Turning into a Daemon

When configured so, SER becomes a daemon during startup. A process is called daemon when it hasn't associated controlling terminal. See function daemonize in file main.c for more details. The function does the following:

• chroot is performed if neccessary. That ensures that the server will have access to a particular directory and its subdirectories only.

• Server's working directory is changed if the new working directory was specified (usually it is /).

• If command line parameter -g was used, the server's group ID is changed to that value.

• If command line parameter -u was used, the server's user ID is changed to that value.

• Perform fork, let the parent process exit. This ensures that we are not a group leader.

• Perform setsid to become a session leader and drop the controlling terminal.

• Fork again to drop group leadership.

• Create a pid file.

• Close all opened file descriptors.