Few questions about simple XML parser

[Bob Bedford]

Hello,

I've to read a XML file and parse it for retrieving some datas.

The problem is that the hosting server has some limitations: Time (10 sec)
and Memory (16mb).

Since reading the whole XML file does throw a memory limit error, I've to
read the file by little blocks.

So my question are:
where may I find a script that read a XML file by blocks and then parse
correctly the datas, maybe putting the datas in an array.

The problem is that I'm scared the XML file will stop read at the block size
and cut a record in the middle. What will appens ?

I've found a script that put the XML file in an array: reading the entire
XML file in one pass isn't possible and trying to read it by block does
create a new array as the new block is readed, without caring if the
previous array has been closed.

I know well PHP, but not the XML part and it seems very complicated since
I've only found examples where file is readed in one block then parsed.

Thanks for any help.

Bob