diff --git a/mod_for_factory_scripts/200patchInitScript b/mod_for_factory_scripts/200patchInitScript
index 312deb4578..017523fe49 100755
--- a/mod_for_factory_scripts/200patchInitScript
+++ b/mod_for_factory_scripts/200patchInitScript
@@ -6,8 +6,8 @@
 
 echo "Applying patch to init scripts."
 
-touch ${ROOT_FS_DIR}/root/.factory_test
-patch -d ${ROOT_FS_DIR} -Np1 <<EOF
+touch "${ROOT_FS_DIR}/root/.factory_test"
+patch -d "${ROOT_FS_DIR}" -Np1 <<EOF
 --- old/etc/init/ui.conf	2010-04-28 21:28:38.886069000 -0700
 +++ new/etc/init/ui.conf	2010-04-28 21:29:42.676163000 -0700
 @@ -5,7 +5,7 @@
@@ -21,7 +21,7 @@ patch -d ${ROOT_FS_DIR} -Np1 <<EOF
  respawn
 EOF
 
-patch -d ${ROOT_FS_DIR} -Np1 <<EOF
+patch -d "${ROOT_FS_DIR}" -Np1 <<EOF
 diff -Naur old/etc/init/boot-complete.conf new/etc/init/boot-complete.conf
 --- old/etc/init/boot-complete.conf	2010-07-21 11:22:30.000000000 +0800
 +++ new/etc/init/boot-complete.conf	2010-07-21 22:13:36.000000000 +0800
@@ -35,7 +35,7 @@ diff -Naur old/etc/init/boot-complete.conf new/etc/init/boot-complete.conf
  task
 EOF
 
-cat > ${ROOT_FS_DIR}/etc/init/factory.conf <<EOF
+cat >"${ROOT_FS_DIR}/etc/init/factory.conf" <<EOF
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -49,18 +49,18 @@ stop on starting halt or starting reboot
 script
 cd /usr/local/autotest
 eval \$(./site_tests/suite_Factory/startx.sh)
-date >> /var/log/factory.log
+date >>/var/log/factory.log
 if [ ! -e factory_started ]; then
   touch factory_started
   cp -f site_tests/suite_Factory/control .
-  ./bin/autotest control >> /var/log/factory.log 2>&1
+  ./bin/autotest control >>/var/log/factory.log 2>&1
 else
-  ./tools/autotest >> /var/log/factory.log 2>&1
+  ./tools/autotest >>/var/log/factory.log 2>&1
 fi
 end script
 EOF
 
-cat > ${ROOT_FS_DIR}/etc/init/factorylog.conf <<EOF
+cat >"${ROOT_FS_DIR}/etc/init/factorylog.conf" <<EOF
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -70,11 +70,11 @@ stop on starting halt or starting reboot
 
 respawn
 script
-tail -n 48 -F /var/log/factory.log > /dev/tty3
+tail -n 48 -F /var/log/factory.log >/dev/tty3
 end script
 EOF
 
-patch -d ${ROOT_FS_DIR} -Np1 <<EOF
+patch -d "${ROOT_FS_DIR}" -Np1 <<EOF
 diff -Nau old/etc/init/chrontel.conf new/etc/init/
 --- old/etc/init/chrontel.conf	2010-08-05 16:32:55.000000000 -0700
 +++ new/etc/init/chrontel.conf	2010-08-05 16:32:45.000000000 -0700
diff --git a/mod_for_factory_scripts/300modifyDescription b/mod_for_factory_scripts/300modifyDescription
index 3937268341..5196142dee 100755
--- a/mod_for_factory_scripts/300modifyDescription
+++ b/mod_for_factory_scripts/300modifyDescription
@@ -6,4 +6,4 @@
 
 echo "Modifying Release Description for Factory."
 FILE="${ROOT_FS_DIR}/etc/lsb-release"
-sed -i 's/Test/Factory/' $FILE
+sed -i 's/Test/Factory/' "${FILE}"
diff --git a/mod_for_factory_scripts/500populateQualDbs b/mod_for_factory_scripts/500populateQualDbs
index fff9a05642..e6bbb2f0ca 100755
--- a/mod_for_factory_scripts/500populateQualDbs
+++ b/mod_for_factory_scripts/500populateQualDbs
@@ -6,16 +6,18 @@
 
 TEST_DIR="${ROOT_FS_DIR}/usr/local/autotest/site_tests/hardware_Components"
 
-pushd ${TEST_DIR} 1> /dev/null
+if [ -d "${TEST_DIR}" ]; then
+  pushd "${TEST_DIR}" >/dev/null
 
-# Remove the DB directories belonging to other boards.
-KEEPDB="data_${BOARD}"
-ls -d data_* 2> /dev/null | grep -v ${KEEPDB} | xargs rm -fr
+  # Remove the DB directories belonging to other boards.
+  KEEPDB="data_${BOARD}"
+  ls -d data_* 2>/dev/null | grep -v "${KEEPDB}" | xargs rm -fr
 
-# Ensure there is DB directory in x86-agz and x86-mario.
-if [ ! -d ${KEEPDB} -a \
-    \( "${BOARD}" = "x86-agz" -o "${BOARD}" = "x86-mario" \) ]; then
-  echo "No component DB directory found at: ${KEEPDB}"
+  # Ensure there is DB directory in x86-agz and x86-mario.
+  if [ ! -d "${KEEPDB}" ] &&
+     [ "${BOARD}" = "x86-agz" -o "{BOARD}" = "x86-mario" ]; then
+    echo "No component DB directory found at: ${KEEPDB}"
+  fi
+
+  popd >/dev/null
 fi
-
-popd 1> /dev/null
diff --git a/mod_for_factory_scripts/600customizeRelease b/mod_for_factory_scripts/600customizeRelease
index 4975f2d147..0c8dd21a76 100755
--- a/mod_for_factory_scripts/600customizeRelease
+++ b/mod_for_factory_scripts/600customizeRelease
@@ -6,17 +6,19 @@
 
 TEST_DIR="${ROOT_FS_DIR}/usr/local/autotest/site_tests/suite_Factory"
 
-pushd ${TEST_DIR} 1> /dev/null
+if [ -d "${TEST_DIR}" ]; then
+  pushd "${TEST_DIR}" >/dev/null
 
-# If there is a customize_$BOARD script for this board, let's run it.
-# This allows adding settings for specific factories or systems.
-CUSTOMIZE="customize_${BOARD}"
-if [ -e "${CUSTOMIZE}" ]; then
-  echo "Running ${CUSTOMIZE}"
-  "./${CUSTOMIZE}"
+  # If there is a customize_$BOARD script for this board, let's run it.
+  # This allows adding settings for specific factories or systems.
+  CUSTOMIZE="customize_${BOARD}"
+  if [ -e "${CUSTOMIZE}" ]; then
+    echo "Running ${CUSTOMIZE}"
+    "./${CUSTOMIZE}"
+  fi
+
+  # We don't need the customize script anymore.
+  rm -f customize_*
+
+  popd >/dev/null
 fi
-
-# We don't need the customize script anymore.
-rm -f customize_*
-
-popd 1> /dev/null