php shell_exec iwgetid忽略引号

I am trying to get the SSID from a Linux machine with PHP, but with shell_exec values between quotes seem to be ignored.

In the cli the result of iwgetid is:

wlan0     ESSID:"test"

However if I do the same with PHP using shell_exec:

$ssidInfo = shell_exec("iwgetid");

I get the following result:

wlan0     ESSID:

Is there a way to work around this?