From 68b6d2ead05ee66a6d548e008c77a135cbb9cdad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20R=C3=BCger?= <manuel@rueg.eu>
Date: Wed, 24 Jun 2020 02:15:20 +0200
Subject: [PATCH] Shellcheck fixes 3 (#2054)

* lib/general.sh: Lint via shellcheck

* lib/compilation-prepare.sh: Lint via shellcheck
---
 lib/compilation-prepare.sh | 279 ++++++++++++++--------------
 lib/general.sh             | 365 +++++++++++++++++++------------------
 2 files changed, 329 insertions(+), 315 deletions(-)

diff --git a/lib/compilation-prepare.sh b/lib/compilation-prepare.sh
index bdb4522040..8650bd4090 100644
--- a/lib/compilation-prepare.sh
+++ b/lib/compilation-prepare.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+#
 # Copyright (c) 2015 Igor Pecovnik, igor.pecovnik@gma**.com
 #
 # This file is licensed under the terms of the GNU General Public
@@ -18,54 +20,54 @@ compilation_prepare()
 	# Maintaining one from central location starting with 5.3+
 	# Temporally set for new "default->legacy,next->current" family naming
 
-	if linux-version compare $version ge 5.6; then
+	if linux-version compare "${version}" ge 5.6; then
 		display_alert "Adjusting" "packaging" "info"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 		process_patch_file "${SRC}/patch/misc/general-packaging-5.6.y.patch" "applying"
 	else
-		if linux-version compare $version ge 5.3; then
+		if linux-version compare "${version}" ge 5.3; then
 			display_alert "Adjusting" "packaging" "info"
-			cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+			cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 			process_patch_file "${SRC}/patch/misc/general-packaging-5.3.y.patch" "applying"
 		fi
 	fi
 
-	if [[ $version == "4.19."* ]] && [[ "$LINUXFAMILY" == sunxi* || "$LINUXFAMILY" == meson64 || \
+	if [[ "${version}" == "4.19."* ]] && [[ "$LINUXFAMILY" == sunxi* || "$LINUXFAMILY" == meson64 || \
 	"$LINUXFAMILY" == mvebu64 || "$LINUXFAMILY" == mt7623 || "$LINUXFAMILY" == mvebu ]]; then
 		display_alert "Adjustin" "packaging" "info"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 		process_patch_file "${SRC}/patch/misc/general-packaging-4.19.y.patch" "applying"
 	fi
 
-	if [[ $version == "4.14."* ]] && [[ "$LINUXFAMILY" == s5p6818 || "$LINUXFAMILY" == mvebu64 || \
+	if [[ "${version}" == "4.14."* ]] && [[ "$LINUXFAMILY" == s5p6818 || "$LINUXFAMILY" == mvebu64 || \
 	"$LINUXFAMILY" == imx7d || "$LINUXFAMILY" == odroidxu4 || "$LINUXFAMILY" == mvebu ]]; then
 		display_alert "Adjustin" "packaging" "info"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 		process_patch_file "${SRC}/patch/misc/general-packaging-4.14.y.patch" "applying"
 	fi
 
-	if [[ $version == "4.4."* || $version == "4.9."* ]] && \
+	if [[ "${version}" == "4.4."* || "${version}" == "4.9."* ]] && \
 	[[ "$LINUXFAMILY" == rockpis || "$LINUXFAMILY" == rk3399 ]]; then
 		display_alert "Adjustin" "packaging" "info"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 		process_patch_file "${SRC}/patch/misc/general-packaging-4.4.y-rk3399.patch" "applying"
 	fi
 
-	if [[ $version == "4.4."* ]] && [[ "$LINUXFAMILY" == rockchip64 ]]; then
+	if [[ "${version}" == "4.4."* ]] && [[ "$LINUXFAMILY" == rockchip64 ]]; then
 		display_alert "Adjustin" "packaging" "info"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 		process_patch_file "${SRC}/patch/misc/general-packaging-4.4.y-rockchip64.patch" "applying"
 	fi
 
-	if [[ $version == "4.4."* ]] && [[ "$LINUXFAMILY" == rockchip || "$LINUXFAMILY" == rk322x ]]; then
+	if [[ "${version}" == "4.4."* ]] && [[ "$LINUXFAMILY" == rockchip || "$LINUXFAMILY" == rk322x ]]; then
                 display_alert "Adjustin" "packaging" "info"
-                cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+                cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
                 process_patch_file "${SRC}/patch/misc/general-packaging-4.4.y.patch" "applying"
         fi
 
-	if [[ $version == "4.9."* ]] && [[ "$LINUXFAMILY" == meson64 || "$LINUXFAMILY" == odroidc4 ]]; then
+	if [[ "${version}" == "4.9."* ]] && [[ "$LINUXFAMILY" == meson64 || "$LINUXFAMILY" == odroidc4 ]]; then
 		display_alert "Adjustin" "packaging" "info"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 		process_patch_file "${SRC}/patch/misc/general-packaging-4.9.y.patch" "applying"
 	fi
 
@@ -73,7 +75,7 @@ compilation_prepare()
 	# mac80211 wireless driver injection features from Kali Linux
 	#
 
-	if linux-version compare $version ge 5.4; then
+	if linux-version compare "${version}" ge 5.4; then
 
 		display_alert "Adding" "Wireless package injections for mac80211 compatible chipsets" "info"
 		process_patch_file "${SRC}/patch/misc/kali-wifi-injection-1.patch" "applying"
@@ -85,21 +87,22 @@ compilation_prepare()
 	#
 	# Older versions have AUFS support with a patch
 
-	if linux-version compare $version ge 5.1 && linux-version compare $version le 5.8 && [ "$AUFS" == yes ]; then
+	if linux-version compare "${version}" ge 5.1 && linux-version compare "${version}" le 5.8 && [ "$AUFS" == yes ]; then
 
 		# attach to specifics tag or branch
-		local aufstag=$(echo ${version} | cut -f 1-2 -d ".")
+		local aufstag
+		aufstag=$(echo "${version}" | cut -f 1-2 -d ".")
 
 		# manual overrides
-		if linux-version compare $version ge 5.4.3 && linux-version compare $version le 5.5 ; then aufstag="5.4.3"; fi
+		if linux-version compare "${version}" ge 5.4.3 && linux-version compare "${version}" le 5.5 ; then aufstag="5.4.3"; fi
 
 		# check if Mr. Okajima already made a branch for this version
-		git ls-remote --exit-code --heads https://github.com/sfjro/aufs5-standalone aufs${aufstag} >/dev/null
+		git ls-remote --exit-code --heads https://github.com/sfjro/aufs5-standalone "aufs${aufstag}" >/dev/null
 
 		if [ "$?" -ne "0" ]; then
 			# then use rc branch
 			aufstag="5.x-rcN"
-			git ls-remote --exit-code --heads https://github.com/sfjro/aufs5-standalone aufs${aufstag} >/dev/null
+			git ls-remote --exit-code --heads https://github.com/sfjro/aufs5-standalone "aufs${aufstag}" >/dev/null
 		fi
 
 		if [ "$?" -eq "0" ]; then
@@ -107,13 +110,13 @@ compilation_prepare()
 			display_alert "Adding" "AUFS ${aufstag}" "info"
 			local aufsver="branch:aufs${aufstag}"
 			fetch_from_repo "https://github.com/sfjro/aufs5-standalone" "aufs5" "branch:${aufsver}" "yes"
-			cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
+			cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
 			process_patch_file "${SRC}/cache/sources/aufs5/${aufsver#*:}/aufs5-kbuild.patch" "applying"
 			process_patch_file "${SRC}/cache/sources/aufs5/${aufsver#*:}/aufs5-base.patch" "applying"
 			process_patch_file "${SRC}/cache/sources/aufs5/${aufsver#*:}/aufs5-mmap.patch" "applying"
 			process_patch_file "${SRC}/cache/sources/aufs5/${aufsver#*:}/aufs5-standalone.patch" "applying"
-			cp -R ${SRC}/cache/sources/aufs5/${aufsver#*:}/{Documentation,fs} .
-			cp ${SRC}/cache/sources/aufs5/${aufsver#*:}/include/uapi/linux/aufs_type.h include/uapi/linux/
+			cp -R "${SRC}/cache/sources/aufs5/${aufsver#*:}"/{Documentation,fs} .
+			cp "${SRC}/cache/sources/aufs5/${aufsver#*:}"/include/uapi/linux/aufs_type.h include/uapi/linux/
 
 		fi
 	fi
@@ -122,7 +125,7 @@ compilation_prepare()
 
 
 	# WireGuard VPN for Linux 3.10 - 5.5
-	if linux-version compare $version ge 3.10 && linux-version compare $version le 5.5 && [ "${WIREGUARD}" == yes ]; then
+	if linux-version compare "${version}" ge 3.10 && linux-version compare "${version}" le 5.5 && [ "${WIREGUARD}" == yes ]; then
 
 		# attach to specifics tag or branch
 		local wirever="branch:master"
@@ -130,23 +133,23 @@ compilation_prepare()
 		display_alert "Adding" "WireGuard VPN for Linux 3.10 - 5.5 ${wirever} " "info"
 		fetch_from_repo "https://git.zx2c4.com/wireguard-linux-compat" "wireguard" "${wirever}" "yes"
 
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/net/wireguard
-		cp -R ${SRC}/cache/sources/wireguard/${wirever#*:}/src/ ${SRC}/cache/sources/${LINUXSOURCEDIR}/net/wireguard
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/net/wireguard"
+		cp -R "${SRC}/cache/sources/wireguard/${wirever#*:}/src/" "${SRC}/cache/sources/${LINUXSOURCEDIR}/net/wireguard"
 		sed -i "/^obj-\\\$(CONFIG_NETFILTER).*+=/a obj-\$(CONFIG_WIREGUARD) += wireguard/" \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Makefile
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Makefile"
 		sed -i "/^if INET\$/a source \"net/wireguard/Kconfig\"" \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Kconfig"
 		# remove duplicates
-		[[ $(cat ${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Makefile | grep wireguard | wc -l) -gt 1 ]] && \
-		sed -i '0,/wireguard/{/wireguard/d;}' ${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Makefile
-		[[ $(cat ${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Kconfig | grep wireguard | wc -l) -gt 1 ]] && \
-		sed -i '0,/wireguard/{/wireguard/d;}' ${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Kconfig
+		[[ $(grep -c wireguard "${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Makefile") -gt 1 ]] && \
+		sed -i '0,/wireguard/{/wireguard/d;}' "${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Makefile"
+		[[ $(grep -c wireguard "${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Kconfig") -gt 1 ]] && \
+		sed -i '0,/wireguard/{/wireguard/d;}' "${SRC}/cache/sources/${LINUXSOURCEDIR}/net/Kconfig"
 		# headers workaround
 		display_alert "Patching WireGuard" "Applying workaround for headers compilation" "info"
 		sed -i '/mkdir -p "$destdir"/a mkdir -p "$destdir"/net/wireguard; \
 		touch "$destdir"/net/wireguard/{Kconfig,Makefile} # workaround for Wireguard' \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/scripts/package/builddeb
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/scripts/package/builddeb"
 
 	fi
 
@@ -155,7 +158,7 @@ compilation_prepare()
 
 	# Wireless drivers for Realtek 8189ES chipsets
 
-	if linux-version compare $version ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
+	if linux-version compare "${version}" ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
 
 		# attach to specifics tag or branch
 		local rtl8189esver="branch:master"
@@ -163,22 +166,22 @@ compilation_prepare()
 		display_alert "Adding" "Wireless drivers for Realtek 8189ES chipsets ${rtl8189esver}" "info"
 
 		fetch_from_repo "https://github.com/jwrdegoede/rtl8189ES_linux" "rtl8189es" "${rtl8189esver}" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es/
-		cp -R ${SRC}/cache/sources/rtl8189es/${rtl8189esver#*:}/{core,hal,include,os_dep,platform} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es/"
+		cp -R "${SRC}/cache/sources/rtl8189es/${rtl8189esver#*:}"/{core,hal,include,os_dep,platform} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es"
 
 		# Makefile
-		cp ${SRC}/cache/sources/rtl8189es/${rtl8189esver#*:}/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es/Makefile
-		cp ${SRC}/cache/sources/rtl8189es/${rtl8189esver#*:}/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es/Kconfig
+		cp "${SRC}/cache/sources/rtl8189es/${rtl8189esver#*:}/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es/Makefile"
+		cp "${SRC}/cache/sources/rtl8189es/${rtl8189esver#*:}/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189es/Kconfig"
 
 		# Add to section Makefile
-		echo "obj-\$(CONFIG_RTL8189ES) += rtl8189es/" >> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		echo "obj-\$(CONFIG_RTL8189ES) += rtl8189es/" >> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/rtl8189es\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 	fi
 
@@ -187,7 +190,7 @@ compilation_prepare()
 
 	# Wireless drivers for Realtek 8189FS chipsets
 
-	if linux-version compare $version ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
+	if linux-version compare "${version}" ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
 
 		# attach to specifics tag or branch
 		local rtl8189fsver="branch:rtl8189fs"
@@ -195,22 +198,22 @@ compilation_prepare()
 		display_alert "Adding" "Wireless drivers for Realtek 8189FS chipsets ${rtl8189fsver}" "info"
 
 		fetch_from_repo "https://github.com/jwrdegoede/rtl8189ES_linux" "rtl8189fs" "${rtl8189fsver}" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs/
-		cp -R ${SRC}/cache/sources/rtl8189fs/${rtl8189fsver#*:}/{core,hal,include,os_dep,platform} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs/"
+		cp -R "${SRC}/cache/sources/rtl8189fs/${rtl8189fsver#*:}"/{core,hal,include,os_dep,platform} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs"
 
 		# Makefile
-		cp ${SRC}/cache/sources/rtl8189fs/${rtl8189fsver#*:}/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs/Makefile
-		cp ${SRC}/cache/sources/rtl8189fs/${rtl8189fsver#*:}/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs/Kconfig
+		cp "${SRC}/cache/sources/rtl8189fs/${rtl8189fsver#*:}/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs/Makefile"
+		cp "${SRC}/cache/sources/rtl8189fs/${rtl8189fsver#*:}/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8189fs/Kconfig"
 
 		# Add to section Makefile
-		echo "obj-\$(CONFIG_RTL8189FS) += rtl8189fs/" >> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		echo "obj-\$(CONFIG_RTL8189FS) += rtl8189fs/" >> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/rtl8189fs\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 	fi
 
@@ -219,7 +222,7 @@ compilation_prepare()
 
 	# Wireless drivers for Realtek 8811, 8812, 8814 and 8821 chipsets
 
-	if linux-version compare $version ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
+	if linux-version compare "${version}" ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
 
 		# attach to specifics tag or branch
 		local rtl8812auver="branch:v5.6.4.2"
@@ -227,22 +230,22 @@ compilation_prepare()
 		display_alert "Adding" "Wireless drivers for Realtek 8811, 8812, 8814 and 8821 chipsets ${rtl8812auver}" "info"
 
 		fetch_from_repo "https://github.com/aircrack-ng/rtl8812au" "rtl8812au" "${rtl8812auver}" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au/
-		cp -R ${SRC}/cache/sources/rtl8812au/${rtl8812auver#*:}/{core,hal,include,os_dep,platform} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au/"
+		cp -R "${SRC}/cache/sources/rtl8812au/${rtl8812auver#*:}"/{core,hal,include,os_dep,platform} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au"
 
 		# Makefile
-		cp ${SRC}/cache/sources/rtl8812au/${rtl8812auver#*:}/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au/Makefile
-		cp ${SRC}/cache/sources/rtl8812au/${rtl8812auver#*:}/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au/Kconfig
+		cp "${SRC}/cache/sources/rtl8812au/${rtl8812auver#*:}/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au/Makefile"
+		cp "${SRC}/cache/sources/rtl8812au/${rtl8812auver#*:}/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8812au/Kconfig"
 
 		# Add to section Makefile
-		echo "obj-\$(CONFIG_88XXAU) += rtl8812au/" >> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		echo "obj-\$(CONFIG_88XXAU) += rtl8812au/" >> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/rtl8812au\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 	fi
 
@@ -250,28 +253,28 @@ compilation_prepare()
 
 
 	# Wireless drivers for Xradio XR819 chipsets
-	if linux-version compare $version ge 4.19 && [[ "$LINUXFAMILY" == sunxi* ]] && [[ "$EXTRAWIFI" == yes ]]; then
+	if linux-version compare "${version}" ge 4.19 && [[ "$LINUXFAMILY" == sunxi* ]] && [[ "$EXTRAWIFI" == yes ]]; then
 
 		display_alert "Adding" "Wireless drivers for Xradio XR819 chipsets" "info"
 
 		fetch_from_repo "https://github.com/karabek/xradio" "xradio" "branch:master" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/
-		cp ${SRC}/cache/sources/xradio/master/*.{h,c} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/"
+		cp "${SRC}"/cache/sources/xradio/master/*.{h,c} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/"
 
 		# Makefile
-		cp ${SRC}/cache/sources/xradio/master/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/Makefile
-		cp ${SRC}/cache/sources/xradio/master/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/Kconfig
+		cp "${SRC}/cache/sources/xradio/master/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/Makefile"
+		cp "${SRC}/cache/sources/xradio/master/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/xradio/Kconfig"
 
 		# Add to section Makefile
 		echo "obj-\$(CONFIG_WLAN_VENDOR_XRADIO) += xradio/" \
-		>> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		>> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/xradio\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 	fi
 
@@ -280,7 +283,7 @@ compilation_prepare()
 
 	# Wireless drivers for Realtek RTL8811CU and RTL8821C chipsets
 
-	if linux-version compare $version ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
+	if linux-version compare "${version}" ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
 
 		# attach to specifics tag or branch
 		local rtl8811cuver="commit:2bebdb9a35c1d9b6e6a928e371fa39d5fcec8a62"
@@ -288,30 +291,30 @@ compilation_prepare()
 		display_alert "Adding" "Wireless drivers for Realtek RTL8811CU and RTL8821C chipsets ${rtl8811cuver}" "info"
 
 		fetch_from_repo "https://github.com/brektrou/rtl8821CU" "rtl8811cu" "${rtl8811cuver}" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/
-		cp -R ${SRC}/cache/sources/rtl8811cu/${rtl8811cuver#*:}/{core,hal,include,os_dep,platform,rtl8821c.mk} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/"
+		cp -R "${SRC}/cache/sources/rtl8811cu/${rtl8811cuver#*:}"/{core,hal,include,os_dep,platform,rtl8821c.mk} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu"
 
 		# Makefile
-		cp ${SRC}/cache/sources/rtl8811cu/${rtl8811cuver#*:}/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Makefile
-		cp ${SRC}/cache/sources/rtl8811cu/${rtl8811cuver#*:}/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Kconfig
+		cp "${SRC}/cache/sources/rtl8811cu/${rtl8811cuver#*:}/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Makefile"
+		cp "${SRC}/cache/sources/rtl8811cu/${rtl8811cuver#*:}/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Kconfig"
 
 		# Disable debug
 		sed -i "s/^CONFIG_RTW_DEBUG.*/CONFIG_RTW_DEBUG = n/" \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Makefile
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Makefile"
 
 		# Address ARM related bug https://github.com/aircrack-ng/rtl8812au/issues/233
 		sed -i "s/^CONFIG_MP_VHT_HW_TX_MODE.*/CONFIG_MP_VHT_HW_TX_MODE = n/" \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Makefile
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8811cu/Makefile"
 
 		# Add to section Makefile
-		echo "obj-\$(CONFIG_RTL8821CU) += rtl8811cu/" >> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		echo "obj-\$(CONFIG_RTL8821CU) += rtl8811cu/" >> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/rtl8811cu\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 	fi
 
@@ -320,34 +323,34 @@ compilation_prepare()
 
 	# Wireless drivers for Realtek 8188EU 8188EUS and 8188ETV chipsets
 
-	if linux-version compare $version ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
+	if linux-version compare "${version}" ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
 
 		# attach to specifics tag or branch
 		local rtl8188euver="branch:v5.7.6.1"
 
-		display_alert "Adding" "Wireless drivers for Realtek 8188EU 8188EUS and 8188ETV chipsets ${rtl8811euver}" "info"
+		display_alert "Adding" "Wireless drivers for Realtek 8188EU 8188EUS and 8188ETV chipsets ${rtl8188euver}" "info"
 
 		fetch_from_repo "https://github.com/aircrack-ng/rtl8188eus" "rtl8188eu" "${rtl8188euver}" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/
-		cp -R ${SRC}/cache/sources/rtl8188eu/${rtl8188euver#*:}/{core,hal,include,os_dep,platform} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/"
+		cp -R "${SRC}/cache/sources/rtl8188eu/${rtl8188euver#*:}"/{core,hal,include,os_dep,platform} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu"
 
 		# Makefile
-		cp ${SRC}/cache/sources/rtl8188eu/${rtl8188euver#*:}/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/Makefile
-		cp ${SRC}/cache/sources/rtl8188eu/${rtl8188euver#*:}/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/Kconfig
+		cp "${SRC}/cache/sources/rtl8188eu/${rtl8188euver#*:}/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/Makefile"
+		cp "${SRC}/cache/sources/rtl8188eu/${rtl8188euver#*:}/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/Kconfig"
 
 		# Disable debug
 		sed -i "s/^CONFIG_RTW_DEBUG.*/CONFIG_RTW_DEBUG = n/" \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/Makefile
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8188eu/Makefile"
 
 		# Add to section Makefile
-		echo "obj-\$(CONFIG_RTL8188EU) += rtl8188eu/" >> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		echo "obj-\$(CONFIG_RTL8188EU) += rtl8188eu/" >> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/rtl8188eu\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 		# kernel 5.6 ->
 		process_patch_file "${SRC}/patch/misc/wireless-rtl8188eu.patch" "applying"
@@ -359,7 +362,7 @@ compilation_prepare()
 
 	# Wireless drivers for Realtek 88x2bu chipsets
 
-	if linux-version compare $version ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
+	if linux-version compare "${version}" ge 3.14 && [ "$EXTRAWIFI" == yes ]; then
 
 		# attach to specifics tag or branch
 		local rtl88x2buver="branch:5.6.1_30362.20181109_COEX20180928-6a6a"
@@ -367,26 +370,26 @@ compilation_prepare()
 		display_alert "Adding" "Wireless drivers for Realtek 88x2bu chipsets ${rtl88x2buver}" "info"
 
 		fetch_from_repo "https://github.com/cilynx/rtl88x2bu" "rtl88x2bu" "${rtl88x2buver}" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/
-		cp -R ${SRC}/cache/sources/rtl88x2bu/${rtl88x2buver#*:}/{core,hal,include,os_dep,platform,halmac.mk,rtl8822b.mk} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/"
+		cp -R "${SRC}/cache/sources/rtl88x2bu/${rtl88x2buver#*:}"/{core,hal,include,os_dep,platform,halmac.mk,rtl8822b.mk} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu"
 
 		# Makefile
-		cp ${SRC}/cache/sources/rtl88x2bu/${rtl88x2buver#*:}/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/Makefile
-		cp ${SRC}/cache/sources/rtl88x2bu/${rtl88x2buver#*:}/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/Kconfig
+		cp "${SRC}/cache/sources/rtl88x2bu/${rtl88x2buver#*:}/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/Makefile"
+		cp "${SRC}/cache/sources/rtl88x2bu/${rtl88x2buver#*:}/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/Kconfig"
 
 		# Adjust path
 		sed -i 's/include $(src)\/rtl8822b.mk /include $(TopDIR)\/drivers\/net\/wireless\/rtl88x2bu\/rtl8822b.mk/' \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/Makefile
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl88x2bu/Makefile"
 
 		# Add to section Makefile
-		echo "obj-\$(CONFIG_RTL8822BU) += rtl88x2bu/" >> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		echo "obj-\$(CONFIG_RTL8822BU) += rtl88x2bu/" >> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/rtl88x2bu\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 	fi
 
@@ -395,7 +398,7 @@ compilation_prepare()
 
 	# Wireless drivers for Realtek 8723DS chipsets
 
-	if linux-version compare $version ge 5.0 && [ "$EXTRAWIFI" == yes ]; then
+	if linux-version compare "${version}" ge 5.0 && [ "$EXTRAWIFI" == yes ]; then
 
 		# attach to specifics tag or branch
 		local rtl8723dsver="branch:master"
@@ -403,26 +406,26 @@ compilation_prepare()
 		display_alert "Adding" "Wireless drivers for Realtek 8723DS chipsets ${rtl8723dsver}" "info"
 
 		fetch_from_repo "https://github.com/lwfinger/rtl8723ds" "rtl8723ds" "${rtl8723dsver}" "yes"
-		cd ${SRC}/cache/sources/${LINUXSOURCEDIR}
-		rm -rf ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds
-		mkdir -p ${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/
-		cp -R ${SRC}/cache/sources/rtl8723ds/${rtl8723dsver#*:}/{core,hal,include,os_dep,platform} \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds
+		cd "${SRC}/cache/sources/${LINUXSOURCEDIR}" || exit
+		rm -rf "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds"
+		mkdir -p "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/"
+		cp -R "${SRC}/cache/sources/rtl8723ds/${rtl8723dsver#*:}"/{core,hal,include,os_dep,platform} \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds"
 
 		# Makefile
-		cp ${SRC}/cache/sources/rtl8723ds/${rtl8723dsver#*:}/Makefile \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/Makefile
-		cp ${SRC}/cache/sources/rtl8723ds/${rtl8723dsver#*:}/Kconfig \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/Kconfig
+		cp "${SRC}/cache/sources/rtl8723ds/${rtl8723dsver#*:}/Makefile" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/Makefile"
+		cp "${SRC}/cache/sources/rtl8723ds/${rtl8723dsver#*:}/Kconfig" \
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/Kconfig"
 
 		# Disable debug
 		sed -i "s/^CONFIG_RTW_DEBUG.*/CONFIG_RTW_DEBUG = n/" \
-		${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/Makefile
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/rtl8723ds/Makefile"
 
 		# Add to section Makefile
-		echo "obj-\$(CONFIG_RTL8723DS) += rtl8723ds/" >> $SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile
+		echo "obj-\$(CONFIG_RTL8723DS) += rtl8723ds/" >> "${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Makefile"
 		sed -i '/source "drivers\/net\/wireless\/ti\/Kconfig"/a source "drivers\/net\/wireless\/rtl8723ds\/Kconfig"' \
-		$SRC/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig
+		"${SRC}/cache/sources/${LINUXSOURCEDIR}/drivers/net/wireless/Kconfig"
 
 	fi
 
diff --git a/lib/general.sh b/lib/general.sh
index dfe70bde29..1667588a74 100644
--- a/lib/general.sh
+++ b/lib/general.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+#
 # Copyright (c) 2015 Igor Pecovnik, igor.pecovnik@gma**.com
 #
 # This file is licensed under the terms of the GNU General Public
@@ -38,50 +40,50 @@ cleaning()
 {
 	case $1 in
 		debs) # delete ${DEB_STORAGE} for current branch and family
-		if [[ -d ${DEB_STORAGE} ]]; then
+		if [[ -d "${DEB_STORAGE}" ]]; then
 			display_alert "Cleaning ${DEB_STORAGE} for" "$BOARD $BRANCH" "info"
 			# easier than dealing with variable expansion and escaping dashes in file names
-			find ${DEB_STORAGE} -name "${CHOSEN_UBOOT}_*.deb" -delete
-			find ${DEB_STORAGE} \( -name "${CHOSEN_KERNEL}_*.deb" -o \
+			find "${DEB_STORAGE}" -name "${CHOSEN_UBOOT}_*.deb" -delete
+			find "${DEB_STORAGE}" \( -name "${CHOSEN_KERNEL}_*.deb" -o \
 				-name "armbian-*.deb" -o \
 				-name "${CHOSEN_KERNEL/image/dtb}_*.deb" -o \
 				-name "${CHOSEN_KERNEL/image/headers}_*.deb" -o \
 				-name "${CHOSEN_KERNEL/image/source}_*.deb" -o \
 				-name "${CHOSEN_KERNEL/image/firmware-image}_*.deb" \) -delete
-			[[ -n $RELEASE ]] && rm -f ${DEB_STORAGE}/$RELEASE/${CHOSEN_ROOTFS}_*.deb
-			[[ -n $RELEASE ]] && rm -f ${DEB_STORAGE}/$RELEASE/armbian-desktop-${RELEASE}_*.deb
+			[[ -n $RELEASE ]] && rm -f "${DEB_STORAGE}/${RELEASE}/${CHOSEN_ROOTFS}"_*.deb
+			[[ -n $RELEASE ]] && rm -f "${DEB_STORAGE}/${RELEASE}/armbian-desktop-${RELEASE}"_*.deb
 		fi
 		;;
 
 		extras) # delete ${DEB_STORAGE}/extra/$RELEASE for all architectures
 		if [[ -n $RELEASE && -d ${DEB_STORAGE}/extra/$RELEASE ]]; then
 			display_alert "Cleaning ${DEB_STORAGE}/extra for" "$RELEASE" "info"
-			rm -rf ${DEB_STORAGE}/extra/$RELEASE
+			rm -rf "${DEB_STORAGE}/extra/${RELEASE}"
 		fi
 		;;
 
 		alldebs) # delete output/debs
-		[[ -d ${DEB_STORAGE} ]] && display_alert "Cleaning" "${DEB_STORAGE}" "info" && rm -rf ${DEB_STORAGE}/*
+		[[ -d "${DEB_STORAGE}" ]] && display_alert "Cleaning" "${DEB_STORAGE}" "info" && rm -rf "${DEB_STORAGE}"/*
 		;;
 
 		cache) # delete output/cache
-		[[ -d $SRC/cache/rootfs ]] && display_alert "Cleaning" "rootfs cache (all)" "info" && find $SRC/cache/rootfs -type f -delete
+		[[ -d "${SRC}"/cache/rootfs ]] && display_alert "Cleaning" "rootfs cache (all)" "info" && find "${SRC}"/cache/rootfs -type f -delete
 		;;
 
 		images) # delete output/images
-		[[ -d $DEST/images ]] && display_alert "Cleaning" "output/images" "info" && rm -rf $DEST/images/*
+		[[ -d "${DEST}"/images ]] && display_alert "Cleaning" "output/images" "info" && rm -rf "${DEST}"/images/*
 		;;
 
 		sources) # delete output/sources and output/buildpkg
-		[[ -d $SRC/cache/sources ]] && display_alert "Cleaning" "sources" "info" && rm -rf $SRC/cache/sources/* $DEST/buildpkg/*
+		[[ -d "${SRC}"/cache/sources ]] && display_alert "Cleaning" "sources" "info" && rm -rf "${SRC}"/cache/sources/* "${DEST}"/buildpkg/*
 		;;
 
 		oldcache) # remove old `cache/rootfs` except for the newest 8 files
-		if [[ -d $SRC/cache/rootfs && $(ls -1 $SRC/cache/rootfs/*.lz4 2> /dev/null | wc -l) -gt ${ROOTFS_CACHE_MAX} ]]; then
+		if [[ -d "${SRC}"/cache/rootfs && $(ls -1 "${SRC}"/cache/rootfs/*.lz4 2> /dev/null | wc -l) -gt "${ROOTFS_CACHE_MAX}" ]]; then
 			display_alert "Cleaning" "rootfs cache (old)" "info"
-			(cd $SRC/cache/rootfs; ls -t *.lz4 | sed -e "1,${ROOTFS_CACHE_MAX}d" | xargs -d '\n' rm -f)
+			(cd "${SRC}"/cache/rootfs; ls -t *.lz4 | sed -e "1,${ROOTFS_CACHE_MAX}d" | xargs -d '\n' rm -f)
 			# Remove signatures if they are present. We use them for internal purpose
-			(cd $SRC/cache/rootfs; ls -t *.asc | sed -e "1,${ROOTFS_CACHE_MAX}d" | xargs -d '\n' rm -f)
+			(cd "${SRC}"/cache/rootfs; ls -t *.asc | sed -e "1,${ROOTFS_CACHE_MAX}d" | xargs -d '\n' rm -f)
 		fi
 		;;
 	esac
@@ -95,11 +97,12 @@ cleaning()
 
 exit_with_error()
 {
-	local _file=$(basename ${BASH_SOURCE[1]})
+	local _file
 	local _line=${BASH_LINENO[0]}
 	local _function=${FUNCNAME[1]}
 	local _description=$1
 	local _highlight=$2
+	_file=$(basename "${BASH_SOURCE[1]}")
 
 	display_alert "ERROR in function $_function" "$_file:$_line" "err"
 	display_alert "$_description" "$_highlight" "err"
@@ -108,9 +111,9 @@ exit_with_error()
 	overlayfs_wrapper "cleanup"
 	# unlock loop device access in case of starvation
 	exec {FD}>/var/lock/armbian-debootstrap-losetup
-	flock -u $FD
+	flock -u "${FD}"
 
-	exit -1
+	exit 255
 }
 
 # get_package_list_hash
@@ -119,7 +122,7 @@ exit_with_error()
 
 get_package_list_hash()
 {
-	( printf '%s\n' $PACKAGE_LIST | sort -u; printf '%s\n' $PACKAGE_LIST_EXCLUDE | sort -u; echo "$1" ) \
+	( printf '%s\n' "${PACKAGE_LIST}" | sort -u; printf '%s\n' "${PACKAGE_LIST_EXCLUDE}" | sort -u; echo "${1}" ) \
 		| md5sum | cut -d' ' -f 1
 }
 
@@ -136,7 +139,7 @@ create_sources_list()
 
 	case $release in
 	stretch|buster|bullseye)
-	cat <<-EOF > $basedir/etc/apt/sources.list
+	cat <<-EOF > "${basedir}"/etc/apt/sources.list
 	deb http://${DEBIAN_MIRROR} $release main contrib non-free
 	#deb-src http://${DEBIAN_MIRROR} $release main contrib non-free
 
@@ -152,7 +155,7 @@ create_sources_list()
 	;;
 
 	xenial|bionic|eoan|focal)
-	cat <<-EOF > $basedir/etc/apt/sources.list
+	cat <<-EOF > "${basedir}"/etc/apt/sources.list
 	deb http://${UBUNTU_MIRROR} $release main restricted universe multiverse
 	#deb-src http://${UBUNTU_MIRROR} $release main restricted universe multiverse
 
@@ -171,7 +174,7 @@ create_sources_list()
 	# workaround for Chromium by downloading it from Debian
 	if [[ $release == focal || $release == eoan ]]; then
 
-		cat <<-EOF > $basedir/etc/apt/preferences.d/chromium.pref
+		cat <<-EOF > "${basedir}"/etc/apt/preferences.d/chromium.pref
 		# Note: 2 blank lines are required between entries
 		Package: *
 		Pin: release a=${release}
@@ -188,7 +191,7 @@ create_sources_list()
 		Pin-Priority: 700
 		EOF
 
-		cat <<-EOF > $basedir/etc/apt/sources.list.d/debian.list
+		cat <<-EOF > "${basedir}"/etc/apt/sources.list.d/debian.list
 		deb http://${DEBIAN_MIRROR} stable main
 		deb http://${DEBIAN_MIRROR} stable-updates main
 		deb http://${DEBIAN_MIRROR}-security stable/updates main
@@ -200,18 +203,18 @@ create_sources_list()
 
 	# stage: add armbian repository and install key
 	if [[ $DOWNLOAD_MIRROR == "china" ]]; then
-		echo "deb http://mirrors.tuna.tsinghua.edu.cn/armbian $RELEASE main ${RELEASE}-utils ${RELEASE}-desktop" > $SDCARD/etc/apt/sources.list.d/armbian.list
+		echo "deb http://mirrors.tuna.tsinghua.edu.cn/armbian $RELEASE main ${RELEASE}-utils ${RELEASE}-desktop" > "${SDCARD}"/etc/apt/sources.list.d/armbian.list
 	else
-		echo "deb http://apt.armbian.com $RELEASE main ${RELEASE}-utils ${RELEASE}-desktop" > $SDCARD/etc/apt/sources.list.d/armbian.list
+		echo "deb http://apt.armbian.com $RELEASE main ${RELEASE}-utils ${RELEASE}-desktop" > "${SDCARD}"/etc/apt/sources.list.d/armbian.list
 	fi
 
 	# add local package server if defined. Suitable for development
-	[[ -n $LOCAL_MIRROR ]] && echo "deb http://$LOCAL_MIRROR $RELEASE main ${RELEASE}-utils ${RELEASE}-desktop" >> $SDCARD/etc/apt/sources.list.d/armbian.list
+	[[ -n $LOCAL_MIRROR ]] && echo "deb http://$LOCAL_MIRROR $RELEASE main ${RELEASE}-utils ${RELEASE}-desktop" >> "${SDCARD}"/etc/apt/sources.list.d/armbian.list
 
 	display_alert "Adding Armbian repository and authentication key" "/etc/apt/sources.list.d/armbian.list" "info"
-	cp $SRC/config/armbian.key $SDCARD
-	chroot $SDCARD /bin/bash -c "cat armbian.key | apt-key add - > /dev/null 2>&1"
-	rm $SDCARD/armbian.key
+	cp "${SRC}"/config/armbian.key "${SDCARD}"
+	chroot "${SDCARD}" /bin/bash -c "cat armbian.key | apt-key add - > /dev/null 2>&1"
+	rm "${SDCARD}"/armbian.key
 }
 
 # fetch_from_repo <url> <directory> <ref> <ref_subdir>
@@ -261,10 +264,10 @@ fetch_from_repo()
 		local workdir=$dir
 	fi
 
-	mkdir -p $SRC/cache/sources/$workdir 2>/dev/null || \
-		exit_with_error "No path or no write permission" "$SRC/cache/sources/$workdir"
+	mkdir -p "${SRC}/cache/sources/${workdir}" 2>/dev/null || \
+		exit_with_error "No path or no write permission" "${SRC}/cache/sources/${workdir}"
 
-	cd $SRC/cache/sources/$workdir
+	cd "${SRC}/cache/sources/${workdir}" || exit
 
 	# check if existing remote URL for the repo or branch does not match current one
 	# may not be supported by older git versions
@@ -274,13 +277,13 @@ fetch_from_repo()
 	if [[ "$(git rev-parse --git-dir 2>/dev/null)" == ".git" && \
 		  "$url" != "$(git remote get-url origin 2>/dev/null)" ]]; then
 		display_alert "Remote URL does not match, removing existing local copy"
-		rm -rf .git *
+		rm -rf .git ./*
 	fi
 
 	if [[ "$(git rev-parse --git-dir 2>/dev/null)" != ".git" ]]; then
 		display_alert "Creating local copy"
 		git init -q .
-		git remote add origin $url
+		git remote add origin "${url}"
 		# Here you need to upload from a new address
 		offline=false
 	fi
@@ -289,26 +292,30 @@ fetch_from_repo()
 
 	# when we work offline we simply return the sources to their original state
 	if ! $offline; then
-		local local_hash=$(git rev-parse @ 2>/dev/null)
+		local local_hash
+		local_hash=$(git rev-parse @ 2>/dev/null)
 
 		case $ref_type in
 			branch)
 			# TODO: grep refs/heads/$name
-			local remote_hash=$(git ls-remote -h $url "$ref_name" | head -1 | cut -f1)
-			[[ -z $local_hash || $local_hash != $remote_hash ]] && changed=true
+			local remote_hash
+			remote_hash=$(git ls-remote -h "${url}" "$ref_name" | head -1 | cut -f1)
+			[[ -z $local_hash || "${local_hash}" != "${remote_hash}" ]] && changed=true
 			;;
 
 			tag)
-			local remote_hash=$(git ls-remote -t $url "$ref_name" | cut -f1)
-			if [[ -z $local_hash || $local_hash != $remote_hash ]]; then
-				remote_hash=$(git ls-remote -t $url "$ref_name^{}" | cut -f1)
-				[[ -z $remote_hash || $local_hash != $remote_hash ]] && changed=true
+			local remote_hash
+			remote_hash=$(git ls-remote -t "${url}" "$ref_name" | cut -f1)
+			if [[ -z $local_hash || "${local_hash}" != "${remote_hash}" ]]; then
+				remote_hash=$(git ls-remote -t "${url}" "$ref_name^{}" | cut -f1)
+				[[ -z $remote_hash || "${local_hash}" != "${remote_hash}" ]] && changed=true
 			fi
 			;;
 
 			head)
-			local remote_hash=$(git ls-remote $url HEAD | cut -f1)
-			[[ -z $local_hash || $local_hash != $remote_hash ]] && changed=true
+			local remote_hash
+			remote_hash=$(git ls-remote "${url}" HEAD | cut -f1)
+			[[ -z $local_hash || "${local_hash}" != "${remote_hash}" ]] && changed=true
 			;;
 
 			commit)
@@ -323,22 +330,22 @@ fetch_from_repo()
 		# remote was updated, fetch and check out updates
 		display_alert "Fetching updates"
 		case $ref_type in
-			branch) git fetch --depth 1 origin $ref_name ;;
-			tag) git fetch --depth 1 origin tags/$ref_name ;;
+			branch) git fetch --depth 1 origin "${ref_name}" ;;
+			tag) git fetch --depth 1 origin tags/"${ref_name}" ;;
 			head) git fetch --depth 1 origin HEAD ;;
 		esac
 
 		# commit type needs support for older git servers that doesn't support fetching id directly
 		if [[ $ref_type == commit ]]; then
 
-			git fetch --depth 1 origin $ref_name
+			git fetch --depth 1 origin "${ref_name}"
 
 			# cover old type
 			if [[ $? -ne 0 ]]; then
 
 				display_alert "Commit checkout not supported on this repository. Doing full clone." "" "wrn"
 				git pull
-				git checkout -fq $ref_name
+				git checkout -fq "${ref_name}"
 				display_alert "Checkout out to" "$(git --no-pager log -2 --pretty=format:"$ad%s [%an]" | head -1)" "info"
 
 			else
@@ -374,9 +381,10 @@ fetch_from_repo()
 		display_alert "Updating submodules" "" "ext"
 		# FML: http://stackoverflow.com/a/17692710
 		for i in $(git config -f .gitmodules --get-regexp path | awk '{ print $2 }'); do
-			cd $SRC/cache/sources/$workdir
-			local surl=$(git config -f .gitmodules --get "submodule.$i.url")
-			local sref=$(git config -f .gitmodules --get "submodule.$i.branch")
+			cd "${SRC}/cache/sources/${workdir}" || exit
+			local surl sref
+			surl=$(git config -f .gitmodules --get "submodule.$i.url")
+			sref=$(git config -f .gitmodules --get "submodule.$i.branch")
 			if [[ -n $sref ]]; then
 				sref="branch:$sref"
 			else
@@ -393,7 +401,7 @@ fetch_from_repo()
 display_alert()
 {
 	# log function parameters to install.log
-	[[ -n $DEST ]] && echo "Displaying message: $@" >> $DEST/debug/output.log
+	[[ -n "${DEST}" ]] && echo "Displaying message: $@" >> "${DEST}"/debug/output.log
 
 	local tmp=""
 	[[ -n $2 ]] && tmp="[\e[0;33m $2 \x1B[0m]"
@@ -428,7 +436,7 @@ display_alert()
 fingerprint_image()
 {
 	display_alert "Fingerprinting"
-	cat <<-EOF > $1
+	cat <<-EOF > "${1}"
 	--------------------------------------------------------------------------------
 	Title:			Armbian $REVISION ${BOARD^} $DISTRIBUTION $RELEASE $BRANCH
 	Kernel:			Linux $VER
@@ -442,7 +450,7 @@ fingerprint_image()
 	EOF
 
 	if [ -n "$2" ]; then
-	cat <<-EOF >> $1
+	cat <<-EOF >> "${1}"
 	--------------------------------------------------------------------------------
 	Partitioning configuration:
 	Root partition type: $ROOTFS_TYPE
@@ -465,9 +473,9 @@ fingerprint_image()
 	EOF
         fi
 
-	cat <<-EOF >> $1
+	cat <<-EOF >> "${1}"
 	--------------------------------------------------------------------------------
-	$(cat $SRC/LICENSE)
+	$(cat "${SRC}"/LICENSE)
 	--------------------------------------------------------------------------------
 	EOF
 }
@@ -482,7 +490,7 @@ function distro_menu ()
 
 	for i in "${!distro_name[@]}"
 	do
-		if [[ $i == $1 ]]; then
+		if [[ "${i}" == "${1}" ]]; then
 			if [[ "${distro_support[$i]}" != "supported" && $EXPERT != "yes" ]]; then
 				:
 			else
@@ -505,16 +513,17 @@ adding_packages()
 # add deb files to repository if they are not already there
 
 	display_alert "Checking and adding to repository $release" "$3" "ext"
-	for f in ${DEB_STORAGE}$2/*.deb
+	for f in "${DEB_STORAGE}${2}"/*.deb
 	do
-		local name=$(dpkg-deb -I $f | grep Package | awk '{print $2}')
-		local version=$(dpkg-deb -I $f | grep Version | awk '{print $2}')
-		local arch=$(dpkg-deb -I $f | grep Architecture | awk '{print $2}')
+		local name version arch
+		name=$(dpkg-deb -I "${f}" | grep Package | awk '{print $2}')
+		version=$(dpkg-deb -I "${f}" | grep Version | awk '{print $2}')
+		arch=$(dpkg-deb -I "${f}" | grep Architecture | awk '{print $2}')
 		# add if not already there
-		aptly repo search -architectures=$arch -config=${SCRIPTPATH}config/${REPO_CONFIG} $1 'Name (% '$name'), $Version (='$version'), $Architecture (='$arch')' &>/dev/null
+		aptly repo search -architectures="${arch}" -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${1}" 'Name (% '${name}'), $Version (='${version}'), $Architecture (='${arch}')' &>/dev/null
 		if [[ $? -ne 0 ]]; then
 			display_alert "Adding" "$name" "info"
-			aptly repo add -force-replace=true -config=${SCRIPTPATH}config/${REPO_CONFIG} $1 ${f} &>/dev/null
+			aptly repo add -force-replace=true -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${1}" "${f}" &>/dev/null
 		fi
 	done
 
@@ -538,74 +547,75 @@ addtorepo()
 		local forceoverwrite=""
 
 		# let's drop from publish if exits
-		if [[ -n $(aptly publish list -config=${SCRIPTPATH}config/${REPO_CONFIG} -raw | awk '{print $(NF)}' | grep $release) ]]; then
-			aptly publish drop -config=${SCRIPTPATH}config/${REPO_CONFIG} $release > /dev/null 2>&1
+		if [[ -n $(aptly publish list -config="${SCRIPTPATH}config/${REPO_CONFIG}" -raw | awk '{print $(NF)}' | grep "${release}") ]]; then
+			aptly publish drop -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}" > /dev/null 2>&1
 		fi
 
 		# create local repository if not exist
-		if [[ -z $(aptly repo list -config=${SCRIPTPATH}config/${REPO_CONFIG} -raw | awk '{print $(NF)}' | grep $release) ]]; then
+		if [[ -z $(aptly repo list -config="${SCRIPTPATH}config/${REPO_CONFIG}" -raw | awk '{print $(NF)}' | grep "${release}") ]]; then
 			display_alert "Creating section" "$release" "info"
-			aptly repo create -config=${SCRIPTPATH}config/${REPO_CONFIG} -distribution=$release -component="main" \
-			-comment="Armbian main repository" ${release} >/dev/null
+			aptly repo create -config="${SCRIPTPATH}config/${REPO_CONFIG}" -distribution="${release}" -component="main" \
+			-comment="Armbian main repository" "${release}" >/dev/null
 		fi
-		if [[ -z $(aptly repo list -config=${SCRIPTPATH}config/${REPO_CONFIG} -raw | awk '{print $(NF)}' | grep "^utils") ]]; then
-			aptly repo create -config=${SCRIPTPATH}config/${REPO_CONFIG} -distribution=$release -component="utils" \
+		if [[ -z $(aptly repo list -config="${SCRIPTPATH}config/${REPO_CONFIG}" -raw | awk '{print $(NF)}' | grep "^utils") ]]; then
+			aptly repo create -config="${SCRIPTPATH}config/${REPO_CONFIG}" -distribution="${release}" -component="utils" \
 			-comment="Armbian utilities (backwards compatibility)" utils >/dev/null
 		fi
-		if [[ -z $(aptly repo list -config=${SCRIPTPATH}config/${REPO_CONFIG} -raw | awk '{print $(NF)}' | grep "${release}-utils") ]]; then
-			aptly repo create -config=${SCRIPTPATH}config/${REPO_CONFIG} -distribution=$release -component="${release}-utils" \
-			-comment="Armbian ${release} utilities" ${release}-utils >/dev/null
+		if [[ -z $(aptly repo list -config="${SCRIPTPATH}config/${REPO_CONFIG}" -raw | awk '{print $(NF)}' | grep "${release}-utils") ]]; then
+			aptly repo create -config="${SCRIPTPATH}config/${REPO_CONFIG}" -distribution="${release}" -component="${release}-utils" \
+			-comment="Armbian ${release} utilities" "${release}-utils" >/dev/null
 		fi
-		if [[ -z $(aptly repo list -config=${SCRIPTPATH}config/${REPO_CONFIG} -raw | awk '{print $(NF)}' | grep "${release}-desktop") ]]; then
-			aptly repo create -config=${SCRIPTPATH}config/${REPO_CONFIG} -distribution=$release -component="${release}-desktop" \
-			-comment="Armbian ${release} desktop" ${release}-desktop >/dev/null
+		if [[ -z $(aptly repo list -config="${SCRIPTPATH}config/${REPO_CONFIG}" -raw | awk '{print $(NF)}' | grep "${release}-desktop") ]]; then
+			aptly repo create -config="${SCRIPTPATH}config/${REPO_CONFIG}" -distribution="${release}" -component="${release}-desktop" \
+			-comment="Armbian ${release} desktop" "${release}-desktop" >/dev/null
 		fi
 
 
 		# adding main
-		if find ${DEB_STORAGE}/ -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
+		if find "${DEB_STORAGE}"/ -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
 			adding_packages "$release" "" "main"
 		else
-			aptly repo add -config=${SCRIPTPATH}config/${REPO_CONFIG} $release ${SCRIPTPATH}config/templates/example.deb >/dev/null
+			aptly repo add -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}" "${SCRIPTPATH}config/templates/example.deb" >/dev/null
 		fi
 
 		local COMPONENTS="main"
 
 		# adding main distribution packages
-		if find ${DEB_STORAGE}/${release} -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
+		if find "${DEB_STORAGE}/${release}" -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
 			adding_packages "$release" "/${release}" "release"
 		else
 			# workaround - add dummy package to not trigger error
-			aptly repo add -config=${SCRIPTPATH}config/${REPO_CONFIG} $release ${SCRIPTPATH}config/templates/example.deb >/dev/null
+			aptly repo add -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}" "${SCRIPTPATH}config/templates/example.deb" >/dev/null
 		fi
 
 		# adding release-specific utils
-		if find ${DEB_STORAGE}/extra/${release}-utils -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
+		if find "${DEB_STORAGE}/extra/${release}-utils" -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
 			adding_packages "${release}-utils" "/extra/${release}-utils" "release utils"
 		else
-			aptly repo add -config=${SCRIPTPATH}config/${REPO_CONFIG} "${release}-utils" ${SCRIPTPATH}config/templates/example.deb >/dev/null
+			aptly repo add -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}-utils" "${SCRIPTPATH}config/templates/example.deb" >/dev/null
 		fi
 		COMPONENTS="${COMPONENTS} ${release}-utils"
 
 		# adding desktop
-		if find ${DEB_STORAGE}/extra/${release}-desktop -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
+		if find "${DEB_STORAGE}/extra/${release}-desktop" -maxdepth 1 -type f -name "*.deb" 2>/dev/null | grep -q .; then
 			adding_packages "${release}-desktop" "/extra/${release}-desktop" "desktop"
 		else
 			# workaround - add dummy package to not trigger error
-			aptly repo add -config=${SCRIPTPATH}config/${REPO_CONFIG} "${release}-desktop" ${SCRIPTPATH}config/templates/example.deb >/dev/null
+			aptly repo add -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}-desktop" "${SCRIPTPATH}config/templates/example.deb" >/dev/null
 		fi
 		COMPONENTS="${COMPONENTS} ${release}-desktop"
 
-		local mainnum=$(aptly repo show -with-packages -config=${SCRIPTPATH}config/${REPO_CONFIG} $release | grep "Number of packages" | awk '{print $NF}')
-		local utilnum=$(aptly repo show -with-packages -config=${SCRIPTPATH}config/${REPO_CONFIG} ${release}-desktop | grep "Number of packages" | awk '{print $NF}')
-		local desknum=$(aptly repo show -with-packages -config=${SCRIPTPATH}config/${REPO_CONFIG} ${release}-utils | grep "Number of packages" | awk '{print $NF}')
+		local mainnum utilnum desknum
+		mainnum=$(aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}" | grep "Number of packages" | awk '{print $NF}')
+		utilnum=$(aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}-desktop" | grep "Number of packages" | awk '{print $NF}')
+		desknum=$(aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}-utils" | grep "Number of packages" | awk '{print $NF}')
 
 		if [ $mainnum -gt 0 ] && [ $utilnum -gt 0 ] && [ $desknum -gt 0 ]; then
 			# publish
-			aptly publish -force-overwrite -passphrase=$GPG_PASS -origin=Armbian -label=Armbian -config=${SCRIPTPATH}config/${REPO_CONFIG} -component=${COMPONENTS// /,} \
-				--distribution=$release repo $release ${COMPONENTS//main/} >/dev/null
+			aptly publish -force-overwrite -passphrase="${GPG_PASS}" -origin=Armbian -label=Armbian -config="${SCRIPTPATH}config/${REPO_CONFIG}" -component="${COMPONENTS// /,}" \
+				--distribution="${release}" repo "${release}" "${COMPONENTS//main/}" >/dev/null
 			if [[ $? -ne 0 ]]; then
-				display_alert "Publishing failed" "$release" "err"
+				display_alert "Publishing failed" "${release}" "err"
 				errors=$((errors+1))
 				exit 0
 			fi
@@ -618,18 +628,18 @@ addtorepo()
 
 	# cleanup
 	display_alert "Cleaning repository" "${DEB_STORAGE}" "info"
-	aptly db cleanup -config=${SCRIPTPATH}config/${REPO_CONFIG}
+	aptly db cleanup -config="${SCRIPTPATH}config/${REPO_CONFIG}"
 
 	# display what we have
 	echo ""
 	display_alert "List of local repos" "local" "info"
-	(aptly repo list -config=${SCRIPTPATH}config/${REPO_CONFIG}) | egrep packages
+	(aptly repo list -config="${SCRIPTPATH}config/${REPO_CONFIG}") | grep -E packages
 
 	# remove debs if no errors found
 	if [[ $errors -eq 0 ]]; then
 		if [[ "$2" == "delete" ]]; then
 			display_alert "Purging incoming debs" "all" "ext"
-			find ${DEB_STORAGE} -name "*.deb" -type f -delete
+			find "${DEB_STORAGE}" -name "*.deb" -type f -delete
 		fi
 	else
 		display_alert "There were some problems $err_txt" "leaving incoming directory intact" "err"
@@ -646,18 +656,18 @@ repo-manipulate() {
 		serve)
 			# display repository content
 			display_alert "Serving content" "common utils" "ext"
-			aptly serve -listen=$(ip -f inet addr | grep -Po 'inet \K[\d.]+' | grep -v 127.0.0.1 | head -1):8080 -config="${SCRIPTPATH}"config/${REPO_CONFIG}
+			aptly serve -listen=$(ip -f inet addr | grep -Po 'inet \K[\d.]+' | grep -v 127.0.0.1 | head -1):8080 -config="${SCRIPTPATH}config/${REPO_CONFIG}"
 			exit 0
 			;;
 		show)
 			# display repository content
 			for release in "${DISTROS[@]}"; do
 				display_alert "Displaying repository contents for" "$release" "ext"
-				aptly repo show -with-packages -config="${SCRIPTPATH}"config/${REPO_CONFIG} "${release}" | tail -n +7
-				aptly repo show -with-packages -config="${SCRIPTPATH}"config/${REPO_CONFIG} "${release}-desktop" | tail -n +7
+				aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}" | tail -n +7
+				aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}-desktop" | tail -n +7
 			done
 			display_alert "Displaying repository contents for" "common utils" "ext"
-			aptly repo show -with-packages -config="${SCRIPTPATH}"config/${REPO_CONFIG} utils | tail -n +7
+			aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" utils | tail -n +7
 			echo "done."
 			exit 0
 			;;
@@ -667,10 +677,10 @@ repo-manipulate() {
 			while true; do
 				LIST=()
 				for release in "${DISTROS[@]}"; do
-					LIST+=( $(aptly repo show -with-packages -config="${SCRIPTPATH}"config/${REPO_CONFIG} "${release}" | tail -n +7) )
-					LIST+=( $(aptly repo show -with-packages -config="${SCRIPTPATH}"config/${REPO_CONFIG} "${release}-desktop" | tail -n +7) )
+					LIST+=( $(aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}" | tail -n +7) )
+					LIST+=( $(aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}-desktop" | tail -n +7) )
 				done
-				LIST+=( $(aptly repo show -with-packages -config="${SCRIPTPATH}"config/${REPO_CONFIG} utils | tail -n +7) )
+				LIST+=( $(aptly repo show -with-packages -config="${SCRIPTPATH}config/${REPO_CONFIG}" utils | tail -n +7) )
 				LIST=( $(echo "${LIST[@]}" | tr ' ' '\n' | sort -u))
 				new_list=()
 				# create a human readable menu
@@ -687,10 +697,10 @@ repo-manipulate() {
 				exec 3>&-
 				if [[ $exitstatus -eq 0 ]]; then
 					for release in "${DISTROS[@]}"; do
-						aptly repo remove -config="${SCRIPTPATH}"config/${REPO_CONFIG}  "${release}" "$TARGET_VERSION"
-						aptly repo remove -config="${SCRIPTPATH}"config/${REPO_CONFIG}  "${release}-desktop" "$TARGET_VERSION"
+						aptly repo remove -config="${SCRIPTPATH}config/${REPO_CONFIG}"  "${release}" "$TARGET_VERSION"
+						aptly repo remove -config="${SCRIPTPATH}config/${REPO_CONFIG}"  "${release}-desktop" "$TARGET_VERSION"
 					done
-					aptly repo remove -config="${SCRIPTPATH}"config/${REPO_CONFIG} "utils" "$TARGET_VERSION"
+					aptly repo remove -config="${SCRIPTPATH}config/${REPO_CONFIG}" "utils" "$TARGET_VERSION"
 				else
 					exit 1
 				fi
@@ -709,16 +719,16 @@ repo-manipulate() {
 				repo-remove-old-packages "$release" "armhf" "5"
 				repo-remove-old-packages "$release" "arm64" "5"
 				repo-remove-old-packages "$release" "all" "5"
-				aptly -config="${SCRIPTPATH}"config/${REPO_CONFIG} -passphrase="${GPG_PASS}" publish update "${release}" > /dev/null 2>&1
+				aptly -config="${SCRIPTPATH}config/${REPO_CONFIG}" -passphrase="${GPG_PASS}" publish update "${release}" > /dev/null 2>&1
 			done
 			exit 0
 			;;
 		purgesource)
 			for release in "${DISTROS[@]}"; do
-				aptly repo remove -config=${SCRIPTPATH}config/${REPO_CONFIG} ${release} 'Name (% *-source*)'
-				aptly -config="${SCRIPTPATH}"config/${REPO_CONFIG} -passphrase="${GPG_PASS}" publish update "${release}"  > /dev/null 2>&1
+				aptly repo remove -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${release}" 'Name (% *-source*)'
+				aptly -config="${SCRIPTPATH}config/${REPO_CONFIG}" -passphrase="${GPG_PASS}" publish update "${release}"  > /dev/null 2>&1
 			done
-			aptly db cleanup -config=${SCRIPTPATH}config/${REPO_CONFIG} > /dev/null 2>&1
+			aptly db cleanup -config="${SCRIPTPATH}config/${REPO_CONFIG}" > /dev/null 2>&1
 			exit 0
 			;;
 		*)
@@ -745,7 +755,7 @@ repo-remove-old-packages() {
     local arch=$2
     local keep=$3
 
-    for pkg in $(aptly repo search -config="${SCRIPTPATH}"config/${REPO_CONFIG} "${repo}" "Architecture ($arch)" | grep -v "ERROR: no results" | sort -rV); do
+    for pkg in $(aptly repo search -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${repo}" "Architecture ($arch)" | grep -v "ERROR: no results" | sort -rV); do
         local pkg_name
         pkg_name=$(echo "${pkg}" | cut -d_ -f1)
         if [ "$pkg_name" != "$cur_pkg" ]; then
@@ -757,7 +767,7 @@ repo-remove-old-packages() {
         ((count+=1))
         if [[ $count -gt $keep ]]; then
             pkg_version=$(echo "${pkg}" | cut -d_ -f2)
-            aptly repo remove -config="${SCRIPTPATH}"config/${REPO_CONFIG} "${repo}" "Name ($pkg_name), Version (<= $pkg_version)"
+            aptly repo remove -config="${SCRIPTPATH}config/${REPO_CONFIG}" "${repo}" "Name ($pkg_name), Version (<= $pkg_version)"
             deleted='yes'
         fi
     done
@@ -921,9 +931,9 @@ prepare_host()
 	# distribution packages are buggy, download from author
 	if [[ ! -f /etc/apt/sources.list.d/aptly.list ]]; then
 		display_alert "Updating from external repository" "aptly" "info"
-		if [ x"" != x$http_proxy ]; then
-			apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --keyserver-options http-proxy=$http_proxy --recv-keys ED75B5A4483DA07C >/dev/null 2>&1
-			apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --keyserver-options http-proxy=$http_proxy --recv-keys ED75B5A4483DA07C >/dev/null 2>&1
+		if [ x"" != x"${http_proxy}" ]; then
+			apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --keyserver-options http-proxy="${http_proxy}" --recv-keys ED75B5A4483DA07C >/dev/null 2>&1
+			apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --keyserver-options http-proxy="${http_proxy}" --recv-keys ED75B5A4483DA07C >/dev/null 2>&1
 		else
 			apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys ED75B5A4483DA07C >/dev/null 2>&1
 			apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys ED75B5A4483DA07C >/dev/null 2>&1
@@ -937,14 +947,14 @@ prepare_host()
 		display_alert "Installing build dependencies"
 		apt-get -q update
 		apt-get -y upgrade
-		apt-get -q -y --no-install-recommends install -o Dpkg::Options::='--force-confold' "${deps[@]}" | tee -a $DEST/debug/hostdeps.log
+		apt-get -q -y --no-install-recommends install -o Dpkg::Options::='--force-confold' "${deps[@]}" | tee -a "${DEST}"/debug/hostdeps.log
 		update-ccache-symlinks
 	fi
 
 	# sync clock
 	if [[ $SYNC_CLOCK != no ]]; then
 		display_alert "Syncing clock" "host" "info"
-		ntpdate -s ${NTP_SERVER:- pool.ntp.org}
+		ntpdate -s "${NTP_SERVER:- pool.ntp.org}"
 	fi
 
 	if [[ $(dpkg-query -W -f='${db:Status-Abbrev}\n' 'zlib1g:i386' 2>/dev/null) != *ii* ]]; then
@@ -952,16 +962,16 @@ prepare_host()
 	fi
 
 	# create directory structure
-	mkdir -p $SRC/{cache,output} $USERPATCHES_PATH
+	mkdir -p "${SRC}"/{cache,output} "${USERPATCHES_PATH}"
 	if [[ -n $SUDO_USER ]]; then
-		chgrp --quiet sudo cache output $USERPATCHES_PATH
+		chgrp --quiet sudo cache output "${USERPATCHES_PATH}"
 		# SGID bit on cache/sources breaks kernel dpkg packaging
-		chmod --quiet g+w,g+s output $USERPATCHES_PATH
+		chmod --quiet g+w,g+s output "${USERPATCHES_PATH}"
 		# fix existing permissions
-		find $SRC/output $USERPATCHES_PATH -type d ! -group sudo -exec chgrp --quiet sudo {} \;
-		find $SRC/output $USERPATCHES_PATH -type d ! -perm -g+w,g+s -exec chmod --quiet g+w,g+s {} \;
+		find "${SRC}"/output "${USERPATCHES_PATH}" -type d ! -group sudo -exec chgrp --quiet sudo {} \;
+		find "${SRC}"/output "${USERPATCHES_PATH}" -type d ! -perm -g+w,g+s -exec chmod --quiet g+w,g+s {} \;
 	fi
-	mkdir -p $DEST/debs-beta/extra $DEST/debs/extra $DEST/{config,debug,patch} $USERPATCHES_PATH/overlay $SRC/cache/{sources,hash,toolchains,utility,rootfs} $SRC/.tmp
+	mkdir -p "${DEST}"/debs-beta/extra "${DEST}"/debs/extra "${DEST}"/{config,debug,patch} "${USERPATCHES_PATH}"/overlay "${SRC}"/cache/{sources,hash,toolchains,utility,rootfs} "${SRC}"/.tmp
 
 	display_alert "Checking for external GCC compilers" "" "info"
 	# download external Linaro compiler and missing special dependencies since they are needed for certain sources
@@ -990,8 +1000,8 @@ prepare_host()
 		download_and_verify "_toolchains" "${toolchain##*/}"
 	done
 
-	rm -rf $SRC/cache/toolchains/*.tar.xz*
-	local existing_dirs=( $(ls -1 $SRC/cache/toolchains) )
+	rm -rf "${SRC}"/cache/toolchains/*.tar.xz*
+	local existing_dirs=( $(ls -1 "${SRC}"/cache/toolchains) )
 	for dir in ${existing_dirs[@]}; do
 		local found=no
 		for toolchain in ${toolchains[@]}; do
@@ -1001,7 +1011,7 @@ prepare_host()
 		done
 		if [[ $found == no ]]; then
 			display_alert "Removing obsolete toolchain" "$dir"
-			rm -rf $SRC/cache/toolchains/$dir
+			rm -rf "${SRC}/cache/toolchains/${dir}"
 		fi
 	done
 
@@ -1015,19 +1025,19 @@ prepare_host()
 		test -e /proc/sys/fs/binfmt_misc/qemu-aarch64 || update-binfmts --enable qemu-aarch64
 	fi
 
-	[[ ! -f $USERPATCHES_PATH/customize-image.sh ]] && cp $SRC/config/templates/customize-image.sh.template $USERPATCHES_PATH/customize-image.sh
+	[[ ! -f "${USERPATCHES_PATH}"/customize-image.sh ]] && cp "${SRC}"/config/templates/customize-image.sh.template "${USERPATCHES_PATH}"/customize-image.sh
 
-	if [[ ! -f $USERPATCHES_PATH/README ]]; then
-		rm -f $USERPATCHES_PATH/readme.txt
-		echo 'Please read documentation about customizing build configuration' > $USERPATCHES_PATH/README
-		echo 'http://www.armbian.com/using-armbian-tools/' >> $USERPATCHES_PATH/README
+	if [[ ! -f "${USERPATCHES_PATH}"/README ]]; then
+		rm -f "${USERPATCHES_PATH}"/readme.txt
+		echo 'Please read documentation about customizing build configuration' > "${USERPATCHES_PATH}"/README
+		echo 'http://www.armbian.com/using-armbian-tools/' >> "${USERPATCHES_PATH}"/README
 
 		# create patches directory structure under USERPATCHES_PATH
-		find $SRC/patch -maxdepth 2 -type d ! -name . | sed "s%/.*patch%/$USERPATCHES_PATH%" | xargs mkdir -p
+		find "${SRC}"/patch -maxdepth 2 -type d ! -name . | sed "s%/.*patch%/$USERPATCHES_PATH%" | xargs mkdir -p
 	fi
 
 	# check free space (basic)
-	local freespace=$(findmnt --target $SRC -n -o AVAIL -b 2>/dev/null) # in bytes
+	local freespace=$(findmnt --target "${SRC}" -n -o AVAIL -b 2>/dev/null) # in bytes
 	if [[ -n $freespace && $(( $freespace / 1073741824 )) -lt 10 ]]; then
 		display_alert "Low free space left" "$(( $freespace / 1073741824 )) GiB" "wrn"
 		# pause here since dialog-based menu will hide this message otherwise
@@ -1063,12 +1073,12 @@ WEBSEED=(
 	fi
 	for toolchain in ${WEBSEED[@]}; do
 		# use only live
-		if [[ `wget -S --spider $toolchain$1 2>&1 >/dev/null | grep 'HTTP/1.1 200 OK'` ]]; then
-			text=$text" "$toolchain$1
+		if [[ $(wget -S --spider "${toolchain}${1}" 2>&1 >/dev/null | grep 'HTTP/1.1 200 OK') ]]; then
+			text="${text} ${toolchain}${1}"
 		fi
 	done
 	text="${text:1}"
-	echo $text
+	echo "${text}"
 }
 
 
@@ -1079,7 +1089,7 @@ download_and_verify()
 
 	local remotedir=$1
 	local filename=$2
-	local localdir=$SRC/cache/${remotedir//_}
+	local localdir="${SRC}"/cache/${remotedir//_}
 	local dirname=${filename//.tar.xz}
 
         if [[ $DOWNLOAD_MIRROR == china ]]; then
@@ -1092,19 +1102,19 @@ download_and_verify()
 		return
 	fi
 
-	cd ${localdir}
+	cd "${localdir}" || exit
 
 	# use local control file
-	if [[ -f $SRC/config/torrents/${filename}.asc ]]; then
-		local torrent=$SRC/config/torrents/${filename}.torrent
-		ln -s $SRC/config/torrents/${filename}.asc ${localdir}/${filename}.asc
-	elif [[ ! `wget -S --spider ${server}${remotedir}/${filename}.asc 2>&1 >/dev/null | grep 'HTTP/1.1 200 OK'` ]]; then
+	if [[ -f "${SRC}"/config/torrents/${filename}.asc ]]; then
+		local torrent="${SRC}"/config/torrents/${filename}.torrent
+		ln -s "${SRC}/config/torrents/${filename}.asc" "${localdir}/${filename}.asc"
+	elif [[ ! $(wget -S --spider "${server}${remotedir}/${filename}.asc" 2>&1 >/dev/null | grep 'HTTP/1.1 200 OK') ]]; then
 		return
 	else
 		# download control file
 		local torrent=${server}torrent/${filename}.torrent
 		aria2c --download-result=hide --disable-ipv6=true --summary-interval=0 --console-log-level=error --auto-file-renaming=false \
-		--continue=false --allow-overwrite=true --dir=${localdir} $(webseed "$remotedir/${filename}.asc") -o "${filename}.asc"
+		--continue=false --allow-overwrite=true --dir="${localdir}" "$(webseed "$remotedir/${filename}.asc")" -o "${filename}.asc"
 		[[ $? -ne 0 ]] && display_alert "Failed to download control file" "" "wrn"
 	fi
 
@@ -1115,75 +1125,75 @@ download_and_verify()
 		local ariatorrent="--summary-interval=0 --auto-save-interval=0 --seed-time=0 --bt-stop-timeout=15 --console-log-level=error \
 		--allow-overwrite=true --download-result=hide --rpc-save-upload-metadata=false --auto-file-renaming=false \
 		--file-allocation=trunc --continue=true ${torrent} \
-		--dht-file-path=$SRC/cache/.aria2/dht.dat --disable-ipv6=true --stderr --follow-torrent=mem --dir=${localdir}"
+		--dht-file-path=${SRC}/cache/.aria2/dht.dat --disable-ipv6=true --stderr --follow-torrent=mem --dir=${localdir}"
 
 		# exception. It throws error if dht.dat file does not exists. Error suppress needed only at first download.
-		if [[ -f $SRC/cache/.aria2/dht.dat ]]; then
-			aria2c ${ariatorrent}
+		if [[ -f "${SRC}"/cache/.aria2/dht.dat ]]; then
+			aria2c "${ariatorrent}"
 		else
-			aria2c ${ariatorrent} &> $DEST/debug/torrent.log
+			aria2c "${ariatorrent}" &> "${DEST}"/debug/torrent.log
 		fi
 		# mark complete
-		[[ $? -eq 0 ]] && touch ${localdir}/${filename}.complete
+		[[ $? -eq 0 ]] && touch "${localdir}/${filename}.complete"
 
 	fi
 
 
 	# direct download if torrent fails
-	if [[ ! -f ${localdir}/${filename}.complete ]]; then
-		if [[ `wget -S --spider ${server}${remotedir}/${filename} 2>&1 >/dev/null \
-			| grep 'HTTP/1.1 200 OK'` ]]; then
+	if [[ ! -f "${localdir}/${filename}.complete" ]]; then
+		if [[ $(wget -S --spider "${server}${remotedir}/${filename}" 2>&1 >/dev/null \
+			| grep 'HTTP/1.1 200 OK') ]]; then
 			display_alert "downloading using http(s) network" "$filename"
 			aria2c --download-result=hide --rpc-save-upload-metadata=false --console-log-level=error \
-			--dht-file-path=$SRC/cache/.aria2/dht.dat --disable-ipv6=true --summary-interval=0 --auto-file-renaming=false --dir=${localdir} $(webseed "$remotedir/$filename") -o ${filename}
+			--dht-file-path="${SRC}"/cache/.aria2/dht.dat --disable-ipv6=true --summary-interval=0 --auto-file-renaming=false --dir="${localdir}" "$(webseed "${remotedir}/${filename}")" -o "${filename}"
 			# mark complete
-			[[ $? -eq 0 ]] && touch ${localdir}/${filename}.complete && echo ""
+			[[ $? -eq 0 ]] && touch "${localdir}/${filename}.complete" && echo ""
 
 		fi
 	fi
 
 	if [[ -f ${localdir}/${filename}.asc ]]; then
 
-		if grep -q 'BEGIN PGP SIGNATURE' ${localdir}/${filename}.asc; then
+		if grep -q 'BEGIN PGP SIGNATURE' "${localdir}/${filename}.asc"; then
 
-			if [[ ! -d $SRC/cache/.gpg ]]; then
-				mkdir -p $SRC/cache/.gpg
-				chmod 700 $SRC/cache/.gpg
-				touch $SRC/cache/.gpg/gpg.conf
-				chmod 600 $SRC/cache/.gpg/gpg.conf
+			if [[ ! -d "${SRC}"/cache/.gpg ]]; then
+				mkdir -p "${SRC}"/cache/.gpg
+				chmod 700 "${SRC}"/cache/.gpg
+				touch "${SRC}"/cache/.gpg/gpg.conf
+				chmod 600 "${SRC}"/cache/.gpg/gpg.conf
 			fi
 
 			# Verify archives with Linaro and Armbian GPG keys
 
-			if [ x"" != x$http_proxy ]; then
-				(gpg --homedir $SRC/cache/.gpg --no-permission-warning --list-keys 8F427EAF >> $DEST/debug/output.log 2>&1\
-				 || gpg --homedir $SRC/cache/.gpg --no-permission-warning \
-				--keyserver hkp://keyserver.ubuntu.com:80 --keyserver-options http-proxy=$http_proxy \
-				--recv-keys 8F427EAF >> $DEST/debug/output.log 2>&1)
+			if [ x"" != x"${http_proxy}" ]; then
+				(gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning --list-keys 8F427EAF >> "${DEST}"/debug/output.log 2>&1\
+				 || gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning \
+				--keyserver hkp://keyserver.ubuntu.com:80 --keyserver-options http-proxy="${http_proxy}" \
+				--recv-keys 8F427EAF >> "${DEST}"/debug/output.log 2>&1)
 
-				(gpg --homedir $SRC/cache/.gpg --no-permission-warning --list-keys 9F0E78D5 >> $DEST/debug/output.log 2>&1\
-				|| gpg --homedir $SRC/cache/.gpg --no-permission-warning \
-				--keyserver hkp://keyserver.ubuntu.com:80 --keyserver-options http-proxy=$http_proxy \
-				--recv-keys 9F0E78D5 >> $DEST/debug/output.log 2>&1)
+				(gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning --list-keys 9F0E78D5 >> "${DEST}"/debug/output.log 2>&1\
+				|| gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning \
+				--keyserver hkp://keyserver.ubuntu.com:80 --keyserver-options http-proxy="${http_proxy}" \
+				--recv-keys 9F0E78D5 >> "${DEST}"/debug/output.log 2>&1)
 			else
-				(gpg --homedir $SRC/cache/.gpg --no-permission-warning --list-keys 8F427EAF >> $DEST/debug/output.log 2>&1\
-				 || gpg --homedir $SRC/cache/.gpg --no-permission-warning \
+				(gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning --list-keys 8F427EAF >> "${DEST}"/debug/output.log 2>&1\
+				 || gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning \
 				--keyserver hkp://keyserver.ubuntu.com:80 \
-				--recv-keys 8F427EAF >> $DEST/debug/output.log 2>&1)
+				--recv-keys 8F427EAF >> "${DEST}"/debug/output.log 2>&1)
 
-				(gpg --homedir $SRC/cache/.gpg --no-permission-warning --list-keys 9F0E78D5 >> $DEST/debug/output.log 2>&1\
-				|| gpg --homedir $SRC/cache/.gpg --no-permission-warning \
+				(gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning --list-keys 9F0E78D5 >> "${DEST}"/debug/output.log 2>&1\
+				|| gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning \
 				--keyserver hkp://keyserver.ubuntu.com:80 \
-				--recv-keys 9F0E78D5 >> $DEST/debug/output.log 2>&1)
+				--recv-keys 9F0E78D5 >> "${DEST}"/debug/output.log 2>&1)
 			fi
 
-			gpg --homedir $SRC/cache/.gpg --no-permission-warning --verify \
-			--trust-model always -q ${localdir}/${filename}.asc >> $DEST/debug/output.log 2>&1
+			gpg --homedir "${SRC}"/cache/.gpg --no-permission-warning --verify \
+			--trust-model always -q "${localdir}/${filename}.asc" >> "${DEST}"/debug/output.log 2>&1
 			[[ ${PIPESTATUS[0]} -eq 0 ]] && verified=true && display_alert "Verified" "PGP" "info"
 
 		else
 
-			md5sum -c --status ${localdir}/${filename}.asc && verified=true && display_alert "Verified" "MD5" "info"
+			md5sum -c --status "${localdir}/${filename}.asc" && verified=true && display_alert "Verified" "MD5" "info"
 
 		fi
 
@@ -1191,8 +1201,8 @@ download_and_verify()
 			if [[ "${filename:(-6)}" == "tar.xz" ]]; then
 
 				display_alert "decompressing"
-				pv -p -b -r -c -N "[ .... ] ${filename}" $filename | xz -dc | tar xp --xattrs --no-same-owner --overwrite
-				[[ $? -eq 0 ]] && touch ${localdir}/$dirname/.download-complete
+				pv -p -b -r -c -N "[ .... ] ${filename}" "${filename}" | xz -dc | tar xp --xattrs --no-same-owner --overwrite
+				[[ $? -eq 0 ]] && touch "${localdir}/${dirname}/.download-complete"
 			fi
 		else
 			exit_with_error "verification failed"
@@ -1206,8 +1216,9 @@ download_and_verify()
 
 show_developer_warning()
 {
-	local temp_rc=$(mktemp)
-	cat <<-'EOF' > $temp_rc
+	local temp_rc
+	temp_rc=$(mktemp)
+	cat <<-'EOF' > "${temp_rc}"
 	screen_color = (WHITE,RED,ON)
 	EOF
 	local warn_text="You are switching to the \Z1EXPERT MODE\Zn
@@ -1222,8 +1233,8 @@ show_developer_warning()
 	- Forum posts related to dev kernel, CSC, WIP and EOS boards
 	should be created in the \Z2\"Community forums\"\Zn section
 	"
-	DIALOGRC=$temp_rc dialog --title "Expert mode warning" --backtitle "$backtitle" --colors --defaultno --no-label "I do not agree" \
-		--yes-label "I understand and agree" --yesno "$warn_text" $TTY_Y $TTY_X
+	DIALOGRC=$temp_rc dialog --title "Expert mode warning" --backtitle "${backtitle}" --colors --defaultno --no-label "I do not agree" \
+		--yes-label "I understand and agree" --yesno "$warn_text" "${TTY_Y}" "${TTY_X}"
 	[[ $? -ne 0 ]] && exit_with_error "Error switching to the expert mode"
 	SHOW_WARNING=no
 }