(UNIX only) Provide program access to the UNIX file descriptor used by a DBPROCESS to read data coming from the server.
int DBIORDESC(dbproc) DBPROCESS *dbproc;
A pointer to the DBPROCESS structure that provides the connection for a particular front-end/server process. It contains all the information that DB-Library uses to manage communications and data between the front end and server.
An integer file descriptor used by the specified DBPROCESS to read data coming from the server.
This routine provides a way for an application to respond effectively to multiple input streams. Depending on the nature of your application, the time between a request for information from the server (usually made using a call to dbsqlsend) and the server’s response (read by calling dbsqlok, dbresults, or dbnextrow) may be significant. You may use this time to service other parts of your application. The DBIORDESC routine provides a way to obtain the I/O descriptor that a DBPROCESS uses to read the data stream from the server. This information may then be used with various operating system facilities (such as the UNIX select call) to allow the application to respond effectively to multiple input streams.
dbpoll checks if a server response has arrived for any of an application’s server connections (represented by DBPROCESS pointers). dbpoll is generally simpler to use than DBIORDESC. For this reason, and because DBIORDESC is non-portable, it is generally preferable to use dbpoll.
The file descriptor returned by DBIORDESC may only be used with operating system facilities that do not read data from the incoming data stream. If data is read from this stream by any means other than through a DB-Library routine, communications between the front end and the server will become hopelessly scrambled.
An application can use the DB-Library DBRBUF routine, in addition to the UNIX select function, to help determine whether any more data from the server is available for reading.
A companion routine, DBIOWDESC, provides access to the file descriptor used to write data to the server.
dbcmd, DBIOWDESC, dbnextrow, dbpoll, DBRBUF, dbresults, dbsqlok, dbsqlsend
