Topic 1 – Little warmup

Task

I'm sure you are all proficient C/C++ programmers, but - just in case you had a long break and forgot some things - lets do a little warmup.

Write your own version of Unix "cp" (copy) command.

As a bare minimum - please write a program that:

accepts source and destination filenames as its arguments (you DO remember how to use argc and argv ?)
makes a copy of indicated file
returns 0 on success, any non-zero value on error
uses ONLY POSIX I/O functions (open, close, read, write - consult appropriate manuals)

NOTICE: Do not assume, that you can read entire file into memory. Please read manuals carefully - pay attention to each function's return value!

I'm sure this task will prove to be to easy to some of you - in this case you can extend your program - for example you can add features to allow:

copy source_file dest_dir (copy source file to the indicated directory, keeping its name)
copy file1 file2 file3 dest_dir (copy files file1...file3 into destination directory)
... ?

As a solution - provide your source code here.