This plugin adds the possibility to use vanilla selectors in non-vanilla commands written in CommandBlock.

Since it hooks into vanilla functions, all of the selector arguments are parsed (@p[distance=..5])

Keep in mind
Selecting entities other than player isn't probably of any use, because after the result is obtained, it parses the command with entity name (Player or mob name), however all of the selectors should work.

@p - targets nearest player
@a - targets all players
@r - targets random player
@e - targets all entities
@s - targets the executor (that is command block, not Player!)

FAQ
Q: Vanilla commands are not working.
A: Plugin scans if the command inside the block starts with /minecraft: or minecraft: so the syntax is ex.: minecraft:kill @p[name="RandomPlayer"]
TL;DR: just add minecraft: before it.

If you have a problem or you have found an error, please text me with a short brief (logs are welcomed help)