feature: add check for a newer version of this script from within script

[klodeckl]

Hello, I just found your script, I like it! How about a self update for the update script?

[LucasLarson]

I like it!

Thank you!

How about a self update

What do you have in mind?

[klodeckl]

Check the version of the file in github and download the new version if available? (But I think my knowledge is too poor to help to develop this.)

[LucasLarson]

Oh that’s a great idea – it didn’t occur to me since I built it just for me.

[LucasLarson]

Check the version of the file in github and download the new version if available

I removed a manually added timestamp in c173aaec9cb. Restoring it and comparing it to the output of

command date -- '+%Y-%m-%d'

is probably the lowest-tech way to add this functionality

[klodeckl]

I don’t really understand, you want to compare the current date of execution with a timestamp?
Why not add a version number in the script and compare it with a version file in the github master branch?
As I remember rpi update (https://github.com/raspberrypi/rpi-update) has a self update included, maybe this could be used as inspiration.