rebasefork

#!/bin/bash

## Brings your fork up to speed with upstream, and informs
## you of how far behind you were! You can supply the -f
## flag to OVERWRITE your forked repo to be the same as
## upstream -- useful if you mangle your fork and want to
## reset it.

############################################################
## YOUR VALUES ##
#################

## Your github username:
GITUSER=andf-crl

############################################################
## BEGIN SCRIPT ##
##################

TMPDIR=/tmp/rebasefork$$

FORCE=""

## Check for FORCE override: for resetting your fork to be
## identical to upstream. WARNING: destroys any fork-specific
## commits!
while getopts ":f" opt; do
  case ${opt} in
    f )
      FORCE=1
      ;;
    \? )
      echo -e "\nERROR: Invalid option: $OPTARG" 1>&2
      echo "       rebasefork only supports the optional -f flag"
      echo -e "       for resetting to match upstream\n"
      exit
      ;;
  esac
done

mkdir -p $TMPDIR
cd $TMPDIR
git clone git@github.com:$GITUSER/docs.git
cd docs
git remote add upstream git@github.com:cockroachdb/docs.git

# Current commit count before:
BEFORE=`git rev-list --left-right --count origin | awk '{print $2}'`

git fetch upstream

# Proceed depending on user-supplied flag:
if [ ! $FORCE ]; then
   git rebase upstream/master
   git push origin master
else
   git reset --hard upstream/master
   git push origin master --force
fi

# New commit count after:
AFTER=`git rev-list --left-right --count origin | awk '{print $2}'`

# Just for fun, report number of commits moved:
NUM_COMMITS=`echo "$AFTER - $BEFORE" | bc`
echo "Moved ahead $NUM_COMMITS commits"

rm -rf $TMPDIR