How to make Vim display colors as indicated by color codes?

Question

In short, I'm in an effort to replace less with vim (vimpager). I have settings for scripts to spit out colors (and bold and everything nice) whenever they can. less understands the color codes and displays them nicely. How can I make vim parse the codes and display colors/boldness the way less does?

If you want a full blown pager based on vim try vimpager or my rewrite for neovim: nvimpager. They use AnsiEsc and a rewrite in lua respectively, and wrap it all up into a script that can be used as a pager without further hacking on your part. — Lucas, May 18 '21 at 13:50

score 63 · Accepted Answer · edited Aug 03 '18 at 14:42

63

Two answers:

A short one: you want to use the vim script AnsiEsc.vim. It will conceal the actual ANSI escape sequences in your file, and use syntax highlighting to color the text appropriately. The problem with using this in a pager is that you will have to make vim recognize when to use this. I am not sure if you can simply always load it, or if it will conflict with other syntax files. You will have to experiment with it.

A long answer: The best you can hope for is a partial non-portable solution. Less does not actually understand the terminal escape sequences, since these are largely terminal dependent, but less can recognize (a subset of) these, and will know to pass them through to the terminal, if you use the -r (or -R) option. The terminal will interprets the escape sequences and changes the attributes of the text (color, bold, underline ...). Vim, being an editor rather than a pager, does not simply pass raw control characters to the terminal. It needs to display them in some way, so you can actually edit them. You can use other features of vim, such as concealment and syntax highlighting to hide the sequences and use them for setting colors of the text, however, it will always handle only a subset of the terminal sequences, and will probably not work on some terminals.

This is really just one of many issues you will run into when you try to use a text editor as a pager.

edited Aug 03 '18 at 14:42

Lucas Walter

223

answered Feb 20 '11 at 18:26

Jan Hlavacek

981

2

To put it in a nutshell, you have to write part of a terminal emulator in Vim, the part that handles the terminal escape sequences that are present in your input. – Gilles 'SO- stop being evil' Feb 20 '11 at 19:02
1

Thanks, I think I'm giving up. If it's not easy it doesn't make much sense anymore. – phunehehe Feb 21 '11 at 02:10
By the way, if all you are trying to do is have a pager with syntax highlighting, look at this link: http://linux-tips.org/article/78/syntax-highlighting-in-less – Jan Hlavacek Feb 21 '11 at 03:00
1

@JanHlavacek link is broken :( – Nitrodist Aug 16 '13 at 20:09
@Nitrodist, Looks fixed now if you still need it. – Stuart Feb 07 '14 at 02:28
40

@Nitrodist: less -r FILE (source) – Adobe Sep 06 '16 at 20:40
1

It seems Jan's link has moved to https://linux-tips.com/t/how-to-enable-syntax-highlighting-in-less/208 – Timothy Zorn Feb 17 '17 at 09:24
To install the script: https://stackoverflow.com/questions/2033078/how-to-install-a-vimball-plugin-with-vba-extension – ntg Sep 21 '21 at 09:29

score 34 · Answer 2 · edited Sep 21 '21 at 10:05

34

Now with vim 8 you can use terminal mode :terminal and then in that terminal do cat myfile and go back to normal mode with Ctrl-w N. This will display ANSI color codes correctly. By automating these steps and reading from standard input instead of a file, it should be possible to use vim to replace less.

For example, you can run ls --color=always >/tmp/colored.txt

or unbuffer ls >/tmp/colored.txt

and then in vim :terminal cat /tmp/colored.txt followed by :only

Then you will have the ls output nicely colored in vim like less would do. As vim supports passing commands as command-line arguments on startup, it is clearly possible to fiddle around to make that solution work for replacing less :)

edited Sep 21 '21 at 10:05

ntg

113

answered May 16 '19 at 11:30

Johannes Riecken

713

2

I took your idea and ran with it! https://gist.github.com/RichardBronosky/94024fac52780e03c936589f4c9ab914 – Bruno Bronosky Mar 04 '21 at 08:48
1

Neovim can do the same, but use <c-\><c-n> to go back to normal mode. – Moberg Sep 14 '21 at 09:10
1

Just Wow! This should be the accepted answer!...Except that if a file is too long (11M in my case), :terminal cat will truncate and loose the head :S – ntg Sep 21 '21 at 08:49
"The commands that would start insert mode, such as 'i' and 'a', return to Terminal-Job mode." Then the terminal can be exited. P.S. I am on Vim 8.2, and it has both <C-w>N and <C-\><C-n> listed for entering Terminal-Normal mode. – Kevin Mar 01 '22 at 14:46
Meh. You can look, but not touch. – Ярослав Рахматуллин May 01 '22 at 17:26
:terminal cat performance not good for large files, but :AnsiEsc fine – yurenchen Sep 01 '22 at 08:47

score 16 · Answer 3 · answered May 08 '20 at 17:49

16

Install the vim plugin Improved AnsiEsc and put the below on your .profile/bash_profile/zprofile and you are good to go.

export PAGER="vim -R +AnsiEsc"

answered May 08 '20 at 17:49

Salman Abedin

353

1

This is a great answer, +1 for export command. – AzP Jun 11 '20 at 09:26
Does this works on vim 7.x or its vim 8.x solution? – Prabhat Kumar Singh Mar 10 '22 at 22:34

score 2 · Answer 4 · answered Mar 09 '21 at 20:58

I installed AnsiEsc like the others and then added the following to my _vimrc:

command Log colorscheme elflord | %s/\[39m//g | AnsiEsc

Now, when I load a file that contains a bunch of color control characters, I type:

:Log

And it looks like the command line, but I'm editing!

score -3 · Answer 5 · answered Mar 20 '20 at 23:08

You can use vim's json syntax highlighting. Normally comes in most default vim installs. May not be all as pretty as the less -R BUT..

If you have python, this makes is human readable with the -mjson.tool

cat filename | python -mjson.tool | vim -c 'set syntax=json' -

If you don't have python but your json is pretty printed

cat filename | vim -c 'set syntax=json' -

Also some browsers have json extensions, and you could pipe it into the browser. Hmmm I wonder if w3m might suffice for a pure cli effort.

Hope that helps.

How to make Vim display colors as indicated by color codes?

5 Answers5

Linked

Related