My Ubuntu stopped saving my files last time I was working on it, saying "insufficient hard disk space". I tried rebooting my PC and it won't open. Rather, a black screen with a single dash appears. I understand that some drivers may be corrupted and would have to be reinstalled from the root shell, but I have no space.
I know how to resize or increase partitions on Ubuntu, but I don't have GParted either, through which this is done. When I try to install it from the root shell, it gives me the same space error.
What can I do to solve this issue?