download_core() {
 61     local DIR=$1
 62     local VERSION=$2
 63     local DOWNLOAD_FILE=$3
 64     local SERVER_DIR=$4
 65     local UNTAR=$5
 66     local UNTARRED_DIR=$6
 67     echo "Downloading dependency: $DIR $VERSION"
 68 
 69     local TMP_DIR="${TMPDIR:-/tmp}/$DIR"
 70     echo ${TMP_DIR} //打印
 71     local TAR="$TMP_DIR/$DOWNLOAD_FILE"
 72     echo ${TAR} //打印
 73     local TMP_TAR="$TAR.tmp"
 74 
 75     mkdir -p "$TMP_DIR"
 76 
 77     if [ ! -f "$TAR" ]; then
 78         echo  "https://static.realm.io/downloads/$SERVER_DIR/$DOWNLOAD_FILE"
 79         curl -f -L -s "https://static.realm.io/downloads/$SERVER_DIR/$DOWNLO    AD_FILE" -o "$TMP_TAR" ||
 80             die "Downloading $DIR failed. Please try again once you have an     Internet connection."
 81         mv "$TMP_TAR" "$TAR"
 82     else
 83         echo "Using cached $DIR from TMPDIR"
 84     fi