Minecraft options.txt Sync

Sync Minecraft options files between instances. Useful with launchers like Prism and MultiMC.

Important

Requires at least bash 4.0. MacOS ships with an ancient bash version, so you'll need to install it yourself.

How it works

Files:

GLOBAL: global options.txt file that should be mirrored to other instances
LOCAL: a Minecraft instance's options.txt file
SYNC: a file containing settings to be synced, as well as their most recent synced value

Modes:

respect: only sync options that have not been changed in LOCAL. this means changing a synced setting locally will not be overwritten
overwrite: overwrite all options denoted in SYNC regardless of whether they've been changed locally or not

When a setting is changed in GLOBAL, it is propagated to LOCAL if

• respect: LOCAL == SYNCED and SYNCED != GLOBAL
• overwrite: always

Usage

Create a sync file associated with your Minecraft instance (e.g. sync.txt). Copy the option lines from the instance's options.txt that you would like to sync into the sync file.

To sync:

$ ./optsync -g /path/to/global/options.txt -l /path/to/instance/options.txt -s /path/to/instance/sync.txt -m respect

Before a sync is performed, LOCAL and SYNC are backed up to a file ending with .bak.

Tips for generating sync.txt

Compare options in GLOBAL and LOCAL:

$ comm -i3 <(sort $GLOBAL) <(sort $LOCAL) | paste - - | column -t

Get all lines from GLOBAL are DIFFERENT than LOCAL:

$ comm -i23 <(sort $GLOBAL) <(sort $LOCAL)

Get all options that are the SAME in GLOBAL and LOCAL:

$ comm -i12 <(sort $GLOBAL) <(sort $LOCAL)

Get all lines from GLOBAL except those that have been changed in LOCAL:

$ comm -i2 <(sort $GLOBAL) <(sort $LOCAL) | awk '{$1=$1};1'

Prism Launcher Pre-Launch Command

To automatically sync settings when you launch the game, add the following script to your Prism Launcher Pre-Launch command (instance settings > settings > Custom Commands > pre-launch):

/path/to/bash /path/to/optsync -g "/path/to/global/options.txt" -l "$INST_MC_DIR/options.txt" -s "$INST_MC_DIR/sync.txt" -y sync

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Minecraft options.txt sync

Usage: optsync [options] <sync|help>

Options:
    -g <file>                 global options.txt file ()
    -l <file>                 local options.txt file ()
    -s <file>                 sync file ()
    -m <respect|overwrite>    sync mode (respect)
    -y                        bypass confirmation (0)
    -n                        dry run (0)