Using UTF-16 syntax to include Unicode characters in Bash prompt (PS1)?

Artur Meinild

11/14/23, 5:14 PM

There is an existing post on Unix & Linux about including Unicode characters in the Bash prompt, but the method it gives for using the UTF-16 code (syntax \uXXXX) doesn't work for me.

Let's take this arrow as an example:

Unicode Character 'BLACK RIGHTWARDS ARROWHEAD' (U+27A4)

As I can see, there should be 3 ways to do Unicode characters in the Bash PS1 prompt:

UTF-8 Octal value - in this case: \342\236\244
UTF-8 HEX value - in this case: \xe2\x9e\xa4
UTF-16 HEX value (combined) - in this case: \u27A4

However, only the first option works in my Ubuntu prompt, as indicated in the image below:

Explanation:

With PS1='[\u@\h \W]\$ \342\236\244 ', the Unicode character is applied correctly.
With PS1='[\u@\h \W]\$ \xe2\x9e\xa4 ', the exact string is applied instead.
With PS1='[\u@\h \W]\$ \u27A4 ', it applies my username (am) and then the exact value 27A4.

I understand that \u is a Bash shortcut for username, which is why I'm confused the other answer states that this works - for me it doesn't.

Is there a way to make the UTF-16 syntax work for PS1 on Ubuntu (since this is both shorter and easier to read)? I'm on Ubuntu 22.04.1 Server.

799

1 + 2

bash

unicode

ps1

Bodo

11/14/23, 5:24 PM

Did you notice the `$'...'` in the other answer, e.g. `PS1=$'\u2234\u2192\u263f\u2605'`?

Artur Meinild

11/14/23, 5:28 PM

Thanks for the hint - I think I'm working it out.

Score:1

Ubuntu

Arnaud Valmary

11/14/23, 5:29 PM

If you want to use \xHH or \uHHHH bash sequences in your pretty prompt, use a $ before first simple quote like this:

PS1=$'[\\u@\\h \\W]$ \xe2\x9e\xa4 '

PS1=$'[\\u@\\h \\W]$ \u27A4 '

Of course, with simple quote, you don't need \ in before $, but with $'...' definition, it's better to put two \\ before each PS1 special fields (u, h, W in your case)

+ 1

Artur Meinild

11/14/23, 5:35 PM

Thanks - I missed this detail, because the default Ubuntu prompt starts with: `PS1='${debian_chroot: ...` And I used a simplified example in my question - but it works now!

Elon Musk

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EN: Using UTF-16 syntax to include Unicode characters in Bash prompt (PS1)?

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