Snippets about linux

Rerun a command whenever a file changes

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

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.

Run a Node app as a systemd service

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

tmux basics

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

Resume a broken download with curl or wget

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

List listening ports on linux

What is this server actually exposing to the world?

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?

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.

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.

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.

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.

Auto mount Samba share on startup in Manjaro

Mount your Samba network share on startup. It even works when you are using WiFi.