dd if=/dev/zero of=/tmp/output.img bs=8k count=256k
rm /tmp/output.img

LC_ALL=(unset) error

Symptom:

# can't set the locale; make sure $LC_* and $LANG are correct

Solution:
Edit /etc/environment, add your preferred locale and reboot

LC_ALL="en_US.utf8"

Filter string from position

# awk '{print substr($0,30)}'

$ sudo apt-get install gnome-session-fallback