diff existing file with its original content from rpm

diff_file_with_rpm_content

diff_file_with_rpm_content()
{

    #
    # EXAMPLES:
    #
    # diff_file_with_rpm_content /etc/sysconfig/somefile
    # diff_file_with_rpm_content /etc/sysconfig/somefile.rpmsave /etc/sysconfig/somefile
    #
    
    local srcfile="$1"
    [ -f "$srcfile" ] || exit 1

    local TMPFILE=$(mktemp /tmp/diff_file_with_rpm_content.XXXX)
    local PACKAGE
    local PACKAGE_FILE

    local file
    if [ -n "$2" ]
    then
        file="$2"
    else 
        file="$srcfile"
    fi

###
    
    echo "Getting package..."

    PACKAGE=$(rpm -q -f "$file")
    echo "$PACKAGE"

    yumdownloader --destdir=/tmp "$PACKAGE"
    

###

    echo "Unpacking rpm content and preparing for diff..."

    PACKAGE_FILE=/tmp/${PACKAGE}.rpm

    rpm2cpio "$PACKAGE_FILE" | cpio -i --to-stdout ".$file" > $TMPFILE


###

    DIFF_TOOL=$"vimdiff --cmd \":colorscheme evening\""

    eval "$DIFF_TOOL" "\$srcfile" "\$TMPFILE"

}