add privilege drop example

goncalopp · goncalopp · commit 2dc465442fca · 2015-10-26T00:07:03.000Z
diff --git a/examples/drop_privileges.py b/examples/drop_privileges.py
@@ -0,0 +1,25 @@
+import uinput
+
+def drop_privileges(uid_name='nobody', gid_name='nogroup'):
+    #https://stackoverflow.com/questions/2699907/dropping-root-permissions-in-python
+    import os, pwd, grp
+    if os.getuid() != 0:
+        return
+    running_uid = pwd.getpwnam(uid_name).pw_uid
+    running_gid = grp.getgrnam(gid_name).gr_gid
+    os.setgroups([])
+    os.setgid(running_gid)
+    os.setuid(running_uid)
+    old_umask = os.umask(077)
+
+
+def main():
+    uinput_fd= uinput.Device.create_uinput_fd()
+    drop_privileges() #no need to be root beyond this line
+
+    events = (uinput.KEY_A,)
+    with uinput.Device(events, fd=uinput_fd) as device:
+        device.emit_click(uinput.KEY_A)
+
+if __name__ == "__main__":
+    main()
