git authorship and email adjustment

gitfix.sh

#!/bin/sh
# This script uses git filter-branch to adjust author names and
# emails. No success is garuenteed. Usage is as follows:
#
# gitfix.sh --name|--email oldValue newValue
#

OLDVALUE=$2
NEWVALUE=$3

if [ "$1" != "--name" ] && [ "$1" != "--email" ]
then
	echo "usage: $0 option oldValue newValue
options:
	--name		adjust GIT_AUTHOR_NAME and GIT_COMMITTER_NAME
	--email		adjust GIT_AUTHOR_EMAIL and GIT_COMMITTER_EMAIL"
fi

if [ "$1" = "--name" ]
then
	git filter-branch -f --env-filter "
if [ \"\$GIT_AUTHOR_NAME\" = \"$OLDVALUE\" ]
then
export GIT_AUTHOR_NAME=\"$NEWVALUE\"
fi
if [ \"\$GIT_COMMITTER_NAME\" = \"$OLDVALUE\" ]
then
export GIT_COMMITTER_NAME=\"$NEWVALUE\"
fi
" HEAD
elif [ "$1" = "--email" ]
then
	git filter-branch --env-filter "
if [ \"\$GIT_AUTHOR_EMAIL\" = \"$OLDVALUE\" ]
then
	export GIT_AUTHOR_EMAIL=\"$NEWVALUE\"
fi
if [ \"\$GIT_COMMITTER_EMAIL\" = \"$OLDVALUE\" ]
then
	export GIT_COMMITTER_EMAIL=\"$NEWVALUE\"
fi
" HEAD
fi