rebase loop for projects with high push frequency and rebase-always policy

rebase-loop.sh

#!/bin/bash

projectdir=$(realpath $1)
frequency=$2

if [[ $frequency == "" ]]; then $frequency=30; fi

if [[ ! -d $projectdir ]]; then echo "first param must be a directory"; exit 2; fi
if [[ ! -d $projectdir/.git ]]; then echo "not a git project"; exit 4; fi

pushd $projectdir

branchname=$(git status -buno --porcelain | sed 's/## //');
if [[ $branchname == "master" ]]; then 
    echo "must not force-push master!"
    popd
    exit 1    
fi

while [[ true ]]; do 
    git fetch
    $diff=$(git diff origin/$branchname)
    if [[ $? != 0]]; then
        echo "error comparing to remote!"
        popd
        exit 8
    fi
    if [[ $diff != "" ]]; then       
        git rebase origin/master 
        git push -f origin $branchname        
    fi
    sleep $frequency
done

popd