How to do some file operation?

[roro4ever]

I wanna do some file operation,
eg:
read others file's content;
create new file;
delete file;
add text into file,

The most wanted is when I load abc.sc,after run,can write back some info into abc.sc self.
When I use script.dll with include,maybe load abc.sc again by call function in abc.sc.

How can I do this.

Thx.