[PHP] File Edit

[Randy Johnson]

Hello,


I want to be able to edit part of a file.  via a text box using php  how do i read a 
file and get the part i want to read and edit it and then write it back to that file 
here is an example:

.....
case "$1" in
  start)

100.123.456.789
321.654.987.231
123.45.456.789
123.456.789.12

;;

........

In this example I want to be able to be able to pull the ipaddresses out and edit them 
and add a new one on to the end and then write the data back to the file.


Thanks in advance


Randy