socket-descriptor

Specifies the name of a fullword field containing the socket descriptor to process.

command

Specifies the name of a fullword field containing the command to perform on the socket. command can be specified as an absolute expression.

argument

Specifies the name of a fullword field containing the argument that applies to some commands. argument can be specified as an absolute expression. While argument is optional, it must be specified for setting functions.

returned-value

Specifies the name of a fullword field that contains the returned information from any retrieval commands. While returned-value is optional, it must be specified for retrieval function.