add dev script list_loaded_kext_ids

For the benefit of Cask authors writing uninstall stanzas

developer/bin/list_loaded_kext_ids

@@ -0,0 +1,32 @@
+#!/bin/bash
+#
+# list_loaded_kext_ids
+#
+
+set -e;               # exit on any uncaught error
+set +o histexpand;    # don't expand history expressions
+shopt -s nocasematch; # case-insensitive regular expressions
+
+_list_loaded_kext_ids () {
+    /usr/sbin/kextstat -kl | /usr/bin/cut -c53- | /usr/bin/cut -f1 -d' ' | /usr/bin/egrep -v '^com\.apple\.'
+}
+
+if [[ $1 =~ ^-+h(elp)?$ ]]; then
+    printf "list_loaded_kext_ids
+
+Print Bundle IDs for currently loaded Kernel Extensions (kexts)
+which may be useful in a Cask uninstall stanza, eg
+
+    uninstall :kext => 'kext.bundle.id.goes.here'
+
+Kexts attributed to Apple are excluded from the output.
+
+See CONTRIBUTING.md for more information.
+
+"
+    exit
+fi
+
+_list_loaded_kext_ids "$@";
+
+#