Slightly off topic...

Does using Server Side Includes (SSI) make a page more portable than 
using PHP?

Does anyone know how to do a SSI "if" statement to check whether a file 
exists or if it is greater than 0 byte?

If the file exists or is greater than 0 byte, I want to insert code for 
a table, then include a text file in the table.  I have a simple file 
include and formatted date working, but I've never done SSI "if" statements.