port-number

Specifies the name of a fullword field containing the port-number to resolve.

protocol-name

Specifies the name of an area containing the name of the protocol to use.

protocol-name-length

Specifies the name of a fullword field containing the length of protocol-name.protocol-name-length can be specified as an absolute expression.

The maximum value for this parameter is 256.

serventp

Specifies the name of a fullword field where the system returns the address of a SERVENT structure containing the information about the service.