php handling special characters?

[thomasamillergoogle@yahoo.com]

I am building a xml file to store a single TCP/IP raw packet.

I need to store "special characters" on the file I am working on. When
I say "special characters" i am talking about tabs, whitespace, crazy
unicode characters, etc etc.


I am using PHP to handle the string that handles the raw packet. What
php datatype/functions will assist in preserving these strange
characters?