Linux

Network Tricks

Connecting to two networks - one Wi-Fi and one wired

Wi-Fi network has internet, wired does not. Then, disable the gateway of the Wired network for internet access.

Show the networks

$ ip route show

Smaller metric number means higher priority for the gateway

Remove the gateway of the wired network

$ sudo ip route del default via 192.168.1.1

chroot into a Raspberry Pi

Mount sequence

mount /dev/sdb3 /mnt
mount /dev/sdb2 /mnt/boot
mount /dev/sdb1 /mnt/boot/firmware
mount -o bind /proc /mnt/proc
mount -o bind /sys /mnt/sys
mount -o bind /dev /mnt/dev
mount -o bind /dev/pts /mnt/dev/pts
cp /usr/bin/qemu-arm-static /mnt/usr/bin
chroot /mnt

Doing stuff in chroot

Example: Fixing a broken apt install

dpkg --configure -a
apt -f install
exit

Unmount sequence

umount /mnt/dev/pts
umount /mnt/dev/
umount /mnt/sys
umount /mnt/proc
umount /mnt/boot/firmware
umount /mnt/boot/
umount /mnt

Creating a desktop launcher on Gnome

Install gnome-panel

sudo apt-get install --no-install-recommends gnome-panel

Open the Create Launcher dialog and enter the details for the launcher

sudo gnome-desktop-item-edit --create-new /usr/share/applications

Done.

Trimming a video

ffmpeg can be used to trim a video from a given start time to end time.

ffmpeg -i video.webm -ss 00:00:00 -t 00:05:04 -async 1 video-cut.webm