diff --git a/f4pga/wrappers/sh/__init__.py b/f4pga/wrappers/sh/__init__.py
index a05bebb..862e7c3 100644
--- a/f4pga/wrappers/sh/__init__.py
+++ b/f4pga/wrappers/sh/__init__.py
@@ -234,7 +234,7 @@ python3 '{share_dir}'/scripts/prjxray_create_place_constraints.py \
   --part '{part}' \
   --vpr_grid_map '{share_dir}/arch/{device}/vpr_grid_map.csv' \
   --input '{ioplace_file}' \
-  --db_root "${{DATABASE_DIR:=$(prjxray-config)}}" \
+  --db_root "${{DATABASE_DIR:-$(prjxray-config)}}" \
   > constraints.place
 """)
 
@@ -268,7 +268,6 @@ fi
 """
     else:
         place_cmds += """
-PCF=${PCF:=}
 echo "Generating constrains ..."
 python3 -m f4pga.wrappers.sh.generate_constraints $EBLIF $NET $PART $DEVICE $ARCH_DEF $PCF
 VPR_PLACE_FILE='constraints.place'
@@ -292,20 +291,17 @@ def synth():
 
 def write_fasm(genfasm_extra_args = None):
     print("[F4PGA] Running (deprecated) write fasm")
-    p_run_bash_cmds(p_vpr_common_cmds('fasm')+"""
-TOP="${EBLIF%.*}"
-FASM_EXTRA="${TOP}_fasm_extra.fasm"
-""" + f"""
+    p_run_bash_cmds(p_vpr_common_cmds('fasm')+f"""
 '{which('genfasm')}' \
   ${{ARCH_DEF}} ${{EBLIF}} --device ${{DEVICE_NAME}} \
   ${{VPR_OPTIONS}} \
   --read_rr_graph ${{RR_GRAPH}} {' '.join(genfasm_extra_args) if genfasm_extra_args is not None else ''}
 """ + """
-echo "FASM extra: $FASM_EXTRA"
+TOP="${EBLIF%.*}"
+FASM_EXTRA="${TOP}_fasm_extra.fasm"
 if [ -f $FASM_EXTRA ]; then
-  echo "writing final fasm"
-  cat ${TOP}.fasm $FASM_EXTRA > tmp.fasm
-  mv tmp.fasm ${TOP}.fasm
+  echo "writing final fasm (extra: $FASM_EXTRA)"
+  cat $FASM_EXTRA >> ${TOP}.fasm
 fi
 """)
     Path('vpr_stdout.log').rename('fasm.log')
@@ -347,7 +343,7 @@ while true; do
     --) break ;;
   esac
 done
-DATABASE_DIR=${DATABASE_DIR:=$(prjxray-config)}
+DATABASE_DIR=${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})
@@ -445,7 +441,7 @@ if [ -z $BIT ]; then echo "Please provide an output bistream file name"; exit 1;
 """ + f"""
 if [[ "$DEVICE" =~ ^(qlf_k4n8.*)$ ]]; then
   '{which('qlf_fasm')}' \
-    --db-root "${{SHARE_DIR_PATH:="$F4PGA_SHARE_DIR"}}/fasm_database/${{DEVICE}}" \
+    --db-root "${{F4PGA_SHARE_DIR}}/fasm_database/${{DEVICE}}" \
     --format "$BIT_FORMAT" \
     --assemble \
     "$FASM" \
@@ -477,7 +473,7 @@ else
   DEVICE_1={device}
 fi
 """ + """
-ARCH_DIR="$F4PGA_SHARE_DIR"/arch/${DEVICE_1}_${DEVICE_1}
+ARCH_DIR="${F4PGA_SHARE_DIR}/arch/${DEVICE_1}_${DEVICE_1}"
 PINMAP_XML=${ARCH_DIR}/${PINMAPXML}
 """ + f"""
 '{python3}' "$F4PGA_SHARE_DIR"/scripts/create_lib.py \
@@ -497,10 +493,8 @@ def ql():
 
 def fasm2bels():
     print("[F4PGA] Running (deprecated) fasm2bels")
-    p_run_bash_cmds("""
+    p_run_bash_cmds(f"""
 set -e
-SHARE_DIR_PATH=${{SHARE_DIR_PATH:="$F4PGA_SHARE_DIR"}}
-""" + f"""
 eval set -- "$(
   getopt \
     --options=d:P:p:b:v:o:q \
@@ -534,8 +528,8 @@ if ! [[ "$DEVICE" =~ ^(ql-eos-s3|ql-pp3e)$ ]]; then echo "ERROR: Unsupported dev
 if [ -z "{PCF}" ]; then PCF_ARGS=""; else PCF_ARGS="--input-pcf ${PCF}"; fi
 echo "Running fasm2bels"
 """ + f"""
-'{python3}' "`readlink -f ${{SHARE_DIR_PATH}}/scripts/fasm2bels.py`" "${{BIT}}" \
-  --phy-db "`readlink -f ${{SHARE_DIR_PATH}}/arch/${{DEVICE}}_wlcsp/db_phy.pickle`" \
+'{python3}' "${{F4PGA_SHARE_DIR}}"/scripts/fasm2bels.py "${{BIT}}" \
+  --phy-db "${{F4PGA_SHARE_DIR}}/arch/${{DEVICE}}_wlcsp/db_phy.pickle" \
   --device-name "${{DEVICE/ql-/}}" \
   --package-name "$PART" \
   --input-type bitstream \
diff --git a/f4pga/wrappers/sh/quicklogic/ql.f4pga.sh b/f4pga/wrappers/sh/quicklogic/ql.f4pga.sh
index d008f31..b453032 100755
--- a/f4pga/wrappers/sh/quicklogic/ql.f4pga.sh
+++ b/f4pga/wrappers/sh/quicklogic/ql.f4pga.sh
@@ -18,7 +18,7 @@
 
 set -e
 
-SHARE_DIR_PATH=${SHARE_DIR_PATH:="$F4PGA_SHARE_DIR"}
+SHARE_DIR_PATH=${SHARE_DIR_PATH:-"$F4PGA_SHARE_DIR"}
 
 source $(dirname "$0")/vpr_common.f4pga.sh
 
@@ -88,62 +88,25 @@ for arg in $@; do
   -h|--help) exit 0 ;;
   *)
     case $OPT in
-      src)
-        SOURCE=$arg
-        OPT=""
-      ;;
-      top)
-        TOP=$arg
-        OPT=""
-      ;;
-      vlog)
-        VERILOG_FILES+="$arg "
-      ;;
-      dev)
-        DEVICE=$arg
-        OPT=""
-      ;;
-      pcf)
-        PCF=$arg
-        OPT=""
-      ;;
-      part)
-        PART=$arg
-        OPT=""
-      ;;
-      json)
-        JSON=$arg
-        OPT=""
-      ;;
-      sdc)
-        SDC=$arg
-        OPT=""
-      ;;
+      src)             SOURCE=$arg;          OPT="" ;;
+      top)             TOP=$arg;             OPT="" ;;
+      dev)             DEVICE=$arg;          OPT="" ;;
+      pcf)             PCF=$arg;             OPT="" ;;
+      part)            PART=$arg;            OPT="" ;;
+      json)            JSON=$arg;            OPT="" ;;
+      sdc)             SDC=$arg;             OPT="" ;;
+      pnr_corner)      PNR_CORNER=$arg;      OPT="" ;;
+      analysis_corner) ANALYSIS_CORNER=$arg; OPT="" ;;
+      build_dir)       BUILDDIR=$arg         OPT="" ;;
       route)
         ROUTE_FLAG0="$arg"
         ROUTE_FLAG0="${ROUTE_FLAG0,,}"
         OPT=""
       ;;
-      pnr_corner)
-        PNR_CORNER=$arg
-        OPT=""
-      ;;
-      analysis_corner)
-        ANALYSIS_CORNER=$arg
-        OPT=""
-      ;;
-      dump)
-        OUT+="$arg "
-      ;;
-      compile_xtra)
-      ;;
-      options_file)
-        COMPILE_EXTRA_ARGS+=("-f \"`realpath $arg`\" ")
-      ;;
-      build_dir)
-        BUILDDIR=$arg
-        OPT=""
-      ;;
+      vlog) VERILOG_FILES+="$arg " ;;
+      dump) OUT+="$arg " ;;
+      compile_xtra) ;;
+      options_file) COMPILE_EXTRA_ARGS+=("-f \"`realpath $arg`\" ") ;;
       *)
         echo "Refer help for more details: ql_symbiflow -h "
         exit 1
@@ -157,69 +120,47 @@ for arg in $@; do
 done
 
 case ${DEVICE} in
-  qlf_k4n8)
-    DEVICE="${DEVICE}_${DEVICE}"
-    FAMILY="qlf_k4n8"
-    DEVICE_CHECK="VALID"
-    USE_PINMAP=1
-  ;;
-  qlf_k6n10)
-    DEVICE="${DEVICE}_${DEVICE}"
-    FAMILY="qlf_k6n10"
-    DEVICE_CHECK="VALID"
-    USE_PINMAP=1
-  ;;
-  ql-eos-s3)
-    DEVICE="${DEVICE}"
-    FAMILY="pp3"
-    DEVICE_CHECK="VALID"
-    USE_PINMAP=0
-  ;;
-  *)
-    echo "Unsupported device '${DEVICE}'"
-    exit 1
-  ;;
+  qlf_k4n8)  DEVICE="${DEVICE}_${DEVICE}"; FAMILY="qlf_k4n8";  DEVICE_CHECK="VALID"; USE_PINMAP=1 ;;
+  qlf_k6n10) DEVICE="${DEVICE}_${DEVICE}"; FAMILY="qlf_k6n10"; DEVICE_CHECK="VALID"; USE_PINMAP=1 ;;
+  ql-eos-s3) DEVICE="${DEVICE}";           FAMILY="pp3";       DEVICE_CHECK="VALID"; USE_PINMAP=0 ;;
+  *) echo "Unsupported device '${DEVICE}'"; exit 1 ;;
 esac
 
-## Check if the source directory exists
 if [[ $1 == "-h" || $1 == "--help" ]];then
   exit 1
-else
-  if [ -z "$SOURCE" ];then
-    SOURCE=$PWD
-  elif [ $SOURCE == "." ];then
-    SOURCE=$PWD
-  elif [ ! -d "$SOURCE" ];then
-    echo "Directory path $SOURCE DOES NOT exists. Please add absolute path"
+fi
+
+## Check if the source directory exists
+SOURCE=${SOURCE:-$PWD}
+if [ $SOURCE == "." ];then
+  SOURCE=$PWD
+elif [ ! -d "$SOURCE" ];then
+  echo "Directory path $SOURCE DOES NOT exists. Please add absolute path"
+  exit 1
+fi
+
+if [ -f $SOURCE/v_list_tmp ];then
+  rm -f $SOURCE/v_list_tmp
+fi
+if [ "$VERILOG_FILES" == "*.v" ];then
+  VERILOG_FILES=`cd ${SOURCE};ls *.v`
+fi
+echo "$VERILOG_FILES" >${SOURCE}/v_list
+
+## Validate the verlog source files
+if [ ${#VERILOG_FILES[@]} -eq 0 ]; then
+  if [[ $1 != "-h" || $1 != "--help" ]];then
+    echo "Please provide at least one Verilog file"
     exit 1
   fi
-
-  if [[ $1 == "-h"  ||  $1 == "--help" ]];then
-    exit 0
-  else
-    if [ -f $SOURCE/v_list_tmp ];then
-      rm -f $SOURCE/v_list_tmp
-    fi
-    if [ "$VERILOG_FILES" == "*.v" ];then
-      VERILOG_FILES=`cd ${SOURCE};ls *.v`
-    fi
-    echo "$VERILOG_FILES" >${SOURCE}/v_list
-  fi
-
-  ## Validate the verlog source files
-  if [ ${#VERILOG_FILES[@]} -eq 0 ]; then
-    if [[ $1 != "-h" || $1 != "--help" ]];then
-      echo "Please provide at least one Verilog file"
-      exit 1
-    fi
-  else
-    echo "verilog files: $VERILOG_FILES"
-    echo $VERILOG_FILES >${SOURCE}/v_list
-    sed '/^$/d' $SOURCE/v_list > $SOURCE/f_list_temp
-    VERILOG_FILES=`cat $SOURCE/f_list_temp`
-  fi
+else
+  echo "verilog files: $VERILOG_FILES"
+  echo $VERILOG_FILES >${SOURCE}/v_list
+  sed '/^$/d' $SOURCE/v_list > $SOURCE/f_list_temp
+  VERILOG_FILES=`cat $SOURCE/f_list_temp`
 fi
 
+
 if [[ $1 == "-compile" || $1 == "-post_verilog" ]]; then
   if [ -z "$DEVICE" ]; then
     echo "DEVICE name is missing. Refer -h/--help"
@@ -344,9 +285,9 @@ elif [[ -f $PCF ]];then
 fi
 
 if [[ $USE_PINMAP -ne 0 ]]; then
-    export PART=${CSV_PATH}
+  export PART=${CSV_PATH}
 else
-    export PART=${PART}
+  export PART=${PART}
 fi
 export JSON=${JSON_PATH}
 export PCF_PATH=${PCF_PATH}
diff --git a/f4pga/wrappers/sh/quicklogic/synth.f4pga.sh b/f4pga/wrappers/sh/quicklogic/synth.f4pga.sh
index b872413..1d19fd8 100755
--- a/f4pga/wrappers/sh/quicklogic/synth.f4pga.sh
+++ b/f4pga/wrappers/sh/quicklogic/synth.f4pga.sh
@@ -18,7 +18,7 @@
 
 set -e
 
-export SHARE_DIR_PATH=${SHARE_DIR_PATH:="$F4PGA_SHARE_DIR"}
+export SHARE_DIR_PATH=${SHARE_DIR_PATH:-"$F4PGA_SHARE_DIR"}
 SPLIT_INOUTS=`realpath ${SHARE_DIR_PATH}/scripts/split_inouts.py`
 CONVERT_OPTS=`realpath ${SHARE_DIR_PATH}/scripts/convert_compile_opts.py`
 
diff --git a/f4pga/wrappers/sh/quicklogic/vpr_common.f4pga.sh b/f4pga/wrappers/sh/quicklogic/vpr_common.f4pga.sh
index 07a9161..4c0a59a 100755
--- a/f4pga/wrappers/sh/quicklogic/vpr_common.f4pga.sh
+++ b/f4pga/wrappers/sh/quicklogic/vpr_common.f4pga.sh
@@ -16,7 +16,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-SHARE_DIR_PATH=${SHARE_DIR_PATH:="$F4PGA_SHARE_DIR"}
+SHARE_DIR_PATH=${SHARE_DIR_PATH:-"$F4PGA_SHARE_DIR"}
 
 if [ -z $VPR_OPTIONS ]; then
   echo "Using default VPR options."
diff --git a/f4pga/wrappers/sh/xc7/synth.f4pga.sh b/f4pga/wrappers/sh/xc7/synth.f4pga.sh
index 9ba3709..37a5440 100755
--- a/f4pga/wrappers/sh/xc7/synth.f4pga.sh
+++ b/f4pga/wrappers/sh/xc7/synth.f4pga.sh
@@ -118,7 +118,7 @@ if [ ${#VERILOG_FILES[@]} -eq 0 ]; then
   exit 1
 fi
 
-DATABASE_DIR=${DATABASE_DIR:=$(prjxray-config)}
+DATABASE_DIR=${DATABASE_DIR:-$(prjxray-config)}
 
 export TOP=${TOP}
 export USE_ROI="FALSE"
@@ -130,7 +130,7 @@ export OUT_SYNTH_V=${TOP}_synth.v
 export OUT_EBLIF=${TOP}.eblif
 export PART_JSON=`realpath ${DATABASE_DIR}/$DEVICE/$PART/part.json`
 export OUT_FASM_EXTRA=${TOP}_fasm_extra.fasm
-export PYTHON3=${PYTHON3:=$(which python3)}
+export PYTHON3=${PYTHON3:-$(which python3)}
 
 LOG=${TOP}_synth.log
 
diff --git a/f4pga/wrappers/sh/xc7/vpr_common.f4pga.sh b/f4pga/wrappers/sh/xc7/vpr_common.f4pga.sh
index 8214c63..fa81a13 100755
--- a/f4pga/wrappers/sh/xc7/vpr_common.f4pga.sh
+++ b/f4pga/wrappers/sh/xc7/vpr_common.f4pga.sh
@@ -16,7 +16,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-SHARE_DIR_PATH=${SHARE_DIR_PATH:="$F4PGA_SHARE_DIR"}
+SHARE_DIR_PATH=${SHARE_DIR_PATH:-"$F4PGA_SHARE_DIR"}
 
 if [ -z $VPR_OPTIONS ]; then
   echo "Using default VPR options."