system("/usr/sbin/wpa_supplicant -Dnl80211 -iwlan0 -f /tmp/wpa_log -c/tmp/wpa_supplicant.conf -d -t -B &");
在/tmp/wpa_log中查看是否有如下的字符串：
1. 針對WPA／WPA2加密方式
//1473218403.305655: wlan0: WPA: 4-Way Handshake failed - pre-shared key may be incorrect
2. WEP加密方式
//1473233833.786157: Line 5: Invalid WEP key length 10 - this network block will be ignored
進而確認密碼是否錯誤
