The program is called diff, and it’s quite simple to use. Launch Terminal (in Applications > Utilities), and then use the cd command to change to the directory containing the folders you’d like to compare. (The folders can be located anywhere, of course, but it’s easiest if they’re in the same folder.).
How do I diff a file in Linux terminal?
The diff is a command line tool, thus you must first launch the Terminal app, found in /Applicaitons/Utilities/ and then you’re ready to begin. The basic syntax for diff at the command line is as follows: diff (file input 1) (file input 2)
What is diff command in Linux?
The diff command was designed to find differences between source code files and to produce an output that could be read and acted upon by other programs, such as the patch command. In this tutorial, we’re going to look at the most useful human-friendly ways to use diff. Let’s dive right in and analyze two files.
Which is the best example of diff without options?
Example 1: Diff without options 1 The order matters 2 Important Symbols in the diff command output. Using the table below as a reference, you can better understand what is happening in your terminal. 3 Explanation of the diff command output. The line 2 of file 1, CHANGE with line 2 of file 2. Change “locket” to “LOCKET” to match file 2.txt
What determines the Order of files in a diff file?
The order of the files on the command line determines which file diff considers to be the ‘first file’ and which it considers to be the “second file.” In the example below alpha1 is the first file, and alpha2 is the second file.
How do you do a diff command-line?
Comparing files (diff command)To compare two files, type the following: diff chap1.bak chap1. This displays the differences between the chap1. ... To compare two files while ignoring differences in the amount of white space, type the following: diff -w prog.c.bak prog.c.
How do I use diff in terminal Mac?
It's accessed through the Terminal, so first you'll open that program from your Applications> Utilities folder. When you've got it ready to go, type diff in at the prompt followed by a space, and then drag the two folders you want to compare and drop them on the Terminal window.
How do I find the difference between two files in terminal?
Using diff to Compare Files in Linux Since diff is a terminal-based program, using it outputs the targeted differences between two files. In other words, the diff output tells you the changes that can be implemented on file1 to make it a match or identical to file2.
How do I run a diff in Linux?
The Linux diff command is used to compare two files line by line and display the difference between them. This command-line utility lists changes you need to apply to make the files identical....Other diff Options.-a / --textView files as text and compare them line-by-line.-e / --edMake output a valid ed script.10 more rows•Dec 29, 2021
How do you find the difference between two files on a Mac?
A file comparison tool helps you compare and merge differences between two (or more) versions of the same file....The 5 Best Mac File Comparison Tools and Diff ToolsMeld. Meld is a simple, cross-platform diff and merge tool. ... Helix P4 Diff and Merge Tool. ... Beyond Compare. ... DeltaWalker. ... Araxis Merge.
How do I diff two folders on a Mac?
In macOS, you can compare and show the differences of files in two folders in the Command Line by using the diff command. With folders you use rq as an argument and pass in the 2 folder names on the command line like so…
Which command is used to compare two files?
#1) cmp: This command is used to compare two files character by character. Example: Add write permission for user, group and others for file1. #2) comm: This command is used to compare two sorted files.
How do I diff two directories in Linux?
Using Meld Visual Diff and Merge Tool Click on directory comparison and move to the next interface. Select the directories you want to compare, note that you can add a third directory by checking the option “3-way Comparison”. Once you selected the directories, click on “Compare”.
How do I compare two files side by side in Linux?
How to Use “diff” Command in Linux to Compare Files:a – Add: Add content in the first file to synch with the second file.c – Change: Indicates that a modification needed in the content of first file to match the second file.d – Delete: Remove content from the first file to match with the second.
How do I use a diff file?
The "diff" tool calculates the differences between two text files. That difference is called a patch. You can apply a patch to another file using the "patch" tool. diff and patch are intended to be used on text files....The First Line of Output.LetterMeaningaContent was added or appendeddContent was deleted1 more row•Feb 6, 2019
What does diff command return?
The first line of the diff output contains: line numbers corresponding to the first file, a letter (a for add, c for change, or d for delete), and. line numbers corresponding to the second file.
What is use of tail command in Linux?
The basic functionality of the Linux tail command is to output the end of a file. Typically, new data added to a file ends up at its tail (i.e., the end). So, the Linux tail command allows us to check if a file has new data attached. Therefore, the Linux tail command is a popular tool to evaluate and monitor log files.
How do I compare files in BBedit?
Use BBedit - free edition (or similar file comparison tool) to compare all files in a folder. Start BBedit and then go to Search->Find Differences. In the find differences window that opens, put the names of the old and new WebPages folders as per the picture below and click Compare.
How do I open FileMerge on Mac?
On MacOS Catalina, you just need to open spotlight (cmd+space) and type "FileMerge".
How do you use meld?
If you start Meld from the command line, you can tell it what to do when it starts. For a two- or three-way file comparison, start Meld with meld file1 file2 or meld file1 file2 file3 respectively. For a two- or three-way directory comparison, start Meld with meld dir1 dir2 or meld dir1 dir2 dir3.
How do I compare two files in an atom?
compare-filesClick on the two files that are to be compared in the tree view.Invoke the command using any of the below:From Command Palette (⌘+⌂+P) invoke Compare Files: Compare.Right click on one of the selected files and choose Compare Files.Use the keyboard shortcut - ⌘+ctrl+C (Windows and Linux: ctrl+alt+C)
How to use diff?
The diff command compares two files and produces a list of the differences between the two. To be more accurate, it produces a list of the changes that would need to be made to the first file, to make it match the second file. If you keep that in mind you’ll find it easier to understand the output from diff. The diff command was designed to find differences between source code files and to produce an output that could be read and acted upon by other programs, such as the patch command. In this tutorial, we’re going to look at the most useful human-friendly ways to use diff.
What is the order of files in a file diff?
Let’s dive right in and analyze two files. The order of the files on the command line determines which file diff considers to be the ‘first file’ and which it considers to be the “second file.” In the example below alpha1 is the first file, and alpha2 is the second file. Both files contain the phonetic alphabet but the second file, alpha2, has had some further editing so that the two files are not identical.
How many lines before and after a line flagged as being different?
We are shown the three lines before and after the line flagged as being different so that we can see the context of the changed line. In the unified view, the lines with the difference are shown one above the other. The line from alpha1 is preceded by a dash and the line from alpha2 is preceded by a plus sign. This display achieves in eight lines what the copied context display above took fifteen to do.
What line must be deleted to match the second file?
d: The line in the first file must be deleted to match the second file.
What is the third change in Alpha2?
The third change refers to a line that has been deleted from alpha2. The label 21d20 is deciphered as “line 21 needs to be deleted from the first file to make both files synchronize from line 20 onwards.” The < Uniform line shows us the content of the line which needs to be deleted from alpha1.
Which diff option offers context?
The second diff option that offers context is the -u (unified context) option.
How many lines of context are there in a diff?
Three lines of context above and below each change is the default value. You can specify how many lines of context you want diff to provide. To do this, use the -C (copied context) option with a capital “C” and provide the number of lines you’d like:
How to compare two folders in Terminal?
When you've got it ready to go, type diff in at the prompt followed by a space, and then drag the two folders you want to compare and drop them on the Terminal window. It doesn't matter what order you do this in, and you don't have to type a space in between, either.
Can you use diff to compare files?
Additionally, you can use diff to compare files instead of folders by dragging a couple of those onto Terminal instead:
What is a diff output?
Since diff is a terminal-based program, using it outputs the targeted differences between two files. In other words, the diff output tells you the changes that can be implemented on file1 to make it a match or identical to file2.
How many columns are in a diff?
The above command assumes the two files in comparison are somewhat large and exceed 50 columns in terms of text size. The diff output will be limited to 50 columns.
Why is file comparison important in Linux?
Being able to flexibly compare two files on a Linux terminal sheds some light on how unique or different a set of files are perceived to be.
What is the first line of a diff?
The first line of the diff output will contain: Line numbers corresponding to the first file, A special symbol and. Line numbers corresponding to the second file. Like in our case, 0a1 which means after lines 0 (at the very beginning of file) you have to add Tamil Nadu to match the second file line number 1.
What does diff stand for in a file?
diff stands for difference. This command is used to display the differences in the files by comparing the files line by line. Unlike its fellow members, cmp and comm, it tells us which lines in one file have is to be changed to make the two files identical.
How many dashes are there in a second file?
After that there are three dashes — followed by a line range from the second file (in our case lines 1 through 4, separated by a comma). Then four dashes —-. Then it shows the contents of the second file.
How to view differences in context mode?
1. -c (context) : To view differences in context mode, use the -c option. Lets try to understand this with example, we have two files file1.txt and file2.txt :
How to make Tamil Nadu and Andhra Pradesh identical?
As a summary to make both the files identical, first add Tamil Nadu in the first file at very beginning to match line 1 of second file after that change line 2 and 3 of first file i.e. Ut tar Pradesh and Kolkata with line 3 of second file i.e. Andhra Pradesh. After that change line 5 of first file i.e. Jammu and Kashmir with line 5 of second file i.e. Uttar Pradesh .
How to compare two files for differences?
Need to quickly compare two files for differences? The command line ‘diff’ tool offers a great choice for users comfortable with the Terminal. Diff allows you to easily compare two files, with the command output reporting back any differences between the inputted files.
What does the greater than and less than symbol mean?
The greater than and less than symbols serve as pointer arrows of sorts, indicating which file the difference originated from in relation to the order presented in the original command syntax.
Does diff work on Mac?
The diff command is available by default on the Mac, and it works the same in Linux and other unix operating systems as well, just in care you were wondering, and for Windows users it’s quite similar to how the ‘fc’ file compare tool works.
Does diff require command line?
Obviously diff requires the command line, but if you’d rather be in the familiar graphical interface of Mac OS when comparing documents there are various options available as well, including comparing two word documents with Microsoft Word or if you’re working with code and syntax, try the Xcode FileMerge tool, git, or even the excellent BBEdit text editor for Mac. And if you’re on windows, the ‘fc’ command works basically the same as the diff command, with ‘fc file1 file2’ achieving more or less the same comparison as diff.
Diving Into Diff
Snappy One-Liners
- If you all you want to know is whether two files are the same, use the -s(report identical files) option. You can use the -q(brief) option to get an equally terse statement about two files being different. One thing to watch out for is that with two identical files the-q(brief) option completely clams up and doesn’t report anything at all.
An Alternative View
- The -y (side by side) option uses a different layout to describe the file differences. It is often convenient to use the -W (width) option with the side by side view, to limit the number of columns that are displayed. This avoids ugly wrap-around lines that make the output difficult to read. Here we have told diffto produce a side by side display and to limit the output to 70 columns. The first …
Add A Splash of Color
- Another utility called colordiff adds color highlighting to the diffoutput. This makes it much easier to see which lines have differences. Use apt-getto install this package onto your system if you’re using Ubuntu or another Debian-based distribution. On other Linux distributions, use your Linux distribution’s package management tool instead. Use colordiff just as you would use diff. In fact, …
Providing Some Context
- To find some middle ground between having all of the lines in the files displayed on the screen and having only the changed lines listed, we can ask diffto provide some context. There are two ways to do this. Both ways achieve the same purpose, which is to show some lines before and after each changed line. You’ll be able to see what’s going on in the file at the place where the di…
Ignoring White Space and Case
- Let’s analyze another two files, test4 and test5. These have the names six of superheroes in them. The results show that difffinds nothing different with the Black Widow, Spider-Man and Thor lines. It does flag up changes with the Captain America, Ironman, and The Hulk lines. So what’s different? Well, in test5 Hulk is spelled with a lowercase “h,” and Captain America has an extra s…