Fix: Mapfile not found on some mac devices

[Matheus3007]

Issue

Depending on the Mac device, the Mapfile may not be found, as shown in this issue. The message presented to the user is as below:

Bash Screensavers v0.0.27 (Mystic Shine)

./screensaver.sh: line 79: mapfile: command not found
  1 .

(Press ^C to exit)

Choose your screensaver:
404 Screensaver Not Found:


Oh no! Screensaver had trouble! Error code: 1

Solution

This quick fix adds a conditional to avoid the "Not Found" error on Macs without Mapfile, and also initializes the screensavers list as to avoid it starting with an empty item.

[jzellis]

I tested it on an M1 running Sequoia with ZSH as my default shell and it works perfectly.

[attogram]

thanks! I added a refactor -- we just use old fashioned read, and remove mapfile entirely.