This subroutine also allows two cooperating processes to synchronize their interaction with a transport provider. For example, a process creates a new process with the fork subroutine and issues an exec subroutine call. The transport provider treats all users of a transport endpoint as a single user. If multiple processes are using the same endpoint, they should coordinate their activities so as not to violate the state of the provider.
Parameters fd Specifies the transport end point.
The specified file descriptor is a valid open file descriptor, but does not refer to a transport endpoint. The transport provider is undergoing a state change. A system error has occurred during execution of this function. The dup subroutine, exec subroutine, fork subroutine, open subroutine.