[linux] How to add flash to Firefox (in 2018)

readme.md

libflashplayer.so.bz2

libflashplayer.so.md5

pluginreg-insert

Here's a script:

cd .mozilla
mkdir -p plugins
curl https://gist.githubusercontent.com/bradenbest/00a946dcbbaedeb2f5f40498a01e1b2d/raw/d961cd0c17f89433e4e2f01aace7418163354d29/libflashplayer.so.bz2 | bunzip2 -c > plugins/libflashplayer.so
curl https://gist.githubusercontent.com/bradenbest/00a946dcbbaedeb2f5f40498a01e1b2d/raw/d961cd0c17f89433e4e2f01aace7418163354d29/pluginreg-insert > /tmp/prinsert
ed firefox/*.default/pluginreg.dat <<< $'/PLUGIN/r /tmp/prinsert\nwq'
rm /tmp/prinsert
echo "Flash should be installed now."

it...

• Creates the .mozilla/plugins directory if it doesn't already exist
• Downloads libflashplayer.so.bz2, runs it through bunzip2, and outputs it in plugins/libflashplayer.so
• Downloads the text to be inserted into pluginreg.dat and saves it as /tmp/prinsert
• Uses ed (the standard editor) to automatically insert that file inside pluginreg.dat.
• Cleans up after itself

It needs these programs to run:

• bash (the shell you'll be running the script in)
• curl
• bzip2
• ed
• mkdir
• rm

You can see whether you have a given command with which, e.g.:

$ which curl

Although if you don't have ed, mkdir or rm for some reason, then you won't have which either, cause your system is broken.

Update

I've tested the script and it works.

Went from a fresh, empty .mozilla directory (tar cf moz.tar .mozilla to backup) that tried to download the SWF, to being able to run the SWF directly, using only the lines in the above script.