diff --git a/extensions/flink/install_flink.sh b/extensions/flink/install_flink.sh
index d59fc9c..ef94fba 100644
--- a/extensions/flink/install_flink.sh
+++ b/extensions/flink/install_flink.sh
@@ -34,7 +34,7 @@ mv /home/hadoop/flink* "${FLINK_INSTALL_DIR}"
 
 # List all task managers (workers) in the slaves file
 # The task managers will be brought up by the job manager (master)
-echo ${WORKERS[@]} | tr ' ' '\n' > ${FLINK_INSTALL_DIR}/conf/slaves
+echo "${WORKERS[@]}" | tr ' ' '\n' > ${FLINK_INSTALL_DIR}/conf/slaves
 
 # Create temp file in hadoop directory which might be mounted to other storage than os
 FLINK_TASKMANAGER_TEMP_DIR="/hadoop/flink/tmp"
diff --git a/extensions/hama/install_hama.sh b/extensions/hama/install_hama.sh
index d0056c3..003dbb9 100644
--- a/extensions/hama/install_hama.sh
+++ b/extensions/hama/install_hama.sh
@@ -44,7 +44,7 @@ cat << EOF > ${HAMA_INSTALL_DIR}/conf/hama-site.xml
 EOF
 
 # Set up all workers to be groomservers.
-echo ${WORKERS[@]} | tr ' ' '\n' > ${HAMA_INSTALL_DIR}/conf/groomservers
+echo "${WORKERS[@]}" | tr ' ' '\n' > ${HAMA_INSTALL_DIR}/conf/groomservers
 
 # Symlink the Hadoop hdfs-site.xml to hama's "copy" of it.
 ln -s ${HADOOP_CONF_DIR}/hdfs-site.xml ${HAMA_INSTALL_DIR}/conf/hdfs-site.xml
diff --git a/extensions/hbase/install_hbase.sh b/extensions/hbase/install_hbase.sh
index 921e84a..24a0539 100644
--- a/extensions/hbase/install_hbase.sh
+++ b/extensions/hbase/install_hbase.sh
@@ -44,7 +44,7 @@ cat << EOF > ${HBASE_INSTALL_DIR}/conf/hbase-site.xml
 EOF
 
 # Set up all workers to be regionservers.
-echo ${WORKERS[@]} | tr ' ' '\n' > ${HBASE_INSTALL_DIR}/conf/regionservers
+echo "${WORKERS[@]}" | tr ' ' '\n' > ${HBASE_INSTALL_DIR}/conf/regionservers
 
 # Symlink the Hadoop hdfs-site.xml to hbase's "copy" of it.
 ln -s ${HADOOP_CONF_DIR}/hdfs-site.xml ${HBASE_INSTALL_DIR}/conf/hdfs-site.xml
diff --git a/extensions/tajo/configure_tajo.sh b/extensions/tajo/configure_tajo.sh
index d2e41a0..7c9898c 100644
--- a/extensions/tajo/configure_tajo.sh
+++ b/extensions/tajo/configure_tajo.sh
@@ -84,7 +84,7 @@ cat << EOF > ${TAJO_INSTALL_DIR}/conf/tajo-site.xml
 EOF
 
 # Set up conf/workers
-echo ${WORKERS[@]} | tr ' ' '\n' > ${TAJO_INSTALL_DIR}/conf/workers
+echo "${WORKERS[@]}" | tr ' ' '\n' > ${TAJO_INSTALL_DIR}/conf/workers
 
 # Set up conf/tajo-env.sh
 cat << EOF >> ${TAJO_INSTALL_DIR}/conf/tajo-env.sh
diff --git a/sampleapps/querytools/scripts/setup-packages__at__master.sh b/sampleapps/querytools/scripts/setup-packages__at__master.sh
index 01ac2d0..9dd4a19 100644
--- a/sampleapps/querytools/scripts/setup-packages__at__master.sh
+++ b/sampleapps/querytools/scripts/setup-packages__at__master.sh
@@ -47,7 +47,7 @@ function setup_pkg_generic() {
 readonly -f setup_pkg_generic
 
 function setup_pkg_hive() {
-  setup_pkg_generic $@
+  setup_pkg_generic "$@"
 
   # Move configuration
   emit ""
@@ -66,7 +66,7 @@ function setup_pkg_hive() {
 readonly -f setup_pkg_hive
 
 function setup_pkg_pig() {
-  setup_pkg_generic $@
+  setup_pkg_generic "$@"
 }
 readonly -f setup_pkg_pig
 
@@ -129,7 +129,7 @@ emit "Installing packages into install directory $MASTER_INSTALL_DIR"
 for pkg in $PACKAGE_LIST; do
   # Get the query-tool specific directory name
   pkg_name=$(pkgutil_pkg_name $MASTER_PACKAGE_DIR/$PACKAGES_DIR $pkg)
-  pkg_upper=$(echo "$pkg_name" | tr '[a-z]' '[A-Z]')
+  pkg_upper=$(echo "$pkg_name" | tr 'a-z' 'A-Z')
 
   # Get the name of the zip file
   pkg_file=$(pkgutil_pkg_file $MASTER_PACKAGE_DIR/$PACKAGES_DIR $pkg)