Making Neofetch aware of Emacs

Author: [mitchmarq42]

Introduction

I have a confession to make. I was, and still technically am, an Arch user (by the way). On my main machines I use ubuntu or fedora, but that’s only because I’m tired of updates and reboots. Computers have always been toys to me, but the OS itself was becoming more of a tool or platform.

Enter Emacs.

If you’re reading this, you probably know how freakin' cool Emacs is. A few days ago, the EAT terminal went public, and it’s great. You can even use it inside Eshell. And with this, it feels like Emacs is my true OS more than the underlying OS itself, I felt it would be a good exercise to have blingy terminal tools reflect that.

Enter Neofetch.

If you somehow haven’t come across Neofetch yet, Kamisama bless your sweet summer soul. It’s the thing that looks like this:

The challenge: Make Neofetch display the Emacs logo

Part 1: how Neofetch works

Neofetch is written in Bash 3.2+, which makes it compatible with even the ancient bash that MacOS ships with. It has a config file which it creates if not present, and will read from at startup. This config file is also written in Bash, and thus you can define custom functions in it that follow the standard format of the built-in ones. For example:

get_pane() {
    pane=$(
        [ -n ${TMUX} ] &&
            echo "${TMUX//%//}"
        [ -z ${TMUX} ] &&
            echo 'N/A'
    )
prin "Tmux Pane" "$pane"
}

This displays the Tmux pane that you’re in, or else “N/A”. I used to use tmux for everything because I wanted to keep processes running despite closing and opening terminals, and splitting windows arbitrarily. Thankfully now Emacs can handle most of that!

Anyway, snippets like the above will get recognized by neofetch when it prints information on the right of the image. It scans for all the “get_*” functions and runs them in the order described in the function print_info (defined at the top of the config). So for tmux all I have to do to enable it is put something like

info "Tmux Pane" pane

before the end of that function.

Problem:

Logos do not work like info lines

All of the ascii art that Neofetch displays happens through a single function called get_distro_ascii which consists of a single 5226-line Case statement, each of which contains a color setting and a mangled-looking heredoc to dump to the terminal.

This is not extensible at all.

The standard advice is to submit a pull request and add the distro/image you want, but the maintainer seems to no longer be active. There are forks, but I really don’t want to rely on that kind of thing. As long as the original Neofetch works, I will use it and only modify my own config file. It’s just simpler that way.

So now, we have a puzzle: How do we advise add to a function in Bash without wiping out the original?

Part 2: Adding to a function in Bash

If this were Elisp, I would just do something like

(setq old-get_distro_ascii (symbol-function 'get_distro_ascii))
(defun get_distro_ascii ()
  (if (<test-are-we-in-emacs>)
      (<display-emacs-things>)
    (funcall old-get_distro_ascii)))

I really didn’t want to bother figuring this out in bash. So I did a web search. And what I discovered, may shock you.

Renaming a function is totally a thing!

So all I would have to do in Bash is

renameFunction get_distro_ascii old--get_distro_ascii
get_distro_ascii ()
if <check-if-emacs>; then
    <display-emacs-things>
else
    old--get_distro_ascii
fi

Now with the technical aspect out of the way, time to do Art.

Part 3: Art

There’s this really handy site https://www.text-image.com/convert/ascii.html. You give it an image and a pixel width, and it spits out ascii art of the image. Good start.

@@@@@@@@@@@@@@@@@&&&&&&@@@@@@@@@@@@@@@@@
@@@@@@@@@@@&#GPYYJJJJJJY5PB#&@@@@@@@@@@@
@@@@@@@@&GYJ????????J?????JJYPB&@@@@@@@@
@@@@@@#5J?????????7!^:..  .7JJJYG&@@@@@@
@@@@&PJ????J?????7!!~~^.    JYYYY5B@@@@@
@@@&5??????^.           ...!YYYYYYYG&@@@
@@&5??????J^    .!7?JJJYYYYYYYYYYYYYG@@@
@@G????JJJJJ?^.  .~7JYYYYYYYYYYY55555#@@
@&5?JJJJJJJYYYY?~.   .:!?YYYY55555555G@@
@&Y?JJJJJY?!^..       .:~?55555555555G&@
@&5JJJJJ7.      .^!?JY555555555555555B@@
@@GJJJY?      :Y555555555555555555555#@@
@@&5JYYY~     .~7?JJYYYYY5555P555555B@@@
@@@&PJYYYY?~:.         .    .:JP555B&@@@
@@@@&GYYYY5555YYJ?7!~^:.   .^7555P#@@@@@
@@@@@@&G5YY555Y?7!!~~!7?JY5PPP5PB&@@@@@@
@@@@@@@@&BP555555555PPPP5555PG#&@@@@@@@@
@@@@@@@@@@@&#BGGPPPPPPPPGB#&@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@&&&&@@@@@@@@@@@@@@@@@@

(the above is the Emacs logo at with a width of 40.)

This is nice, but there’s two problems:

  1. @ Background
  2. Monochrome

Let’s tackle the @ background first:

                 &&&&&&
           &#GPYYJJJJJJY5PB#&
        &GYJ????????J?????JJYPB&
      #5J?????????7!*./eEe.7JJJYG&
    &PJ????J?????7!!~~^/eeeeJYYYY5B
   &5??????^.eeeeeeeeeee/^/!YYYYYYYG&
  &5??????J^eeee.!7?JJJYYYYYYYYYYYYYG
  G????JJJJJ?^\ee\~7JYYYYYYYYYYY55555#
 &5?JJJJJJJYYYY?~\eee.:!?YYYY55555555G
 &Y?JJJJJY?!^./eeeeeee.:~?55555555555G&
 &5JJJJJ7.eeeeee/^!?JY555555555555555B
  GJJJY?eeeeee:Y555555555555555555555#
  &5JYYY~eeeee\.7?JJYYYYY5555P555555B
   &PJYYYY?~:\eeeeeeeeeEeee\.:JP555B&
    &GYYYY5555YYJ?7!~\.>eee/^7555P#
      &G5YY555Y?7!.~~^7?JY5PPP5PB&
        &BP555555555PPPP5555PG#&
           &#BGGPPPPPPPPGB#&
                  &&&&

The @​s were pretty easy to get rid of. I used a lot of evil-Ex commands. Also, you may notice that the giant E has been filled in with little e​s.

Next, the coloring.

How Neofetch works part 2: the coloring

Each clause in that giant Case statement has a set-colors x y line above the art itself. x and y (and posssibly more) are simply the 8/16 terminal colors.

0. Black
1. Red
2. Green

etc.

Color 5 is magenta and color 7 is white. If we allow the “dark/light” colors (8-15) we should probably use 13 (darkmagenta) and 15 (darkwhite), but I don’t particularly want to rely on that, and my theme’s colors may be backwards so we’ll stick to 5 and 7 for now.

Neofetch embeds color escape codes in the ascii art with sequences like ${cX} where X is the slot after set-colors. Thus we can set-colors 5 7 and then access color 5 with ${c1} and color 7 with ${c2}.

Let’s can put ${c1} right before the start of the art. Then when the white E would start we put a ${c2}, and when each line of the E ends another ${c1}. This looks gross:

${c1}                &&&&&&
	  &#GPYYJJJJJJY5PB#&
       &GYJ????????J?????JJYPB&
     #5J?????????7!*${c2}./eEe${c1}.7JJJYG&
   &PJ????J?????7!!~~^${c2}/eeee${c1}JYYYY5B
  &5??????^${c2}.eeeeeeeeeee/^${c1}/!YYYYYYYG&
 &5??????J^${c2}eeee.${c1}!7?JJJYYYYYYYYYYYYYG
 G????JJJJJ?^${c2}\\ee\${c1}~7JYYYYYYYYYYY55555#
&5?JJJJJJJYYYY?~${c2}\\eee.${c1}:!?YYYY55555555G
&Y?JJJJJY?!^${c2}./eeeeeee.${c1}:~?55555555555G&
&5JJJJJ7${c2}.eeeeee/${c1}^!?JY555555555555555B
 GJJJY?${c2}eeeeee${c1}:Y555555555555555555555#
 &5JYYY~${c2}eeeee\.${c1}7?JJYYYYY5555P555555B
  &PJYYYY?~:${c2}\\eeeeeeeeeEeee\.${c1}:JP555B&
   &GYYYY5555YYJ?7!~\${c2}.>eee/${c1}^7555P#
     &G5YY555Y?7!${c2}.~~^${c1}7?JY5PPP5PB&
       &BP555555555PPPP5555PG#&
	  &#BGGPPPPPPPPGB#&
		 &&&&

But the screenshot doesn’t:

Part 4: Putting it all together

Problem: How do we tell neofetch that it’s inside Emacs? Well, there is the variable $INSIDE_EMACS​. The problem is how and where to use it.

I actually didn’t have a perfect solution when I tooted out that screenshot. Nor when I started this article. But I’ve done a minor hack and now have a solution.

In the default config file there’s a line: ascii_distro="auto"​. Neofetch by default auto-detects your distro from various things like uname and ​/​etc​/​issue. It overrides this if you pass the command-line option --ascii-distro​. This all happens before get_distro_ascii is run. Which of course, but that also means we can’t detect whether there was a command-line override within our new get_distro_ascii​.

Looking at it with fresh eyes, we can clearly just check when ascii_distro would get set to auto. So first replace

ascii_distro="auto"

with

ascii_distro=$(
    if [[ $INSIDE_EMACS ]]; then
        echo "Emacs"
    else
        echo "auto"
    fi
            )

Then, below the initial print_info() definition but above everything else, paste the code from that article to rename bash functions. Then use it:

renameFunction get_distro_ascii old--get_distro_ascii

And now we can finally get to the good bit. I’m using a case statement just like the original, since we’re setting $ascii_distro beforehand.

get_distro_ascii() {
    case $(trim "$ascii_distro") in
        "Emacs")
            # set_colors 13 15
            set_colors 5 7
            read -rd '' ascii_data <<'EOF'
${c1}                &&&&&&
          &#GPYYJJJJJJY5PB#&
       &GYJ????????J?????JJYPB&
     #5J?????????7!*${c2}./eEe${c1}.7JJJYG&
   &PJ????J?????7!!~~^${c2}/eeee${c1}JYYYY5B
  &5??????^${c2}.eeeeeeeeeee/^${c1}/!YYYYYYYG&
 &5??????J^${c2}eeee.${c1}!7?JJJYYYYYYYYYYYYYG
 G????JJJJJ?^${c2}\\ee\${c1}~7JYYYYYYYYYYY55555#
&5?JJJJJJJYYYY?~${c2}\\eee.${c1}:!?YYYY55555555G
&Y?JJJJJY?!^${c2}./eeeeeee.${c1}:~?55555555555G&
&5JJJJJ7${c2}.eeeeee/${c1}^!?JY555555555555555B
 GJJJY?${c2}eeeeee${c1}:Y555555555555555555555#
 &5JYYY~${c2}eeeee\.${c1}7?JJYYYYY5555P555555B
  &PJYYYY?~:${c2}\\eeeeeeeeeEeee\.${c1}:JP555B&
   &GYYYY5555YYJ?7!~\${c2}.>eee/${c1}^7555P#
     &G5YY555Y?7!${c2}.~~^${c1}7?JY5PPP5PB&
       &BP555555555PPPP5555PG#&
          &#BGGPPPPPPPPGB#&
                 &&&&
EOF
            ;;
        *)
            # if not in emacs just run the original which displays your distro
            old--get_distro_ascii
    esac
}

Now running neofetch inside any Emacs terminal (again, I recommend Akib’s EAT+Eshell), or with the variable $INSIDE_EMACS set, will display the custom Emacs logo. Running neofetch outside of Emacs should still display your distro’s logo, and running it inside Emacs but with --ascii_distro arch will display the Arch logo.

ADDENDUM: If you’re on Mac you might have to put old_get_distro_ascii instead of old--get_distro_ascii, as their ancient Bash gives an error about invalid identifier.