This ugly and unreadable loop takes a list of packages like "abiword gnumeric" and converts it into "abiword|gnumeric", then passes that through grep, so it filters lines containing one of the package names.
This area had a bug I fixed recently, in https://github.com/puppylinux-woof-CE/w ... 2135/files. 3builddistro didn't filter out comments, so lines containing the word "abiword" in a comment got ignored, and gmp (a dependency of GCC) didn't get added to rootfs-complete, breaking fossa64.
Make sure on you're on the latest woof-CE (git pull), it's fixed now.
EDIT: ha, this typo can break fdrv, not adrv.