diff --git a/bin/kafka-console-consumer.sh b/bin/kafka-console-consumer.sh
index 07c90a9..3944ba0 100755
--- a/bin/kafka-console-consumer.sh
+++ b/bin/kafka-console-consumer.sh
@@ -18,4 +18,4 @@ if [ "x$KAFKA_HEAP_OPTS" = "x" ]; then
     export KAFKA_HEAP_OPTS="-Xmx512M"
 fi
 
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.ConsoleConsumer $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.ConsoleConsumer "$@"
diff --git a/bin/kafka-console-producer.sh b/bin/kafka-console-producer.sh
index ccca66d..a8752a9 100755
--- a/bin/kafka-console-producer.sh
+++ b/bin/kafka-console-producer.sh
@@ -17,4 +17,4 @@
 if [ "x$KAFKA_HEAP_OPTS" = "x" ]; then
     export KAFKA_HEAP_OPTS="-Xmx512M"
 fi
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.ConsoleProducer $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.ConsoleProducer "$@"
diff --git a/bin/kafka-consumer-groups.sh b/bin/kafka-consumer-groups.sh
index f4786db..2de158f 100755
--- a/bin/kafka-consumer-groups.sh
+++ b/bin/kafka-consumer-groups.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.admin.ConsumerGroupCommand $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.admin.ConsumerGroupCommand "$@"
diff --git a/bin/kafka-consumer-offset-checker.sh b/bin/kafka-consumer-offset-checker.sh
index c275f7e..3adad37 100755
--- a/bin/kafka-consumer-offset-checker.sh
+++ b/bin/kafka-consumer-offset-checker.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.ConsumerOffsetChecker $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.ConsumerOffsetChecker "$@"
diff --git a/bin/kafka-consumer-perf-test.sh b/bin/kafka-consumer-perf-test.sh
index ebc513a..96a0343 100755
--- a/bin/kafka-consumer-perf-test.sh
+++ b/bin/kafka-consumer-perf-test.sh
@@ -17,4 +17,4 @@
 if [ "x$KAFKA_HEAP_OPTS" = "x" ]; then
     export KAFKA_HEAP_OPTS="-Xmx512M"
 fi
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.ConsumerPerformance $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.ConsumerPerformance "$@"
diff --git a/bin/kafka-mirror-maker.sh b/bin/kafka-mirror-maker.sh
index 56e342c..5dc18f0 100755
--- a/bin/kafka-mirror-maker.sh
+++ b/bin/kafka-mirror-maker.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.MirrorMaker $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.MirrorMaker "$@"
diff --git a/bin/kafka-preferred-replica-election.sh b/bin/kafka-preferred-replica-election.sh
index ed167c2..ac16666 100755
--- a/bin/kafka-preferred-replica-election.sh
+++ b/bin/kafka-preferred-replica-election.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.admin.PreferredReplicaLeaderElectionCommand $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.admin.PreferredReplicaLeaderElectionCommand "$@"
diff --git a/bin/kafka-producer-perf-test.sh b/bin/kafka-producer-perf-test.sh
index 84ac949..2ce1035 100755
--- a/bin/kafka-producer-perf-test.sh
+++ b/bin/kafka-producer-perf-test.sh
@@ -17,4 +17,4 @@
 if [ "x$KAFKA_HEAP_OPTS" = "x" ]; then
     export KAFKA_HEAP_OPTS="-Xmx512M"
 fi
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.ProducerPerformance $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.ProducerPerformance "$@"
diff --git a/bin/kafka-reassign-partitions.sh b/bin/kafka-reassign-partitions.sh
index 95b4ae0..99092ff 100755
--- a/bin/kafka-reassign-partitions.sh
+++ b/bin/kafka-reassign-partitions.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.admin.ReassignPartitionsCommand $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.admin.ReassignPartitionsCommand "$@"
diff --git a/bin/kafka-replay-log-producer.sh b/bin/kafka-replay-log-producer.sh
index 8e2e713..13da7fb 100755
--- a/bin/kafka-replay-log-producer.sh
+++ b/bin/kafka-replay-log-producer.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.ReplayLogProducer $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.ReplayLogProducer "$@"
diff --git a/bin/kafka-replica-verification.sh b/bin/kafka-replica-verification.sh
index ee6d19e..fd4ab15 100755
--- a/bin/kafka-replica-verification.sh
+++ b/bin/kafka-replica-verification.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.ReplicaVerificationTool $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.ReplicaVerificationTool "$@"
diff --git a/bin/kafka-run-class.sh b/bin/kafka-run-class.sh
index 8c3fa28..71115ca 100755
--- a/bin/kafka-run-class.sh
+++ b/bin/kafka-run-class.sh
@@ -20,7 +20,7 @@ then
   exit 1
 fi
 
-base_dir=$(dirname $0)/..
+base_dir="$(dirname "$0")"/..
 
 # create logs directory
 if [ "x$LOG_DIR" = "x" ]; then
diff --git a/bin/kafka-server-start.sh b/bin/kafka-server-start.sh
index dc01d46..1831de9 100755
--- a/bin/kafka-server-start.sh
+++ b/bin/kafka-server-start.sh
@@ -19,7 +19,7 @@ then
 	echo "USAGE: $0 [-daemon] server.properties [--override property=value]*"
 	exit 1
 fi
-base_dir=$(dirname $0)
+base_dir="$(dirname "$0")"
 
 if [ "x$KAFKA_LOG4J_OPTS" = "x" ]; then
     export KAFKA_LOG4J_OPTS="-Dlog4j.configuration=file:$base_dir/../config/log4j.properties"
@@ -41,4 +41,4 @@ case $COMMAND in
     ;;
 esac
 
-exec $base_dir/kafka-run-class.sh $EXTRA_ARGS kafka.Kafka $@
+exec $base_dir/kafka-run-class.sh $EXTRA_ARGS kafka.Kafka "$@"
diff --git a/bin/kafka-simple-consumer-shell.sh b/bin/kafka-simple-consumer-shell.sh
index 9316f79..024db53 100755
--- a/bin/kafka-simple-consumer-shell.sh
+++ b/bin/kafka-simple-consumer-shell.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.tools.SimpleConsumerShell $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.tools.SimpleConsumerShell "$@"
diff --git a/bin/kafka-topics.sh b/bin/kafka-topics.sh
index b39b272..7765bc4 100755
--- a/bin/kafka-topics.sh
+++ b/bin/kafka-topics.sh
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-exec $(dirname $0)/kafka-run-class.sh kafka.admin.TopicCommand $@
+exec "$(dirname "$0")"/kafka-run-class.sh kafka.admin.TopicCommand "$@"
diff --git a/bin/zookeeper-server-start.sh b/bin/zookeeper-server-start.sh
index d968786..478dd8e 100755
--- a/bin/zookeeper-server-start.sh
+++ b/bin/zookeeper-server-start.sh
@@ -19,7 +19,7 @@ then
 	echo "USAGE: $0 zookeeper.properties"
 	exit 1
 fi
-base_dir=$(dirname $0)
+base_dir="$(dirname "$0")"
 
 if [ "x$KAFKA_LOG4J_OPTS" = "x" ]; then
     export KAFKA_LOG4J_OPTS="-Dlog4j.configuration=file:$base_dir/../config/log4j.properties"
@@ -41,5 +41,5 @@ case $COMMAND in
      ;;
 esac
 
-exec $base_dir/kafka-run-class.sh $EXTRA_ARGS org.apache.zookeeper.server.quorum.QuorumPeerMain $@
+exec $base_dir/kafka-run-class.sh $EXTRA_ARGS org.apache.zookeeper.server.quorum.QuorumPeerMain "$@"
 
diff --git a/bin/zookeeper-server-stop.sh b/bin/zookeeper-server-stop.sh
index 975d9ae..db7720c 100755
--- a/bin/zookeeper-server-stop.sh
+++ b/bin/zookeeper-server-stop.sh
@@ -13,4 +13,4 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-ps ax | grep -i 'zookeeper' | grep -v grep | awk '{print $1}' | xargs kill -SIGINT
+pgrep -f 'zookeeper' | xargs kill -SIGINT
diff --git a/bin/zookeeper-shell.sh b/bin/zookeeper-shell.sh
index 95007fa..df8086b 100755
--- a/bin/zookeeper-shell.sh
+++ b/bin/zookeeper-shell.sh
@@ -20,4 +20,4 @@ then
 	exit 1
 fi
 
-exec $(dirname $0)/kafka-run-class.sh org.apache.zookeeper.ZooKeeperMain -server "$@"
+exec "$(dirname "$0")"/kafka-run-class.sh org.apache.zookeeper.ZooKeeperMain -server "$@"