後來發現裏面有包ping這指令，而且有設置setgid權限，那麼應該是可以執行。只是試了之後，卻不行，然後我就以為不行。之後不死心，把stderr接出來看，才知道我下錯指令，於是修正以後，就可以了。
[java]
final class Helper {
private final String TAG=”Helper”;
private void pingInExec(String host) {
Runtime runtime = Runtime.getRuntime();
String command = String.format(“/system/bin/ping -c 2 %s”, host);
Process proc;
try {
proc = runtime.exec( command );
BufferedReader in = new BufferedReader(new InputStreamReader(proc.getInputStream()));
BufferedReader err = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) {
Log.d(TAG, inputLine );
}
in.close();
while ((inputLine = err.readLine()) != null) {
Log.e(TAG, inputLine );
}
err.close();
proc.waitFor();
int exit = proc.exitValue();
Log.d(TAG, String.format(“exitcode=%d”, exit) );
if (exit == 0) { // normal exit
Log.d(TAG, “RESPONSE_OK”);
} else { // abnormal exit, so decide that the server is not reachable
Log.d(TAG, “RESPONSE_TIMEOUT” );
}
} catch (IOException e) {
Log.e( TAG, e.getMessage() );
} catch (InterruptedException e) {
Log.e( TAG, e.getMessage() );
}
}
}
[/java]