examples: Add example to feed non-imaging virtual driver

Add an example script that can add and remove prints from the
non-imaging virtual driver.

examples/sendvirtcmd.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+
+# This script can be used together with the virtual_imgdev to simulate an
+# image based fingerprint reader.
+#
+# To use, set the FP_VIRTUAL_IMAGE environment variable for both the
+# libfprint using program (e.g. fprintd) and this script.
+#
+# Usually this would work by adding it into the systemd unit file. The
+# best way of doing so is to create
+#  /etc/systemd/system/fprintd.service.d/fprintd-test.conf
+#
+# [Service]
+# RuntimeDirectory=fprint
+# Environment=FP_VIRTUAL_DEVICE=/run/fprint/virtdev_sock
+# Environment=G_MESSAGES_DEBUG=all
+# ReadWritePaths=$RUNTIME_DIR
+#
+# After that run:
+#
+#   systemctl daemon-reload
+#   systemctl restart fprintd.service
+#
+# You may also need to disable selinux.
+#
+# Then run this script with e.g.
+# FP_VIRTUAL_DEVICE=/run/fprint/virtdev_sock ./sendvirtimg.py "ADD <username> <finger> <success|failure>"
+
+
+
+import cairo
+import sys
+import os
+import socket
+import struct
+
+if len(sys.argv) != 2:
+    sys.stderr.write('You need to pass commands!\n')
+    sys.stderr.write('Usage: ./sendvirtimg.py "ADD <finger> <username> <success|failure>"\n')
+    sys.exit(1)
+
+command = sys.argv[1]
+
+# Send image through socket
+sockaddr = os.environ['FP_VIRTUAL_DEVICE']
+if not sockaddr:
+    sockaddr = os.environ['FP_VIRTUAL_DEVICE_IDENT']
+
+sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+sock.connect(sockaddr)
+
+sock.sendall(command.encode('utf-8'))
+