A bash script for automatic sync between a local fork, it's origin and the upstream (on GitHub)

sync_fork.sh

# Flow:
# Find origin
# Find upstream URL
# Go to master
# Rebase upstream to master
# push changes to origin

# Make sure master has not pending changes for commit
# Some credits to an unknown source...

url=$(git config --get remote.origin.url)

# Get the user and repo part from the URL 
# Must be something like part=${url#*//*/}
# Sticking to github specific code as of now.

part=${url#*github.com*/}


upstream=$(curl -s https://api.github.com/repos/${part%.git} | sed -e 's/[{}]/''/g' | awk -v k="text" '{n=split($0,a,","); for (i=1; i<=n; i++) print a[i]}' | grep '"git_url":' | sed 's/:/ /1' | awk -F" " '{ print $2 }' | uniq | tail -1)

git checkout master
git pull upstream master --rebase
git push origin master