offline-minecraft-launcher/README.md

Just start Minecraft. Does not download assets.

Prerequisites:

All the stuff you need to play Minecraft

Java, etc...

7-zip (for extracting natives)

Debian: apt install p7zip
Windows: https://www.7-zip.org/download.html - Copy 7z.exe/7z.dll to the same folder as the launcher.

Python 3.x

(3.4 is supported, lower may work)
Debian: apt install python3
Windows: https://www.python.org/downloads/ (use 3.8.x on Win7, 3.4.4 on WinXP)

Simple usage:

• Edit offline-minecraft-launcher.ini to your liking
• Start offline-minecraft-launcher.py
• Enter data
• Profit

Commandline:

You can automatize entering the data by using commandline arguments. Each argument works like this: key=value - These act like the settings in the ini, and will replace corresponding settings in the ini.

• name: Your player name
• version: The ID of the version you wanna start (Example: b1.8.1)
• console: Whether to show console output (1/0)
• osName: Override your OS in case it isn't detected (windows/linux/macos)
• jvmArguments: The arguments to use to launch your JVM, json formatted - You may need to escape "
• java: The path to the java executable. Try not to append a file ending, as w will be added, if console is 0