main的所有命令行参数

I was wondering what are all command line arguments to main function (in C specifically, but I am guessing this would apply to all languages regardless)? In my compilers class I heard an instructor briefly mention (possibly I misheard or misunderstood that) that there is more to main() arguments than typically mentioned, specifically that at negative offset from argv pointer one can access some information. I could not find anything by Googling or in a couple of textbooks I have. I wrote this small program in C to try. Here are some questions:I was wondering what are all command line argum