php flat file add, edit, delete cells

[spider]

Ok,, im used to going to Codewalkers, but all everyone tells me is that you cant add edit delete cells in a flat file database...
well,, if i can use php to get to that cell, and be able to tell exactly what that cell is, what line, what cell, and what is in the cell... like

Line 1, cell 2 = lineonecelltwo

this is using a text database with
line 1|cell1|cell2
line 2|cell1|cell3

i can list them as categories and sub categories if i want,, naturally..
what im trying to do is add to the database such as
line 1|cell1|cell2|cell3
cell 3 being added...
and edit the cell...
change cell1 to cell11
or delete the cell altogether...
line|cell1|cell3

i have this code so far...
include 'filedb.php';
if($subcat != $Data[$K][$i]){

$Lines = file("$path/cat.dat");
foreach($Lines as $Key => $Val){
$Data[$Key] = explode("|", $Val);
}

for($K = 0; $K < sizeof($Lines); $K++){
for($i = 0; $i < sizeof($Data[$K]); $i++){
echo 'Line '.$K.' cell '.$i;
if($line == $K && $id == $i){

$file = "../inc/data/cat.dat";
//$fp = fopen("$file", $K, "a");
list ($K) = split ('\|', $line);

echo ' = '.$line,' = '.$Data[$line][$id].'
';

//fwrite($fp,"|$subcat");
//fclose($fp);

}else{
echo '
';
}}}}

anyone have any ideas?

[Xnuiem]

read the file into memory using file()

then explode the lines you want

and to edit that line, just edit that part of the file() created array and then recreate the file based on that array.