I am teaching to under-grads and many students asked me to refer some journals or articles which are accessible to them. It would be great if our community helps me out by giving links to journals consisting of  interesting research articles , expository, survey articles, or interesting historical surveys of  concepts or theorems which can develop interest and mathematical maturity in under-grads. For now, I only know Resonance and MAA. Your help would be greatly appreciated. Thanks.
I want to make someone a present by subscribing for him to a mathematical journal. (It should appear every month or every two months). The contents should be comprehensible to an undergraduate in mathematics, and be about a broad selection of topics (for example not only analysis).   I expect the content to be something like proposing interesting problems and then giving solutions with some references for further study. Are there some famous journals you could suggest me?
I have a directory that contains the following:  x.pdf y.zip z.mp3 a.pdf   I want to delete all files apart from x.pdf and a.pdf. How do I do this from the terminal? There are no subdirectories so no need for any recursion.