---
layout: default
title: Linux
has_children: true
parent: Operating Systems
permalink: /linux
---

# Linux
Most of the things I post here are tested on Debian and/or alpine and that's about it, since those are my daily drivers.

## Message of the Day
All important Debian locations:

- `/etc/motd`
- `/etc/motd.d`
- `/etc/update-motd.d`

Here's the [official Debian motd docs](https://wiki.debian.org/motd). Import ecerts below:

> ...motd is generated by pam_motd. pam_motd prints the contents from `/run/motd.dynamic` and the static (and user editable) content from `/etc/motd` and `/etc/motd.d` ... pam_motd updates `/run/motd.dynamic` by **executing all files from `/etc/update-motd.d`** 

## Pretty view markdown
You can use `batcat` on linux, `ccat` on mac, and `gh repo view` if the markdown file is a `README.md` in a repo.

You can also use this lynx trick:
```bash
pandoc README.md | lynx -stdin
```

## apt notes
Thanks to Vaibhav for their solution [here](https://vskulkarni.wordpress.com/2011/10/07/gpg-error-httpppa-launchpad-net/) for when you get this error:
```bash
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 4DEF31B9A9E345C0
```

It's *THIS* command: 

```bash
# 4DEF31B9A9E345C0 is your KEYID from the above error
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 4DEF31B9A9E345C0
```
