diff --git a/acme.sh b/acme.sh
index f8c7e179..195adee0 100755
--- a/acme.sh
+++ b/acme.sh
@@ -411,7 +411,7 @@ _digest() {
 
   outputhex="$2"
 
-  if [ "$alg" = "sha256" ] || [ "$alg" = "sha1" ]; then
+  if [ "$alg" = "sha256" ] || [ "$alg" = "sha1" ] || [ "$alg" = "md5" ]; then
     if [ "$outputhex" ]; then
       openssl dgst -"$alg" -hex | cut -d = -f 2 | tr -d ' '
     else
@@ -2290,10 +2290,10 @@ _findHook() {
   _hookcat="$2"
   _hookname="$3"
 
-  if [ -f "$_SCRIPT_HOME/$_hookdomain/$_hookname" ]; then
-    d_api="$_SCRIPT_HOME/$_hookdomain/$_hookname"
-  elif [ -f "$_SCRIPT_HOME/$_hookdomain/$_hookname.sh" ]; then
-    d_api="$_SCRIPT_HOME/$_hookdomain/$_hookname.sh"
+  if [ -f "$_SCRIPT_HOME/$_hookcat/$_hookname" ]; then
+    d_api="$_SCRIPT_HOME/$_hookcat/$_hookname"
+  elif [ -f "$_SCRIPT_HOME/$_hookcat/$_hookname.sh" ]; then
+    d_api="$_SCRIPT_HOME/$_hookcat/$_hookname.sh"
   elif [ -f "$LE_WORKING_DIR/$_hookdomain/$_hookname" ]; then
     d_api="$LE_WORKING_DIR/$_hookdomain/$_hookname"
   elif [ -f "$LE_WORKING_DIR/$_hookdomain/$_hookname.sh" ]; then
diff --git a/dnsapi/dns_cf.sh b/dnsapi/dns_cf.sh
index 63acb28f..edd48300 100755
--- a/dnsapi/dns_cf.sh
+++ b/dnsapi/dns_cf.sh
@@ -25,7 +25,7 @@ dns_cf_add() {
   _saveaccountconf CF_Email "$CF_Email"
 
   _debug "First detect the root zone"
-  if ! _get_root $fulldomain; then
+  if ! _get_root "$fulldomain"; then
     _err "invalid domain"
     return 1
   fi
@@ -36,7 +36,7 @@ dns_cf_add() {
   _debug "Getting txt records"
   _cf_rest GET "zones/${_domain_id}/dns_records?type=TXT&name=$fulldomain"
 
-  if ! printf "$response" | grep \"success\":true >/dev/null; then
+  if ! printf "%s" "$response" | grep \"success\":true >/dev/null; then
     _err "Error"
     return 1
   fi
@@ -46,7 +46,7 @@ dns_cf_add() {
   if [ "$count" = "0" ]; then
     _info "Adding record"
     if _cf_rest POST "zones/$_domain_id/dns_records" "{\"type\":\"TXT\",\"name\":\"$fulldomain\",\"content\":\"$txtvalue\",\"ttl\":120}"; then
-      if printf -- "%s" "$response" | grep $fulldomain >/dev/null; then
+      if printf -- "%s" "$response" | grep "$fulldomain" >/dev/null; then
         _info "Added, sleeping 10 seconds"
         sleep 10
         #todo: check if the record takes effect
@@ -60,7 +60,7 @@ dns_cf_add() {
   else
     _info "Updating record"
     record_id=$(printf "%s\n" "$response" | _egrep_o \"id\":\"[^\"]*\" | cut -d : -f 2 | tr -d \" | head -n 1)
-    _debug "record_id" $record_id
+    _debug "record_id" "$record_id"
 
     _cf_rest PUT "zones/$_domain_id/dns_records/$record_id" "{\"id\":\"$record_id\",\"type\":\"TXT\",\"name\":\"$fulldomain\",\"content\":\"$txtvalue\",\"zone_id\":\"$_domain_id\",\"zone_name\":\"$_domain\"}"
     if [ "$?" = "0" ]; then
@@ -91,8 +91,8 @@ _get_root() {
   domain=$1
   i=2
   p=1
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     if [ -z "$h" ]; then
       #not valid
       return 1
@@ -102,17 +102,17 @@ _get_root() {
       return 1
     fi
 
-    if printf $response | grep \"name\":\"$h\" >/dev/null; then
+    if printf "%s" "$response" | grep "\"name\":\"$h\"" >/dev/null; then
       _domain_id=$(printf "%s\n" "$response" | _egrep_o \"id\":\"[^\"]*\" | head -n 1 | cut -d : -f 2 | tr -d \")
       if [ "$_domain_id" ]; then
-        _sub_domain=$(printf $domain | cut -d . -f 1-$p)
+        _sub_domain=$(printf "%s" "$domain" | cut -d . -f 1-$p)
         _domain=$h
         return 0
       fi
       return 1
     fi
     p=$i
-    i=$(expr $i + 1)
+    i=$(_math "$i" + 1)
   done
   return 1
 }
@@ -121,7 +121,7 @@ _cf_rest() {
   m=$1
   ep="$2"
   data="$3"
-  _debug $ep
+  _debug "$ep"
 
   _H1="X-Auth-Email: $CF_Email"
   _H2="X-Auth-Key: $CF_Key"
@@ -129,7 +129,7 @@ _cf_rest() {
 
   if [ "$data" ]; then
     _debug data "$data"
-    response="$(_post "$data" "$CF_Api/$ep" "" $m)"
+    response="$(_post "$data" "$CF_Api/$ep" "" "$m")"
   else
     response="$(_get "$CF_Api/$ep")"
   fi
diff --git a/dnsapi/dns_cx.sh b/dnsapi/dns_cx.sh
index 81eb896d..c4d941da 100755
--- a/dnsapi/dns_cx.sh
+++ b/dnsapi/dns_cx.sh
@@ -22,19 +22,19 @@ dns_cx_add() {
     return 1
   fi
 
-  REST_API=$CX_Api
+  REST_API="$CX_Api"
 
   #save the api key and email to the account conf file.
   _saveaccountconf CX_Key "$CX_Key"
   _saveaccountconf CX_Secret "$CX_Secret"
 
   _debug "First detect the root zone"
-  if ! _get_root $fulldomain; then
+  if ! _get_root "$fulldomain"; then
     _err "invalid domain"
     return 1
   fi
 
-  existing_records $_domain $_sub_domain
+  existing_records "$_domain" "$_sub_domain"
   _debug count "$count"
   if [ "$?" != "0" ]; then
     _err "Error get existing records."
@@ -42,9 +42,9 @@ dns_cx_add() {
   fi
 
   if [ "$count" = "0" ]; then
-    add_record $_domain $_sub_domain $txtvalue
+    add_record "$_domain" "$_sub_domain" "$txtvalue"
   else
-    update_record $_domain $_sub_domain $txtvalue
+    update_record "$_domain" "$_sub_domain" "$txtvalue"
   fi
 
   if [ "$?" = "0" ]; then
@@ -78,7 +78,7 @@ existing_records() {
     return 0
   fi
 
-  if printf "$response" | grep '"type":"TXT"' >/dev/null; then
+  if printf "%s" "$response" | grep '"type":"TXT"' >/dev/null; then
     count=1
     record_id=$(printf "%s\n" "$seg" | _egrep_o \"record_id\":\"[^\"]*\" | cut -d : -f 2 | tr -d \")
     _debug record_id "$record_id"
@@ -93,7 +93,7 @@ add_record() {
   root=$1
   sub=$2
   txtvalue=$3
-  fulldomain=$sub.$root
+  fulldomain="$sub.$root"
 
   _info "Adding record"
 
@@ -110,7 +110,7 @@ update_record() {
   root=$1
   sub=$2
   txtvalue=$3
-  fulldomain=$sub.$root
+  fulldomain="$sub.$root"
 
   _info "Updating record"
 
@@ -136,30 +136,30 @@ _get_root() {
     return 1
   fi
 
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     _debug h "$h"
     if [ -z "$h" ]; then
       #not valid
       return 1
     fi
 
-    if printf "$response" | grep "$h." >/dev/null; then
+    if _contains "$response" "$h."; then
       seg=$(printf "%s" "$response" | _egrep_o "\{[^\{]*\"$h\.\"[^\}]*\}")
       _debug seg "$seg"
       _domain_id=$(printf "%s" "$seg" | _egrep_o \"id\":\"[^\"]*\" | cut -d : -f 2 | tr -d \")
       _debug _domain_id "$_domain_id"
       if [ "$_domain_id" ]; then
-        _sub_domain=$(printf $domain | cut -d . -f 1-$p)
-        _debug _sub_domain $_sub_domain
-        _domain=$h
-        _debug _domain $_domain
+        _sub_domain=$(printf "%s" "$domain" | cut -d . -f 1-$p)
+        _debug _sub_domain "$_sub_domain"
+        _domain="$h"
+        _debug _domain "$_domain"
         return 0
       fi
       return 1
     fi
-    p=$i
-    i=$(expr $i + 1)
+    p="$i"
+    i=$(_math "$i" + 1)
   done
   return 1
 }
@@ -168,7 +168,7 @@ _get_root() {
 _rest() {
   m=$1
   ep="$2"
-  _debug $ep
+  _debug "$ep"
   url="$REST_API/$ep"
   _debug url "$url"
 
@@ -180,7 +180,7 @@ _rest() {
 
   sec="$CX_Key$url$data$cdate$CX_Secret"
   _debug sec "$sec"
-  hmac=$(printf "$sec" | openssl md5 | cut -d " " -f 2)
+  hmac=$(printf "%s" "$sec" | _digest md5 hex)
   _debug hmac "$hmac"
 
   _H1="API-KEY: $CX_Key"
@@ -199,7 +199,7 @@ _rest() {
     return 1
   fi
   _debug2 response "$response"
-  if ! printf "$response" | grep '"message":"success"' >/dev/null; then
+  if ! _contains "$response" '"message":"success"'; then
     return 1
   fi
   return 0
diff --git a/dnsapi/dns_dp.sh b/dnsapi/dns_dp.sh
index 8861bfcf..605c541d 100755
--- a/dnsapi/dns_dp.sh
+++ b/dnsapi/dns_dp.sh
@@ -22,19 +22,19 @@ dns_dp_add() {
     return 1
   fi
 
-  REST_API=$DP_Api
+  REST_API="$DP_Api"
 
   #save the api key and email to the account conf file.
   _saveaccountconf DP_Id "$DP_Id"
   _saveaccountconf DP_Key "$DP_Key"
 
   _debug "First detect the root zone"
-  if ! _get_root $fulldomain; then
+  if ! _get_root "$fulldomain"; then
     _err "invalid domain"
     return 1
   fi
 
-  existing_records $_domain $_sub_domain
+  existing_records "$_domain" "$_sub_domain"
   _debug count "$count"
   if [ "$?" != "0" ]; then
     _err "Error get existing records."
@@ -42,9 +42,9 @@ dns_dp_add() {
   fi
 
   if [ "$count" = "0" ]; then
-    add_record $_domain $_sub_domain $txtvalue
+    add_record "$_domain" "$_sub_domain" "$txtvalue"
   else
-    update_record $_domain $_sub_domain $txtvalue
+    update_record "$_domain" "$_sub_domain" "$txtvalue"
   fi
 }
 
@@ -67,14 +67,14 @@ existing_records() {
     return 1
   fi
 
-  if printf "$response" | grep 'No records'; then
+  if _contains "$response" 'No records'; then
     count=0
     return 0
   fi
 
-  if printf "$response" | grep "Action completed successful" >/dev/null; then
-    count=$(printf "$response" | grep '<type>TXT</type>' | wc -l)
-    record_id=$(printf "$response" | grep '^<id>' | tail -1 | cut -d '>' -f 2 | cut -d '<' -f 1)
+  if _contains "$response" "Action completed successful"; then
+    count=$(printf "%s" "$response" | grep '<type>TXT</type>' | wc -l)
+    record_id=$(printf "%s" "$response" | grep '^<id>' | tail -1 | cut -d '>' -f 2 | cut -d '<' -f 1)
     return 0
   else
     _err "get existing records error."
@@ -90,7 +90,7 @@ add_record() {
   root=$1
   sub=$2
   txtvalue=$3
-  fulldomain=$sub.$root
+  fulldomain="$sub.$root"
 
   _info "Adding record"
 
@@ -98,7 +98,7 @@ add_record() {
     return 1
   fi
 
-  if printf "$response" | grep "Action completed successful"; then
+  if _contains "$response" "Action completed successful"; then
 
     return 0
   fi
@@ -112,7 +112,7 @@ update_record() {
   root=$1
   sub=$2
   txtvalue=$3
-  fulldomain=$sub.$root
+  fulldomain="$sub.$root"
 
   _info "Updating record"
 
@@ -120,7 +120,7 @@ update_record() {
     return 1
   fi
 
-  if printf "$response" | grep "Action completed successful"; then
+  if _contains "$response" "Action completed successful"; then
 
     return 0
   fi
@@ -138,8 +138,8 @@ _get_root() {
   domain=$1
   i=2
   p=1
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     if [ -z "$h" ]; then
       #not valid
       return 1
@@ -149,20 +149,20 @@ _get_root() {
       return 1
     fi
 
-    if printf "$response" | grep "Action completed successful" >/dev/null; then
+    if _contains "$response" "Action completed successful"; then
       _domain_id=$(printf "%s\n" "$response" | _egrep_o \"id\":\"[^\"]*\" | cut -d : -f 2 | tr -d \")
       _debug _domain_id "$_domain_id"
       if [ "$_domain_id" ]; then
-        _sub_domain=$(printf $domain | cut -d . -f 1-$p)
-        _debug _sub_domain $_sub_domain
-        _domain=$h
-        _debug _domain $_domain
+        _sub_domain=$(printf "%s" "$domain" | cut -d . -f 1-$p)
+        _debug _sub_domain "$_sub_domain"
+        _domain="$h"
+        _debug _domain "$_domain"
         return 0
       fi
       return 1
     fi
-    p=$i
-    i=$(expr $i + 1)
+    p="$i"
+    i=$(_math "$i" + 1)
   done
   return 1
 }
@@ -172,14 +172,14 @@ _rest() {
   m=$1
   ep="$2"
   data="$3"
-  _debug $ep
+  _debug "$ep"
   url="$REST_API/$ep"
 
   _debug url "$url"
 
   if [ "$data" ]; then
     _debug2 data "$data"
-    response="$(_post $data "$url")"
+    response="$(_post "$data" "$url")"
   else
     response="$(_get "$url")"
   fi
diff --git a/dnsapi/dns_gd.sh b/dnsapi/dns_gd.sh
index 51ca8db5..304d5d3e 100755
--- a/dnsapi/dns_gd.sh
+++ b/dnsapi/dns_gd.sh
@@ -26,7 +26,7 @@ dns_gd_add() {
   _saveaccountconf GD_Secret "$GD_Secret"
 
   _debug "First detect the root zone"
-  if ! _get_root $fulldomain; then
+  if ! _get_root "$fulldomain"; then
     _err "invalid domain"
     return 1
   fi
@@ -67,8 +67,8 @@ _get_root() {
   domain=$1
   i=2
   p=1
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     if [ -z "$h" ]; then
       #not valid
       return 1
@@ -78,11 +78,11 @@ _get_root() {
       return 1
     fi
 
-    if printf "$response" | grep '"code":"NOT_FOUND"' >/dev/null; then
+    if _contains "$response" '"code":"NOT_FOUND"'; then
       _debug "$h not found"
     else
-      _sub_domain=$(printf $domain | cut -d . -f 1-$p)
-      _domain=$h
+      _sub_domain=$(printf "%s" "$domain" | cut -d . -f 1-$p)
+      _domain="$h"
       return 0
     fi
     p=$i
@@ -95,7 +95,7 @@ _gd_rest() {
   m=$1
   ep="$2"
   data="$3"
-  _debug $ep
+  _debug "$ep"
 
   _H1="Authorization: sso-key $GD_Key:$GD_Secret"
   _H2="Content-Type: application/json"
diff --git a/dnsapi/dns_lexicon.sh b/dnsapi/dns_lexicon.sh
index 847b9999..bceab8d5 100755
--- a/dnsapi/dns_lexicon.sh
+++ b/dnsapi/dns_lexicon.sh
@@ -14,9 +14,9 @@ dns_lexicon_add() {
   fulldomain=$1
   txtvalue=$2
 
-  domain=$(printf "$fulldomain" | cut -d . -f 2-999)
+  domain=$(printf "%s" "$fulldomain" | cut -d . -f 2-999)
 
-  if ! _exists $lexicon_cmd; then
+  if ! _exists "$lexicon_cmd"; then
     _err "Please install $lexicon_cmd first: $wiki"
     return 1
   fi
@@ -33,7 +33,7 @@ dns_lexicon_add() {
   eval Lx_name_v="\$$Lx_name"
   _debug "$Lx_name" "$Lx_name_v"
   if [ "$Lx_name_v" ]; then
-    _saveaccountconf $Lx_name "$Lx_name_v"
+    _saveaccountconf "$Lx_name" "$Lx_name_v"
     export "$Lx_name"
   fi
 
@@ -41,7 +41,7 @@ dns_lexicon_add() {
   eval Lx_token_v="\$$Lx_token"
   _debug "$Lx_token" "$Lx_token_v"
   if [ "$Lx_token_v" ]; then
-    _saveaccountconf $Lx_token "$Lx_token_v"
+    _saveaccountconf "$Lx_token" "$Lx_token_v"
     export "$Lx_token"
   fi
 
@@ -49,7 +49,7 @@ dns_lexicon_add() {
   eval Lx_password_v="\$$Lx_password"
   _debug "$Lx_password" "$Lx_password_v"
   if [ "$Lx_password_v" ]; then
-    _saveaccountconf $Lx_password "$Lx_password_v"
+    _saveaccountconf "$Lx_password" "$Lx_password_v"
     export "$Lx_password"
   fi
 
@@ -58,7 +58,7 @@ dns_lexicon_add() {
   _debug "$Lx_domaintoken" "$Lx_domaintoken_v"
   if [ "$Lx_domaintoken_v" ]; then
     export "$Lx_domaintoken"
-    _saveaccountconf $Lx_domaintoken "$Lx_domaintoken_v"
+    _saveaccountconf "$Lx_domaintoken" "$Lx_domaintoken_v"
   fi
 
   $lexicon_cmd "$PROVIDER" create ${domain} TXT --name="_acme-challenge.${domain}." --content="${txtvalue}"
diff --git a/dnsapi/dns_lua.sh b/dnsapi/dns_lua.sh
index efd197c2..a6375e5b 100755
--- a/dnsapi/dns_lua.sh
+++ b/dnsapi/dns_lua.sh
@@ -28,7 +28,7 @@ dns_lua_add() {
   _saveaccountconf LUA_Email "$LUA_Email"
 
   _debug "First detect the root zone"
-  if ! _get_root $fulldomain; then
+  if ! _get_root "$fulldomain"; then
     _err "invalid domain"
     return 1
   fi
@@ -49,7 +49,7 @@ dns_lua_add() {
   if [ "$count" = "0" ]; then
     _info "Adding record"
     if _LUA_rest POST "zones/$_domain_id/records" "{\"type\":\"TXT\",\"name\":\"$fulldomain.\",\"content\":\"$txtvalue\",\"ttl\":120}"; then
-      if printf -- "%s" "$response" | grep $fulldomain >/dev/null; then
+      if printf -- "%s" "$response" | grep "$fulldomain" >/dev/null; then
         _info "Added"
         #todo: check if the record takes effect
         return 0
@@ -62,7 +62,7 @@ dns_lua_add() {
   else
     _info "Updating record"
     record_id=$(printf "%s\n" "$response" | _egrep_o \"id\":[^,]*,\"name\":\"$fulldomain.\",\"type\":\"TXT\" | cut -d: -f2 | cut -d, -f1)
-    _debug "record_id" $record_id
+    _debug "record_id" "$record_id"
 
     _LUA_rest PUT "zones/$_domain_id/records/$record_id" "{\"id\":\"$record_id\",\"type\":\"TXT\",\"name\":\"$fulldomain.\",\"content\":\"$txtvalue\",\"zone_id\":\"$_domain_id\",\"ttl\":120}"
     if [ "$?" = "0" ]; then
@@ -95,24 +95,24 @@ _get_root() {
   if ! _LUA_rest GET "zones"; then
     return 1
   fi
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     if [ -z "$h" ]; then
       #not valid
       return 1
     fi
 
-    if printf $response | grep \"name\":\"$h\" >/dev/null; then
+    if _contains "$response" "\"name\":\"$h\""; then
       _domain_id=$(printf "%s\n" "$response" | _egrep_o \"id\":[^,]*,\"name\":\"$h\" | cut -d : -f 2 | cut -d , -f 1)
       if [ "$_domain_id" ]; then
-        _sub_domain=$(printf $domain | cut -d . -f 1-$p)
-        _domain=$h
+        _sub_domain=$(printf "%s" "$domain" | cut -d . -f 1-$p)
+        _domain="$h"
         return 0
       fi
       return 1
     fi
     p=$i
-    i=$(expr $i + 1)
+    i=$(_math "$i" + 1)
   done
   return 1
 }
@@ -121,7 +121,7 @@ _LUA_rest() {
   m=$1
   ep="$2"
   data="$3"
-  _debug $ep
+  _debug "$ep"
 
   _H1="Accept: application/json"
   _H2="Authorization: Basic $LUA_auth"
diff --git a/dnsapi/dns_me.sh b/dnsapi/dns_me.sh
index abc17475..db4f796a 100755
--- a/dnsapi/dns_me.sh
+++ b/dnsapi/dns_me.sh
@@ -25,7 +25,7 @@ dns_me_add() {
   _saveaccountconf ME_Secret "$ME_Secret"
 
   _debug "First detect the root zone"
-  if ! _get_root $fulldomain; then
+  if ! _get_root "$fulldomain"; then
     _err "invalid domain"
     return 1
   fi
@@ -36,7 +36,7 @@ dns_me_add() {
   _debug "Getting txt records"
   _me_rest GET "${_domain_id}/records?recordName=$_sub_domain&type=TXT"
 
-  if ! printf "$response" | grep \"totalRecords\": >/dev/null; then
+  if ! _contains "$response" "\"totalRecords\":"; then
     _err "Error"
     return 1
   fi
@@ -59,7 +59,7 @@ dns_me_add() {
   else
     _info "Updating record"
     record_id=$(printf "%s\n" "$response" | _egrep_o \"id\":[^,]* | cut -d : -f 2 | head -n 1)
-    _debug "record_id" $record_id
+    _debug "record_id" "$record_id"
 
     _me_rest PUT "$_domain_id/records/$record_id/" "{\"id\":\"$record_id\",\"type\":\"TXT\",\"name\":\"$_sub_domain\",\"value\":\"$txtvalue\",\"gtdLocation\":\"DEFAULT\",\"ttl\":120}"
     if [ "$?" = "0" ]; then
@@ -89,8 +89,8 @@ _get_root() {
   domain=$1
   i=2
   p=1
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     if [ -z "$h" ]; then
       #not valid
       return 1
@@ -100,17 +100,17 @@ _get_root() {
       return 1
     fi
 
-    if printf $response | grep \"name\":\"$h\" >/dev/null; then
+    if _contains "$response" "\"name\":\"$h\""; then
       _domain_id=$(printf "%s\n" "$response" | _egrep_o \"id\":[^,]* | head -n 1 | cut -d : -f 2)
       if [ "$_domain_id" ]; then
-        _sub_domain=$(printf $domain | cut -d . -f 1-$p)
-        _domain=$h
+        _sub_domain=$(printf "%s" "$domain" | cut -d . -f 1-$p)
+        _domain="$h"
         return 0
       fi
       return 1
     fi
     p=$i
-    i=$(expr $i + 1)
+    i=$(_math "$i" + 1)
   done
   return 1
 }
@@ -119,10 +119,10 @@ _me_rest() {
   m=$1
   ep="$2"
   data="$3"
-  _debug $ep
+  _debug "$ep"
 
   cdate=$(date -u +"%a, %d %b %Y %T %Z")
-  hmac=$(printf "$cdate" | _hmac sha1 "$ME_Secret" 1)
+  hmac=$(printf "%s" "$cdate" | _hmac sha1 "$ME_Secret" 1)
 
   _H1="x-dnsme-apiKey: $ME_Key"
   _H2="x-dnsme-requestDate: $cdate"
diff --git a/dnsapi/dns_ovh.sh b/dnsapi/dns_ovh.sh
index 782c0830..ace52225 100755
--- a/dnsapi/dns_ovh.sh
+++ b/dnsapi/dns_ovh.sh
@@ -226,8 +226,8 @@ _get_root() {
   domain=$1
   i=2
   p=1
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     if [ -z "$h" ]; then
       #not valid
       return 1
@@ -238,12 +238,12 @@ _get_root() {
     fi
 
     if ! _contains "$response" "This service does not exist" >/dev/null; then
-      _sub_domain=$(printf $domain | cut -d . -f 1-$p)
-      _domain=$h
+      _sub_domain=$(printf "%s" "$domain" | cut -d . -f 1-$p)
+      _domain="$h"
       return 0
     fi
     p=$i
-    i=$(expr $i + 1)
+    i=$(_math "$i" + 1)
   done
   return 1
 }
@@ -261,7 +261,7 @@ _ovh_rest() {
   m=$1
   ep="$2"
   data="$3"
-  _debug $ep
+  _debug "$ep"
 
   _ovh_url="$OVH_API/$ep"
   _debug2 _ovh_url "$_ovh_url"
diff --git a/dnsapi/dns_pdns.sh b/dnsapi/dns_pdns.sh
index ec82bfe8..7c994eb5 100755
--- a/dnsapi/dns_pdns.sh
+++ b/dnsapi/dns_pdns.sh
@@ -35,7 +35,7 @@ dns_pdns_add() {
   fi
 
   if [ -z "$PDNS_Ttl" ]; then
-    PDNS_Ttl=$DEFAULT_PDNS_TTL
+    PDNS_Ttl="$DEFAULT_PDNS_TTL"
   fi
 
   #save the api addr and key to the account conf file.
@@ -48,7 +48,7 @@ dns_pdns_add() {
   fi
 
   _debug "First detect the root zone"
-  if ! _get_root $fulldomain; then
+  if ! _get_root "$fulldomain"; then
     _err "invalid domain"
     return 1
   fi
@@ -94,22 +94,22 @@ _get_root() {
   p=1
 
   if _pdns_rest "GET" "/api/v1/servers/$PDNS_ServerId/zones"; then
-    _zones_response=$response
+    _zones_response="$response"
   fi
 
-  while [ '1' ]; do
-    h=$(printf $domain | cut -d . -f $i-100)
+  while true; do
+    h=$(printf "%s" "$domain" | cut -d . -f $i-100)
     if [ -z "$h" ]; then
       return 1
     fi
 
-    if printf "$_zones_response" | grep "\"name\": \"$h.\"" >/dev/null; then
-      _domain=$h
+    if _contains "$_zones_response" "\"name\": \"$h.\""; then
+      _domain="$h"
       return 0
     fi
 
     p=$i
-    i=$(expr $i + 1)
+    i=$(_math $i + 1)
   done
   _debug "$domain not found"
   return 1