[RESOLVED] changing the case of header (first line) in a csv file

[newbie271]

Hi
I have a csv file with header (field names) as first line. The header name may be in any case (lowercase, uppercase, mixed).
How to convert the first line all into lowercase in efficient way.
Thanks

[leatherback]

[man]strtolower[/man]

[newbie271]

$inpfile =  'tmpFiles/1312041399_5901.txt';
$handle = fopen($inpfile, "r");
$first = fgets($handle,2048); #get first line.
$first = strtolower($first);
$outfile="temp";
$o = fopen($outfile,"w");
 fwrite($o,$first);
while (!feof($handle)) {
    $buffer = fgets($handle,2048);
    fwrite($o,$buffer);
}
fclose($handle);
fclose($o);
rename($outfile,$inpfile);