This is a utility for KDE that locks a screen and then runs the pm-suspend utility. This couldn't be done with a simple linux hook since pm-suspend can only be run as root but the command to lock the screen requires access to the session dbus of the user. This simple C++ program remedies this situation.
Once you compile the utility (normal gcc locksuspend.cpp -o locksuspend), run the following commands to set the owner to root and then set the uid bit.
sudo chown root locksuspend
sudo chmod u+s locksuspend
The locksuspend command should run then.
The lockhibernate command is just like locksuspend but instead of suspending (saving the system state to RAM) it puts the system in hibernation (saving the system state to hard disk).
This works for KDE 5.x, but I haven't tested it on earlier versions.
My email is: leonardthesalmon@protonmail.com