Snaps are applications packaged with all their dependencies to run on all popular Linux distributions from a single build. They update automatically and roll back gracefully. Whether you’re building for desktop, cloud, or the Internet of Things, publishing as a snap will keep users up to date and make system configuration issues less likely, freeing you to code more and debug less. From Ubuntu
Discover installed snaps
Sometimes you can see a lot of loop devices mounted on your linux
dyego@dyego:~$ df -h
Filesystem Size Used Avail Use% Mounted on
...
/dev/loop3 22M 22M 0 100% /snap/gnome-logs/31
/dev/loop1 3,8M 3,8M 0 100% /snap/gnome-system-monitor/45
/dev/loop2 3,8M 3,8M 0 100% /snap/gnome-system-monitor/51
/dev/loop0 141M 141M 0 100% /snap/gnome-3-26-1604/59
/dev/loop4 2,4M 2,4M 0 100% /snap/gnome-calculator/170
/dev/loop5 15M 15M 0 100% /snap/gnome-logs/37
/dev/loop7 87M 87M 0 100% /snap/core/4650
/dev/loop6 233M 233M 0 100% /snap/pycharm-community/62
/dev/loop10 163M 163M 0 100% /snap/spotify/16
/dev/loop11 5,0M 5,0M 0 100% /snap/canonical-livepatch/39
/dev/loop8 13M 13M 0 100% /snap/gnome-characters/101
/dev/loop9 141M 141M 0 100% /snap/gnome-3-26-1604/70
/dev/loop12 87M 87M 0 100% /snap/core/4830
/dev/loop13 140M 140M 0 100% /snap/gnome-3-26-1604/64
/dev/loop14 13M 13M 0 100% /snap/gnome-characters/103
/dev/loop16 5,0M 5,0M 0 100% /snap/canonical-livepatch/41
/dev/loop15 87M 87M 0 100% /snap/core/4917
/dev/loop17 237M 237M 0 100% /snap/pycharm-community/64
/dev/loop18 2,4M 2,4M 0 100% /snap/gnome-calculator/178
/dev/sda2 96M 37M 60M 38% /boot/efi
/dev/loop20 2,4M 2,4M 0 100% /snap/gnome-calculator/180
/dev/loop19 13M 13M 0 100% /snap/gnome-characters/96
/dev/loop21 227M 227M 0 100% /snap/pycharm-community/74
/dev/loop22 3,8M 3,8M 0 100% /snap/gnome-system-monitor/41
/dev/loop23 15M 15M 0 100% /snap/gnome-logs/34
/dev/loop24 35M 35M 0 100% /snap/gtk-common-themes/319
...
On this case, you can remove that old snaps. First of all, you should list the snaps installed and than remove it:
dyego@dyego:~$ snap list --all
Name Version Rev Tracking Publisher Notes
canonical-livepatch 8.0.1 39 stable canonical disabled
canonical-livepatch 8.0.2 41 stable canonical -
core 16-2.33 4830 stable canonical core,disabled
core 16-2.32.8 4650 stable canonical core,disabled
core 16-2.33.1 4917 stable canonical core
gnome-3-26-1604 3.26.0 59 stable/… canonical disabled
gnome-3-26-1604 3.26.0 70 stable/… canonical -
gnome-3-26-1604 3.26.0 64 stable/… canonical disabled
gnome-calculator 3.28.1 178 stable/… canonical disabled
gnome-calculator 3.28.2 180 stable/… canonical -
gnome-calculator 3.28.1 170 stable/… canonical disabled
gnome-characters 3.28.2 96 stable/… canonical disabled
gnome-characters 3.28.2 103 stable/… canonical -
gnome-characters 3.28.2 101 stable/… canonical disabled
gnome-logs 3.28.2 34 stable/… canonical disabled
gnome-logs 3.28.0 31 stable/… canonical disabled
gnome-logs 3.28.2 37 stable/… canonical -
gnome-system-monitor 3.28.2 51 stable/… canonical -
gnome-system-monitor 3.26.0 41 stable/… canonical disabled
gnome-system-monitor 3.26.0 45 stable/… canonical disabled
gtk-common-themes 0.1 319 stable canonical -
pycharm-community 2018.1.3 62 stable jetbrains disabled,classic
pycharm-community 2018.1.4 64 stable jetbrains disabled,classic
pycharm-community 2018.2 74 stable jetbrains classic
spotify 1.0.80.474.gef6b503e-7 16 stable spotify -
Remove one-by-one
We have some disabled snaps and these could be removed.
dyego@dyego:~$ sudo snap remove canonical-livepatch --revision=39
canonical-livepatch removed
Remove like a boss
But, I guess it is a quite annoying to do one by one, isn’t it? However, we have in our favor a super super tool: Bash!
dyego@dyego:~$ for i in $(snap list --all |grep disabled | awk '{print $1";"$3}'); do sudo snap remove ${i%;*} --revision ${i#*;}; done
core removed
core removed
gnome-3-26-1604 removed
gnome-3-26-1604 removed
gnome-calculator removed
gnome-calculator removed
gnome-characters removed
gnome-characters removed
gnome-logs removed
gnome-logs removed
gnome-system-monitor removed
gnome-system-monitor removed
pycharm-community removed
pycharm-community removed
Understand the magix
The trick here is using bash substring. Instead to use cut or awk again, and use the same loop, this command create a list with name;revision.
canonical-livepatch;39
core;4830
core;4650
gnome-3-26-1604;59
gnome-3-26-1604;64
gnome-calculator;178
gnome-calculator;170
gnome-characters;96
gnome-characters;101
gnome-logs;34
gnome-logs;31
gnome-system-monitor;41
gnome-system-monitor;45
pycharm-community;62
pycharm-community;64
Than, I use the substring to take the each portion from i.
First: ${i%;*}. It’ll remove shortest match from the ; until the end of string *.
${string%substring}
Deletes shortest match of $substring from back of $string.
In the other hand, ${i#*;} will remove shortest match from the begin * until ;.
${string#substring}
Deletes shortest match of $substring from front of $string.