https://superuser.com/questions/668777/how-do-i-make-a-script-to-unrar-archives-in-multiple-folders

Automating RAR extraction across multiple folders can be accomplished using recursive scripts in PowerShell or Batch for Windows, and Bash for Unix-like systems. Utilizing tools like UnRAR.exe (Windows) or unrar (Linux) with recursive commands allows for efficient, bulk unpacking while maintaining directory structures. The process can be further optimized by targeting only .part1.rar files to prevent redundant extractions on multi-part archives. For detailed scripts and instructions, visit the community-driven solution on SuperUser.