Add ShellCheck and shfmt shell code quality analysis (#2712)

* Add ShellCheck and shfmt shell code quality analysis

* kobo/koreader.sh: remove useless $PREFIX

* kobo/koreader.sh: fix rotation issue caused by #2731

* Travis: speed up (caching Luarocks should shave a minute off install process)

.ci/after_success.sh

@@ -1,14 +1,15 @@
 #!/usr/bin/env bash
 
 CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=/dev/null
 source "${CI_DIR}/common.sh"
 
 set +e
 
-if [ ${TRAVIS_PULL_REQUEST} = false ] && [ ${TRAVIS_BRANCH} = 'master' ]; then
+if [ "${TRAVIS_PULL_REQUEST}" = false ] && [ "${TRAVIS_BRANCH}" = 'master' ]; then
     travis_retry luarocks --local install ldoc
     # get deploy key for doc repo
-    openssl aes-256-cbc -k $doc_build_secret -in .ci/koreader_doc.enc -out ~/.ssh/koreader_doc -d
+    openssl aes-256-cbc -k "${doc_build_secret:?}" -in .ci/koreader_doc.enc -out ~/.ssh/koreader_doc -d
     chmod 600 ~/.ssh/koreader_doc  # make agent happy
     eval "$(ssh-agent)" > /dev/null
     ssh-add ~/.ssh/koreader_doc > /dev/null
@@ -17,7 +18,7 @@ if [ ${TRAVIS_PULL_REQUEST} = false ] && [ ${TRAVIS_BRANCH} = 'master' ]; then
 
     # push doc update
     pushd doc
-        luajit $(which ldoc) . 2> /dev/null
+        luajit "$(which ldoc)" . 2> /dev/null
         if [ ! -d html ]; then
             echo "Failed to generate documents..."
             exit 1
@@ -38,5 +39,5 @@ fi
 
 travis_retry make coverage
 pushd koreader-*/koreader
-    luajit $(which luacov-coveralls)
+    luajit "$(which luacov-coveralls)"
 popd

.ci/before_install.sh

@@ -6,7 +6,7 @@ if [ "$CXX" = "g++" ];
 fi
 # in case anything ignores the environment variables, override through PATH
 mkdir bin
-ln -s $(which gcc-4.8) bin/cc
-ln -s $(which gcc-4.8) bin/gcc
-ln -s $(which c++-4.8) bin/c++
-ln -s $(which g++-4.8) bin/g++
+ln -s "$(which gcc-4.8)" bin/cc
+ln -s "$(which gcc-4.8)" bin/gcc
+ln -s "$(which c++-4.8)" bin/c++
+ln -s "$(which g++-4.8)" bin/g++

.ci/common.sh

@@ -1,9 +1,13 @@
+#!/usr/bin/env bash
+
 set -e
 set -o pipefail
 
 ANSI_RED="\033[31;1m"
+# shellcheck disable=SC2034
 ANSI_GREEN="\033[32;1m"
 ANSI_RESET="\033[0m"
+# shellcheck disable=SC2034
 ANSI_CLEAR="\033[0K"
 
 travis_retry() {
@@ -13,17 +17,17 @@ travis_retry() {
 
   while [ $count -le 3 ]; do
     [ $result -ne 0 ] && {
-      echo -e "\n${ANSI_RED}The command \"$@\" failed. Retrying, $count of 3.${ANSI_RESET}\n" >&2
+      echo -e "\n${ANSI_RED}The command \"$*\" failed. Retrying, $count of 3.${ANSI_RESET}\n" >&2
     }
     "$@"
     result=$?
     [ $result -eq 0 ] && break
-    count=$(($count + 1))
+    count=$((count + 1))
     sleep 1
   done
 
   [ $count -gt 3 ] && {
-    echo -e "\n${ANSI_RED}The command \"$@\" failed 3 times.${ANSI_RESET}\n" >&2
+    echo -e "\n${ANSI_RED}The command \"$*\" failed 3 times.${ANSI_RESET}\n" >&2
   }
 
   set -e
@@ -38,19 +42,19 @@ retry_cmd() {
   retry_cnt=$1
   shift 1
 
-  while [ $count -le ${retry_cnt} ]; do
+  while [ $count -le "${retry_cnt}" ]; do
     [ $result -ne 0 ] && {
-      echo -e "\n${ANSI_RED}The command \"$@\" failed. Retrying, $count of ${retry_cnt}${ANSI_RESET}\n" >&2
+      echo -e "\n${ANSI_RED}The command \"$*\" failed. Retrying, $count of ${retry_cnt}${ANSI_RESET}\n" >&2
     }
     "$@"
     result=$?
     [ $result -eq 0 ] && break
-    count=$(($count + 1))
+    count=$((count + 1))
     sleep 1
   done
 
-  [ $count -gt ${retry_cnt} ] && {
-    echo -e "\n${ANSI_RED}The command \"$@\" failed ${retry_cnt} times.${ANSI_RESET}\n" >&2
+  [ $count -gt "${retry_cnt}" ] && {
+    echo -e "\n${ANSI_RED}The command \"$*\" failed ${retry_cnt} times.${ANSI_RESET}\n" >&2
   }
 
   set -e
@@ -59,7 +63,7 @@ retry_cmd() {
 
 export PATH=$PWD/bin:$PATH
 export PATH=$PATH:${TRAVIS_BUILD_DIR}/install/bin
-if [ -f ${TRAVIS_BUILD_DIR}/install/bin/luarocks ]; then
+if [ -f "${TRAVIS_BUILD_DIR}/install/bin/luarocks" ]; then
     # add local rocks to $PATH
-    eval $(luarocks path --bin)
+    eval "$(luarocks path --bin)"
 fi

.ci/install.sh

@@ -1,19 +1,22 @@
 #!/usr/bin/env bash
 
 CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=/dev/null
 source "${CI_DIR}/common.sh"
 
 # install our own updated luarocks
-git clone https://github.com/torch/luajit-rocks.git
-pushd luajit-rocks
-    git checkout 6529891
-    cmake . -DWITH_LUAJIT21=ON -DCMAKE_INSTALL_PREFIX=${TRAVIS_BUILD_DIR}/install
-    make install
-popd
+if [ ! -f "${TRAVIS_BUILD_DIR}/install/bin/luarocks" ]; then
+    git clone https://github.com/torch/luajit-rocks.git
+    pushd luajit-rocks
+        git checkout 6529891
+        cmake . -DWITH_LUAJIT21=ON -DCMAKE_INSTALL_PREFIX="${TRAVIS_BUILD_DIR}/install"
+        make install
+    popd
+fi
 
-mkdir $HOME/.luarocks
-cp ${TRAVIS_BUILD_DIR}/install/etc/luarocks/config.lua $HOME/.luarocks/config.lua
-echo "wrap_bin_scripts = false" >> $HOME/.luarocks/config.lua
+mkdir "${HOME}/.luarocks"
+cp "${TRAVIS_BUILD_DIR}/install/etc/luarocks/config.lua" "$HOME/.luarocks/config.lua"
+echo "wrap_bin_scripts = false" >> "$HOME/.luarocks/config.lua"
 travis_retry luarocks --local install luafilesystem
 # for verbose_print module
 travis_retry luarocks --local install ansicolors
@@ -25,3 +28,18 @@ travis_retry luarocks --local install luasec OPENSSL_LIBDIR=/usr/lib/x86_64-linu
 travis_retry luarocks --local install luacov-coveralls --server=http://rocks.moonscript.org/dev
 travis_retry luarocks --local install luacheck
 travis_retry luarocks --local install lanes  # for parallel luacheck
+
+#install our own updated shellcheck
+SHELLCHECK_URL="https://s3.amazonaws.com/travis-blue-public/binaries/ubuntu/14.04/x86_64/shellcheck-0.4.5.tar.bz2"
+if ! command -v shellcheck ; then
+    curl -sSL "${SHELLCHECK_URL}" | tar --exclude 'SHA256SUMS' --strip-components=1 -C "${HOME}/bin" -xjf -;
+    chmod +x "${HOME}/bin/shellcheck"
+    shellcheck --version
+fi
+
+# install shfmt
+SHFMT_URL="https://github.com/mvdan/sh/releases/download/v1.2.0/shfmt_v1.2.0_linux_amd64"
+if ! command -v shfmt ; then
+    curl -sSL "${SHFMT_URL}" -o "${HOME}/bin/shfmt"
+    chmod +x "${HOME}/bin/shfmt"
+fi

.ci/script.sh

@@ -1,9 +1,12 @@
 #!/usr/bin/env bash
 
 CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=/dev/null
 source "${CI_DIR}/common.sh"
 
 travis_retry make fetchthirdparty
+find . -type f -name '*.sh' -not -path "./base/*" -not -path "./luajit-rocks/*" -print0 | xargs --null shellcheck
+find . -type f -name '*.sh' -not -path "./base/*" -not -path "./luajit-rocks/*" -print0 | xargs shfmt -i 0 -w
 make all
 make testfront
-luajit $(which luacheck) --no-color -q {reader,setupkoenv,datastorage}.lua frontend plugins
+luajit "$(which luacheck)" --no-color -q {reader,setupkoenv,datastorage}.lua frontend plugins

.travis.yml

@@ -8,12 +8,18 @@ compiler:
   - gcc
 
 env:
-  - EMULATE_READER=1
+  global:
+    - "PATH=${HOME}/bin:${PATH}"
+  matrix:
+    - EMULATE_READER=1
 
 cache:
   apt: true
   directories:
-    - $HOME/.ccache
+    - "${HOME}/bin"
+    # compiled luarocks binaries
+    - "${HOME}/build/koreader/koreader/install"
+    - "${HOME}/.ccache"
 
 addons:
   apt:

kodev

@@ -12,7 +12,10 @@ function assert_ret_zero {
 }
 
 function check_submodules {
-    [ -n "$(git submodule status | grep -E '^\-')" ] && kodev-fetch-thirdparty
+    if git submodule status | grep -qE '^\-'
+    then
+        kodev-fetch-thirdparty
+    fi
 }
 
 function setup_env {

platform/android/luajit-launcher

@@ -1 +1 @@
-Subproject commit f304bf86590c426ba9a6dd835c0eaebccdd49d50
+Subproject commit 3bdf92c1272d969af5f419492edf760aa2947cf3

platform/kindle/extensions/koreader/bin/koreader-ext.sh

@@ -9,7 +9,8 @@ KOREADER_DIR="/mnt/us/koreader"
 
 # Load our helper functions...
 if [ -f "${KOREADER_DIR}/libkohelper.sh" ] ; then
-	source "${KOREADER_DIR}/libkohelper.sh"
+	# shellcheck source=/dev/null
+	. "${KOREADER_DIR}/libkohelper.sh"
 else
 	echo "Can't source helper functions, aborting!"
 	exit 1
@@ -19,9 +20,9 @@ fi
 logmsg()
 {
 	# Use the right tools for the platform
-	if [ "${INIT_TYPE}" == "sysv" ] ; then
+	if [ "${INIT_TYPE}" = "sysv" ] ; then
 		msg "koreader: ${1}" "I"
-	elif [ "${INIT_TYPE}" == "upstart" ] ; then
+	elif [ "${INIT_TYPE}" = "upstart" ] ; then
 		f_log I koreader kual "" "${1}"
 	fi
 
@@ -35,7 +36,7 @@ logmsg()
 update_koreader()
 {
 	# Check if we were called by install_koreader...
-	if [ "${1}" == "clean" ] ; then
+	if [ "${1}" = "clean" ] ; then
 		do_clean_install="true"
 	else
 		do_clean_install="false"
@@ -56,19 +57,19 @@ update_koreader()
 		fi
 	done
 
-	if [ "${found_koreader_package}" == "false" ] ; then
+	if [ "${found_koreader_package}" = "false" ] ; then
 		# Go away
 		logmsg "No KOReader package found"
 	else
 		# Do we want to do a clean install?
-		if [ "${do_clean_install}" == "true" ] ; then
+		if [ "${do_clean_install}" = "true" ] ; then
 			logmsg "Removing current KOReader directory . . ."
 			rm -rf /mnt/us/koreader
 			logmsg "Uninstall finished."
 		fi
 
 		# Get the version of the package...
-		if [ "${koreader_pkg_type}" == "tgz" ] ; then
+		if [ "${koreader_pkg_type}" = "tgz" ] ; then
 			koreader_pkg_ver="${found_koreader_package%.*.*}"
 		else
 			koreader_pkg_ver="${found_koreader_package%.*}"
@@ -76,12 +77,14 @@ update_koreader()
 		koreader_pkg_ver="${koreader_pkg_ver#*-v}"
 		# Install it!
 		logmsg "Updating to KOReader ${koreader_pkg_ver} . . ."
-		if [ "${koreader_pkg_type}" == "tgz" ] ; then
+		if [ "${koreader_pkg_type}" = "tgz" ] ; then
 			tar -C "/mnt/us" -xzf "${found_koreader_package}"
+			fail=$?
 		else
 			unzip -q -o "${found_koreader_package}" -d "/mnt/us"
+			fail=$?
 		fi
-		if [ $? -eq 0 ] ; then
+		if [ $fail -eq 0 ] ; then
 			logmsg "Update to v${koreader_pkg_ver} successful :)"
 			# Cleanup behind us...
 			rm -f "${found_koreader_package}"
@@ -115,11 +118,12 @@ set_cre_prop()
 	# Check that the config exists...
 	if [ -f "${cre_config}" ] ; then
 		# dos2unix
+		# shellcheck disable=SC2039
 		sed -e "s/$(echo -ne '\r')$//g" -i "${cre_config}"
 
 		# And finally set the prop
-		sed -re "s/^(${cre_prop_key})(=)(.*?)$/\1\2${cre_prop_value}/" -i "${cre_config}"
-		if [ $? -eq 0 ] ; then
+		if sed -re "s/^(${cre_prop_key})(=)(.*?)$/\1\2${cre_prop_value}/" -i "${cre_config}"
+		then
 			logmsg "Set ${cre_prop_key} to ${cre_prop_value}"
 		else
 			logmsg "Failed to set ${cre_prop_key}"

platform/kindle/koreader.sh

@@ -11,7 +11,8 @@ KOREADER_DIR="/mnt/us/koreader"
 
 # Load our helper functions...
 if [ -f "${KOREADER_DIR}/libkohelper.sh" ] ; then
-	source "${KOREADER_DIR}/libkohelper.sh"
+	# shellcheck source=/dev/null
+	. "${KOREADER_DIR}/libkohelper.sh"
 else
 	echo "Can't source helper functions, aborting!"
 	exit 1
@@ -21,9 +22,9 @@ fi
 logmsg()
 {
 	# Use the right tools for the platform
-	if [ "${INIT_TYPE}" == "sysv" ] ; then
+	if [ "${INIT_TYPE}" = "sysv" ] ; then
 		msg "koreader: ${1}" "I"
-	elif [ "${INIT_TYPE}" == "upstart" ] ; then
+	elif [ "${INIT_TYPE}" = "upstart" ] ; then
 		f_log I koreader wrapper "" "${1}"
 	fi
 
@@ -32,7 +33,7 @@ logmsg()
 }
 
 # Go away if we're on FW 5.0, it's not supported
-if [ "${INIT_TYPE}" == "upstart" ] ; then
+if [ "${INIT_TYPE}" = "upstart" ] ; then
 	if grep '^Kindle 5\.0' /etc/prettyversion.txt > /dev/null 2>&1 ; then
 		logmsg "FW 5.0 is not supported. Update to 5.1!"
 		# And... scene!
@@ -50,11 +51,11 @@ PASSCODE_DISABLED="no"
 FROM_KUAL="no"
 
 # By default, don't stop the framework.
-if [ "$1" == "--framework_stop" ] ; then
+if [ "$1" = "--framework_stop" ] ; then
 	shift 1
 	STOP_FRAMEWORK="yes"
 	NO_SLEEP="no"
-elif [ "$1" == "--asap" ] ; then
+elif [ "$1" = "--asap" ] ; then
 	# Start as soon as possible, without sleeping to workaround UI quirks
 	shift 1
 	NO_SLEEP="yes"
@@ -67,9 +68,9 @@ else
 fi
 
 # Detect if we were started by KUAL by checking our nice value...
-if [ "$(nice)" == "5" ] ; then
+if [ "$(nice)" = "5" ] ; then
 	FROM_KUAL="yes"
-	if [ "${NO_SLEEP}" == "no" ] ; then
+	if [ "${NO_SLEEP}" = "no" ] ; then
 		# Yield a bit to let stuff stop properly...
 		logmsg "Hush now . . ."
 		# NOTE: This may or may not be terribly useful...
@@ -82,7 +83,7 @@ if [ "$(nice)" == "5" ] ; then
 fi
 
 # we're always starting from our working directory
-cd "${KOREADER_DIR}"
+cd "${KOREADER_DIR}" || exit
 
 # Handle pending OTA update
 NEWUPDATE="${KOREADER_DIR}/ota/koreader.updated.tar"
@@ -94,14 +95,17 @@ if [ -f "${NEWUPDATE}" ] ; then
 	if [ -x "${GNUTAR_BIN}" ] ; then
 		# Let our checkpoint script handle the detailed visual feedback...
 		eips_print_bottom_centered "Updating koreader" 1
+		# shellcheck disable=SC2016
 		${GNUTAR_BIN} -C "/mnt/us" --no-same-owner --no-same-permissions --checkpoint=200 --checkpoint-action=exec='./kotar_cpoint $TAR_CHECKPOINT' -xf "${NEWUPDATE}"
+		fail=$?
 	else
 		# Fall back to busybox tar
 		eips_print_bottom_centered "Updating koreader . . ." 1
 		tar -C "/mnt/us" -xf "${NEWUPDATE}"
+		fail=$?
 	fi
 	# Cleanup behind us...
-	if [ $? -eq 0 ] ; then
+	if [ $fail -eq 0 ] ; then
 		mv "${NEWUPDATE}" "${INSTALLED}"
 		logmsg "Update sucessful :)"
 		eips_print_bottom_centered "Update successful :)" 1
@@ -125,7 +129,7 @@ export STARDICT_DATA_DIR="data/dict"
 export EXT_FONT_DIR="/mnt/us/fonts"
 
 # Only setup IPTables on evices where it makes sense to (FW 5.x & K4)
-if [ "${INIT_TYPE}" == "upstart" -o "$(uname -r)" == "2.6.31-rt11-lab126" ] ; then
+if [ "${INIT_TYPE}" = "upstart" ] || [ "$(uname -r)" = "2.6.31-rt11-lab126" ] ; then
 	logmsg "Setting up IPTables rules . . ."
 	# accept input ports for zsync plugin
 	iptables -A INPUT -i wlan0 -p udp --dport 5670 -j ACCEPT
@@ -176,36 +180,38 @@ if [ -f "/var/local/system/userpasswdenabled" ] ; then
 fi
 
 # check if we are supposed to shut down the Amazon framework
-if [ "${STOP_FRAMEWORK}" == "yes" ] ; then
+if [ "${STOP_FRAMEWORK}" = "yes" ] ; then
 	logmsg "Stopping the framework . . ."
 	# Upstart or SysV?
-	if [ "${INIT_TYPE}" == "sysv" ] ; then
+	if [ "${INIT_TYPE}" = "sysv" ] ; then
 		/etc/init.d/framework stop
 	else
 		# The framework job sends a SIGTERM on stop, trap it so we don't get killed if we were launched by KUAL
-		trap "" SIGTERM
+		trap "" TERM
 		stop lab126_gui
 		# NOTE: Let the framework teardown finish, so we don't start before the black screen...
 		usleep 1250000
 		# And remove the trap like a ninja now!
-		trap - SIGTERM
+		trap - TERM
 	fi
 fi
 
 # check if kpvbooklet was launched for more than once, if not we will disable pillow
 # there's no pillow if we stopped the framework, and it's only there on systems with upstart anyway
-if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "upstart" ] ; then
+if [ "${STOP_FRAMEWORK}" = "no" ] && [ "${INIT_TYPE}" = "upstart" ] ; then
 	count=$(lipc-get-prop -eiq com.github.koreader.kpvbooklet.timer count)
-	if [ "$count" == "" -o "$count" == "0" ] ; then
+	if [ "$count" = "" ] || [ "$count" = "0" ] ; then
 		# NOTE: Dump the fb so we can restore something useful on exit...
 		cat /dev/fb0 > /var/tmp/koreader-fb.dump
 		# NOTE: We want to disable the status bar (at the very least). Unfortunately, the soft hide/unhide method doesn't work properly anymore since FW 5.6.5...
+		# shellcheck disable=SC2046
 		if [ "$(printf "%.3s" $(grep '^Kindle 5' /etc/prettyversion.txt 2>&1 | sed -n -r 's/^(Kindle)([[:blank:]]*)([[:digit:].]*)(.*?)$/\3/p' | tr -d '.'))" -ge "565" ] ; then
 			PILLOW_HARD_DISABLED="yes"
 			# FIXME: So we resort to killing pillow completely on FW >= 5.6.5...
 			logmsg "Disabling pillow . . ."
 			lipc-set-prop com.lab126.pillow disableEnablePillow disable
 			# NOTE: And, oh, joy, on FW >= 5.7.2, this is not enough to prevent the clock from refreshing, so, take the bull by the horns, and SIGSTOP the WM while we run...
+			# shellcheck disable=SC2046
 			if [ "$(printf "%.3s" $(grep '^Kindle 5' /etc/prettyversion.txt 2>&1 | sed -n -r 's/^(Kindle)([[:blank:]]*)([[:digit:].]*)(.*?)$/\3/p' | tr -d '.'))" -ge "572" ] ; then
 				logmsg "Stopping awesome . . ."
 				killall -stop awesome
@@ -218,12 +224,12 @@ if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "upstart" ] ; then
 			PILLOW_SOFT_DISABLED="yes"
 		fi
 		# NOTE: We don't need to sleep at all if we've already SIGSTOPped awesome ;)
-		if [ "${NO_SLEEP}" == "no" -a "${AWESOME_STOPPED}" == "no" ] ; then
+		if [ "${NO_SLEEP}" = "no" ] && [ "${AWESOME_STOPPED}" = "no" ] ; then
 			# NOTE: Leave the framework time to refresh the screen, so we don't start before it has finished redrawing after collapsing the title bar
 			usleep 250000
 			# NOTE: If we were started from KUAL, we risk getting a list item to popup right over us, so, wait some more...
 			# The culprit appears to be a I WindowManager:flashTimeoutExpired:window=Root 0 0 600x30
-			if [ "${FROM_KUAL}" == "yes" ] ; then
+			if [ "${FROM_KUAL}" = "yes" ] ; then
 				logmsg "Playing possum to wait for the window manager . . ."
 				usleep 2500000
 			fi
@@ -232,7 +238,7 @@ if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "upstart" ] ; then
 fi
 
 # stop cvm (sysv & framework up only)
-if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "sysv" ] ; then
+if [ "${STOP_FRAMEWORK}" = "no" ] && [ "${INIT_TYPE}" = "sysv" ] ; then
 	logmsg "Stopping cvm . . ."
 	killall -stop cvm
 fi
@@ -240,13 +246,15 @@ fi
 # finally call reader
 logmsg "Starting KOReader . . ."
 # That's not necessary when using KPVBooklet ;).
-if [ "${FROM_KUAL}" == "yes" ] ; then
+if [ "${FROM_KUAL}" = "yes" ] ; then
 	eips_print_bottom_centered "Starting KOReader . . ." 1
 fi
 
 # we keep maximum 500K worth of crash log
-cat crash.log 2> /dev/null | tail -c 500000 > crash.log.new
-mv -f crash.log.new crash.log
+if [ -e crash.log ]; then
+	tail -c 500000 crash.log > crash.log.new
+	mv -f crash.log.new crash.log
+fi
 ./reader.lua "$@" >> crash.log 2>&1
 
 # clean up our own process tree in case the reader crashed (if needed, to avoid flooding KUAL's log)
@@ -280,7 +288,7 @@ if grep ${KOREADER_DIR}/fonts/linkfonts /proc/mounts > /dev/null 2>&1 ; then
 fi
 
 # Resume cvm (only if we stopped it)
-if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "sysv" ] ; then
+if [ "${STOP_FRAMEWORK}" = "no" ] && [ "${INIT_TYPE}" = "sysv" ] ; then
 	logmsg "Resuming cvm . . ."
 	killall -cont cvm
 	# We need to handle the screen refresh ourselves, frontend/device/kindle/device.lua's Kindle3.exit is called before we resume cvm ;).
@@ -289,9 +297,9 @@ if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "sysv" ] ; then
 fi
 
 # Restart framework (if need be)
-if [ "${STOP_FRAMEWORK}" == "yes" ] ; then
+if [ "${STOP_FRAMEWORK}" = "yes" ] ; then
 	logmsg "Restarting framework . . ."
-	if [ "${INIT_TYPE}" == "sysv" ] ; then
+	if [ "${INIT_TYPE}" = "sysv" ] ; then
 		cd / && env -u LD_LIBRARY_PATH /etc/init.d/framework start
 	else
 		cd / && env -u LD_LIBRARY_PATH start lab126_gui
@@ -299,13 +307,13 @@ if [ "${STOP_FRAMEWORK}" == "yes" ] ; then
 fi
 
 # Display chrome bar if need be (upstart & framework up only)
-if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "upstart" ] ; then
+if [ "${STOP_FRAMEWORK}" = "no" ] && [ "${INIT_TYPE}" = "upstart" ] ; then
 	# Depending on the FW version, we may have handled things in a few different manners...
-	if [ "${AWESOME_STOPPED}" == "yes" ] ; then
+	if [ "${AWESOME_STOPPED}" = "yes" ] ; then
 		logmsg "Resuming awesome . . ."
 		killall -cont awesome
 	fi
-	if [ "${PILLOW_HARD_DISABLED}" == "yes" ] ; then
+	if [ "${PILLOW_HARD_DISABLED}" = "yes" ] ; then
 		logmsg "Enabling pillow . . ."
 		lipc-set-prop com.lab126.pillow disableEnablePillow enable
 		# NOTE: Try to leave the user with a slightly more useful FB content than our own last screen...
@@ -315,7 +323,7 @@ if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "upstart" ] ; then
 		# NOTE: In case we ever need an extra full flash refresh...
 		#eips -s w=${SCREEN_X_RES},h=${SCREEN_Y_RES} -f
 	fi
-	if [ "${PILLOW_SOFT_DISABLED}" == "yes" ] ; then
+	if [ "${PILLOW_SOFT_DISABLED}" = "yes" ] ; then
 		logmsg "Restoring the status bar . . ."
 		# NOTE: Try to leave the user with a slightly more useful FB content than our own last screen...
 		cat /var/tmp/koreader-fb.dump > /dev/fb0
@@ -325,7 +333,7 @@ if [ "${STOP_FRAMEWORK}" == "no" -a "${INIT_TYPE}" == "upstart" ] ; then
 	fi
 fi
 
-if [ "${INIT_TYPE}" == "upstart" -o "$(uname -r)" == "2.6.31-rt11-lab126" ] ; then
+if [ "${INIT_TYPE}" = "upstart" ] || [ "$(uname -r)" = "2.6.31-rt11-lab126" ] ; then
 	logmsg "Restoring IPTables rules . . ."
 	# restore firewall rules
 	iptables -D INPUT -i wlan0 -p udp --dport 8134 -j ACCEPT
@@ -333,8 +341,7 @@ if [ "${INIT_TYPE}" == "upstart" -o "$(uname -r)" == "2.6.31-rt11-lab126" ] ; th
 	iptables -D INPUT -i wlan0 -p tcp --dport 49152:49162 -j ACCEPT
 fi
 
-if [ "${PASSCODE_DISABLED}" == "yes" ] ; then
+if [ "${PASSCODE_DISABLED}" = "yes" ] ; then
 	logmsg "Restoring system passcode . . ."
 	touch "/var/local/system/userpasswdenabled"
 fi
-

platform/kindle/libkohelper.sh

@@ -3,13 +3,15 @@
 ## A bit of helper functions...
 # Check which type of init system we're running on
 if [ -d /etc/upstart ] ; then
-	INIT_TYPE="upstart"
+	export INIT_TYPE="upstart"
 	# We'll need that for logging
-	[ -f /etc/upstart/functions ] && source /etc/upstart/functions
+	# shellcheck disable=SC1091
+	[ -f /etc/upstart/functions ] && . /etc/upstart/functions
 else
-	INIT_TYPE="sysv"
+	export INIT_TYPE="sysv"
 	# We'll need that for logging
-	[ -f /etc/rc.d/functions ] && source /etc/rc.d/functions
+	# shellcheck disable=SC1091
+	[ -f /etc/rc.d/functions ] && . /etc/rc.d/functions
 fi
 
 # We need to get the proper constants for our model...
@@ -86,8 +88,8 @@ case "${kmodel}" in
 	;;
 esac
 # And now we can do the maths ;)
-EIPS_MAXCHARS="$((${SCREEN_X_RES} / ${EIPS_X_RES}))"
-EIPS_MAXLINES="$((${SCREEN_Y_RES} / ${EIPS_Y_RES}))"
+EIPS_MAXCHARS="$((SCREEN_X_RES / EIPS_X_RES))"
+EIPS_MAXLINES="$((SCREEN_Y_RES / EIPS_Y_RES))"
 
 # Adapted from libkh[5]
 eips_print_bottom_centered()
@@ -106,10 +108,10 @@ eips_print_bottom_centered()
 
 	# Add the right amount of left & right padding, since we're centered, and eips doesn't trigger a full refresh,
 	# so we'll have to padd our string with blank spaces to make sure two consecutive messages don't run into each other
-	kh_padlen="$(((${EIPS_MAXCHARS} - ${kh_eips_strlen}) / 2))"
+	kh_padlen="$(((EIPS_MAXCHARS - kh_eips_strlen) / 2))"
 
 	# Left padding...
-	while [ ${#kh_eips_string} -lt $((${kh_eips_strlen} + ${kh_padlen})) ] ; do
+	while [ ${#kh_eips_string} -lt $((kh_eips_strlen + kh_padlen)) ] ; do
 		kh_eips_string=" ${kh_eips_string}"
 	done
 
@@ -126,5 +128,5 @@ eips_print_bottom_centered()
 	fi
 
 	# And finally, show our formatted message centered on the bottom of the screen (NOTE: Redirect to /dev/null to kill unavailable character & pixel not in range warning messages)
-	eips 0 $((${EIPS_MAXLINES} - 2 - ${kh_eips_y_shift_up})) "${kh_eips_string}" >/dev/null
+	eips 0 $((EIPS_MAXLINES - 2 - kh_eips_y_shift_up)) "${kh_eips_string}" >/dev/null
 }

platform/kobo/disable-wifi.sh

@@ -9,9 +9,9 @@ ifconfig eth0 down
 
 # Some sleep in between may avoid system getting hung
 # (we test if a module is actually loaded to avoid unneeded sleeps)
-if lsmod | grep -q $WIFI_MODULE ; then
+if lsmod | grep -q "${WIFI_MODULE}" ; then
     usleep 200000
-    rmmod -r $WIFI_MODULE
+    rmmod -r "${WIFI_MODULE}"
 fi
 if lsmod | grep -q sdio_wifi_pwr ; then
     usleep 200000

platform/kobo/enable-wifi.sh

@@ -2,9 +2,9 @@
 
 # Load wifi modules and enable wifi.
 
-lsmod | grep -q sdio_wifi_pwr || insmod /drivers/$PLATFORM/wifi/sdio_wifi_pwr.ko
+lsmod | grep -q sdio_wifi_pwr || insmod "/drivers/${PLATFORM}/wifi/sdio_wifi_pwr.ko"
 # WIFI_MODULE_PATH = /drivers/$PLATFORM/wifi/$WIFI_MODULE.ko
-lsmod | grep -q $WIFI_MODULE || insmod $WIFI_MODULE_PATH
+lsmod | grep -q "${WIFI_MODULE}" || insmod "${WIFI_MODULE_PATH}"
 sleep 1
 
 ifconfig eth0 up

platform/kobo/fmon/koreader.sh

@@ -1 +1,2 @@
-${root}/.kobo/fmon/fmon "${root}/koreader.png" "${root}/.kobo/koreader/koreader.sh" &
+#!/bin/sh
+"${root:?}/.kobo/fmon/fmon" "${root}/koreader.png" "${root}/.kobo/koreader/koreader.sh" &

platform/kobo/koreader.sh

@@ -13,7 +13,7 @@ if [ -f "${NEWUPDATE}" ] ; then
 fi
 
 # we're always starting from our working directory
-cd "${KOREADER_DIR}"
+cd "${KOREADER_DIR}" || exit
 
 # load our own shared libraries if possible
 export LD_LIBRARY_PATH="${KOREADER_DIR}/libs:${LD_LIBRARY_PATH}"
@@ -47,12 +47,13 @@ if [ "${FROM_NICKEL}" = "true" ] ; then
 
 	if [ "${FROM_KFMON}" = "true" ] ; then
 		# Siphon nickel's full environment, since KFMon inherits such a minimal one, and that apparently confuses the hell out of Nickel for some reason if we decide to restart it without a reboot...
-		for env in $(xargs -n 1 -0 < /proc/$(pidof nickel)/environ) ; do
-			export ${env}
+		for env in $(xargs -n 1 -0 < "/proc/$(pidof nickel)/environ") ; do
+			# shellcheck disable=SC2163
+			export "${env}"
 		done
 	else
 		# Siphon a few things from nickel's env...
-		eval "$(xargs -n 1 -0 < /proc/$(pidof nickel)/environ | grep -e DBUS_SESSION_BUS_ADDRESS -e WIFI_MODULE -e PLATFORM -e WIFI_MODULE_PATH -e INTERFACE -e PRODUCT 2>/dev/null)"
+		eval "$(xargs -n 1 -0 < "/proc/$(pidof nickel)/environ" | grep -e DBUS_SESSION_BUS_ADDRESS -e WIFI_MODULE -e PLATFORM -e WIFI_MODULE_PATH -e INTERFACE -e PRODUCT 2>/dev/null)"
 		export DBUS_SESSION_BUS_ADDRESS WIFI_MODULE PLATFORM WIFI_MODULE_PATH INTERFACE PRODUCT
 	fi
 
@@ -81,7 +82,6 @@ fi
 # check whether PLATFORM & PRODUCT have a value assigned by rcS
 if [ ! -n "${PRODUCT}" ] ; then
 	PRODUCT="$(/bin/kobo_config.sh 2>/dev/null)"
-	[ "${PRODUCT}" != "trilogy" ] && PREFIX="${PRODUCT}-"
 	export PRODUCT
 fi
 
@@ -112,21 +112,35 @@ if awk '$4~/(^|,)ro($|,)/' /proc/mounts | grep ' /mnt/sd ' ; then
 fi
 
 # we keep maximum 500K worth of crash log
-cat crash.log 2> /dev/null | tail -c 500000 > crash.log.new
-mv -f crash.log.new crash.log
+if [ -e crash.log ]; then
+	tail -c 500000 crash.log > crash.log.new
+	mv -f crash.log.new crash.log
+fi
 
+# workaround 32-bit without KSM (KSM is indicated by ${ksmroot} being set)
+# shellcheck disable=2154
+if [ -z "${ksmroot+x:?}" ]; then
 # TODO: add support for 32bit framebuffer in koreader. This is a workaround
 # to run koreader in 16bpp. Useful since FW 4.0
+CUR_ROTATE="$(cat "/sys/class/graphics/fb0/rotate")"
 FB_BPP=$(cat /sys/class/graphics/fb0/bits_per_pixel)
-[ "$FB_BPP" -gt 16 ] && /usr/sbin/fbset -depth 16
-# fix rotation issues on Kobo Aura HD (dragon) and Kobo Aura H2O (dahlia)
-case "$PRODUCT" in "dragon" | "dahlia" ) cat /sys/class/graphics/fb0/rotate > /sys/class/graphics/fb0/rotate ;; esac
+[ "${FB_BPP}" -gt 16 ] && /usr/sbin/fbset -depth 16
+# this suffices on normal devices, but H2O is stupid and sets the opposite
+echo "${CUR_ROTATE}" > "/sys/class/graphics/fb0/rotate"
+# this therefore turns it around on H2O (and other potential idiots) and merely
+# innocently repeats on sane devices
+# shellcheck disable=SC2094
+cat "/sys/class/graphics/fb0/rotate" > "/sys/class/graphics/fb0/rotate"
+fi
 
 ./reader.lua "${args}" >> crash.log 2>&1
 RESULT=$?
 
-# back to default depth in framebuffer.
-[ "$FB_BPP" -gt 16 ] && /usr/sbin/fbset -depth "$FB_BPP"
+# workaround 32-bit without KSM (KSM is indicated by s${ksmroot} being set)
+if [ -z "${ksmroot+x:?}" ]; then
+	# back to default depth in framebuffer.
+	[ "${FB_BPP}" -gt 16 ] && /usr/sbin/fbset -depth "${FB_BPP}"
+fi
 
 if [ "${FROM_NICKEL}" = "true" ] ; then
 	if [ "${FROM_KFMON}" != "true" ] ; then

platform/kobo/nickel.sh

@@ -88,6 +88,7 @@ fi
 
 # Rotation weirdness, part II
 echo "${cur_rotate}" > "/sys/class/graphics/fb0/rotate"
+# shellcheck disable=SC2094
 cat "/sys/class/graphics/fb0/rotate" > "/sys/class/graphics/fb0/rotate"
 
 # Handle sdcard

platform/ubuntu-touch/koreader.sh

@@ -7,13 +7,13 @@ KOREADER_DIR="${0%/*}"
 # update to new version from OTA directory
 NEWUPDATE="${KOREADER_DIR}/ota/koreader.updated.tar"
 INSTALLED="${KOREADER_DIR}/ota/koreader.installed.tar"
-if [ -f $NEWUPDATE ]; then
+if [ -f "${NEWUPDATE}" ]; then
     # TODO: any graphic indication for the updating progress?
-    cd .. && tar xf $NEWUPDATE && mv $NEWUPDATE $INSTALLED
+    cd .. && tar xf "${NEWUPDATE}" && mv "${NEWUPDATE}" "${INSTALLED}"
 fi
 
 # we're always starting from our working directory
-cd $KOREADER_DIR
+cd "${KOREADER_DIR}" || exit
 
 # export load library path for some old firmware
 export LD_LIBRARY_PATH=${KOREADER_DIR}/libs:$LD_LIBRARY_PATH
@@ -22,7 +22,7 @@ export LD_LIBRARY_PATH=${KOREADER_DIR}/libs:$LD_LIBRARY_PATH
 export TESSDATA_PREFIX="data"
 
 # export external font directory
-export EXT_FONT_DIR="~/fonts"
+export EXT_FONT_DIR="${HOME}/fonts"
 
 # set fullscreen mode
 export SDL_FULLSCREEN=1