$re = '/{[^{}]+}/m';
$str = '<svg width="500" height="100">
<text x="47.872" y="11.064" id="smartCar">{garage/temp} °C</text>
<circle id="circle1" cx="20" cy="20" r="10"
style="stroke: none; fill: #ff0000;"/>
<text x="47.872" y="11.064" id="smartCar">{home/sensors/temp/kitchen} °C</text>
</svg>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php