Need help with a script

[O_P_T_i_C_S]

Hi im trying to write a script, and i have no idea where to begin
i need kinda like a search engine that scans through a textfile and finds matches...

say i have all this + more in a textfile
a1spinx,172.180.173.108
aaxnjxaa,172.165.29.200
amastafo0,64.11.130.118
anarmeof1,12.251.131.161
apaxworks,195.37.16.120
asxychic,24.84.24.118
blazegunr,24.90.17.66
carnage81,208.141.109.53
cibrstorm,207.3.169.38

i want to be able to go to my website and type in 12.251.131.161 and it to come up with all the matching names that go along with that ip

can anyone help?

[wiley]

<?
//create a form that posts the ip to this script
// for the moment, let's say
$ip = "172.180.173.108";

$fo = fopen("/path goes here/filename.csv","r");
while (!feof ($fo)) {
$data = fgets($fo,4096);
// this bit should work as long as the "+more" is
// delimited by another comma after the ip
$pieces = explode(",", $data);
IF ($pieces[1] == "$ip") {
$name = "$pieces[0]";
}
}
fclose($fo);

echo "user is $name";
?>

cheers, dan