Posts tagged: bash

Vaulted Secrets Without Git Churn

2026-02-26T09:59:57Z

Ansible Vault keeps secrets out of sight, but the ciphertext changes on every encrypt. That turns Git diffs into noise and makes it hard to tell if anything actually changed. Decrypting, editing, and re-encrypting often leaves uncertainty about whether any plaintext changed. This is amplified when secret repos are tightly coupled to dependent repositories. A typical cycle includes decrypting, adding a key, updating a value, applying changes, and returning later with little clarity about what changed while secrets were in plaintext.

Today a new workflow was created with @gpt-5.2-codex to keep diffs clean and avoid re-encrypting when the plaintext is identical.

Waylon Walker

This repo has ansible vaulted secrets and an encrypt/decrypt process, but no way to compare. Please research compare options. The goal is to avoid changing files on encrypt/decrypt when plaintext is unchanged, ideally by comparing decrypted content and reusing the remote encrypted file.

@gpt-5.2-codex

The repo workflow will be reviewed, compare options identified, and a low-churn GitOps approach proposed to avoid re-encrypt noise.

The problem #

Re-encrypting a file with the same content produces different ciphertext. A simple decrypt/encrypt cycle can look like a full file change, even when the plaintext is identical. That creates uncertainty and makes GitOps workflows feel brittle.

Waylon Walker

Minimal changes needed to keep GitOps clear?

@gpt-5.2-codex

Add compare-before-encrypt, decrypted diffs, and ignore cache artifacts.

The solution at a glance #

Three pieces make it work:

Compare-before-encrypt
- just decrypt stores a plaintext hash and caches the current encrypted file.
- just encrypt compares the plaintext hash and, if unchanged, restores the cached ciphertext instead of re-encrypting.
Readable diffs for vaulted files
- .gitattributes sets private/* diff=ansible-vault.
- A small textconv script decrypts for git diff.
Ignored cache artifacts
- .vault-hashes/ and .vault-cache/ are ignored so they never hit the repo.

How it works #

Waylon Walker

How does compare-before-encrypt operate?

@gpt-5.2-codex

Hash plaintext on decrypt, reuse cached ciphertext on encrypt if the hash matches.

Compare-before-encrypt #

When a file is decrypted, a SHA-256 hash of the plaintext is created and stored in .vault-hashes/. A copy of the encrypted file is stored in .vault-cache/.

When encrypting, the current plaintext file is hashed. If the hash matches the cached hash, the cached encrypted file is restored instead of generating new ciphertext. Result: no churn when nothing actually changed.

Decrypted diffs #

Git is configured to use ansible-vault view as a text conversion step for files under private/. As a result, git diff shows decrypted content instead of ciphertext.

Enable the diff driver locally:

git config diff.ansible-vault.textconv "scripts/ansible-vault-diff"

What changes will be seen #

If a secret changes: the diff shows the plaintext change.
If decrypt and re-encrypt occurs without changes: the diff stays clean.
Large base64 blobs may still look like full-line diffs because they are single-line values.

Waylon Walker

What is the day-to-day workflow?

@gpt-5.2-codex

`just decrypt`, edit, then `just encrypt`. Clean diffs, no churn.

Recommended usage #

just decrypt
# apply edits
just encrypt

That is sufficient to keep Git history clean and reduce uncertainty about whether a secret actually changed.

COLUMNS env var

2025-11-26T13:24:38Z

setting COLUMNS env var to a number greater than 0 will make the terminal resize to that number of columns.

COLUMNS=80 uvx --from rich-cli rich myscript.py

Note

Not all programs respct the COLUMNS env var, but rich does, and a lot of stuff I’m building uses rich.

I discovered this when I was trying to make a low effort readme generated from the code, but did not depend on the size of terminal it was ran on.

# justfile
readme:
    echo "# Workspaces" > README.md
    echo "" >> README.md
    echo '``` bash' >> README.md
    COLUMNS=80 ./workspaces.py --help >> README.md
    echo '```' >> README.md

tar over ssh

2025-09-13T10:50:42Z

Today I learned how to use tar over ssh to save hours in file transfers. I keep all of my projects in ~/git (very creative I know, I’ve done it for years and haven’t changed). I just swapped out my main desktop from bazzite to hyprland, and wanted to get all of my projects back. Before killing my bazzite install I moved everything over (16GB of many small files), it took over 14 hours, maybe longer. I had started in the morning and just let it churn.

This was not going to happen for re-seeding all of my projects on my new system, I knew there had to be a better way, I looked at rsync, but for seeding I ran into this tar over ssh technique and it only took me 6m51s to pull all of my projects off of my remote server.

ssh user@192.168.1.100 'tar -C /tank/git -cpf - .' \
  | tar -C "$HOME/git" -xpf -

💭 2025-07-10 Notes

2025-07-18T15:26:28Z

2025-07-09 Notes from yesterday I have temporal stuff kind of going with postiz in a windsurf session working on [[thoughts-to-nostr]] Been cleaning up my z" loading="lazy">

2025-07-10 Notes | Nic Payne

2025-07-09 Notes from yesterday I have temporal stuff kind of going with postiz in a windsurf session working on [[thoughts-to-nostr]] Been cleaning up my z

pype.dev

big fan of eza and dust, I like these aliases to have some common commands at my fingertips. I often use the tree command and yes it sometimes goes too deep to actually be useful.

    alias lt='eza -T --level=2'             # Tree view, 2 levels deep
    alias ltt='eza -T --level=3'            # Tree view, 3 levels deep

    alias du1='dust -d 1'                   # Show only 1 level deep
    alias du2='dust -d 2'                   # Show 2 levels deep

Note

This post is a thought. It’s a short note that I make about someone else’s content online #thoughts

fc

2025-07-18T07:52:53Z

I am a linux user through and through. Desktop, server, vms, containers, everything except my phone is linux. With this I spend a lot of time in the terminal, and have been a long time user of !! to rerun the last command, but with the ability to tack something on at the beginning or end.

TIL about fc, which opens the last command in your shell history in your $EDITOR or pass in your editor -e nvim.

man fc

Rcap of how !! works #

!! pronounces bang bang and will run the last command in your history.

ls -l

!! | wc -l
# ls -l | wc -l

sudo !!
# sudo ls -l | wc -l

!!:s/-l/-l \/tmp
# sudo ls -l /tmp | wc -l

`fc` enters the chat #

Now making complex edits in your shell can be a bit of a chore, so fc moves this work to your $EDITOR.

fc

This pops open your $EDITOR with the last command in your history.

sudo ls -l | wc -l

Shell History #

fc shows up in shell history, but !! does not, !! gets replaced by the command that it becomes.

Up Arrow #

yaya yaya, I know you can also up-arrow c-e, but what fun is that, it’s barely a flex. fc just looks big brained and like you really know what you are doing.

unset multiple environment variables

2025-06-03T11:21:11Z

You can unset multiple environment variables at once. I did not know this was a thing, its something that ended up happening organically on a call and asking someone to run unset. They had never done it before and did not know how it works, but did exactly as I said instead of what I meant. I like this handy shortcut doing it in one line rather than each one individually, I will be using this in the future. You might need this for something like running aws cli commands with localstack.

unset AWS_ACCESS_KEY_ID AWS_SECRET_ACCESS_KEY AWS_DEFAULT_REGION

💭 bic | Static blog generator, in bash

2025-01-09T14:22:47Z

bic

Static blog generator, in bash

bic · bic.sh

Intereresting someone built a blog generator in bash. it comes with normal markdown to html, static content, robots.txt, sitemap, rss, and tags. It uses pandoc to take markdown to html and mustache for page templates.

Note

This post is a thought. It’s a short note that I make about someone else’s content online #thoughts

💭 casey/just: 🤖 Just a command runner

2024-12-14T17:04:06Z

GitHub - casey/just: 🤖 Just a command runner

🤖 Just a command runner. Contribute to casey/just development by creating an account on GitHub.

GitHub · github.com

new versions of just now come with color variables already set.

[group('manage')]
version:
    #!/usr/bin/env bash
    version=$(cat version)
    echo current version {{BOLD}}{{GREEN}}$version{{NORMAL}}

Note

This post is a thought. It’s a short note that I make about someone else’s content online #thoughts

💭 pipedream/justfile at main · thechangelog/pipedream

2024-12-14T16:54:34Z

pipely/justfile at main · thechangelog/pipely

I like the idea of having like this 20-line Varnish config that we deploy around the world, and it’s like: Look at our CDN! - thechangelog/pipely

GitHub · github.com

I found this nugget in thechangelogs justfile, it lets you add color to your justfile with variables quite easily.

# https://linux.101hacks.com/ps1-examples/prompt-color-using-tput/

_BOLD := "$(tput bold)"
_RESET := "$(tput sgr0)"
_BLACK := "$(tput bold)$(tput setaf 0)"
_RED := "$(tput bold)$(tput setaf 1)"
_GREEN := "$(tput bold)$(tput setaf 2)"
_YELLOW := "$(tput bold)$(tput setaf 3)"
_BLUE := "$(tput bold)$(tput setaf 4)"
_MAGENTA := "$(tput bold)$(tput setaf 5)"
_CYAN := "$(tput bold)$(tput setaf 6)"
_WHITE := "$(tput bold)$(tput setaf 7)"
_BLACKB := "$(tput bold)$(tput setab 0)"
_REDB := "$(tput setab 1)$(tput setaf 0)"
_GREENB := "$(tput setab 2)$(tput setaf 0)"
_YELLOWB := "$(tput setab 3)$(tput setaf 0)"
_BLUEB := "$(tput setab 4)$(tput setaf 0)"
_MAGENTAB := "$(tput setab 5)$(tput setaf 0)"
_CYANB := "$(tput setab 6)$(tput setaf 0)"
_WHITEB := "$(tput setab 7)$(tput setaf 0)"

Usage

echo:
    echo {{_BOLD}}{{_GREEN}}hello there{{_RESET}}

Note

This post is a thought. It’s a short note that I make about someone else’s content online #thoughts

urllink

2024-12-14T11:11:52Z

Today I discovered the Urllink function in bash from the ujust tool from ublue.it. Seems like a cool trick, but might not work everywhere.

########
### Special text formating
########
## Function to generate a clickable link, you can call this using
# url=$(Urllink "https://ublue.it" "Visit the ublue website")
# echo "${url}"
function Urllink (){
    URL=$1
    TEXT=$2

    # Generate a clickable hyperlink
    printf "\e]8;;%s\e\\%s\e]8;;\e\\" "$URL" "$TEXT${n}"
}
```j

💭 hostnamectl to easily change hostname | Pype.dev

2024-12-06T14:30:41Z

hostnamectl to easily change hostname | Nic Payne

hostnamectl is apparently a linux utility for easily changing your hostname in a variety of ways I learned there's transient and static hostnames, so that&

pype.dev

For some reason the ublue ecosystem does not prompt you to set your hostname on install and you get a hostname like bazzite showing up. Looks like this is the fix.

hostnamectl –static hostname babyblue-aurora

Note

This post is a thought. It’s a short note that I make about someone else’s content online #thoughts

convert mp4 for twitter with ffmpeg

2024-07-25T12:51:29Z

I’ve had a couple of uploads to twitter fail recently and has been a pain. I tried some online converters for convenience, but none of them worked. I reached out to chatgpt and found succeess with this ffmpeg command.

ffmpeg -i input.mp4 \
  -vf "scale=trunc(oh*a/2)*2:min(720\,trunc(ih*a/2)*2)" \
  -c:v libx264 -profile:v high -level:v 4.1 \
  -b:v 3500k -maxrate 3500k -bufsize 7000k \
  -pix_fmt yuv420p \
  -c:a aac -b:a 128k -ar 44100 \
  -movflags +faststart \
  output.mp4

cli auth

2023-12-17T20:09:03Z

Authentication from cli tools can be a bit of a bear, and I have to look it up every time. This is my reference guide for future me to remember how to easily do it.

I set up a fastapi server running on port 8000, it uses a basic auth with waylonwalker as the username and asdf as the password. The server follows along with what comes out of the docs. I have it setup to take basic auth, form username and password, or a bearer token for authentication.

curl #

The og of command line url tools.

# basic auth
curl -u 'waylonwalker:asdf' -X POST localhost:8000/token
# basic auth with password prompt
curl -u 'waylonwalker' -X POST localhost:8000/token
# token
curl -H 'Authorization: bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ3YXlsb253YWxrZXIiLCJleHAiOjE3MDI5NTI2MDJ9.GeYNt7DNal6LTiPoavJnqypaMt4vYeriXdq5lqu1ILg' -X POST localhost:8000/token

wget #

My go to if I want the result to go into a file.

# basic auth
wget -q -O - --auth-no-challenge --http-user=waylonwalker --http-password=asdf --post-data '' localhost:8000/token

# token
wget -q -O - --header="Authorization: bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ3YXlsb253YWxrZXIiLCJleHAiOjE3MDI5NTI2MDJ9.GeYNt7DNal6LTiPoavJnqypaMt4vYeriXdq5lqu1ILg" -O - --post-data '' localhost:8000/token

httpx #

An http client written in python, primarilty used with the python api, but has a nice cli.

# install
python3 -m pip install httpx

# basic auth
httpx -m POST --auth waylonwalker asdf http://localhost:8000/token

# basic auth with password prompt
httpx -m POST --auth waylonwalker - http://localhost:8000/token

# token
httpx -m POST --headers="Authorization" "bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ3YXlsb253YWxrZXIiLCJleHAiOjE3MDI5NTI2MDJ9.GeYNt7DNal6LTiPoavJnqypaMt4vYeriXdq5lqu1ILg" http://localhost:8000/token

httpie #

A modern http client written in python.

# install
python3 -m pip install httpie

# basic auth
http POST localhost:8000/token -a waylonwalker:asdf

# basic auth with password prompt
http POST localhost:8000/token -a waylonwalker

# token
http POST localhost:8000/token -A bearer -a eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ3YXlsb253YWxrZXIiLCJleHAiOjE3MDI5NTI2MDJ9.GeYNt7DNal6LTiPoavJnqypaMt4vYeriXdq5lqu1ILg

httpie with plugin #

# install
python3 -m pip install httpie-credential-store
# usage
http POST localhost:8000/token -A creds

httpie prompt #

http-prompt comes from the httpie org, and has an interactive cli interface into apis. You can even specify a spec file to autocomplete on api methods.

http-prompt localhost:8000 --auth waylonwalker:asdf --spec openapi.json

jpillora-installer

2023-10-04T19:28:33Z

jpillora/installer is the install script generator I have been looking for. It downloads binaries for your machine from GitHub releases and unzips them for you. It grabs the latest release, so you can easily update them. I have tried scripting these installs in the past and struggled to consistently get the latest version for every package and unpack it correctly.

Also these pre-compiled binaries install rediculously fast compared to building them from source.

Check out some example links.

opening in a browser will show metadata

https://i.jpillora.com/serve

If you pass in script=true it will instead return the install script as it would by default through curl.

https://i.jpillora.com/serve?script=true

Use it to install neovim #

All you need to do to generate an install script is to pass in the GitHub repo slug with the org.

curl https://i.jpillora.com/neovim/neovim | bash

The shell script that it generates for neovim looks like this.

#!/bin/bash
if [ "$DEBUG" == "1" ]; then
    set -x
fi
TMP_DIR=$(mktemp -d -t jpillora-installer-XXXXXXXXXX)
function cleanup {
    rm -rf $TMP_DIR > /dev/null
}
function fail {
    cleanup
    msg=$1
    echo "============"
    echo "Error: $msg" 1>&2
    exit 1
}
function install {
    #settings
    USER="neovim"
    PROG="neovim"
    ASPROG=""
    MOVE="false"
    RELEASE="stable"
    INSECURE="false"
    OUT_DIR="$(pwd)"
    GH="https://github.com"
    #bash check
    [ ! "$BASH_VERSION" ] && fail "Please use bash instead"
    [ ! -d $OUT_DIR ] && fail "output directory missing: $OUT_DIR"
    #dependency check, assume we are a standard POISX machine
    which find > /dev/null || fail "find not installed"
    which xargs > /dev/null || fail "xargs not installed"
    which sort > /dev/null || fail "sort not installed"
    which tail > /dev/null || fail "tail not installed"
    which cut > /dev/null || fail "cut not installed"
    which du > /dev/null || fail "du not installed"
    #choose an HTTP client
    GET=""
    if which curl > /dev/null; then
        GET="curl"
        if [[ $INSECURE = "true" ]]; then GET="$GET --insecure"; fi
        GET="$GET --fail -# -L"
    elif which wget > /dev/null; then
        GET="wget"
        if [[ $INSECURE = "true" ]]; then GET="$GET --no-check-certificate"; fi
        GET="$GET -qO-"
    else
        fail "neither wget/curl are installed"
    fi
    #debug HTTP
    if [ "$DEBUG" == "1" ]; then
        GET="$GET -v"
    fi
    #optional auth to install from private repos
    #NOTE: this also needs to be set on your instance of installer
    AUTH="${GITHUB_TOKEN}"
    if [ ! -z "$AUTH" ]; then
        GET="$GET -H 'Authorization: $AUTH'"
    fi
    #find OS #TODO BSDs and other posixs
    case `uname -s` in
    Darwin) OS="darwin";;
    Linux) OS="linux";;
    *) fail "unknown os: $(uname -s)";;
    esac
    #find ARCH
    if uname -m | grep -E '(arm|arch)64' > /dev/null; then
        ARCH="arm64"

        # no m1 assets. if on mac arm64, rosetta allows fallback to amd64
        if [[ $OS = "darwin" ]]; then
            ARCH="amd64"
        fi

    elif uname -m | grep 64 > /dev/null; then
        ARCH="amd64"
    elif uname -m | grep arm > /dev/null; then
        ARCH="arm" #TODO armv6/v7
    elif uname -m | grep 386 > /dev/null; then
        ARCH="386"
    else
        fail "unknown arch: $(uname -m)"
    fi
    #choose from asset list
    URL=""
    FTYPE=""
    case "${OS}_${ARCH}" in
    "linux_amd64")
        URL="https://github.com/neovim/neovim/releases/download/stable/nvim-linux64.tar.gz"
        FTYPE=".tar.gz"
        ;;
    "darwin_amd64")
        URL="https://github.com/neovim/neovim/releases/download/stable/nvim-macos.tar.gz"
        FTYPE=".tar.gz"
        ;;
    *) fail "No asset for platform ${OS}-${ARCH}";;
    esac
    #got URL! download it...
    echo -n "Downloading"
    echo -n " $USER/$PROG"
    if [ ! -z "$RELEASE" ]; then
        echo -n " $RELEASE"
    fi
    if [ ! -z "$ASPROG" ]; then
        echo -n " as $ASPROG"
    fi
    echo -n " (${OS}/${ARCH})"

    echo "....."

    #enter tempdir
    mkdir -p $TMP_DIR
    cd $TMP_DIR
    if [[ $FTYPE = ".gz" ]]; then
        which gzip > /dev/null || fail "gzip is not installed"
        bash -c "$GET $URL" | gzip -d - > $PROG || fail "download failed"
    elif [[ $FTYPE = ".tar.bz" ]] || [[ $FTYPE = ".tar.bz2" ]]; then
        which tar > /dev/null || fail "tar is not installed"
        which bzip2 > /dev/null || fail "bzip2 is not installed"
        bash -c "$GET $URL" | tar jxf - || fail "download failed"
    elif [[ $FTYPE = ".tar.gz" ]] || [[ $FTYPE = ".tgz" ]]; then
        which tar > /dev/null || fail "tar is not installed"
        which gzip > /dev/null || fail "gzip is not installed"
        bash -c "$GET $URL" | tar zxf - || fail "download failed"
    elif [[ $FTYPE = ".zip" ]]; then
        which unzip > /dev/null || fail "unzip is not installed"
        bash -c "$GET $URL" > tmp.zip || fail "download failed"
        unzip -o -qq tmp.zip || fail "unzip failed"
        rm tmp.zip || fail "cleanup failed"
    elif [[ $FTYPE = ".bin" ]]; then
        bash -c "$GET $URL" > "neovim_${OS}_${ARCH}" || fail "download failed"
    else
        fail "unknown file type: $FTYPE"
    fi
    #search subtree largest file (bin)
    TMP_BIN=$(find . -type f | xargs du | sort -n | tail -n 1 | cut -f 2)
    if [ ! -f "$TMP_BIN" ]; then
        fail "could not find find binary (largest file)"
    fi
    #ensure its larger than 1MB
    #TODO linux=elf/darwin=macho file detection?
    if [[ $(du -m $TMP_BIN | cut -f1) -lt 1 ]]; then
        fail "no binary found ($TMP_BIN is not larger than 1MB)"
    fi
    #move into PATH or cwd
    chmod +x $TMP_BIN || fail "chmod +x failed"
    DEST="$OUT_DIR/$PROG"
    if [ ! -z "$ASPROG" ]; then
        DEST="$OUT_DIR/$ASPROG"
    fi
    #move without sudo
    OUT=$(mv $TMP_BIN $DEST 2>&1)
    STATUS=$?
    # failed and string contains "Permission denied"
    if [ $STATUS -ne 0 ]; then
        if [[ $OUT =~ "Permission denied" ]]; then
            echo "mv with sudo..."
            sudo mv $TMP_BIN $DEST || fail "sudo mv failed"
        else
            fail "mv failed ($OUT)"
        fi
    fi
    echo "Downloaded to $DEST"
    #done
    cleanup
}
install

self-host-your-own">Self Host Your Own #

I’d reccomend self hosting your own. This way you know that it’s consistent and unlikely to change in a way that breaks your use.

curl -s https://i.jpillora.com/installer | bash

Repos I am using installer for #

Here are the repos I am using installer for.

atuinsh/atuin
benbjohnson/litestream
bootandy/dust
BurntSushi/ripgrep
chmln/sd
cjbassi/ytop
dalance/procs
dbrgn/tealdeer
ducaale/xh
go-task/task
imsnif/bandwhich
imsnif/diskonaut
kovidgoyal/kitty
mgdm/htmlq
neovim/neovim
ogham/dog
ogham/exa
pemistahl/grex
sharkdp/bat
sharkdp/fd
sharkdp/pastel
sirwart/ripsecrets
starship/starship
topgrade-rs/topgrade
zellij-org/zellij

💭 Deleting Specific Lines in a File with sed or yq

2023-07-28T14:59:37Z

Deleting Specific Lines in a File with sed or yq — Nick Janetakis

Nick Janetakis · nickjanetakis.com

sed can be a tricky beast, I often stumble when trying to pipe into it. Next time I need to use sed, I should reference this article by Nick Janetakis. He makes it looks much easier than my experience has been, and it appears to behave like a vim :%s/ substitution does, or a g/ g command.

Note

This post is a thought. It’s a short note that I make about someone else’s content online #thoughts

dash e your github docker actions

2022-12-07T13:09:37Z

Give github actions the -e flag in the shebang #! so they fail on any one command failure. Otherwise each line will set the exit status, but only the last one will be passed to ci.

#!/bin/bash -e

What is -e #

The -e flag to the bash command allows your script to exit immediately if any command within the script returns a non-zero exit status. This can be useful for ensuring that your script exits with an error if any of the commands it runs fail, which can help you identify and debug issues in your script. For example, if you have a script that runs several commands and one of those commands fails, the script will continue running without the -e flag, but will exit immediately if the -e flag is present. This can make it easier to troubleshoot your script and ensure that it runs correctly.

Solution for Windows #

In windows the solution is not quite as simple. You can define a function in a Windows batch script that wraps an if statement to check the exit status of a command and handle any errors that may have occurred. Here is an example of how you might define a function called “check_error” that does this:

:check_error
if errorlevel 1 (
  echo An error occurred!
  exit /b 1
)

To use this function in your script, you would simply call it after running a command, like this:

some_command
call :check_error

This would run the “some_command” and then call the “check_error” function to check the exit status and handle any errors that may have occurred. This approach allows you to reuse the error-checking logic in your script, which can make it easier to write and maintain.

Bash function to edit scripts faster

2022-05-10T14:57:35Z

I am often editing my own scripts as I develop them. I want to make a better workflow for working with scripts like this.

Currently #

Currently I am combining nvim with a which subshell to etit these files like this.

for now lets use my todo command as an example

nvim `which todo`

First pass #

On first pass I made a bash function to do exactly what I have been doing.

ewhich () {$EDITOR `which "$1"`}

The $1 will pass the first input to the which subshell. Now we can edit our todo script like this.

ewich todo

Note, I use bash functions instead of aliases for things that require input.

Final State #

This works fine for commands that are files, but not aliases or shell functions. Next I jumped to looking at the output of command -V $1.

if the command is not found, search for a file
if its a builtin, exit
if its an alias, open my ~/.alias file to that line
if its a function, open my ~/.alias file to that line

ewhich () {
case `command -V $1` in
    "$1 not found")
        FILE=`fzf --prompt "$1 not found searching ..." --query $1`
        [ -z "$FILE" ] && echo "closing" || $EDITOR $FILE;;
    *"is a shell builtin"*)
        echo "$1 is a builtin";;
    *"is an alias"*)
        $EDITOR ~/.alias +/alias\ $1;;
    *"is a shell function"*)
        $EDITOR ~/.alias +/^$1;;
    *)
        $EDITOR `which "$1"`;;
esac

a bit more ergo, and less readable #

To make it easier to type, at the sacrifice of readability for anyone watching I added a single character e alias to ewhich. So when I want to edit anything I just use e.

alias e=ewhich

Results #

Here is a quick screencast of how it works.

Sorry, your browser doesn't support embedded videos.

Unzip minecraft mods to their directory from the command line

2022-04-02T16:20:34Z

This morning I was trying to install a modpack on my minecraft server after getting a zip file, and its quite painful when I unzip everything in the current directory rather than the directory it belongs in.

I had the files on a Windows Machine #

So I’ve been struggling to get mods installed on linux lately and the easiest way to download the entire pack rather than each mod one by one seems to be to use the overwolf application on windows. Once I have the modpack I can start myself a small mod-server by zipping it, putting it in a mod-server directory and running a python http.server

python -m http.server

Downoading on the server #

Then I go back to my server and download the modpack with wget.

wget 10.0.0.171:8000/One%2BBlock%2BServer%2BPack-1.4.zip

Unzip to the minecraft-data directory #

Now I can unzip my mods into the minecraft-data directory.

unzip One+Block+Server+Pack-1.4.zip -d minecraft-data

Running the server with docker #

I run the minecraft server with docker, which is setup to mount the minecraft-data directory.

Running a Minecraft Server in Docker

A bit more on that in the other post, but when I download the whole modpack like this I make these changes to my docker compose. (commented out lines)

version: "3.8"

services:
  mc:
    container_name: walkercraft
    image: itzg/minecraft-server:java8
    environment:
      EULA: "TRUE"
      TYPE: "FORGE"
      VERSION: 1.15.2
      # MODS_FILE: /extras/mods.txt
      # REMOVE_OLD_MODS: "true"
    tty: true
    stdin_open: true
    restart: unless-stopped
    ports:
      - 25565:25565
    volumes:
      - ./minecraft-data:/data
      # - ./mods.txt:/extras/mods.txt:ro

volumes:
  data:

Bash mktemp

2022-03-02T14:52:08Z

There is GNU coreutils command called mktemp that is super handy in shell scripts to make temporary landing spots for files so that they never clash with another instance, and will automatically get cleaned up when you restart, or whenever /tmp gets wiped. I’m not sure when that is, but I don’t expect it to be long.

Making temp directories #

Here are some examples of making temp directories in different places, my favorite is mktemp -dt mytemp-XXXXXX.

# makes a temporary directory in /tmp/ with the defaul template tmp.XXXXXXXXXX
mktemp

# makes a temporary directory in your current directory
mktemp --directory mytemp-XXXXXX
# shorter version
mktemp -d mytemp-XXXXXX

# same thing, but makes a file
mktemp mytemp-XXXXXX

# makes a temporary directory in your /tmp/ directory (or what ever you have configured as your TMPDIR)
mktemp --directory --tmpdir mytemp-XXXXXX
# shorter version
mktemp -dt mytemp-XXXXXX

# same thing, but makes a file
mktemp --tmpdir mytemp-XXXXXX
# shorter version
mktemp -t mytemp-XXXXXX

Use Case #

Here is a sample script that shows how to capture the tempdir as a variable and reuse it. Here is an example of curling my bootstrap file into a temp directory and running it from that directory.

local tmp=`mktemp -dt bootstrap-XXXXXX`
pushd $tmp
curl https://raw.githubusercontent.com/WaylonWalker/devtainer/main/bootstrap > bootstrap
bash bootstrap
popd

Templates #

You must have at least 3 trailing X’s that mktemp will replace with random characters. I played with it for a bit, it kinda allows for some trailing characters, and will not fill groups of X’s earlier in your template, only the last consecutive string.

My randomm samples I played with.

waylonwalker.com on  main [!?]  v3.9.7 (waylonwalker.com) took 2m24s
❯ mktemp myXtemp-XaXbXXXX -dt
/tmp/myXtemp-XaXbx9hn

waylonwalker.com on  main [!?]  v3.9.7 (waylonwalker.com)
❯ mktemp myXtemp-XaXbXXXXs -dt
/tmp/myXtemp-XaXb2tpGs

waylonwalker.com on  main [!?]  v3.9.7 (waylonwalker.com)
❯ mktemp myXtemp-XaXbXXcXXs -dt
mktemp: too few X's in template ‘myXtemp-XaXbXXcXXs’

waylonwalker.com on  main [!?]  v3.9.7 (waylonwalker.com)
❯ mktemp myXtemp-XaXbXXcXXs -dt

waylonwalker.com on  main [!?]  v3.9.7 (waylonwalker.com)
❯ mktemp myXtemp-XaXbXXXXt -dt
/tmp/myXtemp-XaXbe8PWt

waylonwalker.com on  main [!?]  v3.9.7 (waylonwalker.com)
❯ mktemp myXtemp-XXX-you-XXX -dt
/tmp/myXtemp-XXX-you-48l

waylonwalker.com on  main [!?]  v3.9.7 (waylonwalker.com)
❯ mktemp myXtemp-XXX-you-XX -dt
mktemp: too few X's in template ‘myXtemp-XXX-you-XX’

RTFM #

The man page has good stuff on all the flags that you might need.

man mktemp

View AWS event bridge rules with visidata

2022-02-15T03:04:26Z

Reading eventbridge rules from the command line can be a total drag, pipe it into visidata to make it a breeze.

I just love when I start thinking through how to parse a bunch of json at the command line, maybe building out my own custom cli, then the solution is as simple as piping it into visidata. Which is a fantastic tui application that had a ton of vim-like keybindings and data features.

alias awsevents = aws events list-rules | visidata -f json

Posts tagged: bash

Vaulted Secrets Without Git Churn

The problem #

The solution at a glance #

How it works #

Compare-before-encrypt #

Decrypted diffs #

What changes will be seen #

Recommended usage #

COLUMNS env var

tar over ssh

💭 2025-07-10 Notes

fc

Rcap of how !! works #

fc enters the chat #

Shell History #

Up Arrow #

unset multiple environment variables

💭 bic | Static blog generator, in bash

💭 casey/just: 🤖 Just a command runner

💭 pipedream/justfile at main · thechangelog/pipedream

urllink

💭 hostnamectl to easily change hostname | Pype.dev

convert mp4 for twitter with ffmpeg

cli auth

curl #

wget #

httpx #

httpie #

httpie with plugin #

httpie prompt #

jpillora-installer

Use it to install neovim #

self-host-your-own">Self Host Your Own #

Repos I am using installer for #

💭 Deleting Specific Lines in a File with sed or yq

dash e your github docker actions

What is -e #

Solution for Windows #

Bash function to edit scripts faster

Currently #

First pass #

Final State #

a bit more ergo, and less readable #

Results #

Unzip minecraft mods to their directory from the command line

I had the files on a Windows Machine #

Downoading on the server #

Unzip to the minecraft-data directory #

Running the server with docker #

Bash mktemp

Making temp directories #

Use Case #

Templates #

RTFM #

View AWS event bridge rules with visidata

`fc` enters the chat #