Updated the program so it breaks out the config settings into env files. The script store each TLD → WHOIS server mapping in an associative array, If a TLD has already been checked, reuse it instead of calling whois.iana.org again. This is to prevent such TLD's as .contact from not being found.

domain_expiry_check.sh

@@ -0,0 +1,90 @@
+#!/bin/bash
+
+# Load environment variables
+source /PATH/TO/domains.env
+source /PATH/TO/notification.env
+
+# Read the list of domains
+domains=$(cat "$DOMAINS_FILE")
+
+# Initialize
+declare -A whois_cache        # TLD → WHOIS server cache
+expiring_domains=()
+current_datetime=$(date +%Y-%m-%d_%H:%M:%S)
+
+# --- Functions ---
+
+# Get the authoritative WHOIS server for a TLD (with in-memory cache)
+get_whois_server() {
+    local domain=$1
+    local tld="${domain##*.}"
+
+    # Return cached entry if present
+    if [[ -n "${whois_cache[$tld]}" ]]; then
+        echo "${whois_cache[$tld]}"
+        return
+    fi
+
+    # Query whois.iana.org for authoritative WHOIS server
+    local server
+    server=$(whois -h whois.iana.org "$tld" 2>/dev/null | grep -i "whois:" | awk '{print $2}' | head -n1)
+
+    # Store result in cache (even if blank)
+    whois_cache[$tld]="$server"
+
+    echo "$server"
+}
+
+# Get the expiration date for a domain from the correct WHOIS server
+get_expiration_date() {
+    local domain=$1
+    local whois_server=$2
+    local whois_output
+
+    if [[ -n "$whois_server" ]]; then
+        whois_output=$(whois -h "$whois_server" "$domain" 2>/dev/null)
+    else
+        whois_output=$(whois "$domain" 2>/dev/null)
+    fi
+
+    echo "$whois_output" | grep -Ei 'Expiration Date|Expiry Date|Registry Expiry Date' | awk -F ':' '{print $2}' | head -n1
+}
+
+# --- Main Loop ---
+
+for domain in $domains; do
+    whois_server=$(get_whois_server "$domain")
+    expiration_date=$(get_expiration_date "$domain" "$whois_server")
+
+    # Calculate days left
+    if [[ -n "$expiration_date" ]]; then
+        expiration_timestamp=$(date -d "$expiration_date" +%s 2>/dev/null)
+        if [[ -n "$expiration_timestamp" ]]; then
+            days_left=$(( (expiration_timestamp - $(date +%s)) / 86400 ))
+        else
+            days_left=""
+        fi
+    fi
+
+    # Check if expiring soon
+    if [[ -n "$days_left" && "$days_left" -lt "$DAYS_WITHIN" ]]; then
+        expiring_domains+=("$domain: $days_left days left (WHOIS: ${whois_server:-default})")
+    fi
+done
+
+# --- Notifications ---
+
+if [[ ${#expiring_domains[@]} -gt 0 ]]; then
+    subject="Domain Expiration Alert - $current_datetime"
+    body="The following domains are expiring within $DAYS_WITHIN days:\n\n${expiring_domains[@]/%/\\n}"
+
+    # Email
+    echo -e "$body" | mail -s "$subject" -a "From: $SENDER_EMAIL" "$RECEIVER_EMAIL"
+
+    # Discord
+    curl -H "Content-Type: application/json" \
+         -X POST \
+         --data "{\"content\": null, \"embeds\": [{\"title\": \"$subject\", \"description\": \"$body\"}]}" \
+         "$WEBHOOK_URL"
+fi
+

domains.env

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+# domains.env
+DOMAINS_FILE="/LOCATION/OF/domains.txt"
+DAYS_WITHIN=30

notification.env

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+# notification.env
+SENDER_EMAIL="SENDER_NAME"
+RECEIVER_EMAIL="RECEIVER_EMAIL"
+WEBHOOK_URL="WEBHOOK_URL"