What are special characters in linux

Ubuntu Documentation

You can enter and view thousands of characters from most of the world’s writing systems, even those not found on your keyboard. This page lists some different ways you can enter special characters.

Methods to enter characters

Characters

The character map application allows you to find and insert unusual characters, including emoji, by browsing character categories or searching for keywords.

You can launch Characters from the Activities overview.

Compose key

A compose key is a special key that allows you to press multiple keys in a row to get a special character. For example, to type the accented letter Г© , you can press compose then ‘ then e .

Keyboards don’t have specific compose keys. Instead, you can define one of the existing keys on your keyboard as a compose key.

You need to have Tweaks installed on your computer to change this setting.

Define a compose key

Open the Activities overview and start typing Tweaks .

Click Tweaks to open the application.

Click the Keyboard & Mouse tab.

Click Disabled next to the Compose Key setting.

Turn the switch on in the dialog and pick the keyboard shortcut you want to use.

Tick the checkbox of the key that you want to set as the Compose key.

Close the dialog.

Close the Tweaks window.

You can type many common characters using the compose key, for example:

Press compose then ‘ then a letter to place an acute accent over that letter, such as Г© .

Press compose then ` (back tick) then a letter to place a grave accent over that letter, such as ГЁ .

Press compose then » then a letter to place an umlaut over that letter, such as Г« .

Press compose then — then a letter to place a macron over that letter, such as Д“ .

For more compose key sequences, see the compose key page on Wikipedia .

Code points

You can enter any Unicode character using only your keyboard with the numeric code point of the character. Every character is identified by a four-character code point. To find the code point for a character, look it up in the Characters application. The code point is the four characters after U+ .

To enter a character by its code point, press Ctrl + Shift + U , then type the four-character code and press Space or Enter . If you often use characters that you can’t easily access with other methods, you might find it useful to memorize the code point for those characters so you can enter them quickly.

Keyboard layouts

You can make your keyboard behave like the keyboard for another language, regardless of the letters printed on the keys. You can even easily switch between different keyboard layouts using an icon in the top bar. To learn how, see Use alternative keyboard layouts .

Input methods

An Input Method expands the previous methods by allowing to enter characters not only with keyboard but also any input devices. For instance you could enter characters with a mouse using a gesture method, or enter Japanese characters using a Latin keyboard.

To choose an input method, right-click over a text widget, and in the menu Input Method , choose an input method you want to use. There is no default input method provided, so refer to the input methods documentation to see how to use them.

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What are special characters in Linux?

How do I use special characters in Linux?

On Linux, one of three methods should work: Hold Ctrl + ⇧ Shift and type U followed by up to eight hex digits (on main keyboard or numpad). Then release Ctrl + ⇧ Shift .

What are special characters in Unix?

5. Basic Unix : special characters

• single quotes.
• double quotes.
• backslash characters.
• pound characters.
• cat : display a text file in the terminal window.
• gedit : a graphical editor.
• 3dDeconvolve -help.

What is a special character?

: a symbol used in writing, typing, etc., that represents something other than a letter or number.

What is the meaning of special character in bash?

Special characters. Some characters are evaluated by Bash to have a non-literal meaning. Instead, these characters carry out a special instruction, or have an alternate meaning; they are called “special characters”, or “meta-characters”.

How do you write special characters?

Ensure that the Num Lock key has been pressed, to activate the numeric key section of the keyboard. Press the Alt key, and hold it down. While the Alt key is pressed, type the sequence of numbers (on the numeric keypad) from the Alt code in the above table.

What are all the special characters?

Password Special Characters

Character	Name	Unicode
Space	U+0020
!	Exclamation	U+0021
”	Double quote	U+0022
#	Number sign (hash)	U+0023

How do I remove special characters in Unix?

Remove CTRL-M characters from a file in UNIX

1. The easiest way is probably to use the stream editor sed to remove the ^M characters. Type this command: % sed -e “s/^M//” filename > newfilename. …
2. You can also do it in vi: % vi filename. Inside vi [in ESC mode] type: :%s/^M//g. …
3. You can also do it inside Emacs. To do so, follow these steps:

What is $$ in bash?

$$ is the pid (process id) of the shell interpreter running your script. … It’s the process ID of the bash process. No concurrent processes will ever have the same PID.

Why is used in Unix?

Unix is an operating system. It supports multitasking and multi-user functionality. Unix is most widely used in all forms of computing systems such as desktop, laptop, and servers. On Unix, there is a Graphical user interface similar to windows that support easy navigation and support environment.

What’s a special character example?

A special character is a character that is not an alphabetic or numeric character. Punctuation marks and other symbols are examples of special characters. … For example, when creating a web page with HTML, the quote (“) symbol is used to store attribute values.

How many special characters are there?

The 33 characters classified as ASCII Punctuation & Symbols are also sometimes referred to as ASCII special characters. See § Latin-1 Supplement and § Unicode symbols for additional “special characters”.

Is a number a special character?

A special character is one that is not considered a number or letter. Symbols, accent marks, and punctuation marks are considered special characters. Similarly, ASCII control characters and formatting characters like paragraph marks are also special characters.

What is bash symbol?

Special bash characters and their meaning

Special bash character	Meaning
#	# is used to comment a single line in bash script
$$	$$ is used to reference process id of any command or bash script
$0	$0 is used to get the name of the command in a bash script.
$name	$name will print the value of variable “name” defined in the script.

What does $1 do in bash?

$1 is the first command-line argument passed to the shell script. … $0 is the name of the script itself (script.sh) $1 is the first argument (filename1) $2 is the second argument (dir1)

What is shell command?

A shell is a computer program that presents a command line interface which allows you to control your computer using commands entered with a keyboard instead of controlling graphical user interfaces (GUIs) with a mouse/keyboard combination. … The shell makes your work less error-prone.

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How to Quickly Type Special Characters in Linux

From time to time you may find a need to type in special characters such as when writing in a foreign language that has accentuated letters or when using mathematical symbols for homework or reports.

Although your keyboard has many keys, many of these special characters will be missing. So how do you type them into your documents?

You can use the built-in Character Map application which is bundled with your Operating System or install an application such as GNOME Characters to find the character you want and then copy and paste from there, but this is bound to be slow and tedious, especially if you need to do this on a regular basis.

This article provides two ways you can quickly type special Unicode characters in Linux without the need for an external application.

1. Unicode Code Points

Each Unicode character has a code point assigned to it. For example, the code point for the dollar sign character ($) is U+0024 . The code point is the part after U+ which in this case is “0024.”

If you do not have this character on your keyboard and want to insert it into a document, press Ctrl + Shift + U on your keyboard followed by the 4 character code point, then press Enter to produce the output.

This method requires that you memorise the Unicode code points for the characters you type often. You can find the code points for some of the most important characters for English readers in this Wikipedia article.

Also read: How to Use Emojis in Linux

2. Compose Key

Utilising a compose key sequence is a simple and fast way to insert a special character in Linux. Keyboards do not have a specific compose key built in; you’ll have to define one of your existing keys as the compose key.

To define a compose key in GNOME, you’ll need to have the Gnome Tweak Tool installed. You can install it in Ubuntu by typing the following command into the terminal:

Once it’s installed, launch it and select “Keyboard & Mouse” in the sidebar, then Click “Disabled” next to the Compose Key setting. Turn the switch on in the dialog and pick the key you want to use.

Do note that any key you set as your compose key will only function as the one you designate and not the one originally intended.

Once you have set your compose key, you can type in any character by pressing the Compose key followed by the sequence required to produce that character.

You can find the compose key sequences for many common Unicode characters on this page.

For instance, the sequence for the copyright character © is oc . To insert this character, press the Compose key followed by oc .

Likewise, to type the degree sign °, hit the Compose key followed by oo .

Notice that the compose key sequence bears some resemblance to the actual character you want to insert and does not contain more than two characters which makes it a lot easier to commit to memory.

Wrap-up

We have covered two quick ways to insert special characters into your documents in Linux. Don’t forget to tell us which method you prefer or other alternative methods in the comments section below.

Ayo Isaiah is a freelance writer from Lagos who loves everything technology with a particular interest in open-source software. Follow him on Twitter.

10 comments

As usual, the author assumes that Ubuntu == Linux and that GNOME is the only DE people use. The article is useless for anybody using other distros and DEs.

Yes I agree totally .. non-attentive people tend to lump everything together instead of:
– linux is the kernel
-gnu refers to all the base utilityes
-gnome is a desktop environment
-kde is another desktop environment
-ubuntu may be popular, but its one of at least 100 other common distros.
– they have different package managers and file system layouts

My Gnome Tweaks does not have the Compose choice, and the EMACs is not a seperate choice, but in one of the other right side menus.

Far TOO complicated! Just use the Character map and copy and paste!
Need more?
Check out onscreen keyboards!
Of course it does depend on how often you need these characters, if you use them often then a dedicated keyboard, in the language that you are using, may be a better answer.

The easiest and most straight-forward way to write special characters in Linux is to start the LibreOffice writer and then from the menu select Insert->Special Character… From the dialog box that appears you can select any possible character. Select the desired character(s) and then press the button Insert. From the LibreOffice writer document you can copy and paste them anywhere.
If you want to write larger chunks of texts containing special characters (let’s say Greek or Cyrillic letters), this method is not very convenient. Instead, install an additional keyboard and define e.g. Alt+Shift to be the keyboard sequence that will switch keyboards. Now if you want to write Greek letters just press Alt+Shift. Press it once again to switch back to English. For example, the Greek letter beta is: β.
A further method to insert special characters into pdf or html documents is LATEX. In LATEX each special character has its own symbol, for example, the degree sign is circ (to be written as a superscript) and the infinity sign is infty.

But what about if I wanted to use special characters in my login password?

I would not recommend the use of special characters in login passwords (I am not sure if they work at all).

I have used the Compose key technique for a number of years and usually have no problems. On Fedora 26 + KDE, this time I was unable to assign either Windows key as the Control key, and couldn’t figure out how to shutoff the default behavior. I ended up using the Scroll Lock key instead.
Using Insert -> Special Character is very cumbersome.

From what I’ve seen, using English, French, or German seems to be easiest.
Not sure about Spanish, Dutch or Italian … and then there’s Africa and Asia which is a whole other ball of wax.

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