create_virtual_directories.sh

#!/bin/bash
# create_virtual_directories.sh

# Mod Organizer configuration file for mod install order
modlist='/home/zixaphir/Games/mod-organizer-2/ModOrganizer2/profiles/Default/modlist.txt'

# Directory containing mods, each mod is a subdirectory
modsdir='/home/zixaphir/Games/mod-organizer-2/ModOrganizer2/mods/'

# Directory containing original Skyrim data folder
# Renamed because I'm not sure OverlayFS can mount over existing data?
dirs='/home/zixaphir/Games/SteamLibrary/steamapps/common/Skyrim Special Edition/Data_orig/'

# Read the modslist. Enabled mods are the directory names, prefixed with a
# symbol, `#` meaning unmanaged, `*` meaning disabled,  and `+` meaning
# enabled. We look for the `+`, parse it out, and then assemble a list
# of directories to use. The modslist uses windows line endings, so those
# have to be trimmed with sed.
while read -r line; do
    if [[ $line =~ ^\+ ]]; then
        dirs="${dirs}:$modsdir$(echo $line | sed s/\+// | sed s/\\r//)"
    fi;
done < $modlist

# Mount the virtual filesystem, using Mod Organizer's `overwrite` directory
# as the top level, where all changes to the virtual directory should be
# dumped. The workdir must be an empty directory that exists on the same
# host filesystem as the upperdir!!
sudo mount -t overlay overlay -o \
lowerdir="$dirs",\
upperdir="/home/zixaphir/Games/mod-organizer-2/ModOrganizer2/overwrite",\
workdir="/home/zixaphir/Games/vfs_working" \
"/home/zixaphir/Games/SteamLibrary/steamapps/common/Skyrim Special Edition/Data/"