Twelve Days of Shell

[aargh_aargh]

The good: Nice exercises for beginners. Tab-completion, accepts readline characters like ctrl-u.

The bad: You don't see the (wrong) output if you don't get it right the first time, making it hard to work iteratively and having to guess what the question actually intended.

E.g. 'Seven files that start with "Santa"' actually wants file names that start with Santa, after some questions that had you use "grep" to search file contents. Where I actually struggled with what's expected is Day 11.

The ugly: Actually a very nice design.

[pekim]

> Where I actually struggled with what's expected is Day 11.

Just the lines from the files are wanted, not the files names. It took me a little while to cotton on to that.

Semi-spoiler follows.

So you need to use the appropriate flag with grep to suppress the file names.

[Retr0id]

The tab completion sorta works but it seems to be simulated, doesn't understand subdirectories etc.

[oneeyedpigeon]

I think the instructions need more detail. 'Five lines that start with "the"' doesn't scream 'or "The", or "thE"' to me...

[hdjrudni]

Yeah, I was very confused why it wasn't accepting my grep at first.

[bArray]

Great idea, but a few feedback points:

1. It's difficult to know that it is following from the previous problem, and then on some problems it changes the workspace.

2. It's not always easy to know what it wants.

3. The question about finding a line starting with "The" I successfully cheated:

     cat night-before-christmas.txt | grep "The "

4. Likewise the ending "!":

    cat night-before-christmas.txt | grep "!"

5. On the eighth day I get a "runner error" with the command:

     mv *lve* Workshop

I'm globbing for the filename match, I'm not sure if it's "elve" or "Elve" and then trying to move to the target directory.

Otherwise it's quite fun - the instant feedback is great.

[iN7h33nD]

iirc Elves is a directory with them inside.

[arionmiles]

I've recently reached a point where I feel I've reached an upper limit with how much efficiency I can extract from my usual toolset/editors. So I've gone on a journey where I'm finally exploring tools that make living in the command line a productive and pleasant experience for me.

I've long put off learning or even exploring tmux or learning more than a few handful of vim keybinds. So I started digging into configuring them and learning them well enough to be able to regularly use them for work and personal computers.

It's been very pleasant, to say the least. There's still a few ways I need to go where I do everything from the command line and the keyboard, but I think it's worth training your muscles to be comfortable with doing things purely using the keyboard.

I've switched to vim mode for a few tools that offer it. I started seriously using vimium on chrome and firefox (a friend had introduced me to it about 7 years ago but I never cared enough to learn it well).

Another reason I finally made the jump was that I've been having RSI pain on my right hand due to using mouse too much and in un-ergonomic positions. While I've taken measures to improve ergonomic use of the mouse and keyboard, I'm just totally impressed with the capabilities of keyboard navigation and how much value you can extract out of your keyboard.

My friends have been egging on me about the bell curve meme, but I think it's important for me to figure out the limits and then maybe I will finally go back to defaults and simpler tools. The only way to be on the right side of the bell curve is through the middle.

[johncoltrane]

Forget cheatsheets, tweets, videos, books, etc. Vim comes with a very well made built-in tutorial that will gently pull you toward maximum efficiency.

[kalaksi]

For learning vim, I recommend searching for a "vim cheat sheet" that has an image of a keyboard layout with vim commands in it and printing that. Makes it easier to check and learn more, little by little.

Another one is online tutorials that make you practice interactively. Haven't used those much but the little I did, it was helpful.

[Izkata]

I have an odd suggestion for learning more of vim: Check out gvim.

It's vim with a GUI, dropdowns for nice discoverability and most importantly the shortcuts on each menu item are the commands to use it in regular vim. It's how I found out vim even had folding waaay back.

For Firefox, I use Tridactyl. After Vimperator died I tried several replacements and found Vimium very limited (IIRC it was the one that was just hotkeys and didn't have modes like vim, no idea how it's grown since then). I have Tridactyl configured to open gvim with the contents of any text input when I hit ctrl+i so I can use vim for them.

[ratrocket]

Not commenting on the larger gist of the comment, only:

> I've been having RSI pain on my right hand due to using mouse too much and in un-ergonomic positions

If you can, try using a left-hand vertical mouse. I use an Evoluent but there are a million brands. Get a cheapo and try it out. I figure it took me about a week to adjust and my wrists have been happier ever since.

[kace91]

I went back and forth over the years with vim. Lazyvim plus the ebook (lazyvim for ambitious devs or something like that, it’s free online) is what allowed me to stick.

I can’t be doing real work and suddenly realize I don’t know the way to do a certain basic action. Lazyvim makes it so that for everything you want to do, there’s an already configured way, and then you have all the time in the world to fiddle for a better alternative if you don’t like it.

[rramadass]

GNU Screen + dvtm/mtm + Vim (with some minimal plugins; especially for buffer mgmt) on a large Monitor is what you need to live on the command line :-)

Just have some minimal configs for the above and learn more of the default key bindings/behaviour etc. That way you can easily take the above setup to any machine that you move to.

[derrida]

Hey this doesn’t work : first solution “ls -al” which I use all the time to list directories was rejected in the second question I used awk and was rejected it expected grep

I think a beginner could be doing it right but then be told they are wrong as you aren’t evaluating actual commands

Best would be to like actually run it* and then check solutions out with awk that it pattern matches

* aka give me a shell ok worth a try lol xD

Edit: also I was expecting something a bit more challenging (also that is correct) to like exercise the brain for those of us that use shell (this is hacker news) something that takes a few minutes and isn’t just commands used all the time

[comprev]

"ls" shows only visible files whereas "ls -a" also displays those starting with a dot. Given the question doesn't that make your answer the correct one?

[Retr0id]

It does seem to actually run the submitted commands, and awk is there.

[prmoustache]

it also doesn't accept the find command.

[janmatejka]

'Seven files that start with Santa' is actually about filenames. That's pretty confusing especially since users are primed with file contents from the previous exercises already.

And from pipers piping description I had no idea what was wanted of me.

[Kakist0crat]

I think that may be the point, the subtlety of "lines of pipers piping" got me for a second - as opposed to the 11 pipers piping files (which is what I thought it wanted).

[blenderob]

Looks nice but it's rejecting valid commands as incorrect. Like when it told me to search for "laugh" I ran

  grep laugh *

There's only one file in the directory. So that's a correct answer but the game wants me to run

  grep laugh night-before-christmas.txt 

It's like those weird interviewers who have a specific answer in mind and they'll accept nothing other than the answer they have in mind.

[charlie-83]

`grep laugh *` worked for me

[ggirelli]

Or cat night-before-christmas.txt | grep laugh

[lcuff]

I thought there was too much ambiguity to several of the challenges:

I gave up after the following exercise:

On the eighth day of Shell my true love gave to me Eight elves in Santa's Workhop/ ... Hint: Try finding files named after Elves and moving them to the Workshop/ directory.

It turns out, all they want is the files in the ./Elves directory to the ./Workshop directory. But I didn't figure that out.

[imp0cat]

You're overthinking it. You can get quite far with a bit of ls or find . -type f exploration

[throw0101d]

Meta: the first day of the Twelve Days of Christmas is Christmas Day (December 25) itself:

* https://en.wikipedia.org/wiki/Twelve_Days_of_Christmas

The days before the 25th are part of the season of Advent:

* https://en.wikipedia.org/wiki/Advent

[xnorswap]

Too many people I know spend their boxing day packing up their tree. Christmas is over before it's barely begun!

But that's kind of understandable when Christmas begins in September if you believe the retailers.

[beardyw]

As a developer I've been through 10 different languages and about the same number of operating systems, and I barely managed to remember any of them, even at the time. And I assume soon using natural language as the main interface will become commonplace, which will finally let me off the hook.

I will give this a go, but I doubt any of it will stick!

[k_bx]

Shell quotes is the last frontier LLM's seem to keep getting wrong. Esp when it's Github CI yaml which needs to ssh somewhere and run command running another command there. Needs AGI apparrently.

[bluecalm]

It looks very nice. One problem I've encountered is that when you make a mistake then the name of the file you have to use disappears and it's impossible to get it back. What is this website created with btw? I like the style a lot.

[ilvez]

Constantly hit Ctrl-w and close the tab. Ctrl-Shift-Tab to get back to it :-) God bless saved state, otherwise I would not have completed :D

[Barathkanna]

Fun idea. It’s basically an Advent calendar for shell one-liners. Nice way to level up your CLI muscles without diving into full projects.

[jll29]

Neat.

Perhaps it would be even nicer if the "advent" theme was more prominently present, e.g. using the Bible as the target data file to be used.

Here's three examples tasks from me:

(1) Write an sh script (using only POSIX standard commands) to create a Keywords in Context (KWIC) concordance of the new testament.

(2) Write a bash script that uses grep with regular expressions to extracts all literal quotes of what Jesus said in the New Testament. [Incidentally, doing this task manually marked the beginnings of philology and later automating it marked the beginning of what was later called literary and linguistic computing, corpus linguistics, computational linguistics, and digital humanities.]

(3) How many times is Jesus mentioned by each of the four accounts of his life (Matthew, Mark, Luke, and John)?

(You may begin by extracting the New Testament from the end of the Bible with a grep command.)

Dataset: https://openbible.com/textfiles/kjv.txt

[haolez]

The way that worked for me to properly learn shell is to do a non-shell project with it.

Like, do a complex background worker for a web server that listens to a socket, does complicated stuff, exports functions (if in Bash), etc.

You don't have to use it afterwards. The value is in the journey. It's fun :)

[sannysanoff]

Fluent in shell, but cultural context is more difficult, especially with pipers, had to do guess work.

[ggirelli]

I think that's part of the fun :)

[kwar13]

#11 was confusing as hell: this is what worked 'grep -R 'piping' ./place-for-pipers | cut -d: -f2-'

only content no filenames. Need to see the output if it's wrong to baseline what's being asked.

[cornonthecobra]

It doesn't handle backspace correctly. The character is erased visually, but not removed from the buffer, so when you type the next character, the erased character reappears. Make one typo and you have to reload the page.

[6LLvveMx2koXfwn]

"Try sending the command ls in the command box to list all files in the directory."

  My answer: `ls -a`

er, wrong. Then don't put all in the question!

[naikrovek]

I use the shell all day every day and I got stopped at the SECOND question.

"lines that contain 'laugh'". lines of what? Doesn't tell you without looking at the answer.

genius.

[FailMore]

How would one make a true shell in a website like this one? (As in, is there an open source library to host an interactive shell for educational purposes - eg codecademy)

[ctippett]

I couldn't tell you the exact details (I'm only passingly familiar with how it works myself), but you'd almost certainly want to start by looking into web assembly.

I found a-Shell's documentation[1] quite interesting, it describes their use of web assembly and offers some practical tips for compiling stuff so it can work in a sandboxed environment.

[1]: https://bianshen00009.gitbook.io/a-guide-to-a-shell/lets-do-...

[benterix]

It would be nice if the instructions spelled out what to do, then I could do it. Otherwise I have to guess what author meant. But all in, a nice small exercise, thanks!

[pstoll]

Neat idea à la regex golf.

But doesn’t seem to do enough shell escaping or correctly. Also seems underspecified, ie “find 5 lines starting with ‘the” doesn’t require a pipe to head -5.

[oneeyedpigeon]

> find 5 lines

Especially since the previous two questions used head/tail. IMO, the wording would be better as "find all the lines" since that's what the command does.

[einpoklum]

I tried to grep for "♫ piping ♫" at some point and the website got stuck. I wonder what it was trying to do...

other than that - nice exercise for newbie shell dabblers :-)

[mejthemage]

I would love something like this that puts me in my own shell. Like a light CTF that is really just shell commands rather than breaking into a VM

[mejthemage]

I went searching and realized overthewire has a bash specific course called "Bandit". Still a VM you SSH to

[chillfox]

That's a nice little challenge.

I did have some issues with Day 11 figuring out what it wanted, but overall it was fun.

[lozf]

If you like things like this you'll probably enjoy

     b64(r13(MaE3o3OmYz5yqPNtqUu0VPOxnJpX))

[tensility]

Not giving real output is a complete fail. Try again.

[franticgecko3]

Tab complete is completely broken on Firefox mobile (Android)

[sva_]

Cool idea but very opinionated and no room for variation

[ParadisoShlee]

I assumed this was some kind of hacking challenge.

[smusamashah]

That font is not very easy to read quickly.

[entropie]

I have serious issues reading that font

[skinwill]

Viewing the page with Safari 26.1 the questions stopped showing up after the second challenge. I was left with only Learn and View Solutions, which was not very fun since both showed a form of the answer.

TL;DR: The page stopped loading properly.

[Milpotel]

> Safari [..] The page stopped loading properly.

Who would've guessed...

[Biganon]

I mean if you ask for the lines that start with "the" and expect lines that start with "The", maybe you should say it in the instructions.

After the 3rd time I had to peek at "learn" to understand what was even asked, I gave up. This is more annoying than fun.

[dncornholio]

Terrible. You cannot 'ls' if ls is not the right answer. Completely useless.

[imp0cat]

That's not true. You can absolutely use ls and other commands to poke around before creating the winning command.