These instructions are for installing the Calibre book management software on a Raspberry Pi 4 running Ubuntu 20.04 but should work with Raspian or other Debian-derived operating systems. This is just a briefer version of the same instructions that are posted here.

Install the calibre-bin package and its dependencies:

$ sudo apt update && sudo apt install -y $ sudo apt install calibre-bin

Create a ‘git’ user:

$ sudo adduser git

Login as the ‘git’ user and download the gitea binary from the gitea website (choose the latest version):

wget -O gitea https://dl.gitea.io/gitea/1.14.5/gitea-1.14.5-linux-amd64 chmod +x gitea

Create a service. We’re keeping it simple here so we don’t need a lot of the database-specific stuff:

Here are some bash environment variables that are useful to know when you’re using the command prompt:

$0 - name of shell or shell script $1, $2, $3, … - positional parameters to script $# - count of positional parameters $? - exit status of most recent foreground task $- - current options that are set for the shell $$ - PID of the current shell (not subshell) $! - the PID of the most recent background command $DESKTOP_SESSION - path to the current display manager $EDITOR - preferred text editor $LANG - current language $PATH - directory list to search for executables (programs) $PWD - current working directory $SHELL - current shell $USER - current username $HOME - current user’s home directory $HOSTNAME - current name of the host $TERM - current terminal

Here are some quick keyboard shortcuts you can use at the command prompt:

ctrl-l – clear screen ctrl-r – does a search in the previously given commands so that you don’t have to repeat long command. ctrl-u – clears the typing before the hotkey. ctrl-a – takes you to the begining of the command you are currently typing. ctrl-e – takes you to the end of the command you are currently typing in. esc-b – takes you back by one word while typing a command. ctrl-c – kills the current command or process. ctrl-d – kills the shell. ctrl-h – deletes one letter at a time from the command you are typing in. ctrl-z – puts the currently running process in background, the process can be brought back to run state by using fg command. esc-p – like ctrl-r lets you search through the previously given commands. esc-. – gives the last command you typed.

This is a quick and dirty way which will list all of the files that are shell scripts:

for i in * do type=$(file ${i}|awk -F, ‘{print $2}’) if [[ “${type}” = " ASCII text executable" ]]; then echo “${i} is a shell script” fi done

If you need to do a ‘diff’ on 2 folders and one of them is remote then you can accomplish that as follows:

$ diff <(ssh username@192.168.1.60 ls -R /home/username/dir1) <(ls -R /home/username/dir2) 

To activate the Administrator account on Windows, open the Command Prompt as Administrator from the Start Menu, or you can right-click on the “Start” menu and select the “Powershell” menu item, then enter:

net user administrator /active: yes

into the window. You should disable the account again when you’re done.

If you want to convert one or more HTML files to EPUB quickly using the command line you can try pandoc.

pandoc -f html -t epub3 -o output.epub input.html

You can add metadata for epub:

pandoc -f html -t epub3 --epub-metadata=metadata.xml -o output.epub input.html

You can find other resources here:

How to convert various eBook formats for Amazon Kindle on Linux

You can post to Mastodon using their API using cURL.

Create or Find Your Access Token

Once you have a Mastodon account, you need your account’s access token. The steps you need to get that:

1. Sign into your Mastodon account
2. Click on In the "Preferences" link.
3. On the bottom left corner of that page, click the "Development" link.
4. On the "Your Applications" page, click the blue NEW APPLICATION button.
5. Give your application a name, and decide what kind of access you want to have when you connect to your account via the Mastodon API (iread, write, and follow are the defaults). You can always change this later.
6. At the bottom of the page, click the blue SUBMIT button.
7. You will be directed back to the Your applications page, but now you should see your application name. Click that.
8. In your application’s page, there are three tokens. For this tutorial, you need the Your access token one. Note: if your access token is ever compromised, you can click regenerate, and your old access token will stop working, and you’ll be shown a new one.

Post a Status Update using cURL

Create the key. Note those are two single quotes after the -N (for a blank passwd) $ ssh-keygen -t rsa -b 4096 -N ’’ Copy it to the target server $ cat .ssh/id_rsa.pub | ssh username@192.168.1.123 ‘cat » .ssh/authorized_keys’ Test it $ ssh username@192.168.1.123