git-author-rewrite

#!/usr/bin/env bash

# see https://help.github.com/articles/changing-author-info/

NAME=`basename ${BASH_SOURCE[0]}`
DESCRIPTION="Change any commits that previously had the old email address in its author or committer fields to use the correct name and email address."

# Define help function
function help(){
    if [[ -z "$1" ]]; then echo "${NAME}: ${DESCRIPTION}"; else echo ${NAME}: $1; fi
    # echo "${NAME} - ${DESCRIPTION}";
    echo "Usage example: ${NAME} -o value -n value -e value";
    echo "Options:";
    echo "  -o: OLD_EMAIL. Required.";
    echo "  -n: CORRECT_NAME. Required.";
    echo "  -e: CORRECT_EMAIL. Required.";
    exit 1;
}
 
while getopts ":o:n:e:h" optname
do
    case "$optname" in
      "h")
        help
        ;;  
      "o")
        OLD_EMAIL=$OPTARG
        ;;
      "n")
        CORRECT_NAME=$OPTARG
        ;;
      "e")
        CORRECT_EMAIL=$OPTARG
        ;;
      "?")
        help "Invalid option: -$OPTARG"
        ;;
      ":")
        help "Option -$OPTARG requires an argument."
        ;;
      *)
        help "Unknown error while processing options"
        ;;
    esac
done

shift $((OPTIND-1))

# Check required arguments
if [[ -z "$OLD_EMAIL" ]]; then help "Option -o is required"; fi
if [[ -z "$CORRECT_NAME" ]]; then help "Option -n is required"; fi
if [[ -z "$CORRECT_EMAIL" ]]; then help "Option -e is required"; fi    

echo \'$OLD_EMAIL\' \'$CORRECT_NAME\' \'$CORRECT_EMAIL\'

git filter-branch --env-filter $'
OLD_EMAIL="'$OLD_EMAIL$'"
CORRECT_NAME="'$CORRECT_NAME$'"
CORRECT_EMAIL="'$CORRECT_EMAIL$'"
if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags