Linux is a good system for modifying textual content on the command line as a result of there are such a lot of instruments that may change textual content. Many have been round because the days of Unix. Listed below are some instruments each Linux person ought to learn about.


reduce: Choose fields

Cut command selecting "How" and "Geek" from "How To Geek" separated by tabs.


reduce is a rudimentary utility that may take columns of tabular information and show one or a number of of them. The -f choices selects one discipline, a number of fields, or ranges. The default delimiter is a tab, however you’ll be able to change that with the -d possibility. For instance, to pick fields 1 and three utilizing an area as a delimiter 



reduce -f 1,3 -d ' '

Whereas reduce is serviceable, there are higher instruments obtainable talked about beneath. awk is a strong device for pulling aside tabular plain textual content information. It is also rather a lot smarter about white area, with the ability to pick and manipulate fields extra simply.

type: Type Textual content within the Terminal

Using the cat command on a list of words in a text file, followed by the same filed sorted using the sort command in the Linux terminal.

The kind command types any textual content it receives. The standard methodology is that strains with numbers come first and are sorted so as, adopted by strains beginning with letters, that are sorted in alphabetical order. You possibly can change this with choices. You should use -d for “dictionary order.”

type is used most successfully in pipelines corresponding to this: 


some_command | reduce -f1 | type -d

One other helpful possibility is -i to disregard case and -n to pressure a numerical type. There are heaps extra choices within the guide web page, corresponding to for the GNU version.

uniq: Take away Duplicates

Outputting a text file with duplicate words in the Linux terminal using cat, then removing them with the uniq command.


uniq is beneficial for eradicating duplicates from textual content. In different phrases, it sifts out the “distinctive” objects, therefore its identify. Whenever you run textual content via uniq, both a textual content file as an argument like “uniq file” or from normal enter, it is going to print the textual content stream to the display screen until redirected as a file with any duplicate entries omitted.

For instance, in a file that incorporates:

  • canine
  • cat
  • apple
  • apple
  • moose

You will get again:


The phrase “apple” now seems solely as soon as.

As with the opposite utilities, it shines while you use it in pipelines engaged on standard I/O: 


some_command | reduce -f1 | type -d | uniq

You possibly can see how efficient this method of stringing instructions collectively in a pipeline might be from Brian Kernighan, one of many unique Unix builders at Bell Labs and one of many co-authors of the well-known e-book, “The C Programming Language.”

You possibly can see him MacGyver a spell checker utilizing these utilities proper within the terminal on this video from 1982 beginning at 5:15:


tr: Change characters

tr is a utility that allows you to change particular person characters in textual content. Once more, that is most helpful in a textual content stream. You possibly can change a selected character, corresponding to a with c, or a spread of characters.

tr’s default arguments are the characters you wish to change and what you wish to change them with.

Using the tr command to change a text file to uppercase in the Linux terminal.

For instance, in case you needed to capitalize each lowercase letter in a textual content stream, you’d use this command: This tells tr to take any lowercase character within the vary “a” via “z” and alter it into its uppercase counterpart. Enclose the patterns you need in single quotes so the shell is aware of that you really want tr to deal with them. In any other case, the shell will give a syntax error.


In case you needed to transform to lowercase, you can reverse the order: 

tr 'A-Z' 'a-z'

sed: Discover and Change Textual content

Replacing the word "apple" with "orange" in a text file with sed in the Linux terminal.

If you need extra highly effective textual content alternative, sed is one utility it is best to have a look at. It is too difficult to enter all its options, however I will present certainly one of its hottest makes use of, looking and changing textual content with common expressions.

Regular expressions are a strong means of trying to find textual content that allows you to specify searches all the way down to the character. On this instance, we’ll change Home windows with Linux: 

sed 's/Home windows/Linux/'

This command tells sed to search for the sample of characters “Linux” and change them with the expression “Home windows.” Common expressions are extensively utilized in Linux, together with within the grep command in addition to many editors, in order that they’re important in case you’re critical about utilizing Linux utilities.


Once more, put the instructions in single quotes in order that they go to sed as an alternative of the shell.

awk: Highly effective Sample Scanning

Using the awk command with input from the ps command to pick out username and command fields in the Linux terminal.

awk is a powerful command that’s really a programming language in itself. It was initially named after its creators, Alfred Aho, Peter Weinberger, and our pal Brian Kernighan.

It is effectively suited to choosing out patterns in textual content streams. For instance, if we needed to print the customers and the instructions they’re operating, we would use this pipeline: 


ps aux | awk '{print $1, 11}'

This tells awk to take the output of the ps command and print the primary and eleventh fields. There’s much more of awk than might be coated on this part, however you’ll be able to see how helpful it’s.

Your Favourite Textual content Editor: Choose Your Weapon

Editing a list of words in Vim in the Linux terminal.


Maybe crucial textual content enhancing device is your text editor. It appears everyone seems to be enthusiastic about their selection of editor. The basic “editor wars” are between Emacs and Vi, or slightly Vim. In case you’re critical about Linux, that is the place you may spend an enormous chunk of your time. If you have not selected one, attempt a number of and see how you want them.

Many editors have their very own characteristic set. A number of the choice comes all the way down to style. I simply discover the vi command type of Vim most comfy for my fingers, however your expertise could be completely different.


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