Add check_ptr.sh

check_ptr.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+# Test if any IP4 and IP6 addresses of a hostname blocked on a DNSBL
+# 2024-02-23
+# by Sandros
+
+# Parameter check
+if [[ $# -ne 1 ]]; then
+    echo "Usage: ./${0##*/} <hostname>"
+    exit 1
+fi
+
+# Get IPs
+IPS="$(dig +short $1 A | sort -u) $(dig +short $1 AAAA | sort -u)"
+
+# Loop through IPs
+for IP in $IPS; do
+        # Performs the actual lookup against blacklists
+        RESULT=$(host $IP | rev | cut -d" " -f1 | rev | sed 's/.$//')
+        if [ "$RESULT" != "$1" ]; then
+                echo 1
+                exit 0
+        fi
+done
+
+echo 0
+exit 0