PHP preg_match_all() Matching

I want to match FDSize: <value> in the following:

Gid:    48      48      48      48
FDSize: 64
Groups: 48 425
VmPeak:   289928 kB

It comes from /proc/status

<value> is not a fixed length, and neither are the lines above or below.

Try something like this:

preg_match_all('`FDSize: (\\d+)`s', $subject, $matches);
print_r($matches);

Not really sure why/how/when you have to do this. I should've asked questions before posting an answer but i didn't. Here are some ways to get that out of a line though...

$line = 'Gid: 48 48 48 48 FDSize: 64 Groups: 48 425 VmPeak: 289928 kB';

// in a loop...
echo current( explode(' ', end( explode( 'FDSize: ', $line ) ) ) );

// or

preg_match_all('~fdsize: (\d+)~i', $line, $matches);

$mystr='Gid: 48 48 48 48 FDSize: 64 Groups: 48 425 VmPeak: 289928 kB';
$str = explode(":",$mystr);
foreach($str as $k=>$word){
    if(strpos($word,"FDSize") !== FALSE){
        print $str[$k+1];
    }
}

try

preg_match_all("/FDSize:\s([0-9]+)/msiU", $data_in, $matches);