I have a process that I want run on every folder on a file system. The operation has to happen from the deepest child folder first then back to the parent. Some folders will have many folders, which is where parallel fits well. However, all child folders must be processed before their parent.
Using a recursive script works well so that the operations on all the children always happen before the parent no matter how deep the folder tree goes. But when combined with 'parallel' in some cases I end up with too many processes running at once, choking the system.
Is there a way so that multiple 'parallel' processes become aware of each other and never run more than a specified number of processes at once, yet still satisfies the dependency order? Or maybe there's a better way to approach this problem?