you must be talking about FileObjects.
It allows you to write, read, and create/delete files.
to add a item, heres the syntax, but there are 2 different modes for writing; Write and Append.
Write clears the file and then writes lines.
Append opens the file and writes to the end of the file.%blah = new FileObject();
%blah.openForWrite("filepath");
%blah.writeLine("enter text here");
%blah.close();
%blah.delete();
Thats to overwrite.
And to append:%blah = new FileObject();
%blah.openForAppend("filepath");
%blah.writeLine("enter text here");
%blah.close();
%blah.delete();
To read, its the same thing, just change a couple things:%blah = new FileObject();
%blah.openForRead("filepath");
%blah.readLine();
%blah.close();
%blah.delete();