Just for fun, I want to make a program that checks some directory in my computer and another directory in my external hard drive. Then, it will automatically detect which files are missing in the hard drive and add them. Think of it as an automatic backup process. I don't want anything fancy, just some script I can run from the terminal. I have a pretty good idea about how to do it, I just have some questions:
There will be a large number of files in my directories (at least 20,000 but could be many more). So I am concerned about performance. I would like to know if you have any advice about the algorithms or data structures that may be more efficient. I was thinking about using a hashtable for the files, but I'm not sure if this would be the best approach.
I use Mac OS and I still haven't decided what language to use. I can program with c, c++, java and c# (mono). Because of performance, I guess it would be better to use c or c++. Please let me know your comments about this. Thanks.
