source: mainline/tools/srepl@ d4a829e

#!/bin/sh

function usage {
        echo "Usage:"
        echo
        echo "  $0 search_pattern [-- <pathspec> ]"
        echo "  $0 search_pattern replacement [-- <pathspec> ]"
        echo
        echo "Pattern should be a basic regexp as accepted by grep and sed."
        echo "For information on pathspec syntax, see git documentation."
        echo
        exit 1
}


if [ "$1" == "--" ]; then
        usage
elif [ "$#" -eq 1 ]  || [ "$2" == "--" ]; then
        pattern="$1"
        shift
        git grep -I -n "$pattern" "$@"
elif [ "$#" -eq 2 ] || [ "$3" == "--" ]; then

        if ( git status --porcelain | grep '^.[^ ]' ); then
                echo "You have unstaged changes in your tree."
                echo "Either stage them with 'git add', commit them,"
                echo "or discard them with 'git checkout -- .'"
                exit 1
        fi

        pattern="$1"
        replacement="$2"
        shift
        shift
        git grep -I -l "$pattern" "$@" | xargs sed -i "s/$pattern/$replacement/g"
else
        usage
fi