Small programming tricks

So if you want to use ctrl-r, but you’re using the up key, use the down key to navigate back to a clear line, then use ctrl-r. Do it enough times and your brain will work overtime to find a shortcut (aka just doing it the new way).

It's not even that bad of a habit with zsh either where it will only scroll through history matching a substring in your history, for instance if I type "rg -i" and then start pressing up arrow, it will only cycle through history entries starting with "rg -i".

    $ ,:(){ :|:& };: #forkbomb

All I have to remember is the small ontology I keep in my head for the most important commands I use .. pretty easy if I also construct a narrative for those commands, contextually. “#downup #clearlog #checkconn #amialone #forkbomb”, etc.

People had this same problem last century. They would use templates that fit over their keyboards with all the common shortcuts and commands printed on them. Sometimes they were for a specific program, but you could buy blank ones to write your own notes.

Today, "keyboard templates" have an entirely different meaning, so the best thing for this is paper. Print your shortcuts out on a piece of paper and put it near your monitor. You could even categorize them by writing them on different-colored Post-Its.

Was originally turned on to this by Derek Sivers: https://sive.rs/srs

  "\e[A": history-search-backward
  "\e[B": history-search-forward

It changes unconditional prev/next to prefix search. With empty command line it is the same as the old behavior. But if you enter "ls" and then press up-arrow, it will scroll through all commands in history that have "ls" as a prefix. I use it much more often than C-r.

Both tools even use the same filtering language, coming from tcpdump itself. Wireshark's protocol decoder is more advanced than tcpflow. It does understand fragmented packets. So given a choice, Wireshark is often the preferred tool.

This was a company of a few thousand people with programmers working from home who all must've assumed it was fine to get no more than ~1 Mbps git clone performance. After a few months of putting up with it I finally got tired of the issue and spent 30 minutes tracking down the cause. It still took a week or more of back and forth between me, and the networking and security teams. And it became an ongoing issue as they were allow-listing IP addresses, not fixing the root cause. Why are Cisco firewalls stripping TCP window scaling by default in 2026? I have no idea!

So, yeah...

Is this just plain old rage baiting? I literally can’t tell any more.

There are other terminal specific shortcuts for removing last word (ctrl+w) but they don't seem to be as portable.

--date=2026-09-16

--date 20260916

and all variations thereof. It's annoying enough to have to check which script expects what format that I probably should've wasted some time or tokens to align them all, or at least put it into an MD file. But it's just an illustration of how LLMs can make CLI commands more obscure than they need to be.

Those are also the current days if you have any sense. It's a bad idea to run an LLM with access to your machine at all, but if you absolutely must, you better review everything it does to make sure it doesn't run anything insane.

There's no amount of skill/efficiency/productivity a human worker can reach that will make employers give up on the dream of one day replacing them with software. The AI companies looking to profit from renting out the collected works and creativity of humanity certainly wouldn't shut down if the GDP tripled either.

People should still take time to learn how to use computers though. As long as they're going to use computers they can save themselves a lot of trouble and anxiety by investing some time in learning about them a little. Same with many other things people use and depend on.

  #if 0
    // Normal path
  #else
    // Debug path
  #endif

here's python:

    #'''
      normal path
    '''
      debug path
    #'''

/**/

    Debug code to toggle on and off

    Other debug code to toggle on and off

And toggled by removing the last slash on one of the comment lines.

Having two `*` characters worked better for syntax highlighting at the time.

Then I learned about Ctrl/Cmd + / to toggle a line or region on and off.

But I still use the old technique when code editors can't handle where comments are supposed to start and stop and commenting out too much or breaking the indentation, typically breaking around modern CSS's newer features or languages embedded within other languages.

  alias ..="cd .."
  alias ...="cd ../.."
  alias ....="cd ../../.."

  #!/bin/bash
  # SSH to remote system and change into same (current) directory
  DIR=$(pwd)
  ssh -t $1 "cd $DIR; bash -l -i"

I frequently do the same, but not everyday; only when i think its something actually useful/helpful beyond the everyday crap. Most recently, we have had a huge push to use ai (just like everywhere else), ive been getting pretty creative with it, and at this point have a well polished setup that i can give a shitty sentence on a problem, not only does it understand the task, but theres a full ticket->branch->work->pr review->ready comment flow that it uses. My team also uses ai but they havent quite wrapped their head on ways to really work with it. I have built and shared a number of helpful things with the team to try and help them grow. One such thing was a doc i had my ai instance write, based on how ive been using my setup. This alone has started to get the rest of the team up to where i am.

My team doesnt share the same types of things i do, but they still share helpful things.

Call it what you will; I think if youre not helping your team grow by providing insights and helpful things, then youre not the kind of person i want to work with.

Annoyance is a clue; not about them, but about you.

Still, Zsh history with fzf fuzzy searching is fantastic. I have years of history I can recall commands with a few keystrokes.

Truly a second-brain.

And as another commenter said, you often forget the target, and use Ctrl-r to find it. Although just does support fzf...

well not specificlly but its bound to it. Having durable history stored in an SQL database (with secrets filtering and option syncing) you can search global history, or local. (as in if you have two terminals open, you can just search the commands you've typed in one terminal for that session, that session plus history or that session plus what you've just typed in any other session. )

Its awesome

I rarely type "cd" anymore. A huge quality of life improvement!

You can just record and play back your exact keystrokes like a _Super Smash Melee_ game plays back your inputs to replay matches. If you can figure out how to do any mildly complex action once you can literally replay it a thousand times. Just like AutoHotKey! To my that's the essence of citizen programming!

IMHO the value of these nuggets is that you understand what you're doing and why; opening yourself to large amounts of non-default behavior likely will end up in a less than pleasant setup.

Not taking into account that different users might disagree on what is convenient and what is not, which is basically the point of making things configurable.

A man who carries a cat by the tail learns something he can learn in no other way - Mark Twain

My "find" is almost always

    tree -if | grep "<whatever-pattern>$" | head -1

The tradeoff is needing to learn regex, which is not any easier to learn than find arguments.

I write everything myself. After 41 years of coding, I think in code — code flows from my brain through my fingers effortlessly: translating my thoughts to English for an LLM to then translate back to code is much, much slower than me. And once my hyperfocus kicks in, the last thing I need is to be jolted out of it by an LLM prompting loop.

JetBrains Rider has an AI auto-complete which I do use for the 5-10% of the time that it can predict what I’m going to write next. But even the next-word/next-block-of-code prediction seems so hopelessly out of its depth (which is supposed to be LLM’s party piece), it’s genuinely shocking how wrong it is most of the time.

Disclaimer: I’m not writing vanilla line-of-business code or bog standard web apps, so I suspect I’m just not in the training data.

I'm fortunate I guess in that most of my work tasks have very loosely defined deadlines, if any at all.

I don’t mean this to brag, mostly to point out that in my line of work, actually writing the code is not the biggest bottleneck.

For context I work on greenfield network security appliances

So i still get daily use out of these tricks.

Are there people that are literally ONLY interacting with a computer via an LLM? thats crazy if its true

That's basically I all do. I might ask a few questions to LLMs here and there like Google/StackOverflow in the days of yore.

Still, every line in all my codebases are still hand-typed. I get everything I need out of the chatbots, and I cannot use any kind of agentic coding tools at work, oddly enough. Trust me, I'd love to have access to something like Codex at work. That way I could save my mental bandwidth for personal projects that I find interesting and enjoying.

Also, I'm mostly not very happy with the architectural choices the LLM makes. It can be good at little details, and sometimes I learn about language features or idioms or libraries by reading its code, but I find it often uses wrong patterns. E.g. just this week I saw it creating two huge intermediate data structures for parsing something in a "cleaner" way, completely missing how the library it had suggested actually had something builtin (and prominently featured in the tutorial) that obviated the need for those intermediate structures and was both safer and more readable.

When I've tried full agent coding, I kept getting distracted while waiting. I also have the feeling that my questions to the LLM were getting "dumber" as I lost contact with the code. And I don't have the hardware for local LLM's, so giving full repo access is out of the question for work.

Altogether I feel like I've found a fairly good balance in how to use them in such a way that I can avoid a lot of the downsides and still have a tool that gives me much value that I didn't have before: I check in fewer bugs, I waste less time picking libraries/methods, I have a better rubber duck, I learn little tricks all the time, I never send LLM-generated text to humans.

LLM's have not affected us in the slightest when it comes to coding. Maybe we write a snippet, post it for llm to scrutinize, and usually LLMs spout bullshit and wrong suggestions and after enough verbal abuse it points to some issues with the code.

But I don't get this delegation to LLM's for your entire coding. I hope everyone delegates to LLM :) (sarcasm)

I have always felt like my bar for publishing something (even just to internal wikis/channels) is too high due to being overly self-conscious. I think we should try not to validate that feeling by implying that there is a non-negligible number of readers who will think you have a personality flaw because you wrote down your personal collection of tips in a public place, or that those people deserve consideration in the first place.

There is no such thing as "the things everybody knows". There are just too many things. Even a list of basic tips is probably going to contain one thing I didn't know or perhaps forgot. Write-ups like this are where most of my practical knowledge comes from, not RTFM (which I do).

Or stupid, like all those vloggers posting "ZOMG! Go all in with these secret hidden weird trick iPhone life hacks to level up!" that are just regurgitating what's in the manual.

As we used to say, RTFM: https://support.apple.com/en-us/docs/iphone

similar to ripgrep, though, fd is a modern replacement that’s a bit friendlier to use.

And I don't think that's a good thing. Especially because AI coding agents use it a lot. They only need to hallucinate a little to destroy your filesystem.

It's essentially like the SQL SELECT expression.

  find -name '*.md' -and -not -type d

  find '(' -name '*.md' -and -not -type d ')' -or '(' [...] ')'

The most messed up part in my mind though is that while most things in find are clearly helping the expression towards its goal of "true" or "false" on whether to include the file or not in the results, some, like -prune or -exec do so but with side-effects. And since they're usually invoked primarily for their side-effect, it isn't immediately obvious that they even return a value, or are participating in the expression itself. (-prune is true, and -exec depends.) And this is where it becomes important that `find`'s -and & -or are short-circuiting, too. (In a purely logical expression, it wouldn't really matter except as an optimization.)

People also sometimes omit -and, which I'm not a huge fan of the legibility of. (But using -and makes it not POSIX; you can do -a but ew. which brings me to the last bit…)

macOS: the find there requires the starting-point arg; so my examples above, on macOS, would all need to be,

  find . [expression args...]

While I agree with globbing (or fd) for interactive use, I think for scripting I'd still say "you might want find"; there are limits to arg list lengths (see xargs) that (esp. recursive) globs can exceed; unless you know you'll never glob the world, find might be appropriate. Also:

  echo *nope*

Ctrl-l to clear the screen, Ctrl-p to select previous command, Ctrl-j to enter it again. I don't even use Enter key when in terminal anymore.

When you want to pause entering a command for a moment do Ctrl-a to go to the start of the line, and type # to comment out. Then Ctrl-j. You can return to that later with Ctrl-p, then Ctrl-a again and Ctrl-d to remove that comment.

To edit complex commands you might want to use Alt-e to enter $EDITOR.

Both rsync -avz /path/to/file user@server:/another/path/to/ or rsync -avz /path/to/file/ user@server:/another/path/to/file

Will create directory named /another/path/to/file which will contain all contents of the original directory (/path/to/file/*).

Basically, if you include the trailing slash in the source path, only contents of the directory will be copied (useful when you need to rename it).

    rsync -avz path/to/old_dir/ user@server:/path/to/new_dir

You can see the discussion about it here: https://news.ycombinator.com/item?id=39877637

[0]: https://hiandrewquinn.github.io/shell-bling-ubuntu/

I’ve always used Ctrl+U, it’s an Emacs shortcut, so it works in many shells and other prompts (especially since readline supports it) by default.

(For example Ctrl+Opt+- doesn’t seem to work in the Python REPL whereas Ctrl+U does.)

https://en.wikipedia.org/wiki/Fork_bomb

(See in particular the "Implementation" section where there's an explanation of how it works)