Add script for listing email addresses of active users

Author: AgenttiX

samba/list_user_email_addresses.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Get the email addresses of users who have logged in with SSH since a specified number of days ago.
+
+if [ "$#" -eq 0 ]; then
+  DAYS=30
+elif [ "$#" -eq 1 ]; then
+  DAYS=$1
+else
+  echo "Wrong number of arguments. Usage: $0 [days]"
+  echo "The optional argument \"days\" specifies how many days back to look for user logins."
+fi
+
+DATE=$(date --date "-${DAYS} days" -I)
+echo "Looking for users who have logged in with SSH since ${DATE}. This requires sudo access."
+USERS=$(sudo journalctl -u ssh --since "${DATE}" | grep "Accepted" | awk '{print $9}' | sort --unique)
+
+echo "Searching the LDAP directory for email addresses of the users."
+EMAILS=$(for USERNAME in $USERS; do
+  ldapsearch "(cn=${USERNAME})" mail | awk '/^mail:/ {print $2}'
+done | sort --unique)
+
+echo "Email addresses of users who logged in since ${DATE}:"
+echo "${EMAILS}"