Trace specific thread id in java thread using jstack

tracethread.php

<?php
//Usage: php tracethread.php <pid> <tid>
//Get the <tid> from a jstack call 

$pid = intval($_SERVER['argv'][1]);
$tid = $_SERVER['argv'][2];

echo "Tracing thread: $pid : $tid\n";
while(true) {
        $dump = shell_exec("jstack $pid");
        $startOffset = stripos($dump,$tid);
        $endOffset = stripos($dump,"\n\n",$startOffset);

        if ($startOffset === FALSE) {
                echo "$tid not found\n";
                break;
        }
        $trace = substr($dump,$startOffset,$endOffset-$startOffset);
        $lines = explode("\n",$trace);
        $out = implode("\n",array_slice($lines,0,400));
        passthru('clear');
        echo chr(27).'[0;0f';

        echo "$out\n\n";
        sleep(2);
}