There are two modes of operation. In standalone mode,
smapd detaches itself from the terminal and listens on
incoming requests in background. In other words, it becomes a
daemon. When a connection arrives, the server spawns a copy
of itself (called child process) to handle it. Thus, a number
of incoming connections are handled in parallel. This is the default
mode.
In inetd mode, smapd does not listen on network
addresses nor becomes a daemon. Instead, it reads requests from its
standard input and sends replies on its standard output. As its name
implies, this mode is intended for use from the inetd.conf
file.
The inetd mode is requested from command line using the --inetd (-i) option, or from configuration file, using ‘inet-mode yes’ statement.