Snippets about cmd

Trusted certificates for localhost with mkcert

HTTPS on your dev server without the browser warning, in three commands.

Tail CloudWatch logs

Watch a Lambda's logs live, from the terminal, like tail -f.

Resize images in bulk with ImageMagick

Shrink a folder of photos for the web in one command.

Open WSL folders in Explorer and the other way around

Moving between the Linux and the Windows side without copying files.

Find the slowest pages in a Stati build

Build metrics, the HTML report, and two jq one-liners.

Run a throwaway container with the current folder mounted

Try a tool, a Node version or a Python version without installing anything.

Rerun a command whenever a file changes

A poor man's watch mode for anything that doesn't have one.

Reverse proxy a Node app with nginx

Your app listens on 3000, the world talks to nginx on 443.

Copy your public key to a server

One command instead of pasting into authorized_keys by hand.

chmod numbers explained

What 755 and 644 actually mean, so you stop copying them blindly.

Check when an SSL certificate expires from the terminal

Before the browser warning does it for you.

stati invalidate cheat sheet

Clear Stati's build cache by tag, path, glob or age, and what each query really matches.

Purge the Cloudflare cache from the terminal

After a deploy, make Cloudflare forget the old pages, without clicking through the dashboard.

Run a Node app as a systemd service

Start on boot, restart on crash, logs in journalctl. No pm2 needed.

Scale pixel art video without blur in ffmpeg

Recording a 320 × 180 game and uploading it at 1080p without the smear.

tmux basics

Start a long job on a server, close the laptop, come back to it later.

Switch AWS CLI profiles

Work and personal accounts in one terminal without mixing them up.

Resume a broken download with curl or wget

The 8 GB ISO died at 97%. Don't start over.

jq basics

Read, filter and reshape JSON in the terminal.

Sync a folder to S3

Upload a built site to a bucket, sending only what changed.

Tunnel to a remote database over SSH

Use your local database tools on a server's database that isn't exposed to the internet.

List listening ports on linux

What is this server actually exposing to the world?

Upscale pixel art with ImageMagick without blur

Turn a 32 px sprite into a 256 px image where every pixel stays a square.

Find and replace text in many files with sed

Rename a function across a project from the terminal.

Disable SSH password login on a server

Once your key works, close the door the bots keep knocking on.

Check if a port is open from the terminal

Is it the firewall, the service, or me?

Find the processes eating your memory

The server is swapping. Who's responsible?

Send JSON with curl

POST a JSON body to an API from the terminal, and read the answer.

Crontab cheat sheet

The five fields, the shortcuts and the two mistakes everybody makes.

Copy files with rsync over SSH

Like scp, but it only sends what changed, and it can resume.

Open a shell in a running container

Poke around inside a container to see what it actually looks like in there.

Create a new user with sudo rights on Ubuntu

Stop working as root on a fresh server.

Create a swap file on Ubuntu

Small VPS, no swap, and npm install gets killed. Give it some room.

Redirect www and http to https in nginx

One canonical address for your site, everything else gets a 301.

Trim a video without re-encoding with ffmpeg

Cut a clip out of a long recording in a second, with no quality loss.

Dump and restore a MariaDB database

Backups, moving a database to another server, or copying production to your machine.

Generate a random password in the terminal

No password generator website needed.

Follow a log file live

Watch a log as it is being written, with and without systemd.

Clean up Docker disk space

Docker quietly ate 40 GB of my disk. Here is how to get it back.

SSH config aliases

Stop typing [email protected] -p 2222 every single time.

Find the largest files and folders on linux

The disk is full again. Here is how to find what is eating it.

Kill the process that is using a port

Find out what is squatting on port 3000 and get rid of it.

Add more VSFTPD virtual user accounts

How to add more virtual user accounts to your VSFTPD on linux.

Mount samba share on Ubuntu 20.04 server

How to mount samba shares on the latest Ubuntu LTS release.

Compress and extract TAR files on linux

How to compress and extract TAR files on linux with gzip easily.

File sizes on linux

See files sizes easily in megabyte or gigabyte values.

Reset MariaDB root password on linux

An easy way to reset the password of the root user on linux.

Fix MariaDB missing tables on Manjaro/Arch linux

Here is how to fix the missing tables in MariaDB that you may encounter on a fresh install on Manjaro or Arch linux.

List all users and groups on linux

Simple way to check your user list with your groups.

Chown basics on linux

Change the owner of files on a linux machine.

Ubuntu run command in the background

Sometimes you just need to run commands in the background.

Certbot snippets

Useful commands for SSL cert generation with Certbot.