diff --git a/_scripts/sh/create_pages.sh b/_scripts/sh/create_pages.sh
index 12e8068..248ae77 100755
--- a/_scripts/sh/create_pages.sh
+++ b/_scripts/sh/create_pages.sh
@@ -20,15 +20,15 @@ tag_count=0
 
 
 _read_yaml() {
-  local _endline=$(grep -n "\-\-\-" $1 | cut -d: -f 1 | sed -n '2p')
-  head -$_endline $1
+  local _endline="$(grep -n "\-\-\-" "$1" | cut -d: -f 1 | sed -n '2p')"
+  head -"$_endline" "$1"
 }
 
 
 read_categories() {
-  local _yaml=$(_read_yaml $1)
-  local _categories=$(echo "$_yaml" | grep "^categories:")
-  local _category=$(echo "$_yaml" | grep "^category:")
+  local _yaml="$(_read_yaml "$1")"
+  local _categories="$(echo "$_yaml" | grep "^categories:")"
+  local _category="$(echo "$_yaml" | grep "^category:")"
 
   if [[ ! -z "$_categories" ]]; then
     echo "$_categories" | sed "s/categories: *//;s/\[//;s/\].*//;s/, */,/g;s/\"//g;s/'//g"
@@ -39,7 +39,7 @@ read_categories() {
 
 
 read_tags() {
-  local _yaml=$(_read_yaml $1)
+  local _yaml="$(_read_yaml "$1")"
   echo "$_yaml" | grep "^tags:" | sed "s/tags: *//;s/\[//;s/\].*//;s/, */,/g;s/\"//g;s/'//g"
 }
 
@@ -65,14 +65,14 @@ init() {
 create_category() {
   if [[ ! -z $1 ]]; then
     local _name=$1
-    local _filepath="categories/$(echo $_name | sed 's/ /-/g' | awk '{print tolower($0)}').html"
+    local _filepath="categories/$(echo "$_name" | sed 's/ /-/g' | awk '{print tolower($0)}').html"
 
-    if [[ ! -f $_filepath ]]; then
-      echo "---" > $_filepath
-      echo "layout: category" >> $_filepath
-      echo "title: $_name" >> $_filepath
-      echo "category: $_name" >> $_filepath
-      echo "---" >> $_filepath
+    if [[ ! -f "$_filepath" ]]; then
+      echo "---" > "$_filepath"
+      echo "layout: category" >> "$_filepath"
+      echo "title: $_name" >> "$_filepath"
+      echo "category: $_name" >> "$_filepath"
+      echo "---" >> "$_filepath"
 
       ((category_count=category_count+1))
     fi
@@ -83,15 +83,15 @@ create_category() {
 create_tag() {
   if [[ ! -z $1 ]]; then
     local _name=$1
-    local _filepath="tags/$( echo $_name | sed "s/ /-/g;s/'//g" | awk '{print tolower($0)}' ).html"
+    local _filepath="tags/$( echo "$_name" | sed "s/ /-/g;s/'//g" | awk '{print tolower($0)}' ).html"
 
-    if [[ ! -f $_filepath ]]; then
+    if [[ ! -f "$_filepath" ]]; then
 
-      echo "---" > $_filepath
-      echo "layout: tag" >> $_filepath
-      echo "title: $_name" >> $_filepath
-      echo "tag: $_name" >> $_filepath
-      echo "---" >> $_filepath
+      echo "---" > "$_filepath"
+      echo "layout: tag" >> "$_filepath"
+      echo "title: $_name" >> "$_filepath"
+      echo "tag: $_name" >> "$_filepath"
+      echo "---" >> "$_filepath"
 
       ((tag_count=tag_count+1))
     fi
@@ -116,13 +116,13 @@ create_pages() {
 
       $TYPE_CATEGORY)
         for i in ${_string#,}; do
-          create_category $i
+          create_category "$i"
         done
         ;;
 
       $TYPE_TAG)
         for i in ${_string#,}; do
-          create_tag $i
+          create_tag "$i"
         done
         ;;
 
diff --git a/_scripts/sh/dump_lastmod.sh b/_scripts/sh/dump_lastmod.sh
index ceb8ba5..235adac 100755
--- a/_scripts/sh/dump_lastmod.sh
+++ b/_scripts/sh/dump_lastmod.sh
@@ -35,8 +35,8 @@ _init() {
 
 
 _has_changed() {
-  local _log_count=`git log --pretty=%ad $1 | wc -l | sed 's/ *//'`
-  _log_count=$(($_log_count + 0))
+  local _log_count="$(git log --pretty=%ad "$1" | wc -l | sed 's/ *//')"
+  _log_count=$((_log_count + 0))
 
   if [[ $_log_count > 1 ]]; then
     return 0 # true
@@ -56,7 +56,7 @@ _has_changed() {
 #     the file '_data/updates.yml'
 ###################################
 _dump() {
-  local _lasmod="`git log -1 --pretty=%ad --date=iso $2`"
+  local _lasmod="$(git log -1 --pretty=%ad --date=iso "$2")"
 
   if [[ ! -f "$OUTPUT_DIR/$OUTPUT_FILE" ]]; then
     touch "$OUTPUT_DIR/$OUTPUT_FILE"
@@ -76,7 +76,7 @@ main() {
 
   for _file in $(find ${POST_DIR} -type f \( -iname \*.md -o -iname \*.markdown \))
   do
-    _filename=$(basename $_file | sed 's/-\-\+/-/;s/[[:digit:]]\([[:digit:]]*-\)//g;s/\..*//' ) # remove date and extension
+    _filename="$(basename "$_file" | sed 's/-\-\+/-/;s/[[:digit:]]\([[:digit:]]*-\)//g;s/\..*//' )" # remove date and extension
 
     if _has_changed "$_file"; then
       _dump "$_filename" "$_file"
diff --git a/_scripts/sh/sync_monitor.sh b/_scripts/sh/sync_monitor.sh
index fd7840e..fa74896 100644
--- a/_scripts/sh/sync_monitor.sh
+++ b/_scripts/sh/sync_monitor.sh
@@ -11,28 +11,28 @@
 # $3 -> the destination sync directory
 
 # Omit the system temp file
-if [[ ! -f $1 ]]; then
+if [[ ! -f "$1" ]]; then
   exit 0
 fi
 
-src_dir=`dirname $(realpath $1)`
+src_dir="$(dirname $(realpath "$1"))"
 
-dir_prefix="$(realpath $2)/"
+dir_prefix="$(realpath "$2")/"
 
 related_dir="${src_dir:${#dir_prefix}}"
 
 
-dest="$(realpath $3)/${related_dir}"
+dest="$(realpath "$3")/${related_dir}"
 
 if [[ ! -d "$dest" ]]; then
   mkdir -p "$dest"
 fi
 
 if [[ -f "$1" ]]; then
-  cp $1 $dest
+  cp "$1" "$dest"
 fi
 
-if [[ $related_dir == "_posts" ]]; then
-  bash $3/_scripts/sh/create_pages.sh
-  bash $3/_scripts/sh/dump_lastmod.sh
+if [[ "$related_dir" == "_posts" ]]; then
+  bash "$3"/_scripts/sh/create_pages.sh
+  bash "$3"/_scripts/sh/dump_lastmod.sh
 fi
diff --git a/tools/build.sh b/tools/build.sh
index d99b67f..db9ff0c 100755
--- a/tools/build.sh
+++ b/tools/build.sh
@@ -10,11 +10,11 @@ set -eu
 
 CMD="JEKYLL_ENV=production bundle exec jekyll b"
 
-WORK_DIR=$(dirname $(dirname $(realpath "$0")))
+WORK_DIR="$(dirname $(dirname $(realpath "$0")))"
 
-CONTAINER=${WORK_DIR}/.container
+CONTAINER="${WORK_DIR}/.container"
 
-DEST=${WORK_DIR}/_site
+DEST="${WORK_DIR}/_site"
 
 
 _help() {
@@ -30,44 +30,44 @@ _help() {
 
 
 _init() {
-  cd $WORK_DIR
+  cd "$WORK_DIR"
 
-  if [[ -d $CONTAINER ]]; then
-    rm -rf $CONTAINER
+  if [[ -d "$CONTAINER" ]]; then
+    rm -rf "$CONTAINER"
   fi
 
-  if [[ -d _site ]]; then
+  if [[ -d "_site" ]]; then
     jekyll clean
   fi
 
-  local _temp=$(mktemp -d)
-  cp -r * $_temp
-  cp -r .git $_temp
-  mv $_temp $CONTAINER
+  local _temp="$(mktemp -d)"
+  cp -r ./* "$_temp"
+  cp -r ./.git "$_temp"
+  mv "$_temp" "$CONTAINER"
 }
 
 
 _build() {
-  cd $CONTAINER
+  cd "$CONTAINER"
   echo "$ cd $(pwd)"
 
-  bash _scripts/sh/create_pages.sh
-  bash _scripts/sh/dump_lastmod.sh
+  bash "_scripts/sh/create_pages.sh"
+  bash "_scripts/sh/dump_lastmod.sh"
 
-  CMD+=" -d ${DEST}"
+  CMD+=" -d $DEST"
   echo "\$ $CMD"
-  eval $CMD
+  eval "$CMD"
   echo -e "\nBuild success, the site files have been placed in '${DEST}'."
 
-  if [[ -d ${DEST}/.git ]]; then
-    if [[ ! -z $(git -C $DEST status -s) ]]; then
-      git -C $DEST add .
-      git -C $DEST commit -m "[Automation] Update site files." -q
+  if [[ -d "${DEST}/.git" ]]; then
+    if [[ ! -z $(git -C "$DEST" status -s) ]]; then
+      git -C "$DEST" add .
+      git -C "$DEST" commit -m "[Automation] Update site files." -q
       echo -e "\nPlease push the changes of $DEST to remote master branch.\n"
     fi
   fi
 
-  cd .. && rm -rf $CONTAINER
+  cd .. && rm -rf "$CONTAINER"
 }
 
 
@@ -95,8 +95,8 @@ main() {
         shift
         ;;
       -d|--destination)
-        _check_unset $2
-        DEST=$(realpath $2)
+        _check_unset "$2"
+        DEST="$(realpath "$2")"
         shift;
         shift;
         ;;
diff --git a/tools/deploy.sh b/tools/deploy.sh
index 66580d3..f3aebfd 100755
--- a/tools/deploy.sh
+++ b/tools/deploy.sh
@@ -14,17 +14,18 @@ PAGES_BRANCH="gh-pages"
 
 _no_branch=false
 
-if [[ -z `git branch -av | grep $PAGES_BRANCH` ]]; then
+if [[ -z $(git branch -av | grep "$PAGES_BRANCH") ]]; then
   _no_branch=true
-  git checkout -b $PAGES_BRANCH
+  git checkout -b "$PAGES_BRANCH"
 else
-  git checkout $PAGES_BRANCH
+  git checkout "$PAGES_BRANCH"
 fi
 
 mv _site ../
 mv .git ../
 
-rm -rf * && rm -rf .[^.] .??*
+rm -rf ./*
+rm -rf .[^.] .??*
 
 mv ../_site/* .
 mv ../.git .
diff --git a/tools/publish.sh b/tools/publish.sh
index a794f75..755d0ae 100755
--- a/tools/publish.sh
+++ b/tools/publish.sh
@@ -13,12 +13,12 @@ CATEGORIES=false
 TAGS=false
 LASTMOD=false
 
-WORK_DIR=$(dirname $(dirname $(realpath "$0")))
+WORK_DIR="$(dirname $(dirname $(realpath "$0")))"
 
 check_status() {
   local _change=$(git status . -s)
 
-  if [[ ! -z ${_change} ]]; then
+  if [[ ! -z $_change ]]; then
     echo "Warning: Commit the following changes first:"
     echo "$_change"
     exit 1
@@ -81,7 +81,7 @@ push() {
 
 main() {
 
-  cd $WORK_DIR
+  cd "$WORK_DIR"
 
   check_status
 
diff --git a/tools/pv.sh b/tools/pv.sh
index cd45992..19a9b92 100755
--- a/tools/pv.sh
+++ b/tools/pv.sh
@@ -15,12 +15,12 @@
 
 set -eu
 
-WORK_DIR=$(dirname $(dirname $(realpath "$0")))
-URL_FILE=${WORK_DIR}/_config.yml
-PV_CACHE=${WORK_DIR}/assets/js/data/pageviews.json
+WORK_DIR="$(dirname $(dirname $(realpath "$0")))"
+URL_FILE="${WORK_DIR}/_config.yml"
+PV_CACHE="${WORK_DIR}/assets/js/data/pageviews.json"
 
-PROXY_URL=$(grep "proxy_endpoint:" $URL_FILE | sed "s/.*: '//g;s/'.*//")
+PROXY_URL="$(grep "proxy_endpoint:" "$URL_FILE" | sed "s/.*: '//g;s/'.*//")"
 
-wget $PROXY_URL -O $PV_CACHE
+wget "$PROXY_URL" -O "$PV_CACHE"
 
 echo "ls $PV_CACHE"
\ No newline at end of file
diff --git a/tools/run.sh b/tools/run.sh
index 339ea7e..24896ad 100755
--- a/tools/run.sh
+++ b/tools/run.sh
@@ -41,21 +41,21 @@ _cleanup() {
     jekyll clean
   fi
 
-  rm -rf ${WORK_DIR}/${CONTAINER}
+  rm -rf "${WORK_DIR}/${CONTAINER}"
   ps aux | grep fswatch | awk '{print $2}' | xargs kill -9 > /dev/null 2>&1
 }
 
 
 _init() {
 
-  if [[ -d ${WORK_DIR}/${CONTAINER} ]]; then
-    rm -rf ${WORK_DIR}/${CONTAINER}
+  if [[ -d "${WORK_DIR}/${CONTAINER}" ]]; then
+    rm -rf "${WORK_DIR}/${CONTAINER}"
   fi
 
-  temp=$(mktemp -d)
-  cp -r ${WORK_DIR}/* $temp
-  cp -r ${WORK_DIR}/.git $temp
-  mv $temp ${WORK_DIR}/${CONTAINER}
+  temp="$(mktemp -d)"
+  cp -r "$WORK_DIR"/* "$temp"
+  cp -r "${WORK_DIR}/.git" "$temp"
+  mv "$temp" "${WORK_DIR}/${CONTAINER}"
 
   trap _cleanup INT
 }
@@ -70,7 +70,7 @@ _check_unset() {
 
 
 _check_command() {
-  if [[ -z $(command -v $1) ]]; then
+  if [[ -z $(command -v "$1") ]]; then
     echo "Error: command '$1' not found !"
     echo "Hint: Get '$1' on <$2>"
     exit 1
@@ -81,16 +81,16 @@ _check_command() {
 main() {
   _init
 
-  cd ${WORK_DIR}/${CONTAINER}
+  cd "${WORK_DIR}/${CONTAINER}"
   bash _scripts/sh/create_pages.sh
   bash _scripts/sh/dump_lastmod.sh
 
   if [[ $realtime = true ]]; then
-    fswatch -0 -e "\\$CONTAINER" -e "\.git" ${WORK_DIR} | xargs -0 -I {} bash ./${SYNC_TOOL} {} $WORK_DIR . &
+    fswatch -0 -e "\\$CONTAINER" -e "\.git" "$WORK_DIR" | xargs -0 -I {} bash "./${SYNC_TOOL}" {} "$WORK_DIR" . &
   fi
 
   echo "\$ $cmd"
-  eval $cmd
+  eval "$cmd"
 }
 
 
@@ -99,20 +99,20 @@ do
   opt="$1"
   case $opt in
     -H|--host)
-      _check_unset $2
+      _check_unset "$2"
       cmd+=" -H $2"
       shift # past argument
       shift # past value
       ;;
     -P|--port)
-      _check_unset $2
+      _check_unset "$2"
       cmd+=" -P $2"
       shift
       shift
       ;;
     -b|--baseurl)
-      _check_unset $2
-      if [[ $2 == \/* ]]
+      _check_unset "$2"
+      if [[ "$2" == \/* ]]
       then
         cmd+=" -b $2"
       else
@@ -127,7 +127,7 @@ do
       shift
       ;;
     -r|--realtime)
-      _check_command fswatch 'http://emcrisostomo.github.io/fswatch/'
+      _check_command fswatch "http://emcrisostomo.github.io/fswatch/"
       realtime=true
       shift
       ;;