30 files changed, 130 insertions, 128 deletions
diff --git a/bin/beeline b/bin/beeline
index 1bda4dba50..3fcb6df343 100755
--- a/bin/beeline
+++ b/bin/beeline
@@ -24,7 +24,7 @@
 set -o posix
 
 # Figure out where Spark is installed
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
 CLASS="org.apache.hive.beeline.BeeLine"
 exec "$FWDIR/bin/spark-class" $CLASS "$@"
diff --git a/bin/compute-classpath.sh b/bin/compute-classpath.sh
index 16b794a159..15c6779402 100755
--- a/bin/compute-classpath.sh
+++ b/bin/compute-classpath.sh
@@ -23,9 +23,9 @@
 SCALA_VERSION=2.10
 
 # Figure out where Spark is installed
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
-. $FWDIR/bin/load-spark-env.sh
+. "$FWDIR"/bin/load-spark-env.sh
 
 # Build up classpath
 CLASSPATH="$SPARK_CLASSPATH:$SPARK_SUBMIT_CLASSPATH:$FWDIR/conf"
@@ -63,7 +63,7 @@ else
   assembly_folder="$ASSEMBLY_DIR"
 fi
 
-num_jars=$(ls "$assembly_folder" | grep "spark-assembly.*hadoop.*\.jar" | wc -l)
+num_jars="$(ls "$assembly_folder" | grep "spark-assembly.*hadoop.*\.jar" | wc -l)"
 if [ "$num_jars" -eq "0" ]; then
   echo "Failed to find Spark assembly in $assembly_folder"
   echo "You need to build Spark before running this program."
@@ -77,7 +77,7 @@ if [ "$num_jars" -gt "1" ]; then
   exit 1
 fi
 
-ASSEMBLY_JAR=$(ls "$assembly_folder"/spark-assembly*hadoop*.jar 2>/dev/null)
+ASSEMBLY_JAR="$(ls "$assembly_folder"/spark-assembly*hadoop*.jar 2>/dev/null)"
 
 # Verify that versions of java used to build the jars and run Spark are compatible
 jar_error_check=$("$JAR_CMD" -tf "$ASSEMBLY_JAR" nonexistent/class/path 2>&1)
@@ -103,8 +103,8 @@ else
   datanucleus_dir="$FWDIR"/lib_managed/jars
 fi
 
-datanucleus_jars=$(find "$datanucleus_dir" 2>/dev/null | grep "datanucleus-.*\\.jar")
-datanucleus_jars=$(echo "$datanucleus_jars" | tr "\n" : | sed s/:$//g)
+datanucleus_jars="$(find "$datanucleus_dir" 2>/dev/null | grep "datanucleus-.*\\.jar")"
+datanucleus_jars="$(echo "$datanucleus_jars" | tr "\n" : | sed s/:$//g)"
 
 if [ -n "$datanucleus_jars" ]; then
   hive_files=$("$JAR_CMD" -tf "$ASSEMBLY_JAR" org/apache/hadoop/hive/ql/exec 2>/dev/null)
diff --git a/bin/load-spark-env.sh b/bin/load-spark-env.sh
index 493d3785a0..6d4231b204 100644
--- a/bin/load-spark-env.sh
+++ b/bin/load-spark-env.sh
@@ -25,9 +25,9 @@ if [ -z "$SPARK_ENV_LOADED" ]; then
   export SPARK_ENV_LOADED=1
 
   # Returns the parent of the directory this script lives in.
-  parent_dir="$(cd `dirname $0`/..; pwd)"
+  parent_dir="$(cd "`dirname "$0"`"/..; pwd)"
 
-  user_conf_dir=${SPARK_CONF_DIR:-"$parent_dir/conf"}
+  user_conf_dir="${SPARK_CONF_DIR:-"$parent_dir"/conf}"
 
   if [ -f "${user_conf_dir}/spark-env.sh" ]; then
     # Promote all variable declarations to environment (exported) variables
diff --git a/bin/pyspark b/bin/pyspark
index 26a16dd600..5142411e36 100755
--- a/bin/pyspark
+++ b/bin/pyspark
@@ -18,18 +18,18 @@
 #
 
 # Figure out where Spark is installed
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
 # Export this as SPARK_HOME
 export SPARK_HOME="$FWDIR"
 
-source $FWDIR/bin/utils.sh
+source "$FWDIR/bin/utils.sh"
 
 SCALA_VERSION=2.10
 
 function usage() {
   echo "Usage: ./bin/pyspark [options]" 1>&2
-  $FWDIR/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
+  "$FWDIR"/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
   exit 0
 }
 
@@ -48,7 +48,7 @@ if [ ! -f "$FWDIR/RELEASE" ]; then
   fi
 fi
 
-. $FWDIR/bin/load-spark-env.sh
+. "$FWDIR"/bin/load-spark-env.sh
 
 # Figure out which Python executable to use
 if [[ -z "$PYSPARK_PYTHON" ]]; then
@@ -57,12 +57,12 @@ fi
 export PYSPARK_PYTHON
 
 # Add the PySpark classes to the Python path:
-export PYTHONPATH=$SPARK_HOME/python/:$PYTHONPATH
-export PYTHONPATH=$SPARK_HOME/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH
+export PYTHONPATH="$SPARK_HOME/python/:$PYTHONPATH"
+export PYTHONPATH="$SPARK_HOME/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH"
 
 # Load the PySpark shell.py script when ./pyspark is used interactively:
-export OLD_PYTHONSTARTUP=$PYTHONSTARTUP
-export PYTHONSTARTUP=$FWDIR/python/pyspark/shell.py
+export OLD_PYTHONSTARTUP="$PYTHONSTARTUP"
+export PYTHONSTARTUP="$FWDIR/python/pyspark/shell.py"
 
 # If IPython options are specified, assume user wants to run IPython
 if [[ -n "$IPYTHON_OPTS" ]]; then
@@ -99,10 +99,10 @@ fi
 if [[ "$1" =~ \.py$ ]]; then
   echo -e "\nWARNING: Running python applications through ./bin/pyspark is deprecated as of Spark 1.0." 1>&2
   echo -e "Use ./bin/spark-submit <python file>\n" 1>&2
-  primary=$1
+  primary="$1"
   shift
   gatherSparkSubmitOpts "$@"
-  exec $FWDIR/bin/spark-submit "${SUBMISSION_OPTS[@]}" $primary "${APPLICATION_OPTS[@]}"
+  exec "$FWDIR"/bin/spark-submit "${SUBMISSION_OPTS[@]}" "$primary" "${APPLICATION_OPTS[@]}"
 else
   # PySpark shell requires special handling downstream
   export PYSPARK_SHELL=1
diff --git a/bin/run-example b/bin/run-example
index 68a35702ed..34dd71c718 100755
--- a/bin/run-example
+++ b/bin/run-example
@@ -19,7 +19,7 @@
 
 SCALA_VERSION=2.10
 
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 export SPARK_HOME="$FWDIR"
 EXAMPLES_DIR="$FWDIR"/examples
 
@@ -35,12 +35,12 @@ else
 fi
 
 if [ -f "$FWDIR/RELEASE" ]; then
-  export SPARK_EXAMPLES_JAR=`ls "$FWDIR"/lib/spark-examples-*hadoop*.jar`
+  export SPARK_EXAMPLES_JAR="`ls "$FWDIR"/lib/spark-examples-*hadoop*.jar`"
 elif [ -e "$EXAMPLES_DIR"/target/scala-$SCALA_VERSION/spark-examples-*hadoop*.jar ]; then
-  export SPARK_EXAMPLES_JAR=`ls "$EXAMPLES_DIR"/target/scala-$SCALA_VERSION/spark-examples-*hadoop*.jar`
+  export SPARK_EXAMPLES_JAR="`ls "$EXAMPLES_DIR"/target/scala-$SCALA_VERSION/spark-examples-*hadoop*.jar`"
 fi
 
-if [[ -z $SPARK_EXAMPLES_JAR ]]; then
+if [[ -z "$SPARK_EXAMPLES_JAR" ]]; then
   echo "Failed to find Spark examples assembly in $FWDIR/lib or $FWDIR/examples/target" 1>&2
   echo "You need to build Spark before running this program" 1>&2
   exit 1
diff --git a/bin/spark-class b/bin/spark-class
index c6543545a5..5f5f9ea748 100755
--- a/bin/spark-class
+++ b/bin/spark-class
@@ -27,12 +27,12 @@ esac
 SCALA_VERSION=2.10
 
 # Figure out where Spark is installed
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
 # Export this as SPARK_HOME
 export SPARK_HOME="$FWDIR"
 
-. $FWDIR/bin/load-spark-env.sh
+. "$FWDIR"/bin/load-spark-env.sh
 
 if [ -z "$1" ]; then
   echo "Usage: spark-class <class> [<args>]" 1>&2
@@ -105,7 +105,7 @@ else
     exit 1
   fi
 fi
-JAVA_VERSION=$($RUNNER -version 2>&1 | sed 's/java version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q')
+JAVA_VERSION=$("$RUNNER" -version 2>&1 | sed 's/java version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q')
 
 # Set JAVA_OPTS to be able to load native libraries and to set heap size
 if [ "$JAVA_VERSION" -ge 18 ]; then
@@ -117,7 +117,7 @@ JAVA_OPTS="$JAVA_OPTS -Xms$OUR_JAVA_MEM -Xmx$OUR_JAVA_MEM"
 
 # Load extra JAVA_OPTS from conf/java-opts, if it exists
 if [ -e "$FWDIR/conf/java-opts" ] ; then
-  JAVA_OPTS="$JAVA_OPTS `cat $FWDIR/conf/java-opts`"
+  JAVA_OPTS="$JAVA_OPTS `cat "$FWDIR"/conf/java-opts`"
 fi
 
 # Attention: when changing the way the JAVA_OPTS are assembled, the change must be reflected in CommandUtils.scala!
@@ -126,21 +126,21 @@ TOOLS_DIR="$FWDIR"/tools
 SPARK_TOOLS_JAR=""
 if [ -e "$TOOLS_DIR"/target/scala-$SCALA_VERSION/spark-tools*[0-9Tg].jar ]; then
   # Use the JAR from the SBT build
-  export SPARK_TOOLS_JAR=`ls "$TOOLS_DIR"/target/scala-$SCALA_VERSION/spark-tools*[0-9Tg].jar`
+  export SPARK_TOOLS_JAR="`ls "$TOOLS_DIR"/target/scala-$SCALA_VERSION/spark-tools*[0-9Tg].jar`"
 fi
 if [ -e "$TOOLS_DIR"/target/spark-tools*[0-9Tg].jar ]; then
   # Use the JAR from the Maven build
   # TODO: this also needs to become an assembly!
-  export SPARK_TOOLS_JAR=`ls "$TOOLS_DIR"/target/spark-tools*[0-9Tg].jar`
+  export SPARK_TOOLS_JAR="`ls "$TOOLS_DIR"/target/spark-tools*[0-9Tg].jar`"
 fi
 
 # Compute classpath using external script
-classpath_output=$($FWDIR/bin/compute-classpath.sh)
+classpath_output=$("$FWDIR"/bin/compute-classpath.sh)
 if [[ "$?" != "0" ]]; then
   echo "$classpath_output"
   exit 1
 else
-  CLASSPATH=$classpath_output
+  CLASSPATH="$classpath_output"
 fi
 
 if [[ "$1" =~ org.apache.spark.tools.* ]]; then
@@ -153,9 +153,9 @@ if [[ "$1" =~ org.apache.spark.tools.* ]]; then
 fi
 
 if $cygwin; then
-  CLASSPATH=`cygpath -wp $CLASSPATH`
+  CLASSPATH="`cygpath -wp "$CLASSPATH"`"
   if [ "$1" == "org.apache.spark.tools.JavaAPICompletenessChecker" ]; then
-    export SPARK_TOOLS_JAR=`cygpath -w $SPARK_TOOLS_JAR`
+    export SPARK_TOOLS_JAR="`cygpath -w "$SPARK_TOOLS_JAR"`"
   fi
 fi
 export CLASSPATH
diff --git a/bin/spark-shell b/bin/spark-shell
index 0ab4e14f5b..4a0670fc6c 100755
--- a/bin/spark-shell
+++ b/bin/spark-shell
@@ -29,11 +29,11 @@ esac
 set -o posix
 
 ## Global script variables
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
 function usage() {
   echo "Usage: ./bin/spark-shell [options]"
-  $FWDIR/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
+  "$FWDIR"/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
   exit 0
 }
 
@@ -41,7 +41,7 @@ if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
   usage
 fi
 
-source $FWDIR/bin/utils.sh
+source "$FWDIR"/bin/utils.sh
 SUBMIT_USAGE_FUNCTION=usage
 gatherSparkSubmitOpts "$@"
 
@@ -54,11 +54,11 @@ function main() {
     # (see https://github.com/sbt/sbt/issues/562).
     stty -icanon min 1 -echo > /dev/null 2>&1
     export SPARK_SUBMIT_OPTS="$SPARK_SUBMIT_OPTS -Djline.terminal=unix"
-    $FWDIR/bin/spark-submit --class org.apache.spark.repl.Main "${SUBMISSION_OPTS[@]}" spark-shell "${APPLICATION_OPTS[@]}"
+    "$FWDIR"/bin/spark-submit --class org.apache.spark.repl.Main "${SUBMISSION_OPTS[@]}" spark-shell "${APPLICATION_OPTS[@]}"
     stty icanon echo > /dev/null 2>&1
   else
     export SPARK_SUBMIT_OPTS
-    $FWDIR/bin/spark-submit --class org.apache.spark.repl.Main "${SUBMISSION_OPTS[@]}" spark-shell "${APPLICATION_OPTS[@]}"
+    "$FWDIR"/bin/spark-submit --class org.apache.spark.repl.Main "${SUBMISSION_OPTS[@]}" spark-shell "${APPLICATION_OPTS[@]}"
   fi
 }
 
diff --git a/bin/spark-sql b/bin/spark-sql
index 2a3cb31f58..ae096530ca 100755
--- a/bin/spark-sql
+++ b/bin/spark-sql
@@ -27,7 +27,7 @@ CLASS="org.apache.spark.sql.hive.thriftserver.SparkSQLCLIDriver"
 CLASS_NOT_FOUND_EXIT_STATUS=1
 
 # Figure out where Spark is installed
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
 function usage {
   echo "Usage: ./bin/spark-sql [options] [cli option]"
@@ -38,10 +38,10 @@ function usage {
   pattern+="\|--help"
   pattern+="\|======="
 
-  $FWDIR/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
+  "$FWDIR"/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
   echo
   echo "CLI options:"
-  $FWDIR/bin/spark-class $CLASS --help 2>&1 | grep -v "$pattern" 1>&2
+  "$FWDIR"/bin/spark-class $CLASS --help 2>&1 | grep -v "$pattern" 1>&2
 }
 
 if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
@@ -49,7 +49,7 @@ if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
   exit 0
 fi
 
-source $FWDIR/bin/utils.sh
+source "$FWDIR"/bin/utils.sh
 SUBMIT_USAGE_FUNCTION=usage
 gatherSparkSubmitOpts "$@"
 
diff --git a/bin/spark-submit b/bin/spark-submit
index 277c4ce571..c557311b4b 100755
--- a/bin/spark-submit
+++ b/bin/spark-submit
@@ -19,7 +19,7 @@
 
 # NOTE: Any changes in this file must be reflected in SparkSubmitDriverBootstrapper.scala!
 
-export SPARK_HOME="$(cd `dirname $0`/..; pwd)"
+export SPARK_HOME="$(cd "`dirname "$0"`"/..; pwd)"
 ORIG_ARGS=("$@")
 
 while (($#)); do
@@ -59,5 +59,5 @@ if [[ "$SPARK_SUBMIT_DEPLOY_MODE" == "client" && -f "$SPARK_SUBMIT_PROPERTIES_FI
   fi
 fi
 
-exec $SPARK_HOME/bin/spark-class org.apache.spark.deploy.SparkSubmit "${ORIG_ARGS[@]}"
+exec "$SPARK_HOME"/bin/spark-class org.apache.spark.deploy.SparkSubmit "${ORIG_ARGS[@]}"
 
diff --git a/dev/check-license b/dev/check-license
index 558e038afc..9ff0929e9a 100755
--- a/dev/check-license
+++ b/dev/check-license
@@ -23,16 +23,16 @@ acquire_rat_jar () {
   URL1="http://search.maven.org/remotecontent?filepath=org/apache/rat/apache-rat/${RAT_VERSION}/apache-rat-${RAT_VERSION}.jar"
   URL2="http://repo1.maven.org/maven2/org/apache/rat/apache-rat/${RAT_VERSION}/apache-rat-${RAT_VERSION}.jar"
 
-  JAR=$rat_jar
+  JAR="$rat_jar"
   
   if [[ ! -f "$rat_jar" ]]; then
     # Download rat launch jar if it hasn't been downloaded yet
     if [ ! -f "$JAR" ]; then
     # Download
     printf "Attempting to fetch rat\n"
-    JAR_DL=${JAR}.part
+    JAR_DL="${JAR}.part"
     if hash curl 2>/dev/null; then
-      (curl --silent ${URL1} > "$JAR_DL" || curl --silent ${URL2} > "$JAR_DL") && mv "$JAR_DL" "$JAR"
+      (curl --silent "${URL1}" > "$JAR_DL" || curl --silent "${URL2}" > "$JAR_DL") && mv "$JAR_DL" "$JAR"
     elif hash wget 2>/dev/null; then
       (wget --quiet ${URL1} -O "$JAR_DL" || wget --quiet ${URL2} -O "$JAR_DL") && mv "$JAR_DL" "$JAR"
     else
@@ -50,7 +50,7 @@ acquire_rat_jar () {
 }
 
 # Go to the Spark project root directory
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 cd "$FWDIR"
 
 if test -x "$JAVA_HOME/bin/java"; then
@@ -60,17 +60,17 @@ else
 fi
 
 export RAT_VERSION=0.10
-export rat_jar=$FWDIR/lib/apache-rat-${RAT_VERSION}.jar
-mkdir -p $FWDIR/lib
+export rat_jar="$FWDIR"/lib/apache-rat-${RAT_VERSION}.jar
+mkdir -p "$FWDIR"/lib
 
 [[ -f "$rat_jar" ]] || acquire_rat_jar || {
     echo "Download failed. Obtain the rat jar manually and place it at $rat_jar"
     exit 1
 }
 
-$java_cmd -jar $rat_jar -E $FWDIR/.rat-excludes  -d $FWDIR > rat-results.txt
+$java_cmd -jar "$rat_jar" -E "$FWDIR"/.rat-excludes  -d "$FWDIR" > rat-results.txt
 
-ERRORS=$(cat rat-results.txt | grep -e "??")
+ERRORS="$(cat rat-results.txt | grep -e "??")"
 
 if test ! -z "$ERRORS"; then 
     echo "Could not find Apache license headers in the following files:"
diff --git a/dev/lint-python b/dev/lint-python
index 79bf70f0b8..772f856154 100755
--- a/dev/lint-python
+++ b/dev/lint-python
@@ -18,10 +18,10 @@
 #
 
 SCRIPT_DIR="$( cd "$( dirname "$0" )" && pwd )"
-SPARK_ROOT_DIR="$(dirname $SCRIPT_DIR)"
+SPARK_ROOT_DIR="$(dirname "$SCRIPT_DIR")"
 PEP8_REPORT_PATH="$SPARK_ROOT_DIR/dev/pep8-report.txt"
 
-cd $SPARK_ROOT_DIR
+cd "$SPARK_ROOT_DIR"
 
 # Get pep8 at runtime so that we don't rely on it being installed on the build server.
 #+ See: https://github.com/apache/spark/pull/1744#issuecomment-50982162
@@ -45,7 +45,7 @@ fi
 #+ first, but we do so so that the check status can
 #+ be output before the report, like with the
 #+ scalastyle and RAT checks.
-python $PEP8_SCRIPT_PATH $PEP8_PATHS_TO_CHECK > "$PEP8_REPORT_PATH"
+python "$PEP8_SCRIPT_PATH" $PEP8_PATHS_TO_CHECK > "$PEP8_REPORT_PATH"
 pep8_status=${PIPESTATUS[0]} #$?
 
 if [ $pep8_status -ne 0 ]; then
diff --git a/dev/mima b/dev/mima
index 09e4482af5..f9b9b03538 100755
--- a/dev/mima
+++ b/dev/mima
@@ -21,12 +21,12 @@ set -o pipefail
 set -e
 
 # Go to the Spark project root directory
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 cd "$FWDIR"
 
 echo -e "q\n" | sbt/sbt oldDeps/update
 
-export SPARK_CLASSPATH=`find lib_managed \( -name '*spark*jar' -a -type f \) | tr "\\n" ":"`
+export SPARK_CLASSPATH="`find lib_managed \( -name '*spark*jar' -a -type f \) | tr "\\n" ":"`"
 echo "SPARK_CLASSPATH=$SPARK_CLASSPATH"
 
 ./bin/spark-class org.apache.spark.tools.GenerateMIMAIgnore
diff --git a/dev/run-tests b/dev/run-tests
index 90a8ce16f0..49a88085c8 100755
--- a/dev/run-tests
+++ b/dev/run-tests
@@ -18,7 +18,7 @@
 #
 
 # Go to the Spark project root directory
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname $0`"/..; pwd)"
 cd "$FWDIR"
 
 if [ -n "$AMPLAB_JENKINS_BUILD_PROFILE" ]; then
diff --git a/dev/scalastyle b/dev/scalastyle
index eb9b467965..efb5f291ea 100755
--- a/dev/scalastyle
+++ b/dev/scalastyle
@@ -19,7 +19,7 @@
 
 echo -e "q\n" | sbt/sbt -Phive scalastyle > scalastyle.txt
 # Check style with YARN alpha built too
-echo -e "q\n" | sbt/sbt -Pyarn -Phadoop-0.23 -Dhadoop.version=0.23.9 yarn-alpha/scalastyle \
+echo -e "q\n" | sbt/sbt -Pyarn-alpha -Phadoop-0.23 -Dhadoop.version=0.23.9 yarn-alpha/scalastyle \
   >> scalastyle.txt
 # Check style with YARN built too
 echo -e "q\n" | sbt/sbt -Pyarn -Phadoop-2.2 -Dhadoop.version=2.2.0 yarn/scalastyle \
diff --git a/make-distribution.sh b/make-distribution.sh
index 14aed4a4b6..9b012b9222 100755
--- a/make-distribution.sh
+++ b/make-distribution.sh
@@ -28,7 +28,7 @@ set -o pipefail
 set -e
 
 # Figure out where the Spark framework is installed
-FWDIR="$(cd `dirname $0`; pwd)"
+FWDIR="$(cd "`dirname "$0"`"; pwd)"
 DISTDIR="$FWDIR/dist"
 
 SPARK_TACHYON=false
diff --git a/python/run-tests b/python/run-tests
index f2a80b4f18..226e9e2c37 100755
--- a/python/run-tests
+++ b/python/run-tests
@@ -19,7 +19,7 @@
 
 
 # Figure out where the Spark framework is installed
-FWDIR="$(cd `dirname $0`; cd ../; pwd)"
+FWDIR="$(cd "`dirname "$0"`"; cd ../; pwd)"
 
 # CD into the python directory to find things on the right path
 cd "$FWDIR/python"
@@ -33,7 +33,9 @@ rm -rf metastore warehouse
 
 function run_test() {
     echo "Running test: $1"
-    SPARK_TESTING=1 $FWDIR/bin/pyspark $1 2>&1 | tee -a unit-tests.log
+
+    SPARK_TESTING=1 "$FWDIR"/bin/pyspark $1 2>&1 | tee -a unit-tests.log
+
     FAILED=$((PIPESTATUS[0]||$FAILED))
 
     # Fail and exit on the first test failure.
diff --git a/sbin/slaves.sh b/sbin/slaves.sh
index f89547fef9..1d4dc5edf9 100755
--- a/sbin/slaves.sh
+++ b/sbin/slaves.sh
@@ -36,29 +36,29 @@ if [ $# -le 0 ]; then
   exit 1
 fi
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 . "$sbin/spark-config.sh"
 
 # If the slaves file is specified in the command line,
 # then it takes precedence over the definition in
 # spark-env.sh. Save it here.
-HOSTLIST=$SPARK_SLAVES
+HOSTLIST="$SPARK_SLAVES"
 
 # Check if --config is passed as an argument. It is an optional parameter.
 # Exit if the argument is not a directory.
 if [ "$1" == "--config" ]
 then
   shift
-  conf_dir=$1
+  conf_dir="$1"
   if [ ! -d "$conf_dir" ]
   then
     echo "ERROR : $conf_dir is not a directory"
     echo $usage
     exit 1
   else
-    export SPARK_CONF_DIR=$conf_dir
+    export SPARK_CONF_DIR="$conf_dir"
   fi
   shift
 fi
@@ -79,7 +79,7 @@ if [ "$SPARK_SSH_OPTS" = "" ]; then
 fi
 
 for slave in `cat "$HOSTLIST"|sed  "s/#.*$//;/^$/d"`; do
- ssh $SPARK_SSH_OPTS $slave $"${@// /\\ }" \
+ ssh $SPARK_SSH_OPTS "$slave" $"${@// /\\ }" \
    2>&1 | sed "s/^/$slave: /" &
  if [ "$SPARK_SLAVE_SLEEP" != "" ]; then
    sleep $SPARK_SLAVE_SLEEP
diff --git a/sbin/spark-config.sh b/sbin/spark-config.sh
index 5c87da5815..2718d6cba1 100755
--- a/sbin/spark-config.sh
+++ b/sbin/spark-config.sh
@@ -21,19 +21,19 @@
 
 # resolve links - $0 may be a softlink
 this="${BASH_SOURCE-$0}"
-common_bin=$(cd -P -- "$(dirname -- "$this")" && pwd -P)
+common_bin="$(cd -P -- "$(dirname -- "$this")" && pwd -P)"
 script="$(basename -- "$this")"
 this="$common_bin/$script"
 
 # convert relative path to absolute path
-config_bin=`dirname "$this"`
-script=`basename "$this"`
-config_bin=`cd "$config_bin"; pwd`
+config_bin="`dirname "$this"`"
+script="`basename "$this"`"
+config_bin="`cd "$config_bin"; pwd`"
 this="$config_bin/$script"
 
-export SPARK_PREFIX=`dirname "$this"`/..
-export SPARK_HOME=${SPARK_PREFIX}
+export SPARK_PREFIX="`dirname "$this"`"/..
+export SPARK_HOME="${SPARK_PREFIX}"
 export SPARK_CONF_DIR="$SPARK_HOME/conf"
 # Add the PySpark classes to the PYTHONPATH:
-export PYTHONPATH=$SPARK_HOME/python:$PYTHONPATH
-export PYTHONPATH=$SPARK_HOME/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH
+export PYTHONPATH="$SPARK_HOME/python:$PYTHONPATH"
+export PYTHONPATH="$SPARK_HOME/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH"
diff --git a/sbin/spark-daemon.sh b/sbin/spark-daemon.sh
index 9032f23ea8..bd476b400e 100755
--- a/sbin/spark-daemon.sh
+++ b/sbin/spark-daemon.sh
@@ -37,8 +37,8 @@ if [ $# -le 1 ]; then
   exit 1
 fi
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 . "$sbin/spark-config.sh"
 
@@ -50,14 +50,14 @@ sbin=`cd "$sbin"; pwd`
 if [ "$1" == "--config" ]
 then
   shift
-  conf_dir=$1
+  conf_dir="$1"
   if [ ! -d "$conf_dir" ]
   then
     echo "ERROR : $conf_dir is not a directory"
     echo $usage
     exit 1
   else
-    export SPARK_CONF_DIR=$conf_dir
+    export SPARK_CONF_DIR="$conf_dir"
   fi
   shift
 fi
@@ -100,12 +100,12 @@ if [ "$SPARK_LOG_DIR" = "" ]; then
   export SPARK_LOG_DIR="$SPARK_HOME/logs"
 fi
 mkdir -p "$SPARK_LOG_DIR"
-touch $SPARK_LOG_DIR/.spark_test > /dev/null 2>&1
+touch "$SPARK_LOG_DIR"/.spark_test > /dev/null 2>&1
 TEST_LOG_DIR=$?
 if [ "${TEST_LOG_DIR}" = "0" ]; then
-  rm -f $SPARK_LOG_DIR/.spark_test
+  rm -f "$SPARK_LOG_DIR"/.spark_test
 else
-  chown $SPARK_IDENT_STRING $SPARK_LOG_DIR
+  chown "$SPARK_IDENT_STRING" "$SPARK_LOG_DIR"
 fi
 
 if [ "$SPARK_PID_DIR" = "" ]; then
@@ -113,8 +113,8 @@ if [ "$SPARK_PID_DIR" = "" ]; then
 fi
 
 # some variables
-log=$SPARK_LOG_DIR/spark-$SPARK_IDENT_STRING-$command-$instance-$HOSTNAME.out
-pid=$SPARK_PID_DIR/spark-$SPARK_IDENT_STRING-$command-$instance.pid
+log="$SPARK_LOG_DIR/spark-$SPARK_IDENT_STRING-$command-$instance-$HOSTNAME.out"
+pid="$SPARK_PID_DIR/spark-$SPARK_IDENT_STRING-$command-$instance.pid"
 
 # Set default scheduling priority
 if [ "$SPARK_NICENESS" = "" ]; then
@@ -136,7 +136,7 @@ case $startStop in
     fi
 
     if [ "$SPARK_MASTER" != "" ]; then
-      echo rsync from $SPARK_MASTER
+      echo rsync from "$SPARK_MASTER"
       rsync -a -e ssh --delete --exclude=.svn --exclude='logs/*' --exclude='contrib/hod/logs/*' $SPARK_MASTER/ "$SPARK_HOME"
     fi
 
diff --git a/sbin/spark-executor b/sbin/spark-executor
index 3621321a9b..674ce906d9 100755
--- a/sbin/spark-executor
+++ b/sbin/spark-executor
@@ -17,10 +17,10 @@
 # limitations under the License.
 #
 
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
-export PYTHONPATH=$FWDIR/python:$PYTHONPATH
-export PYTHONPATH=$FWDIR/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH
+export PYTHONPATH="$FWDIR/python:$PYTHONPATH"
+export PYTHONPATH="$FWDIR/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH"
 
 echo "Running spark-executor with framework dir = $FWDIR"
-exec $FWDIR/bin/spark-class org.apache.spark.executor.MesosExecutorBackend
+exec "$FWDIR"/bin/spark-class org.apache.spark.executor.MesosExecutorBackend
diff --git a/sbin/start-all.sh b/sbin/start-all.sh
index 5c89ab4d86..1baf57cea0 100755
--- a/sbin/start-all.sh
+++ b/sbin/start-all.sh
@@ -21,8 +21,8 @@
 # Starts the master on this node.
 # Starts a worker on each node specified in conf/slaves
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 TACHYON_STR=""
 
diff --git a/sbin/start-history-server.sh b/sbin/start-history-server.sh
index 580ab471b8..7172ad15d8 100755
--- a/sbin/start-history-server.sh
+++ b/sbin/start-history-server.sh
@@ -24,8 +24,8 @@
 # Use the SPARK_HISTORY_OPTS environment variable to set history server configuration.
 #
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 . "$sbin/spark-config.sh"
 . "$SPARK_PREFIX/bin/load-spark-env.sh"
diff --git a/sbin/start-master.sh b/sbin/start-master.sh
index c5c02491f7..17fff58f4f 100755
--- a/sbin/start-master.sh
+++ b/sbin/start-master.sh
@@ -19,8 +19,8 @@
 
 # Starts the master on the machine this script is executed on.
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 START_TACHYON=false
 
diff --git a/sbin/start-slave.sh b/sbin/start-slave.sh
index b563400dc2..2fc35309f4 100755
--- a/sbin/start-slave.sh
+++ b/sbin/start-slave.sh
@@ -20,7 +20,7 @@
 # Usage: start-slave.sh <worker#> <master-spark-URL>
 #   where <master-spark-URL> is like "spark://localhost:7077"
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 "$sbin"/spark-daemon.sh start org.apache.spark.deploy.worker.Worker "$@"
diff --git a/sbin/start-slaves.sh b/sbin/start-slaves.sh
index 4912d0c0c7..ba1a84abc1 100755
--- a/sbin/start-slaves.sh
+++ b/sbin/start-slaves.sh
@@ -17,8 +17,8 @@
 # limitations under the License.
 #
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 
 START_TACHYON=false
@@ -46,11 +46,11 @@ if [ "$SPARK_MASTER_PORT" = "" ]; then
 fi
 
 if [ "$SPARK_MASTER_IP" = "" ]; then
-  SPARK_MASTER_IP=`hostname`
+  SPARK_MASTER_IP="`hostname`"
 fi
 
 if [ "$START_TACHYON" == "true" ]; then
-  "$sbin/slaves.sh" cd "$SPARK_HOME" \; "$sbin"/../tachyon/bin/tachyon bootstrap-conf $SPARK_MASTER_IP
+  "$sbin/slaves.sh" cd "$SPARK_HOME" \; "$sbin"/../tachyon/bin/tachyon bootstrap-conf "$SPARK_MASTER_IP"
 
   # set -t so we can call sudo
   SPARK_SSH_OPTS="-o StrictHostKeyChecking=no -t" "$sbin/slaves.sh" cd "$SPARK_HOME" \; "$sbin/../tachyon/bin/tachyon-start.sh" worker SudoMount \; sleep 1
@@ -58,12 +58,12 @@ fi
 
 # Launch the slaves
 if [ "$SPARK_WORKER_INSTANCES" = "" ]; then
-  exec "$sbin/slaves.sh" cd "$SPARK_HOME" \; "$sbin/start-slave.sh" 1 spark://$SPARK_MASTER_IP:$SPARK_MASTER_PORT
+  exec "$sbin/slaves.sh" cd "$SPARK_HOME" \; "$sbin/start-slave.sh" 1 "spark://$SPARK_MASTER_IP:$SPARK_MASTER_PORT"
 else
   if [ "$SPARK_WORKER_WEBUI_PORT" = "" ]; then
     SPARK_WORKER_WEBUI_PORT=8081
   fi
   for ((i=0; i<$SPARK_WORKER_INSTANCES; i++)); do
-    "$sbin/slaves.sh" cd "$SPARK_HOME" \; "$sbin/start-slave.sh" $(( $i + 1 ))  spark://$SPARK_MASTER_IP:$SPARK_MASTER_PORT --webui-port $(( $SPARK_WORKER_WEBUI_PORT + $i ))
+    "$sbin/slaves.sh" cd "$SPARK_HOME" \; "$sbin/start-slave.sh" $(( $i + 1 ))  "spark://$SPARK_MASTER_IP:$SPARK_MASTER_PORT" --webui-port $(( $SPARK_WORKER_WEBUI_PORT + $i ))
   done
 fi
diff --git a/sbin/start-thriftserver.sh b/sbin/start-thriftserver.sh
index c519a77df4..4ce40fe750 100755
--- a/sbin/start-thriftserver.sh
+++ b/sbin/start-thriftserver.sh
@@ -24,7 +24,7 @@
 set -o posix
 
 # Figure out where Spark is installed
-FWDIR="$(cd `dirname $0`/..; pwd)"
+FWDIR="$(cd "`dirname "$0"`"/..; pwd)"
 
 CLASS="org.apache.spark.sql.hive.thriftserver.HiveThriftServer2"
 CLASS_NOT_FOUND_EXIT_STATUS=1
@@ -38,10 +38,10 @@ function usage {
   pattern+="\|======="
   pattern+="\|--help"
 
-  $FWDIR/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
+  "$FWDIR"/bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
   echo
   echo "Thrift server options:"
-  $FWDIR/bin/spark-class $CLASS --help 2>&1 | grep -v "$pattern" 1>&2
+  "$FWDIR"/bin/spark-class $CLASS --help 2>&1 | grep -v "$pattern" 1>&2
 }
 
 if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
@@ -49,7 +49,7 @@ if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
   exit 0
 fi
 
-source $FWDIR/bin/utils.sh
+source "$FWDIR"/bin/utils.sh
 SUBMIT_USAGE_FUNCTION=usage
 gatherSparkSubmitOpts "$@"
 
diff --git a/sbin/stop-all.sh b/sbin/stop-all.sh
index 60b358d374..298c6a9859 100755
--- a/sbin/stop-all.sh
+++ b/sbin/stop-all.sh
@@ -21,8 +21,8 @@
 # Run this on the master nde
 
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 # Load the Spark configuration
 . "$sbin/spark-config.sh"
diff --git a/sbin/stop-history-server.sh b/sbin/stop-history-server.sh
index c0034ad641..6e60563595 100755
--- a/sbin/stop-history-server.sh
+++ b/sbin/stop-history-server.sh
@@ -19,7 +19,7 @@
 
 # Stops the history server on the machine this script is executed on.
 
-sbin=`dirname "$0"`
-sbin=`cd "$sbin"; pwd`
+sbin="`dirname "$0"`"
+sbin="`cd "$sbin"; pwd`"
 
 "$sbin"/spark-daemon.sh stop org.apache.spark.deploy.history.HistoryServer 1
diff --git a/sbt/sbt b/sbt/sbt
index 1b1aa1483a..c172fa74bc 100755
--- a/sbt/sbt
+++ b/sbt/sbt
@@ -3,32 +3,32 @@
 # When creating new tests for Spark SQL Hive, the HADOOP_CLASSPATH must contain the hive jars so
 # that we can run Hive to generate the golden answer.  This is not required for normal development
 # or testing.
-for i in $HIVE_HOME/lib/*
-do HADOOP_CLASSPATH=$HADOOP_CLASSPATH:$i
+for i in "$HIVE_HOME"/lib/*
+do HADOOP_CLASSPATH="$HADOOP_CLASSPATH:$i"
 done
 export HADOOP_CLASSPATH
 
 realpath () {
 (
-  TARGET_FILE=$1
+  TARGET_FILE="$1"
 
-  cd $(dirname $TARGET_FILE)
-  TARGET_FILE=$(basename $TARGET_FILE)
+  cd "$(dirname "$TARGET_FILE")"
+  TARGET_FILE="$(basename "$TARGET_FILE")"
 
   COUNT=0
   while [ -L "$TARGET_FILE" -a $COUNT -lt 100 ]
   do
-      TARGET_FILE=$(readlink $TARGET_FILE)
-      cd $(dirname $TARGET_FILE)
-      TARGET_FILE=$(basename $TARGET_FILE)
+      TARGET_FILE="$(readlink "$TARGET_FILE")"
+      cd $(dirname "$TARGET_FILE")
+      TARGET_FILE="$(basename $TARGET_FILE)"
       COUNT=$(($COUNT + 1))
   done
 
-  echo $(pwd -P)/$TARGET_FILE
+  echo "$(pwd -P)/"$TARGET_FILE""
 )
 }
 
-. $(dirname $(realpath $0))/sbt-launch-lib.bash
+. "$(dirname "$(realpath "$0")")"/sbt-launch-lib.bash
 
 
 declare -r noshare_opts="-Dsbt.global.base=project/.sbtboot -Dsbt.boot.directory=project/.boot -Dsbt.ivy.home=project/.ivy"
diff --git a/sbt/sbt-launch-lib.bash b/sbt/sbt-launch-lib.bash
index fecc3d38a5..7f05d2ef49 100755
--- a/sbt/sbt-launch-lib.bash
+++ b/sbt/sbt-launch-lib.bash
@@ -7,7 +7,7 @@
 # TODO - Should we merge the main SBT script with this library?
 
 if test -z "$HOME"; then
-  declare -r script_dir="$(dirname $script_path)"
+  declare -r script_dir="$(dirname "$script_path")"
 else
   declare -r script_dir="$HOME/.sbt"
 fi
@@ -46,20 +46,20 @@ acquire_sbt_jar () {
 
   if [[ ! -f "$sbt_jar" ]]; then
     # Download sbt launch jar if it hasn't been downloaded yet
-    if [ ! -f ${JAR} ]; then
+    if [ ! -f "${JAR}" ]; then
     # Download
     printf "Attempting to fetch sbt\n"
-    JAR_DL=${JAR}.part
+    JAR_DL="${JAR}.part"
     if hash curl 2>/dev/null; then
-      (curl --silent ${URL1} > ${JAR_DL} || curl --silent ${URL2} > ${JAR_DL}) && mv ${JAR_DL} ${JAR}
+      (curl --silent ${URL1} > "${JAR_DL}" || curl --silent ${URL2} > "${JAR_DL}") && mv "${JAR_DL}" "${JAR}"
     elif hash wget 2>/dev/null; then
-      (wget --quiet ${URL1} -O ${JAR_DL} || wget --quiet ${URL2} -O ${JAR_DL}) && mv ${JAR_DL} ${JAR}
+      (wget --quiet ${URL1} -O "${JAR_DL}" || wget --quiet ${URL2} -O "${JAR_DL}") && mv "${JAR_DL}" "${JAR}"
     else
       printf "You do not have curl or wget installed, please install sbt manually from http://www.scala-sbt.org/\n"
       exit -1
     fi
     fi
-    if [ ! -f ${JAR} ]; then
+    if [ ! -f "${JAR}" ]; then
     # We failed to download
     printf "Our attempt to download sbt locally to ${JAR} failed. Please install sbt manually from http://www.scala-sbt.org/\n"
     exit -1