diff --git a/env b/env
index 1e51c5b5..a8c0d483 100644
--- a/env
+++ b/env
@@ -1,9 +1,29 @@
 #!/bin/bash
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
+ENVPATH=$(realpath "${BASH_SOURCE[0]}")
+ENVPATH=$(dirname "${ENVPATH}")
 
-if [ -z $VPRPATH ]; then
-	export VPRPATH=$MYPATH
-	export PYTHONPATH=${VPRPATH}/python:${VPRPATH}/python/prjxray:${PYTHONPATH}
-fi
+DATABASE_DIR=${DATABASE_DIR:-$(prjxray-config)}
+
+SHARE_DIR_PATH=$(realpath "${ENVPATH}/../share/symbiflow")
+export SHARE_DIR_PATH
+export TECHMAP_PATH=${SHARE_DIR_PATH}/techmaps/xc7_vpr/techmap
+export UTILS_PATH=${SHARE_DIR_PATH}/scripts
+
+find_device_from_part() {
+	# Try to find device name. Accept only when exactly one is found
+
+	local PART=$1
+	[[ -n ${PART} ]] || return 1
+	PART_DIRS=("${DATABASE_DIR}"/*/"${PART}")
+	if [[ ${#PART_DIRS[@]} -eq 1 ]]; then
+		basename -- "$(dirname "${PART_DIRS[0]}")"
+		return 0
+	else
+		echo "Could not determine device from part name alone - please specify a device"
+		return 1
+	fi
+}
+
+export VPRPATH=${VPRPATH:-$ENVPATH}
+export PYTHONPATH=${VPRPATH}/python:${VPRPATH}/python/prjxray:${PYTHONPATH:-}
diff --git a/symbiflow_generate_constraints b/symbiflow_generate_constraints
index a973e577..99812c63 100755
--- a/symbiflow_generate_constraints
+++ b/symbiflow_generate_constraints
@@ -1,10 +1,10 @@
 #!/bin/bash
-set -e
+set -eu
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
-
-export SHARE_DIR_PATH=`realpath ${MYPATH}/../share/symbiflow`
+MYPATH=$(realpath "$0")
+MYPATH=$(dirname "${MYPATH}")
+# shellcheck source=env
+source "${MYPATH}/env"
 
 EBLIF=$1
 NET=$2
@@ -13,17 +13,27 @@ DEVICE=$4
 ARCH_DEF=$5
 PCF=$6
 
-if [ ! -z $PCF ]; then
-    PCF_OPTS="--pcf $PCF"
+if [[ -n ${PCF} ]]; then
+    PCF_OPTS=(--pcf "${PCF}")
 fi
 
 VPR_GRID_MAP=${SHARE_DIR_PATH}/arch/${DEVICE}/vpr_grid_map.csv
 PINMAP=${SHARE_DIR_PATH}/arch/${DEVICE}/${PART}/pinmap.csv
 IOGEN=${SHARE_DIR_PATH}/scripts/prjxray_create_ioplace.py
 CONSTR_GEN=${SHARE_DIR_PATH}/scripts/prjxray_create_place_constraints.py
-PROJECT=$(basename -- "$EBLIF")
+PROJECT=$(basename -- "${EBLIF}")
 IOPLACE_FILE="${PROJECT%.*}.ioplace"
 
-python3 ${IOGEN} --blif $EBLIF --map $PINMAP --net $NET $PCF_OPTS > ${IOPLACE_FILE}
-python3 ${CONSTR_GEN} --net $NET --arch ${ARCH_DEF} --blif $EBLIF --vpr_grid_map ${VPR_GRID_MAP} --input ${IOPLACE_FILE} > constraints.place
+python3 "${IOGEN}" \
+    --blif "${EBLIF}" \
+    --map "${PINMAP}" \
+    --net "${NET}" \
+    "${PCF_OPTS[@]}" > "${IOPLACE_FILE}"
+
+python3 "${CONSTR_GEN}" \
+    --net "${NET}" \
+    --arch "${ARCH_DEF}" \
+    --blif "${EBLIF}" \
+    --vpr_grid_map "${VPR_GRID_MAP}" \
+    --input "${IOPLACE_FILE}" > constraints.place
 
diff --git a/symbiflow_pack b/symbiflow_pack
index 9f4371ea..d355fa55 100755
--- a/symbiflow_pack
+++ b/symbiflow_pack
@@ -1,15 +1,18 @@
 #!/bin/bash
-set -e
+set -eu
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
+MYPATH=$(realpath "$0")
+MYPATH=$(dirname "${MYPATH}")
 
-source ${MYPATH}/env
-source ${VPRPATH}/vpr_common
+# shellcheck source=env
+source "${MYPATH}/env"
 
-parse_args "$@"
+OUT_NOISY_WARNINGS=noisy_warnings_pack.log
+
+# shellcheck source=vpr_common
+source "${VPRPATH}/vpr_common"
 
-export OUT_NOISY_WARNINGS=noisy_warnings-${DEVICE}_pack.log
+parse_args "$@"
 
 run_vpr --pack
 
diff --git a/symbiflow_place b/symbiflow_place
index 09b10817..574779a6 100755
--- a/symbiflow_place
+++ b/symbiflow_place
@@ -1,27 +1,30 @@
 #!/bin/bash
-set -e
+set -eu
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
+MYPATH=$(realpath "$0")
+MYPATH=$(dirname "${MYPATH}")
 
-source ${MYPATH}/env
-source ${MYPATH}/vpr_common
+# shellcheck source=env
+source "${MYPATH}/env"
+
+OUT_NOISY_WARNINGS=noisy_warnings_place.log
+
+# shellcheck source=vpr_common
+source "${VPRPATH}/vpr_common"
 
 parse_args "$@"
 
-if [ -z $PCF ]; then
+if [[ -z ${PCF} ]]; then
     PCF=""
 fi
 
-if [ -z $NET ]; then
+if [[ -z ${NET} ]]; then
      echo "Please provide net file name"
      exit 1
 fi
 
-OUT_NOISY_WARNINGS=noisy_warnings-${DEVICE}_place.log
-
 echo "Generating coinstrains ..."
-symbiflow_generate_constraints $EBLIF $NET $PART $DEVICE $ARCH_DEF $PCF
+symbiflow_generate_constraints "${EBLIF}" "${NET}" "${PART}" "${DEVICE}" "${ARCH_DEF}" "${PCF}"
 
 run_vpr --fix_clusters constraints.place --place
 
diff --git a/symbiflow_route b/symbiflow_route
index ac8ede98..a4c8f4f2 100755
--- a/symbiflow_route
+++ b/symbiflow_route
@@ -1,15 +1,18 @@
 #!/bin/bash
-set -e
+set -eu
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
+MYPATH=$(realpath "$0")
+MYPATH=$(dirname "${MYPATH}")
 
-source ${MYPATH}/env
-source ${VPRPATH}/vpr_common
+# shellcheck source=env
+source "${MYPATH}/env"
 
-parse_args "$@"
+OUT_NOISY_WARNINGS=noisy_warnings_route.log
+
+# shellcheck source=vpr_common
+source "${VPRPATH}/vpr_common"
 
-export OUR_NOISY_WARNINGS=noisy_warnings-${DEVICE}_pack.log
+parse_args "$@"
 
 run_vpr --route
 
diff --git a/symbiflow_synth b/symbiflow_synth
index e9c3910e..302991ee 100755
--- a/symbiflow_synth
+++ b/symbiflow_synth
@@ -1,14 +1,11 @@
 #!/bin/bash
-set -e
+set -eu
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
+MYPATH=$(realpath "$0")
+MYPATH=$(dirname "${MYPATH}")
+# shellcheck source=env
+source "${MYPATH}/env"
 
-export SHARE_DIR_PATH=`realpath ${MYPATH}/../share/symbiflow`
-export TECHMAP_PATH=${SHARE_DIR_PATH}/techmaps/xc7_vpr/techmap
-
-
-export UTILS_PATH=${SHARE_DIR_PATH}/scripts
 SYNTH_TCL_PATH=${UTILS_PATH}/xc7/synth.tcl
 CONV_TCL_PATH=${UTILS_PATH}/xc7/conv.tcl
 SPLIT_INOUTS=${UTILS_PATH}/split_inouts.py
@@ -25,11 +22,9 @@ TOPNAME=0
 DEVICENAME=0
 PARTNAME=0
 
-for arg in $@; do
-	echo $arg
-	case "$arg" in
+for arg in "$@"; do
+	case "${arg}" in
 		-t|--top)
-			echo "adding top"
 			VERILOGLIST=0
 			XDCLIST=0
 			TOPNAME=1
@@ -65,16 +60,16 @@ for arg in $@; do
 			PARTNAME=1
 			;;
 		*)
-			if [ $VERILOGLIST -eq 1 ]; then
-				VERILOG_FILES+=($arg)
-			elif [ $XDCLIST -eq 1 ]; then
-				XDC_FILES+=($arg)
-			elif [ $TOPNAME -eq 1 ]; then
-				TOP=$arg
-			elif [ $DEVICENAME -eq 1 ]; then
-				DEVICE=$arg
-			elif [ $PARTNAME -eq 1 ]; then
-				PART=$arg
+			if [[ ${VERILOGLIST} -eq 1 ]]; then
+				VERILOG_FILES+=("${arg}")
+			elif [[ ${XDCLIST} -eq 1 ]]; then
+				XDC_FILES+=("${arg}")
+			elif [[ ${TOPNAME} -eq 1 ]]; then
+				TOP=${arg}
+			elif [[ ${DEVICENAME} -eq 1 ]]; then
+				DEVICE=${arg}
+			elif [[ ${PARTNAME} -eq 1 ]]; then
+				PART=${arg}
 			else
 				echo "Usage: synth [-t|--top <top module name> -v|--verilog <Verilog files list> [-x|--xdc <XDC files list>]"
 				echo "             [-d|--device <device type (e.g. artix7)>] [-p|--part <part name>]"
@@ -85,26 +80,24 @@ for arg in $@; do
 	esac
 done
 
-if [ ${#VERILOG_FILES[@]} -eq 0 ]; then
+if [[ ${#VERILOG_FILES[@]} -eq 0 ]]; then
 	echo "Please provide at least one Verilog file"
 	exit 1
 fi
 
-DATABASE_DIR=${DATABASE_DIR:=$(prjxray-config)}
-
-export TOP=${TOP}
+export TOP
 export USE_ROI="FALSE"
 export INPUT_XDC_FILE=${XDC_FILES[*]}
-export OUT_JSON=$TOP.json
+export OUT_JSON=${TOP}.json
 export OUT_SDC=${TOP}.sdc
 export SYNTH_JSON=${TOP}_io.json
 export OUT_SYNTH_V=${TOP}_synth.v
 export OUT_EBLIF=${TOP}.eblif
-export PART_JSON=`realpath ${DATABASE_DIR}/$DEVICE/$PART/part.json`
+PART_JSON=$(realpath "${DATABASE_DIR}/${DEVICE}/${PART}/part.json")
+export PART_JSON
 export OUT_FASM_EXTRA=${TOP}_fasm_extra.fasm
-export PYTHON3=${PYTHON3:=$(which python3)}
 LOG=${TOP}_synth.log
 
-yosys -p "tcl ${SYNTH_TCL_PATH}" -l $LOG ${VERILOG_FILES[*]}
-python3 ${SPLIT_INOUTS} -i ${OUT_JSON} -o ${SYNTH_JSON}
-yosys -p "read_json $SYNTH_JSON; tcl ${CONV_TCL_PATH}"
+yosys -p "tcl ${SYNTH_TCL_PATH}" -l "${LOG}" "${VERILOG_FILES[@]}"
+python3 "${SPLIT_INOUTS}" -i "${OUT_JSON}" -o "${SYNTH_JSON}"
+yosys -p "read_json ${SYNTH_JSON}; tcl ${CONV_TCL_PATH}"
diff --git a/symbiflow_write_bitstream b/symbiflow_write_bitstream
index f3ee2e1b..ca970eaf 100755
--- a/symbiflow_write_bitstream
+++ b/symbiflow_write_bitstream
@@ -1,22 +1,23 @@
 #!/bin/bash
-set -e
+set -eu
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
+MYPATH=$(realpath "$0")
+MYPATH=$(dirname "${MYPATH}")
 
-source ${MYPATH}/env
+# shellcheck source=env
+source "${MYPATH}/env"
 echo "Writing bitstream ..."
 
-FRM2BIT=""
-if [ ! -z ${FRAMES2BIT} ]; then
-	FRM2BIT="--frm2bit ${FRAMES2BIT}"
+FRM2BIT=()
+if [[ -v FRAMES2BIT ]]; then
+	FRM2BIT=(--frm2bit "${FRAMES2BIT}")
 fi
 
 OPTS=d:f:b:p:
 LONGOPTS=device:,fasm:,bit:,part:
 
-PARSED_OPTS=`getopt --options=${OPTS} --longoptions=${LONGOPTS} --name $0 -- $@`
-eval set -- ${PARSED_OPTS}
+PARSED_OPTS=$(getopt --options="${OPTS}" --longoptions="${LONGOPTS}" --name "$0" -- "$@")
+eval set -- "${PARSED_OPTS}"
 
 DEVICE=""
 FASM=""
@@ -44,33 +45,37 @@ while true; do
 		--)
 			break
 			;;
+		*)
+			echo "Usage:"
+			echo "symbiflow_write_bitstream (-f|--fasm) FASM_INPUT_FILE (-b|--bit) BIT_INPUT_FILE"
+			echo "                          [(-d|--device) DEVICE_TYPE] [(-p|--part) PART_NAME]"
+			exit 1
 	esac
 done
 
-DATABASE_DIR=${DATABASE_DIR:=$(prjxray-config)}
-
-if [ -z $DEVICE ]; then
-	# Try to find device name. Accept only when exactly one is found
-	PART_DIRS=(${DATABASE_DIR}/*/${PART})
-	if [ ${#PART_DIRS[@]} -eq 1 ]; then
-		DEVICE=$(basename $(dirname "${PART_DIRS[0]}"))
-	else
-		echo "Please provide device name"
-		exit 1
-	fi
+if [[ -z ${DEVICE} ]]; then
+	DEVICE=$(find_device_from_part "${PART}")
 fi
 
-DBROOT=`realpath ${DATABASE_DIR}/${DEVICE}`
+DBROOT=$(realpath "${DATABASE_DIR}/${DEVICE}")
 
-if [ -z $FASM ]; then
+if [[ -z ${FASM} ]]; then
 	echo "Please provide fasm file name"
 	exit 1
 fi
 
-if [ -z $BIT ]; then
+if [[ -z ${BIT} ]]; then
 	echo "Please provide bit file name"
 	exit 1
 fi
 
-xcfasm --db-root ${DBROOT} --part ${PART} --part_file ${DBROOT}/${PART}/part.yaml --sparse --emit_pudc_b_pullup --fn_in ${FASM} --bit_out ${BIT} ${FRM2BIT}
+xcfasm \
+	--db-root "${DBROOT}" \
+	--part "${PART}" \
+	--part_file "${DBROOT}/${PART}/part.yaml" \
+	--sparse \
+	--emit_pudc_b_pullup \
+	--fn_in "${FASM}" \
+	--bit_out "${BIT}" \
+	"${FRM2BIT[@]}"
 
diff --git a/symbiflow_write_fasm b/symbiflow_write_fasm
index ec4f8561..d4ea43ba 100755
--- a/symbiflow_write_fasm
+++ b/symbiflow_write_fasm
@@ -1,26 +1,28 @@
 #!/bin/bash
-set -e
+set -eu
 
-MYPATH=`realpath $0`
-MYPATH=`dirname ${MYPATH}`
+MYPATH=$(realpath "$0")
+MYPATH=$(dirname "${MYPATH}")
 
-source ${MYPATH}/env
-source ${VPRPATH}/vpr_common
+# shellcheck source=env
+source "${MYPATH}/env"
+
+OUT_NOISY_WARNINGS=noisy_warnings_fasm.log
+
+# shellcheck source=vpr_common
+source "${VPRPATH}/vpr_common"
 
 parse_args "$@"
 
 TOP="${EBLIF%.*}"
 FASM_EXTRA=${TOP}_fasm_extra.fasm
 
-export OUT_NOISY_WARNINGS=noisy_warnings-${DEVICE}_fasm.log
-
 run_genfasm
 
-echo "FASM extra: $FASM_EXTRA"
-if [ -f $FASM_EXTRA ]; then
+if [[ -f ${FASM_EXTRA} ]]; then
 	echo "writing final fasm"
-	cat ${TOP}.fasm $FASM_EXTRA > tmp.fasm
-	mv tmp.fasm ${TOP}.fasm
+	cat "${TOP}.fasm" "${FASM_EXTRA}" > tmp.fasm
+	mv tmp.fasm "${TOP}.fasm"
 fi
 
 mv vpr_stdout.log fasm.log
diff --git a/vpr_common b/vpr_common
index 8a831587..6d540000 100644
--- a/vpr_common
+++ b/vpr_common
@@ -1,6 +1,8 @@
 #!/bin/bash
 
-if [ -z $VPR_OPTIONS ]; then
+[[ -v SHARE_DIR_PATH ]] || { echo "Error: env must be sourced before vpr_common"; exit 1; }
+
+if [[ -z ${VPR_OPTIONS:+} ]]; then
      echo "Using default VPR options."
      VPR_OPTIONS="@VPR_ARGS@"
 fi
@@ -10,7 +12,7 @@ function parse_args {
      OPTS=d:e:p:n:P:s:a:
      LONGOPTS=device:,eblif:,pcf:,net:,part:,sdc:,additional_vpr_options:
 
-     PARSED_OPTS=`getopt --options=${OPTS} --longoptions=${LONGOPTS} --name $0 -- "$@"`
+     PARSED_OPTS=$(getopt --options="${OPTS}" --longoptions="${LONGOPTS}" --name "$0" -- "$@")
      eval set -- "${PARSED_OPTS}"
 
      DEVICE=""
@@ -49,66 +51,58 @@ function parse_args {
                     shift 2
                     ;;
                -a|--additional_vpr_options)
-                    ADDITIONAL_VPR_OPTIONS="$2"
+                    read -ra ADDITIONAL_VPR_OPTIONS <<<"$2"
+                    VPR_OPTIONS+=("${ADDITIONAL_VPR_OPTIONS[@]}")
                     shift 2
 		    ;;
                --)
                     break
                     ;;
+               *)
+                    echo "Unknown argument: $1"
+                    exit 1
+                    ;;
           esac
      done
 
-     if [ -z $DEVICE ] && [ -n $PART ]; then
-          # Try to find device name. Accept only when exactly one is found
-          PART_DIRS=(${MYPATH}/../share/symbiflow/arch/*/${PART})
-          if [ ${#PART_DIRS[@]} -eq 1 ]; then
-               DEVICE=$(basename $(dirname "${PART_DIRS[0]}"))
-          fi
-     fi
-     if [ -z $DEVICE ]; then
-          echo "Please provide device name"
-          exit 1
+     if [[ -z ${DEVICE} ]]; then
+          DEVICE=$(find_device_from_part "${PART}")
      fi
 
-     if [ -z $EBLIF ]; then
+     if [[ -z ${EBLIF} ]]; then
           echo "Please provide blif file name"
           exit 1
      fi
 
-     export DEVICE=$DEVICE
-     export EBLIF=$EBLIF
-     export PCF=$PCF
-     export NET=$NET
-     export SDC=$SDC
-     export VPR_OPTIONS="$VPR_OPTIONS $ADDITIONAL_VPR_OPTIONS"
+     export DEVICE EBLIF PCF NET SDC VPR_OPTIONS
 
-     export ARCH_DIR=`realpath ${MYPATH}/../share/symbiflow/arch/$DEVICE`
+     export ARCH_DIR=${SHARE_DIR_PATH}/arch/${DEVICE}
      export ARCH_DEF=${ARCH_DIR}/arch.timing.xml
      export LOOKAHEAD=${ARCH_DIR}/rr_graph_${DEVICE}.lookahead.bin
      export RR_GRAPH=${ARCH_DIR}/rr_graph_${DEVICE}.rr_graph.real.bin
      export RR_GRAPH_XML=${ARCH_DIR}/rr_graph_${DEVICE}.rr_graph.real.xml
      export PLACE_DELAY=${ARCH_DIR}/rr_graph_${DEVICE}.place_delay.bin
-     export DEVICE_NAME=`echo $DEVICE | sed -n 's/_/-/p'`
+     export DEVICE_NAME=${DEVICE//_/-}
 }
 
 function run_vpr {
      set -e
 
-     SDC_OPTIONS=""
-     if [ ! -z $SDC ]
+     SDC_OPTIONS=()
+     if [[ -n ${SDC} ]]
      then
-          SDC_OPTIONS="--sdc_file $SDC"
+          SDC_OPTIONS=(--sdc_file "${SDC}")
      fi
 
-     vpr ${ARCH_DEF} \
-         ${EBLIF} \
-         --device ${DEVICE_NAME} \
-         ${VPR_OPTIONS} \
-         --read_rr_graph ${RR_GRAPH} \
-         --read_router_lookahead ${LOOKAHEAD} \
-         --read_placement_delay_lookup ${PLACE_DELAY} \
-         ${SDC_OPTIONS} \
-         $@
+     vpr "${ARCH_DEF}" \
+         "${EBLIF}" \
+         --device "${DEVICE_NAME}" \
+         "${VPR_OPTIONS[@]}" \
+         --read_rr_graph "${RR_GRAPH}" \
+         --read_router_lookahead "${LOOKAHEAD}" \
+         --read_placement_delay_lookup "${PLACE_DELAY}" \
+         "${SDC_OPTIONS[@]}" \
+         "$@"
 
      return $?
 }
@@ -116,12 +110,12 @@ function run_vpr {
 function run_genfasm {
      set -e
 
-     genfasm ${ARCH_DEF} \
-         ${EBLIF} \
-         --device ${DEVICE_NAME} \
-         ${VPR_OPTIONS} \
-         --read_rr_graph ${RR_GRAPH} \
-         $@
+     genfasm "${ARCH_DEF}" \
+         "${EBLIF}" \
+         --device "${DEVICE_NAME}" \
+         "${VPR_OPTIONS[@]}" \
+         --read_rr_graph "${RR_GRAPH}" \
+         "$@"
 
      return $?
 }
@@ -129,11 +123,11 @@ function run_genfasm {
 function run_vpr_xml_rr_graph {
      set -e
 
-     vpr ${ARCH_DEF} \
-          ${EBLIF} \
-          --read_rr_graph ${RR_GRAPH}
-          --write_rr_graph ${RR_GRAPH_XML}
-          $@
+     vpr "${ARCH_DEF}" \
+          "${EBLIF}" \
+          --read_rr_graph "${RR_GRAPH}" \
+          --write_rr_graph "${RR_GRAPH_XML}" \
+          "$@"
 
      return $?
 }