Is a Package Installed?

Is cryptsetup installed?

Most generally useful is:

apt search cryptsetup

Or to concentrate on cryptsetup exactly:

apt list cryptsetup

To get all the details of the package

apt show cryptsetup

There are various other ways in which we can interrogate both dpkg and apt


dpkg --status cryptsetup

apt-cache policy cryptsetup

apt-cache search cryptsetup

Which Package Provides a File?

Which package will give me a java compiler?

apt search java


gives endless output

apt-file search "javac"

falls over in various ways:

---

Fail Better:

sudo apt update ; sudo apt install apt-file; sudo apt update

apt-file search "javac "

To Manually Install get_iplayer on Debian (version 9.9)

Instructions found here:

https://github.com/get-iplayer/get_iplayer




But all I needed to do was:

sudo apt-get install libwww-perl liblwp-protocol-https-perl libmojolicious-perl libxml-libxml-perl libcgi-pm-perl atomicparsley ffmpeg

wget https://raw.githubusercontent.com/get-iplayer/get_iplayer/master/get_iplayer

sudo install -m 755 ./get_iplayer /usr/local/bin






Test with:

get_iplayer --release-check

get_iplayer ".*"

To actually fetch something(s)

get_iplayer --get ".*Example.*"

To Convert a Load of Document Files into Plain Text (In Order to Diff Them)

for i in * ; 
do 
  echo "$i" ;
  libreoffice --headless --convert-to txt:Text "$i" ; 
done

To Play a Random Sound File in a Tree

mplayer "$(find . -name "*.3gp" | shuf -n1)"

To type Latin Macrons āēīōū

in X generally, you need to use the Compose key, most keyboards don't have one, so Compose is usually done with shift+Alt Gr,

Compose - a and Compose a - will both produce an ā

but it's more convenient to make the right Alt key (AltGr) be the compose key

to try it in a terminal
setxkbmap -option "compose:ralt"

to make it the system default:
sudo dpkg-reconfigure keyboard-configuration

you can also get it to work just in your desktop environment with e.g. in xfce, Applications/Settings/Keyboard/Layout

To play all the sound files in a tree

find . -name "*.3gp" -exec mplayer {} \;