List Files: Write a program that lists files in the given directory. When called without any arguments, the program should just print the file names. When invoked with the -l flag, the program should print out information about each file, such as the owner, group, permissions, and other information obtained from the stat() system call. The program should take one additional argument, which is the directory to read, e.g., myls -l directory. If no directory is given, the program should just use the current working directory.

Must be written in C

Useful interfaces: stat(), opendir(), readdir(), getcwd().