diff --git a/src/dynamic-ip b/src/dynamic-ip
index 3a8cfdc..41788e4 100755
--- a/src/dynamic-ip
+++ b/src/dynamic-ip
@@ -43,14 +43,12 @@ valid_ip() {
 valid_ipv4() {
     local  ip=$1
     local  stat=1
+    local  ipaddr
 
     if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
-        OIFS=$IFS
-        IFS='.'
-        ip=($ip)
-        IFS=$OIFS
-        [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 \
-            && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]
+        IFS='.' read -ra ipaddr <<< "$ip"
+        [[ ${ipaddr[0]} -le 255 && ${ipaddr[1]} -le 255 \
+            && ${ipaddr[2]} -le 255 && ${ipaddr[3]} -le 255 ]]
         stat=$?
     fi
     return $stat
@@ -73,7 +71,7 @@ getRecords() {
     if [[ ! -r "$file" ]]; then
         return 1
     else
-        while read r;
+        while read -r r;
         do
             r=$(trim "$r")
             [[ ${r:0:1} == '#' ]] && continue
@@ -138,11 +136,13 @@ getIPv6() {
 
 getDnsNS() {
     local rec=$1
-    local domain=$(sed 's/[^.]*\.\([^.]*\..*\)/\1/' <<<"$rec")
+    local domain
     local result
     local err
 
-    result=$(dig +short @8.8.8.8 NS $domain | sed -e 's/.$//')
+    domain=$(sed 's/[^.]*\.\([^.]*\..*\)/\1/' <<<"$rec")
+
+    result=$(dig +short @8.8.8.8 NS "$domain" | sed -e 's/.$//')
     err=$?
 
     if [[ $err -eq 0 ]]
@@ -167,7 +167,7 @@ getDnsRecord() {
     do
         [[ "$i" = "ERROR" ]] && return 1
 
-        result=$(dig +short @${i} ${rectype} ${rec} | head -n1)
+        result=$(dig +short @"$i" "$rectype" "$rec" | head -n1)
         err=$?
 
         if [[ $err -ne 0 ]] || [[ -z "$result" ]]; then
@@ -189,7 +189,7 @@ getIPv6Prefix() {
     local result
     local err
 
-    if valid_ipv6 $rec
+    if valid_ipv6 "$rec"
     then
         result=$(echo "$rec" | cut -d':' -f1-4)
         result="${result}::/64"
@@ -260,12 +260,12 @@ log() {
 }
 
 logerr() {
-	>&2 log $*
+	>&2 log "$@"
 }
 
 run-parts() {
     # Ignore *~ and *, scripts
-    for i in $(LC_ALL=C; echo ${1%/}/*[^~,]) ; do
+    for i in $(LC_ALL=C; echo "${1%/}"/*[^~,]) ; do
         [[ -d $i ]] && continue
         # Don't run *.{rpmsave,rpmorig,rpmnew,swp,cfsaved} scripts
         [[ "${i%.cfsaved}" != "${i}" ]] && continue
@@ -301,24 +301,25 @@ run-parts() {
 run-hook() {
     local hook_dir=$1
     local errors=0
+    local hook_script
     shift
 
     if [[ ! -d "${hook_dir}" ]]; then
         return 0
     fi
 
-    while read s
+    while read -r hook_script
     do
-        log "Running agent: $(basename "$s")"
+        log "Running agent: $(basename "$hook_script")"
         DIP_FUNCTIONS="$(readlink -f "$0")" \
-        DIP_AGENT_NAME="$(basename "$(readlink -f "$s")")" \
-        DIP_AGENT_EXEC="$(basename "$s")" \
-        DIP_AGENT_DIR="$(dirname "$(readlink -f "$s")")" \
+        DIP_AGENT_NAME="$(basename "$(readlink -f "$hook_script")")" \
+        DIP_AGENT_EXEC="$(basename "$hook_script")" \
+        DIP_AGENT_DIR="$(dirname "$(readlink -f "$hook_script")")" \
         DIP_BASE_DIR="${script_dir}" \
         DIP_CUR_IP="$1" \
         DIP_OLD_IP="$2" \
         DIP_RECORD="$3" \
-        "$s" $*
+        "$hook_script" "$@"
         err=$?
 
         if [[ $err -ne 0 ]]; then
@@ -400,7 +401,7 @@ check-update() {
     [[ -z "$iptype" ]] && return 1
     [[ -z "$record" ]] && return 1
 
-    getCurrentIP $iptype $record
+    getCurrentIP "$iptype" "$record"
     err=$?
 
     case $err in
@@ -427,7 +428,7 @@ check-update() {
             logerr "DEBUG: dig output '$externalip'"
             ;;
         *)  logerr "Unknown fatal error occurred"
-            eclogerrho "(${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): }"
+            logerr "(${BASH_SOURCE[0]}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): }"
             exit $err
             ;;
     esac
@@ -445,8 +446,8 @@ prog_lock() {
     LOCKFD=99
 
     # PRIVATE
-    _lock()             { flock -$1 $LOCKFD; }
-    _no_more_locking()  { _lock u; _lock xn && rm -f $LOCKFILE; }
+    _lock()             { flock -"$1" $LOCKFD; }
+    _no_more_locking()  { _lock u; _lock xn && rm -f "$LOCKFILE"; }
     _prepare_locking()  { eval "exec $LOCKFD>\"$LOCKFILE\""; trap _no_more_locking EXIT; }
 
     # ON START
@@ -473,27 +474,16 @@ prog_lock() {
 if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
     # Internal Initialization
 
-    prog_name=$(basename "$0")
+    #prog_name=$(basename "$0")
     script_dir=$(dirname "$(readlink -f "$0")")
 
-    if [[ -z "$1" ]]; then
-        logerr "ERROR: Need to provide a DNS record or file to look-up"
-        exit 1
-    else
-        if [[ -r "$1" ]]; then
-            record_file=$1
-        else
-            record=$1
-        fi
-    fi
-
     prog_lock
 
 
     # Main
     if [[ -r "${script_dir}/plugins/${1}" ]]; then
+        # shellcheck source=plugins/update-ipv4
         source "${script_dir}/plugins/${1}"
-        plugin_name=${1,,}
     else
         logerr "ERROR: Unknown plugin '${1}'"
     fi