go to root folder of git repo from a bash script

cd-to-git-root.sh

#!/bin/bash

# first, switch to the directory of where the currently executing script is located
cd "$( dirname "${BASH_SOURCE[0]}" )"

# now, find the git repo root, and switch to that directory
cd "./"$(git rev-parse --show-cdup)

# now, run stuff from the git root
./somefolder/do-stuff.sh

# The advantages of doing the first two steps as above is:
# 1. Regardless from where the script is executed, it will run exactly in the same way
# 2. The script is future-proof: when it gets moved to a subfolder, it will still
#     work the same (provided that the scripts it calls inside are not moved);
#     whereas doing things like "cd ../" is not future-proof; if you move the script
#     to a subfolder, you'd have to change it to "cd ../../"