One of the core principles of Unix systems is the extensive use of text data: configuration files, as well as input and output data in *nix systems, are often organized as plain text. Regular expressions are a powerful tool for manipulating text data. This guide delves into the intricacies of using regular expressions in Bash, helping you fully harness the power of the command line and scripts in Linux. What Are Regular Expressions? Regular expressions are specially formatted strings used to search for character patterns in text. They resemble shell wildcards in some ways, but their capabilities are much broader. Many text-processing utilities in Linux and programming languages include a regular expression engine. However, different programs and languages often employ different regular expression dialects. This article focuses on the POSIX standard to which most Linux utilities adhere. The grep Utrequires at least one match of theility The grep program is the primary tool for working with regular expressions. grep reads data from standard input, searches for matches to a specified pattern, and outputs all matching lines. grep is typically pre-installed on most distributions. You can try the commands in a virtual machine or a VPS to practice using regular expressions. The syntax of grep is as follows: grep [options] regular_expression [file...] The simplest use case for grep is finding lines that contain a fixed substring. In the example below, grep outputs all lines that contain the sequence nologin: grep nologin /etc/passwd Output: daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin bin:x:2:2:bin:/bin:/usr/sbin/nologin sys:x:3:3:sys:/dev:/usr/sbin/nologin games:x:5:60:games:/usr/games:/usr/sbin/nologin ... grep has many options, which are detailed in the documentation. Here are some useful options for working with regular expressions: -v — Inverts the match criteria. With this option, grep outputs lines that do not contain matches: ls /bin | grep -v zip# Output:411toppm 7z 7za 7zr ... -i — Ignores case. -o — Outputs only the matches, not the entire lines: ls /bin | grep -o zip# Output:zip zip zip zip ... -w — Searches for lines containing whole words matching the pattern. ls /bin | grep -w zip# Output:gpg-zipzip For comparison, the same command without the -w option also includes lines where the pattern appears as a substring within a word. ls /bin | grep zip# Output:bunzip2 bzip2 bzip2recover funzip Basic Regular Expressions (BRE) As previously mentioned, there are multiple dialects of regular expressions. The POSIX standard defines two main types of implementations: Basic Regular Expressions (BRE), which are supported by almost all POSIX-compliant programs, and Extended Regular Expressions (ERE), which allow for more complex patterns but aren't supported by all utilities. We'll start by exploring the features of BRE. Metacharacters and Literals We've already encountered simple regular expressions. For example, the expression “zip” represents a string with the following criteria: it must contain at least three characters; it includes the characters “z”, “i”, and “p” in that exact order; and there are no other characters in between. Characters that match themselves (like “z”, “i”, and “p”) are called literals. Another category is metacharacters, which are used to define various search criteria. Metacharacters in BRE include: ^ $ . [ ] * \ - To use a metacharacter as a literal, you need to escape it with a backslash (\). Note that some metacharacters have special meanings in the shell, so enclose it in quotes when passing a regular expression as a command argument. Any Character The dot (.) metacharacter matches any character in that position. For example: ls /bin | grep '.zip' Output: bunzip2 bzip2 bzip2recover funzip gpg-zip gunzip gzip mzip p7zip pbzip2 preunzip prezip prezip-bin streamzip unzip unzipsfx One important detail: the zip program itself isn’t included in the output because the dot (.) metacharacter increases the required match length to four characters. Anchors The caret (^) and dollar sign ($) in regular expressions serve as anchors. This means that, when included, a match can only occur at the start of a line (^) or at the end ($). ls /bin | grep '^zip'# Output:zip zipcloak zipdetails zipgrep …ls /bin | grep 'zip$'# Output:funzip gpg-zip gunzip ...ls /bin | grep '^zip$'# Output:zip The regular expression ^$ matches empty lines. Character Sets Besides matching any character in a given position (.), regular expressions allow for matching a character from a specific set. This is done with square brackets. The following example searches for strings matching bzip or gzip: ls /bin | grep '[bg]zip'# Output:bzip2bzip2recovergzip All metacharacters lose their special meaning within square brackets, except two. If a caret (^) is placed immediately after the opening bracket, the characters in the set are treated as excluded from that position. For example: ls /bin | grep '[^bg]zip' Output: bunzip2 funzip gpg-zip gunzip mzip p7zip preunzip prezip prezip-bin streamzip unzip unzipsfx With negation, we get a list of filenames containing zip but preceded by any character other than b or g. Note that zip is not included here; the negation requires the presence of some character in that position. The caret serves as a negation only if it appears immediately after the opening bracket; otherwise, it loses its special meaning. Using a hyphen (-), you can specify character ranges. This lets you match a range of characters or even multiple ranges. For instance, to find all filenames that start with a letter or a number: ls ~ | grep '^[A-Za-z0-9]' Output: backup bin Books Desktop docker Documents Downloads GNS3 ... POSIX Character Classes When using character ranges, one challenge is that ranges can be interpreted differently based on locale settings. For instance, the range [A-Z] may sometimes be interpreted lexicographically, potentially excluding lowercase a. To address this, the POSIX standard provides several classes that represent various character sets. Some of these classes include: [:alnum:] — Alphanumeric characters; equivalent to [A-Za-z0-9] in ASCII. [:alpha:] — Alphabetic characters; equivalent to [A-Za-z] in ASCII. [:digit:] — Digits from 0 to 9. [:lower:] and [:upper:] — Lowercase and uppercase letters, respectively. [:space:] — Whitespace characters, including space, tab, carriage return, newline, vertical tab, and form feed. Character classes don’t provide an easy way to express partial ranges, like [A-M]. Here’s an example of using a character class: ls ~ | grep '[[:upper:]].*' Output: Books Desktop Documents Downloads GNS3 GOG Games Learning Music ... Extended Regular Expressions (ERE) Most POSIX-compliant applications and those using BRE (such as grep and the stream editor sed) support the features discussed above. The POSIX ERE standard allows for more expressive regular expressions, though not all programs support it. The egrep program traditionally supported the ERE dialect, but the GNU version of grep also supports ERE when run with the -E option. In ERE, the set of metacharacters is expanded to include: ( ) { } ? + | Alternation Alternation allows for a match with one of multiple expressions. Similar to square brackets that allow a character to match one of several characters, alternation allows for matching one of multiple strings or regular expressions. Alternation is represented by the pipe (|): echo "AAA" | grep -E 'AAA|BBB'# Output:AAA echo "BBB" | grep -E 'AAA|BBB'# Output:BBB echo "CCC" | grep -E 'AAA|BBB'# Output: (no match) Grouping You can group elements of regular expressions and treat them as a single unit using parentheses. The following expression matches filenames starting with bz, gz, or zip. Without the parentheses, the regular expression would change meaning to match filenames starting with bz or containing gz or zip. ls /bin | grep -E '^(bz|gz|zip)' Output: bzcat bzgrep bzip2 bzip2recover bzless bzmore gzexe gzip zip zipdetails zipgrep zipinfo zipsplit Quantifiers Quantifiers specify the number of times an element can occur. BRE supports several quantifiers: ? — Matches the preceding element zero or one time, meaning the previous element is optional: echo "tet" | grep -E 'tes?t'# Output:tet echo "test" | grep -E 'tes?t'# Output:test echo "tesst" | grep -E 'tes?t'# Output: (no match) * — Matches the preceding element zero or more times. Unlike ?, this element can appear any number of times: echo "tet" | grep -E 'tes*t'# Output:tet echo "test" | grep -E 'tes*t'# Output:test echo "tesst" | grep -E 'tes*t'# Output:tesst + — Similar to *, but requires at least one match of the preceding element: echo "tet" | grep -E 'tes+t'# Output: (no match) echo "test" | grep -E 'tes+t'# Output:test echo "tesst" | grep -E 'tes+t'# Output:tesst In BRE, special metacharacters { and } allow you to specify minimum and maximum match counts for the preceding element in four possible ways: {n} — Matches if the preceding element occurs exactly n times. {n,m} — Matches if the preceding element occurs at least n and at most m times. {n,} — Matches if the preceding element occurs n or more times. {,m} — Matches if the preceding element occurs no more than m times. Example: echo "tet" | grep -E "tes{1,3}t"# Output: (no match) echo "test" | grep -E "tes{1,3}t"# Output:test echo "tesst" | grep -E "tes{1,3}t"# Output:tesst echo "tessst" | grep -E "tes{1,3}t"# Output:tessst echo "tesssst" | grep -E "tes{1,3}t"# Output: (no match) Only the lines where s appears one, two, or three times match the pattern. Regular Expressions in Practice To conclude, let’s look at a couple of practical examples of how regular expressions can be applied. Validating Phone Numbers Suppose we have a list of phone numbers where the correct format is (nnn) nnn-nnnn. Out of a list of 10 numbers, three are incorrectly formatted. cat phonenumbers.txt Output: (185) 136-1035 (95) 213-1874 (37) 207-2639 (285) 227-1602 (275) 298-1043 (107) 204-2197 (799) 240-1839 (218) 750-7390 (114) 776-2276 (7012) 219-3089 The task is to identify the incorrect numbers. We can use the following command: grep -Ev '^\([0-9]{3}\) [0-9]{3}-[0-9]{4}$' phonenumbers.txt Output: (95) 213-1874(37) 207-2639(7012) 219-3089 Here, we used the -v option to invert the match and output only lines that do not match the specified format. Since parentheses are considered metacharacters in ERE, we escaped them with backslashes to treat them as literals. Finding Improper File Names The find command supports checking paths with regular expressions. It’s important to note that, unlike grep which matches parts of lines, find requires the whole path to match. Suppose we want to identify files and directories containing spaces or potentially problematic characters. find . -regex '.*[^-_./0-9a-zA-Z].*' The .* sequences at the beginning and end represent any number of any characters, which is necessary because find expects the entire path to match. Inside the square brackets, we use negation to exclude valid filename characters, meaning any file or directory name containing characters other than hyphens, underscores, digits, or Latin letters will appear in the output. Conclusion This article has covered a few practical examples of Bash regular expressions. Creating complex regular expressions might seem challenging at first. But over time, you’ll gain experience and skill in using regular expressions for searches across various applications that support them.
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How to Use DNF to Manage Packages on CentOS

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How to Use the diff Command in Linux

The diff command in Linux is a powerful tool that allows users to compare files and directories. With the help of this command, one can identify differences between files, and perform tasks like code reviews, configuration management, and version control.  This tutorial will guide users through what is the diff command, its possible methods, and practical examples. Introduction The diff command is used in Linux to compare the content of two files line by line. When executed, this command analyzes the two files and outputs the differences in a specific format. The output shows which lines need to be added, deleted, or changed to make the files identical. Basic Syntax and Options for diff The basic syntax for the Linux diff command is provided below: diff [options] file1 file2 Here, diff is the command itself. [options] are optional flags used to modify the behavior of the diff Linux command. file1 and file2 are the two files used for Linux file comparison. The following table describes a few options that can be used with diff: Option Description -a Process every file as a text file and perform a line-by-line comparison. -b Does not consider white space differences. -c Show differences with a few lines of context around them. -d Opt for a different algorithm to pinpoint a more concise set of changes. -e Output an ed script. -E Ignore changes due to tab expansion. --binary Compare files in binary mode. -i Ignore case differences in file contents. -l Paginate the output through pr. -N Treat absent files as empty. -q Report only when files differ. -s Report when files are identical. -u Display output in a unified format, showing differences more compactly. -w Ignore all white space. For more details and to explore more options, the users can get help by opening the diff manual using the following command: man diff Comparing Two Text Files Using diff There are two ways to compare files on Linux with diff. Basic Comparison of Two Text Files The basic way to use the diff in Linux is to compare two files line by line and display their differences. To compare two text files, file1.txt and file2.txt, one can use the following command: diff file1.txt file2.txt This command will output the differences between file1.txt and file2.txt. Display Differences in a Unified Format For a more readable format, the -u option can be used with diff. This option provides a unified format that includes a few lines of context around the differences. This makes it easier to understand the changes. Follow the command provided below: diff -u file1.txt file2.txt The unified format output includes line numbers, context lines, and change indicators. Lines starting with - indicate deletions, lines starting with + indicate additions and lines starting with a space are unchanged context lines. Using diff for Directory Comparisons The Linux command diff can also be used to compare directories, it can be done using the -r option. For example: diff -r dir1 dir2 The above command when executed will recursively compare all files and subdirectories within dir1 and dir2. Understanding diff Output and Symbols The diff output uses specific symbols to indicate changes, these are provided below: ---: Denotes the first file. +++: Denotes the second file.  @@ -1,4 +1,4 @@: This line is part of the unified diff format. It gives context about where the changes are happening in the files. @@ indicates the start of a change hunk. -1,4 means the chunk starts at line 1 in the first file and spans 4 lines. +1,4 means the chunk starts at line 1 in the second file and spans 4 lines. <: This marker signifies lines that exist in the first file but not in the second one. Such lines must be removed from the first file to match the second file exactly. >: This marker indicates lines that are in the second file but not in the first one. These lines should be added to the first file to make it identical to the second file. -: This marker shows lines that have been deleted from the first file. +: This marker indicates lines that have been inserted into the second file. Let’s look at an example to make it clearer. Suppose there are two files, file1.txt and file2.txt. Contents of file1.txt: applebananacherrydate Contents of file2.txt: applebananadateraspberry Running the command diff file1.txt file2.txt will produce the following output: Here’s how to interpret this output: 3d2: This means that line 3 in file1.txt (cherry) needs to be deleted to match file2.txt. The d stands for "delete". < cherry: This indicates that cherry is present in file1.txt but not in file2.txt. 4a4: This means that after line 4 in file1.txt, users need to add "raspberry" to match file2.txt. The a stands for "add". > raspberry: This indicates that raspberry is present in file2.txt but not in file1.txt. Creating Patch Files with diff To create a patch file, the -u (unified) option is used, which provides a more readable format by showing a few lines of context around the changes. The output is then redirected to a file, typically with a .patch extension. For example: diff -u file1.txt file2.txt > changes.patch diff -u: Compares file1.txt and file2.txt and generates a unified diff. >: Redirects the output to a file named changes.patch. To apply the patch, use the patch command like this: patch file1.txt < changes.patch Using diff with Various Output Formats The diff also supports multiple output formats, here are a few examples. Unified Format This format gives users a snapshot of the changes with a few lines of context before and after each change. It’s great for quickly seeing what was added or removed. diff -u file1.txt file2.txt Context Format This format shows more surrounding lines for each change and gives users a bigger picture of where the changes happened. diff -c file1.txt file2.txt Side-by-Side Format This format places the two files next to each other and makes it easy to compare them line by line. diff -y file1.txt file2.txt Brief Format This format gives a summary of whether the files differ but does not show the actual changes. diff -q file1.txt file2.txt Practical Examples of Using diff Here are some practical examples of using the diff command in Linux. Ignoring Case Differences When comparing files, sometimes the case of the letters might differ, but the content is essentially the same. The -i option is used to ignore case differences. For example: diff -i file3.txt file4.txt In this example, diff will treat "Hello" and "hello" as identical, ignoring the case difference. Ignoring White Space White space differences, such as extra spaces or tabs, can be ignored using the -w option. This is useful when formatting changes have been made but the content remains the same. For example: diff -w file1.txt file2.txt Here, diff will ignore all white spaces, treating "Hello   World" and "Hello World" as identical. Comparing Binary Files The diff in Linux can also be used to compare binary files using the --binary option. This is helpful when users need to check if two binary files are identical or not. For example: diff --binary file1.bin file2.bin In this case, diff will compare the binary data of file1.bin and file2.bin and report any differences. Ignoring Blank Lines To ignore blank lines when comparing files, simply use the -B option, which is useful when blank lines have been added or removed. diff -B file1.txt file2.txt Conclusion The diff is a versatile command in Linux for comparing files and directories. By understanding its syntax, options, and output formats, users can efficiently identify differences and manage changes. Whether for code reviews, configuration management, or version control, the diff command is an essential part of any Linux user’s toolkit. On Hostman, you can try Linux VPS hosting for your projects. 
17 October 2024 · 7 min to read

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