bin:*.sh: Fix all shellcheck errors

18 files changed, 123 insertions, 125 deletions

diff --git a/bin/alsa_record_playback.sh b/bin/alsa_record_playback.sh
index e86d7d1..30b2fbd 100755
--- a/bin/alsa_record_playback.sh
+++ b/bin/alsa_record_playback.sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 
-OUTPUT=`mktemp -d`
+OUTPUT=$(mktemp -d)
 gst_pipeline_test.py -t 5 "autoaudiosrc ! audioconvert ! level name=recordlevel interval=10000000 ! audioconvert ! wavenc ! filesink location=$OUTPUT/test.wav"
-aplay $OUTPUT/test.wav
-rm $OUTPUT/test.wav
-rmdir $OUTPUT
+aplay "$OUTPUT"/test.wav
+rm "$OUTPUT"/test.wav
+rmdir "$OUTPUT"
diff --git a/bin/audio_bluetooth_loopback_test.sh b/bin/audio_bluetooth_loopback_test.sh
index 9661ec4..dac3699 100755
--- a/bin/audio_bluetooth_loopback_test.sh
+++ b/bin/audio_bluetooth_loopback_test.sh
@@ -23,8 +23,8 @@
 # human validate that record/playback is working, human can speak into
 # microphone and just ensure the speech can be heard instantly in the headset.
 
-[ -x "`which pactl`" ] || exit 1
-[ -x "`which pacat`" ] || exit 1
+[ -x "$(command -v pactl)" ] || exit 1
+[ -x "$(command -v pacat)" ] || exit 1
 
 SINK=$(pactl list | sed -n '/monitor/d;s/Name: \(bluez_sink\.\)/\1/p')
 SOURCE=$(pactl list | sed -n '/monitor/d;s/Name: \(bluez_source\.\)/\1/p')
@@ -33,6 +33,7 @@ SOURCE=$(pactl list | sed -n '/monitor/d;s/Name: \(bluez_source\.\)/\1/p')
 if [ -n "$SINK" ] && [ -n "$SOURCE" ]; then
 PLAYBACK_LOG=$(mktemp --tmpdir audio_bluetooth_loopback.XXXXX)
 RECORD_LOG=$(mktemp --tmpdir audio_bluetooth_loopback.XXXXX)
+ # shellcheck disable=SC2064
 trap "rm $PLAYBACK_LOG $RECORD_LOG" EXIT
 # ensure we exit with failure if parec fails, and not with pacat
 # --playback's error code
@@ -43,14 +44,14 @@ if [ -n "$SINK" ] && [ -n "$SOURCE" ]; then
 # time out after 6 seconds, forcibly kill after 8 seconds if pacat didn't
 # respond
 echo "Recording and playing back, please speak into bluetooth microphone"
- timeout -k 8 6 pacat $LATENCY --record -v -d $SOURCE 2>$RECORD_LOG | \
- pacat $LATENCY --playback -v -d $SINK 2>$PLAYBACK_LOG
+ timeout -k 8 6 pacat $LATENCY --record -v -d "$SOURCE" 2>"$RECORD_LOG" | \
+ pacat $LATENCY --playback -v -d "$SINK" 2>"$PLAYBACK_LOG"
 
 echo "RECORD LOG"
- cat $RECORD_LOG
+ cat "$RECORD_LOG"
 echo ""
 echo "PLAYBACK LOG"
- cat $PLAYBACK_LOG
+ cat "$PLAYBACK_LOG"
 else
 echo "No bluetooth audio device found"
 exit 1
diff --git a/bin/bluetooth_transfer_stress.sh b/bin/bluetooth_transfer_stress.sh
index 36e4de7..1b86dd1 100755
--- a/bin/bluetooth_transfer_stress.sh
+++ b/bin/bluetooth_transfer_stress.sh
@@ -31,18 +31,18 @@ DESTINATION=$(mktemp --tmpdir bluetooth-stress.XXXXXX)
 REMOTE=$RANDOM
 SIZEKB=10240
 echo "Creating ${SIZEKB}KB file to test transfer"
-dd if=/dev/urandom of=$ORIGIN count=$SIZEKB bs=1024
-ORIGIN_SUM=$(sha256sum $ORIGIN | cut -f 1 -d ' ')
+dd if=/dev/urandom of="$ORIGIN" count=$SIZEKB bs=1024
+ORIGIN_SUM=$(sha256sum "$ORIGIN" | cut -f 1 -d ' ')
 set -o pipefail
 echo "Sending file using Bluetooth"
-time obexftp -v -b $BTDEVADDR -o $REMOTE --put $ORIGIN 2>&1 | ansi_parser.py
+time obexftp -v -b "$BTDEVADDR" -o $REMOTE --put "$ORIGIN" 2>&1 | ansi_parser.py
 sleep 5
 echo "Receiving file using Bluetooth"
-time obexftp -v -b $BTDEVADDR -o $DESTINATION --get $REMOTE 2>&1 | ansi_parser.py
+time obexftp -v -b "$BTDEVADDR" -o "$DESTINATION" --get $REMOTE 2>&1 | ansi_parser.py
 # Now checksum destination and compare
-DESTINATION_SUM=$(sha256sum $DESTINATION | cut -f 1 -d ' ')
+DESTINATION_SUM=$(sha256sum "$DESTINATION" | cut -f 1 -d ' ')
 # Clean up before reporting
-rm $ORIGIN $DESTINATION
+rm "$ORIGIN" "$DESTINATION"
 if [ "$ORIGIN_SUM" = "$DESTINATION_SUM" ]; then
 echo "Checksums match, file transfer succeeded"
 exit 0
diff --git a/bin/broadband_info.sh b/bin/broadband_info.sh
index aec2ccb..01ec7dc 100755
--- a/bin/broadband_info.sh
+++ b/bin/broadband_info.sh
@@ -2,5 +2,5 @@
 
 for i in $(mmcli --simple-status -L | \
 awk '/freedesktop\/ModemManager1\/Modem/ {print $1;}'); do
- mmcli -m $i
+ mmcli -m "$i"
 done
diff --git a/bin/check_is_laptop.sh b/bin/check_is_laptop.sh
index 5820a37..b197441 100755
--- a/bin/check_is_laptop.sh
+++ b/bin/check_is_laptop.sh
@@ -2,15 +2,15 @@
 
 # Establish the system type based on DMI info
 TYPE=$(dmidecode -t 3 | awk '/Type:/ { print $2 }')
-echo "Type: " $TYPE
+echo "Type: " "$TYPE"
 
 BATTERY="NO"
-for device in `find /sys -name "type"`
+while IFS= read -r -d '' device
 do
- if [ "$(cat $device)" == "Battery" ]; then
+ if [ "$(cat "$device")" == "Battery" ]; then
 BATTERY="YES"
 fi
-done
+done < <(find /sys -name "type" -print0)
 
 echo "Battery: " $BATTERY
 
diff --git a/bin/connect_wireless.sh b/bin/connect_wireless.sh
index e39f52c..fc696b2 100755
--- a/bin/connect_wireless.sh
+++ b/bin/connect_wireless.sh
@@ -2,8 +2,7 @@
 
 # Check nmcli version
 NMCLI_GTE_0_9_10=0
-nmcli general 2>&1 >/dev/null
-if [ $? -eq 0 ]; then
+if nmcli general > /dev/null 2>&1; then
 NMCLI_GTE_0_9_10=1
 fi
 
@@ -11,25 +10,23 @@ fi
 conn=''
 
 if [ $NMCLI_GTE_0_9_10 -eq 0 ]; then
- active_connection=$(nmcli -f SSID,ACTIVE dev wifi list | grep yes)
- if [ $? -eq 0 ]; then
- ap=$(echo $active_connection | awk -F\' '{print $2}')
- conn=$(nmcli -t -f UUID,TYPE,NAME con list | grep wireless | grep -e "$ap$" | head -n 1 | awk -F\: '{print $1}')
+ if active_connection=$(nmcli -f SSID,ACTIVE dev wifi list | grep yes); then
+ ap=$(echo "$active_connection" | awk -F\' '{print $2}')
+ conn=$(nmcli -t -f UUID,TYPE,NAME con list | grep wireless | grep -e "$ap$" | head -n 1 | awk -F: '{print $1}')
 else
- conn=$(nmcli -t -f UUID,TYPE con list | grep wireless | head -n 1 | awk -F\: '{print $1}')
+ conn=$(nmcli -t -f UUID,TYPE con list | grep wireless | head -n 1 | awk -F: '{print $1}')
 fi
 else
- active_connection=$(nmcli -f SSID,ACTIVE dev wifi | grep yes)
- if [ $? -eq 0 ]; then
- ap=$(echo $active_connection | awk '{print $1}')
- conn=$(nmcli -t -f UUID,TYPE,NAME con show | grep wireless | grep -e "$ap$" | head -n 1 | awk -F\: '{print $1}')
+ if active_connection=$(nmcli -f SSID,ACTIVE dev wifi | grep yes); then
+ ap=$(echo "$active_connection" | awk '{print $1}')
+ conn=$(nmcli -t -f UUID,TYPE,NAME con show | grep wireless | grep -e "$ap$" | head -n 1 | awk -F: '{print $1}')
 else
- conn=$(nmcli -t -f UUID,TYPE con show | grep wireless | head -n 1 | awk -F\: '{print $1}')
+ conn=$(nmcli -t -f UUID,TYPE con show | grep wireless | head -n 1 | awk -F: '{print $1}')
 fi
 fi
 
 #Strip trailing/leading whitespace
-conn=$(echo $conn |sed 's/^[ \t]*//;s/[ \t]*$//')
+conn=$(echo "$conn" |sed 's/^[ \t]*//;s/[ \t]*$//')
 
 # Find out if wireless is enabled
 if [ $NMCLI_GTE_0_9_10 -eq 0 ]; then
@@ -37,6 +34,7 @@ if [ $NMCLI_GTE_0_9_10 -eq 0 ]; then
 else
 nmcli radio wifi | grep -q 'enabled'
 fi
+# shellcheck disable=SC2181
 if [ $? -ne 0 ]
 then
 # Find out why
@@ -45,21 +43,21 @@ then
 then
 blkmessage='Your wireless may be hardware blocked. You may need
 to use your wireless key/switch to re-enable it.'
- echo $blkmessage
+ echo "$blkmessage"
 fi
 fi
 
 # Check if there's a connection already (wireless or otherwise)
-nmcli dev status | grep -q '\<connected\>'
-if [ $? -eq 0 ]
+
+if nmcli dev status | grep -q '\<connected\>';
 then
 # Disconnect, pause for a short time
- for iface in `(nmcli -f GENERAL dev list 2>/dev/null || nmcli -f GENERAL dev show) | grep 'GENERAL.DEVICE' | awk '{print $2}'`
+ for iface in $( (nmcli -f GENERAL dev list 2>/dev/null || nmcli -f GENERAL dev show) | grep 'GENERAL.DEVICE' | awk '{print $2}')
 do
 if [ $NMCLI_GTE_0_9_10 -eq 0 ]; then
- nmcli dev disconnect iface $iface
+ nmcli dev disconnect iface "$iface"
 else
- nmcli dev disconnect $iface
+ nmcli dev disconnect "$iface"
 fi
 done
 sleep 2
diff --git a/bin/cycle_vts.sh b/bin/cycle_vts.sh
index c5e1677..a42f8c1 100755
--- a/bin/cycle_vts.sh
+++ b/bin/cycle_vts.sh
@@ -4,7 +4,7 @@ set -o errexit
 
 # NB: This script must be run with root privileges in order to have any effect!
 
-CURRENT_VT=`/bin/fgconsole`
+CURRENT_VT=$(/bin/fgconsole)
 
 if [ "$CURRENT_VT" == "" ]
 then
@@ -24,7 +24,7 @@ chvt "$CURRENT_VT"
 sleep 2
 
 # make sure we switched back
-END_VT=`/bin/fgconsole`
+END_VT=$(/bin/fgconsole)
 if [ "$END_VT" -ne "$CURRENT_VT" ]
 then
 echo "didn't get back to the original VT" >&2
diff --git a/bin/disk_cpu_load.sh b/bin/disk_cpu_load.sh
index adad55f..a4c45cb 100755
--- a/bin/disk_cpu_load.sh
+++ b/bin/disk_cpu_load.sh
@@ -44,7 +44,6 @@ set -e
 
 get_params() {
 disk_device="/dev/sda"
- short_device="sda"
 verbose=0
 max_load=30
 xfer=4096
@@ -59,9 +58,8 @@ get_params() {
 --verbose) verbose=1
 ;;
 *) disk_device="/dev/$1"
- disk_device=`echo $disk_device | sed "s/\/dev\/\/dev/\/dev/g"`
- short_device=$(echo $disk_device | sed "s/\/dev//g")
- if [ ! -b $disk_device ] ; then
+ disk_device=$(echo "$disk_device" | sed "s/\/dev\/\/dev/\/dev/g")
+ if [ ! -b "$disk_device" ] ; then
 echo "Unknown block device \"$disk_device\""
 echo "Usage: $0 [ --max-load <load> ] [ --xfer <mebibytes> ]"
 echo " [ device-file ]"
@@ -82,8 +80,8 @@ get_params() {
 sum_array() {
 local array=("${@}")
 total=0
- for i in ${array[@]}; do
- let total+=$i
+ for i in "${array[@]}"; do
+ (( total+=i ))
 done
 } # sum_array()
 
@@ -98,10 +96,10 @@ sum_array() {
 compute_cpu_load() {
 local start_use
 local end_use
- IFS=' ' read -r -a start_use <<< $1
- IFS=' ' read -r -a end_use <<< $2
+ IFS=' ' read -r -a start_use <<< "$1"
+ IFS=' ' read -r -a end_use <<< "$2"
 local diff_idle
- let diff_idle=${end_use[3]}-${start_use[3]}
+ (( diff_idle=end_use[3]-start_use[3] ))
 
 sum_array "${start_use[@]}"
 local start_total=$total
@@ -110,8 +108,8 @@ compute_cpu_load() {
 
 local diff_total
 local diff_used
- let diff_total=${end_total}-${start_total}
- let diff_used=$diff_total-$diff_idle
+ (( diff_total=end_total-start_total ))
+ (( diff_used=diff_total-diff_idle ))
 
 if [ "$verbose" == "1" ] ; then
 echo "Start CPU time = $start_total"
@@ -136,7 +134,7 @@ get_params "$@"
 retval=0
 echo "Testing CPU load when reading $xfer MiB from $disk_device"
 echo "Maximum acceptable CPU load is $max_load"
-blockdev --flushbufs $disk_device
+blockdev --flushbufs "$disk_device"
 start_load="$(grep "cpu " /proc/stat | tr -s " " | cut -d " " -f 2-)"
 if [ "$verbose" == "1" ] ; then
 echo "Beginning disk read...."
diff --git a/bin/disk_read_performance_test.sh b/bin/disk_read_performance_test.sh
index 7734543..f0b954c 100755
--- a/bin/disk_read_performance_test.sh
+++ b/bin/disk_read_performance_test.sh
@@ -6,17 +6,17 @@
 #Default to a lower bound of 15 MB/s
 DEFAULT_BUF_READ=${DISK_READ_PERF:-15}
 
-for disk in $@; do
+for disk in "$@"; do
 
 echo "Beginning $0 test for $disk"
 echo "---------------------------------------------------"
 
- disk_type=`udevadm info --name /dev/$disk --query property | grep "ID_BUS" | awk '{gsub(/ID_BUS=/," ")}{printf $1}'`
- dev_path=`udevadm info --name /dev/$disk --query property | grep "DEVPATH" | awk '{gsub(/DEVPATH=/," ")}{printf $1}'`
+ disk_type=$(udevadm info --name /dev/"$disk" --query property | grep "ID_BUS" | awk '{gsub(/ID_BUS=/," ")}{printf $1}')
+ dev_path=$(udevadm info --name /dev/"$disk" --query property | grep "DEVPATH" | awk '{gsub(/DEVPATH=/," ")}{printf $1}')
 # /sys/block/$disk/queue/rotational was added with Linux 2.6.29. If file is
 # not present, test below will fail & disk will be considered an HDD, not
 # an SSD.
- rotational=`cat /sys/block/$disk/queue/rotational`
+ rotational=$(cat /sys/block/"$disk"/queue/rotational)
 if [[ $dev_path =~ dm ]]; then
 disk_type="devmapper"
 fi
@@ -48,9 +48,9 @@ for disk in $@; do
 
 # Increase MIN_BUF_READ if a USB3 device is plugged in a USB3 hub port
 if [[ $dev_path =~ ((.*usb[0-9]+).*\/)[0-9]-[0-9\.:\-]+\/.* ]]; then
- device_version=`cat '/sys/'${BASH_REMATCH[1]}'/version'`
- hub_port_version=`cat '/sys/'${BASH_REMATCH[2]}'/version'`
- if [ $(echo "$device_version >= 3.00"|bc -l) -eq 1 -a $(echo "$hub_port_version >= 3.00"|bc -l) -eq 1 ]; then
+ device_version=$(cat '/sys/'"${BASH_REMATCH[1]}"'/version')
+ hub_port_version=$(cat '/sys/'"${BASH_REMATCH[2]}"'/version')
+ if [ "$(echo "$device_version >= 3.00"|bc -l)" -eq 1 ] && [ "$(echo "$hub_port_version >= 3.00"|bc -l)" -eq 1 ]; then
 MIN_BUF_READ=80
 fi
 fi
@@ -73,8 +73,8 @@ for disk in $@; do
 echo "Beginning hdparm timing runs"
 echo "---------------------------------------------------"
 
- for iteration in `seq 1 10`; do
- speed=`hdparm -t /dev/$disk 2>/dev/null | grep "Timing buffered disk reads" | awk -F"=" '{print $2}' | awk '{print $1}'`
+ for iteration in $(seq 1 10); do
+ speed=$(hdparm -t /dev/"$disk" 2>/dev/null | grep "Timing buffered disk reads" | awk -F"=" '{print $2}' | awk '{print $1}')
 echo "INFO: Iteration $iteration: Detected speed is $speed MB/sec"
 
 if [ -z "$speed" ]; then
@@ -83,7 +83,7 @@ for disk in $@; do
 fi
 
 speed=${speed/.*}
- if [ $speed -gt $max_speed ]; then
+ if [ "$speed" -gt $max_speed ]; then
 max_speed=$speed
 fi
 done
@@ -91,7 +91,7 @@ for disk in $@; do
 echo "---------------------------------------------------"
 echo ""
 result=0
- if [ $max_speed -gt $MIN_BUF_READ ]; then
+ if [ "$max_speed" -gt "$MIN_BUF_READ" ]; then
 echo "PASS: $disk Max Speed of $max_speed MB/sec is faster than Minimum Buffer Read Speed of $MIN_BUF_READ MB/sec"
 else
 echo "FAIL: $disk Max Speed of $max_speed MB/sec is slower than Minimum Buffer Read Speed of $MIN_BUF_READ MB/sec"
diff --git a/bin/disk_stats_test.sh b/bin/disk_stats_test.sh
index 60b48f5..41ef626 100755
--- a/bin/disk_stats_test.sh
+++ b/bin/disk_stats_test.sh
@@ -16,7 +16,7 @@ check_return_code() {
 shift
 shift
 for item in "$@"; do
- echo "output: "$item
+ echo "output: ""$item"
 done
 fi
 fi
@@ -29,19 +29,19 @@ fi
 nvdimm="pmem"
 if [ -z "${DISK##*$nvdimm*}" ];then
 echo "Disk $DISK appears to be an NVDIMM, skipping"
- exit $STATUS
+ exit "$STATUS"
 fi
 
 #Check /proc/partitions, exit with fail if disk isn't found
-grep -w -q $DISK /proc/partitions
+grep -w -q "$DISK" /proc/partitions
 check_return_code $? "Disk $DISK not found in /proc/partitions"
 
 #Next, check /proc/diskstats
-grep -w -q -m 1 $DISK /proc/diskstats
+grep -w -q -m 1 "$DISK" /proc/diskstats
 check_return_code $? "Disk $DISK not found in /proc/diskstats"
 
 #Verify the disk shows up in /sys/block/
-ls /sys/block | grep -w -q $DISK
+ls /sys/block/*"$DISK"* > /dev/null 2>&1
 check_return_code $? "Disk $DISK not found in /sys/block"
 
 #Verify there are stats in /sys/block/$DISK/stat
@@ -49,8 +49,8 @@ check_return_code $? "Disk $DISK not found in /sys/block"
 check_return_code $? "stat is either empty or nonexistant in /sys/block/$DISK/"
 
 #Get some baseline stats for use later
-PROC_STAT_BEGIN=`grep -w -m 1 $DISK /proc/diskstats`
-SYS_STAT_BEGIN=`cat /sys/block/$DISK/stat`
+PROC_STAT_BEGIN=$(grep -w -m 1 "$DISK" /proc/diskstats)
+SYS_STAT_BEGIN=$(cat /sys/block/"$DISK"/stat)
 
 #Generate some disk activity using hdparm -t
 hdparm -t "/dev/$DISK" 2&> /dev/null
@@ -59,8 +59,8 @@ hdparm -t "/dev/$DISK" 2&> /dev/null
 sleep 5
 
 #Make sure the stats have changed:
-PROC_STAT_END=`grep -w -m 1 $DISK /proc/diskstats`
-SYS_STAT_END=`cat /sys/block/$DISK/stat`
+PROC_STAT_END=$(grep -w -m 1 "$DISK" /proc/diskstats)
+SYS_STAT_END=$(cat /sys/block/"$DISK"/stat)
 
 [[ "$PROC_STAT_BEGIN" != "$PROC_STAT_END" ]]
 check_return_code $? "Stats in /proc/diskstats did not change" \
@@ -73,4 +73,4 @@ if [[ $STATUS -eq 0 ]]; then
 echo "PASS: Finished testing stats for $DISK"
 fi
 
-exit $STATUS
+exit "$STATUS"
diff --git a/bin/graphics_env.sh b/bin/graphics_env.sh
index 5160ae6..b3ee60b 100755
--- a/bin/graphics_env.sh
+++ b/bin/graphics_env.sh
@@ -12,15 +12,15 @@ INDEX=$2
 # We only want to set the DRI_PRIME env variable on systems with more than
 # 1 GPU running the amdgpu/radeon drivers.
 if [[ $DRIVER == "amdgpu" || $DRIVER == "radeon" ]]; then
- NB_GPU=`udev_resource.py -l VIDEO | grep -oP -m1 '\d+'`
- if [ $NB_GPU -gt 1 ]; then
- if [ $INDEX -gt 1 ]; then
+ NB_GPU=$(udev_resource.py -l VIDEO | grep -oP -m1 '\d+')
+ if [[ $NB_GPU -gt 1 ]]; then
+ if [[ $INDEX -gt 1 ]]; then
 # See https://wiki.archlinux.org/index.php/PRIME
 echo "Setting up PRIME GPU offloading for AMD discrete GPU"
 if ! cat /var/log/Xorg.0.log ~/.local/share/xorg/Xorg.0.log 2>&1 | grep -q DRI3; then
- PROVIDER_ID=`xrandr --listproviders | grep "Sink Output" | awk {'print $4'} | tail -1`
- SINK_ID=`xrandr --listproviders | grep "Source Output" | awk {'print $4'} | tail -1`
- xrandr --setprovideroffloadsink ${PROVIDER_ID} ${SINK_ID}
+ PROVIDER_ID=$(xrandr --listproviders | grep "Sink Output" | awk '{print $4}' | tail -1)
+ SINK_ID=$(xrandr --listproviders | grep "Source Output" | awk '{print $4}' | tail -1)
+ xrandr --setprovideroffloadsink "${PROVIDER_ID}" "${SINK_ID}"
 fi
 export DRI_PRIME=1
 else
diff --git a/bin/led_hdd_test.sh b/bin/led_hdd_test.sh
index eac6ae2..f3f9808 100755
--- a/bin/led_hdd_test.sh
+++ b/bin/led_hdd_test.sh
@@ -1,20 +1,22 @@
 #!/bin/bash
 
 TIMEOUT=3
-TEMPFILE=`mktemp`
+TEMPFILE=$(mktemp)
 
+# shellcheck disable=SC2064
 trap "rm $TEMPFILE" EXIT
 
+# shellcheck disable=SC2034
 for i in $(seq $TIMEOUT); do
 #launch background writer
- dd if=/dev/urandom of=$TEMPFILE bs=1024 oflag=direct &
+ dd if=/dev/urandom of="$TEMPFILE" bs=1024 oflag=direct &
 WRITE_PID=$!
 echo "Writing..."
 sleep 1
 kill $WRITE_PID
 sync
 echo "Reading..."
- dd if=$TEMPFILE of=/dev/null bs=1024 iflag=direct
+ dd if="$TEMPFILE" of=/dev/null bs=1024 iflag=direct
 done
 
 echo "OK, now exiting"
diff --git a/bin/light_sensor_test.sh b/bin/light_sensor_test.sh
index f413396..cb8fbe9 100755
--- a/bin/light_sensor_test.sh
+++ b/bin/light_sensor_test.sh
@@ -20,18 +20,18 @@ echo -e "\e[92mwaiting for sensor to be covered......\e[0m"
 sleep 3
 
 #Output and print light sensor events 5 sec to light_sensor_test.log
-timeout 5 monitor-sensor | tee $PLAINBOX_SESSION_SHARE/light_sensor_test.log &
+timeout 5 monitor-sensor | tee "$PLAINBOX_SESSION_SHARE"/light_sensor_test.log &
 
 
 #Print backlight value for 5 sec on the screen
 for i in {1..10}
 do
- echo "Current Backlight Percentage is:" $(gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method org.freedesktop.DBus.Properties.Get org.gnome.SettingsDaemon.Power.Screen Brightness)| tr -d '()<>,'
+ echo "Current Backlight Percentage is:" "$(gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method org.freedesktop.DBus.Properties.Get org.gnome.SettingsDaemon.Power.Screen Brightness)"| tr -d '()<>,'
 sleep 0.5
 done
 
 # Fail when the user didn't wave their hand and no events have been collected.
-if [[ $(cat $PLAINBOX_SESSION_SHARE/light_sensor_test.log | grep "Light changed" | wc -l) -lt 5 ]]; then
+if [[ $(grep -c "Light changed" "$PLAINBOX_SESSION_SHARE"/light_sensor_test.log) -lt 5 ]]; then
 echo -e "\e[91mFAIL: Not enough data to be collect, Please rerun the test case and wave your hand around Light Sensor.\e[0m"
 exit 1
 fi
@@ -40,7 +40,7 @@ fi
 #Print 5 values of the Light sensor value form log file
 for i in {1..5}
 do 
- echo "Ambient light sensor value " $i: `grep 'Light' $PLAINBOX_SESSION_SHARE/light_sensor_test.log | awk '{print $3}' | sed -n "$i"p`
+ echo "Ambient light sensor value " $i: "$(grep 'Light' "$PLAINBOX_SESSION_SHARE"/light_sensor_test.log | awk '{print $3}' | sed -n "$i"p)"
 done
 exit 0
 
diff --git a/bin/maas-version-check.sh b/bin/maas-version-check.sh
index 678088a..6856354 100755
--- a/bin/maas-version-check.sh
+++ b/bin/maas-version-check.sh
@@ -22,13 +22,13 @@ MIN_VERSION="2.0"
 
 # Is the file there?
 if [ -s $MAAS_FILE ]; then
- maas_version=`cat $MAAS_FILE`
- echo $maas_version
+ maas_version=$(cat $MAAS_FILE)
+ echo "$maas_version"
 else
 echo "ERROR: This system does not appear to have been installed by MAAS"
- echo "ERROR: " $(ls -l $MAAS_FILE 2>&1)
+ echo "ERROR: " "$(ls -l $MAAS_FILE 2>&1)"
 exit 1
 fi
 
 #is the version appropriate
-exit `dpkg --compare-versions $maas_version "ge" $MIN_VERSION`
+exit "$(dpkg --compare-versions "$maas_version" "ge" $MIN_VERSION)"
diff --git a/bin/network_configs.sh b/bin/network_configs.sh
index b2fcc99..4fd354b 100755
--- a/bin/network_configs.sh
+++ b/bin/network_configs.sh
@@ -1,13 +1,13 @@
 #!/bin/bash
 
-if `grep -q "replaced by netplan" /etc/network/interfaces`; then
+if grep -q "replaced by netplan" /etc/network/interfaces; then
 # Get our configs from netplan
 for directory in "etc" "run" "lib"; do
- for configfile in `find /$directory/netplan -type f -name *.yaml`; do
+ while IFS= read -r -d '' configfile; do
 echo "Config File $configfile:"
- cat $configfile
+ cat "$configfile"
 echo ""
- done
+ done < <(find /$directory/netplan -type f -name "*.yaml" -print0)
 done
 else
 # get configs from Network Manager instead
diff --git a/bin/network_printer_test.sh b/bin/network_printer_test.sh
index 19d98d2..2633b6c 100755
--- a/bin/network_printer_test.sh
+++ b/bin/network_printer_test.sh
@@ -19,7 +19,7 @@ while [ $# -gt 0 ]
 do
 case "$1" in
 -p)
- if echo ${2} | grep -q -c '^-'; then
+ if echo "${2}" | grep -q -c '^-'; then
 usage
 exit 1
 fi
@@ -27,7 +27,7 @@ do
 shift
 ;;
 -s)
- if echo ${2} | grep -q -c '^-'; then
+ if echo "${2}" | grep -q -c '^-'; then
 usage
 exit 1
 fi
@@ -42,16 +42,16 @@ do
 shift
 done
 
-if [ -z $server ]; then
+if [ -z "$server" ]; then
 echo "Nothing to do with no server defined. (See $0 --usage)"
 exit 0
 fi
 
 printer=${printer:-PDF}
 
-lpadmin -E -v ipp://${server}/printers/${printer}
-cupsenable ${printer}
-cupsaccept ${printer}
+lpadmin -E -v ipp://"${server}"/printers/"${printer}"
+cupsenable "${printer}"
+cupsaccept "${printer}"
 
-lsb_release -a | lp -t "lsb_release" -d ${printer}
+lsb_release -a | lp -t "lsb_release" -d "${printer}"
 
diff --git a/bin/network_wait.sh b/bin/network_wait.sh
index f0637d0..16d474c 100755
--- a/bin/network_wait.sh
+++ b/bin/network_wait.sh
@@ -2,8 +2,7 @@
 
 x=1
 while true; do
- state=$(/usr/bin/nmcli -t -f STATE nm 2>/dev/null)
- if [[ $? != 0 ]]; then
+ if ! state=$(/usr/bin/nmcli -t -f STATE nm 2>/dev/null); then
 state=$(/usr/bin/nmcli -t -f STATE general 2>/dev/null)
 rc=$?
 if [[ $rc != 0 ]]; then
@@ -11,13 +10,13 @@ while true; do
 fi
 fi
 if [ "$state" = "connected" ]; then
- echo $state
+ echo "$state"
 exit 0
 fi
 
- x=$(($x + 1))
+ x=$((x + 1))
 if [ $x -gt 12 ]; then
- echo $state
+ echo "$state"
 exit 1
 fi
 
diff --git a/bin/optical_write_test.sh b/bin/optical_write_test.sh
index b127667..ca1dc79 100755
--- a/bin/optical_write_test.sh
+++ b/bin/optical_write_test.sh
@@ -11,7 +11,7 @@ create_working_dirs(){
 # First, create the temp dir and cd there
 echo "Creating Temp directory and moving there ..."
 mkdir -p $TEMP_DIR || return 1
- cd $TEMP_DIR
+ cd $TEMP_DIR || return 1
 echo "Now working in $PWD ..."
 }
 
@@ -26,18 +26,18 @@ generate_md5(){
 # Generate the md5sum
 echo "Generating md5sums of sample files ..."
 CUR_DIR=$PWD
- cd $SAMPLE_FILE
- md5sum * > $TEMP_DIR/$MD5SUM_FILE
+ cd $SAMPLE_FILE || return 1
+ md5sum -- * > $TEMP_DIR/$MD5SUM_FILE
 # Check the sums for paranoia sake
 check_md5 $TEMP_DIR/$MD5SUM_FILE
 rt=$?
- cd $CUR_DIR
+ cd "$CUR_DIR" || exit 1
 return $rt
 }
 
 check_md5(){
 echo "Checking md5sums ..."
- md5sum -c $1
+ md5sum -c "$1"
 return $?
 }
 
@@ -55,10 +55,10 @@ burn_iso(){
 echo "Beginning image burn ..."
 if [ "$OPTICAL_TYPE" == 'cd' ]
 then
- wodim -eject dev=$OPTICAL_DRIVE $ISO_NAME
+ wodim -eject dev="$OPTICAL_DRIVE" $ISO_NAME
 elif [ "$OPTICAL_TYPE" == 'dvd' ] || [ "$OPTICAL_TYPE" == 'bd' ]
 then
- growisofs -dvd-compat -Z $OPTICAL_DRIVE=$ISO_NAME
+ growisofs -dvd-compat -Z "$OPTICAL_DRIVE=$ISO_NAME"
 else
 echo "Invalid type specified '$OPTICAL_TYPE'"
 exit 1
@@ -76,9 +76,9 @@ check_disk(){
 echo "Waiting up to 5 minutes for drive to be mounted ..."
 while true; do
 sleep $INTERVAL
- SLEEP_COUNT=`expr $SLEEP_COUNT + $INTERVAL`
+ SLEEP_COUNT=$((SLEEP_COUNT + INTERVAL))
 
- mount $OPTICAL_DRIVE 2>&1 |egrep -q "already mounted"
+ mount "$OPTICAL_DRIVE" 2>&1 | grep -E -q "already mounted"
 rt=$?
 if [ $rt -eq 0 ]; then
 echo "Drive appears to be mounted now"
@@ -96,8 +96,8 @@ check_disk(){
 
 echo "Deleting original data files ..."
 rm -rf $SAMPLE_FILE
- if [ -n "$(mount | grep $OPTICAL_DRIVE)" ]; then
- MOUNT_PT=$(mount | grep $OPTICAL_DRIVE | awk '{print $3}')
+ if mount | grep -q "$OPTICAL_DRIVE"; then
+ MOUNT_PT=$(mount | grep "$OPTICAL_DRIVE" | awk '{print $3}')
 echo "Disk is mounted to $MOUNT_PT"
 else
 echo "Attempting best effort to mount $OPTICAL_DRIVE on my own"
@@ -105,7 +105,7 @@ check_disk(){
 echo "Creating temp mount point: $MOUNT_PT ..."
 mkdir $MOUNT_PT
 echo "Mounting disk to mount point ..."
- mount $OPTICAL_DRIVE $MOUNT_PT
+ mount "$OPTICAL_DRIVE" $MOUNT_PT
 rt=$?
 if [ $rt -ne 0 ]; then
 echo "ERROR: Unable to re-mount $OPTICAL_DRIVE!" >&2
@@ -120,24 +120,24 @@ check_disk(){
 
 cleanup(){
 echo "Moving back to original location"
- cd $START_DIR
+ cd "$START_DIR" || exit 1
 echo "Now residing in $PWD"
 echo "Cleaning up ..."
 umount "$MOUNT_PT"
 rm -fr $TEMP_DIR
 echo "Ejecting spent media ..."
- eject $OPTICAL_DRIVE
+ eject "$OPTICAL_DRIVE"
 }
 
 failed(){
- echo $1
+ echo "$1"
 echo "Attempting to clean up ..."
 cleanup
 exit 1
 }
 
-if [ -e $1 ]; then
- OPTICAL_DRIVE=$(readlink -f $1)
+if [ -e "$1" ]; then
+ OPTICAL_DRIVE=$(readlink -f "$1")
 else
 OPTICAL_DRIVE='/dev/sr0'
 fi