1.curl: curl -O fileurl -->download file use filename in url
2.tar :tar -zxvf *.tar.gz extract tar.gz file
3.mount usb disk :1)use cat /dev look usb disk ,usually /dev/da0s1;
2)mkdir /mnt/usbdisk
3)mount -t msdosfs /dev/da0s1 /mnt/usbdisk
4)umount /mnt/usbdisk
4.cp :copy filename dirname,copy file to dir with file name;
5. freebsd: init 1, return to single user mode ,can exit xorg/xfce4...
6.update nvidia driver ; first unload modules: kldunload -n nvidia.ko nvidia-modeset.ko
