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Obtains a destination descriptor for a named call socket. Use with TCP access
only.
Syntax
IPCLOOKUP ( socketname, nlen [,location] [,loclen] [,flags],
destdesc [,protocol] [,socketkind] [,result] )
Parameters
- socketname (input)
- Character array, by reference. The name of the socket.
- nlen (input)
- 32-bit integer, by value. The length in bytes of the specified
socket name. Maximum is 16.
- location (input)
- Character array, by reference. An environment ID or node name
indicating where the socket registry search is to take place. The domain
and organization names which fully qualify the node/environment
designation are optional. If no location is specified, the local socket
registry is searched. This parameter can be a maximum of 50 characters
long.
- loclen (input)
- 32-bit integer, by value. The length in bytes of the location
parameter. A zero value indicates that the socket registry search is to
take place on the local node.
- flags (input)
- 32 bits, by reference. A bit representation of various options.
The only flag defined is: flags [0]. It causes the destination
descriptor to be "protected." A protected destination descriptor is one
which only privileged users may create or use.
- destdesc (output)
- 32-bit integer, by reference. The returned destination descriptor,
which the calling process may use to access the named socket as a
destination. This descriptor is required by the IPCCONNECT
intrinsic.
- protocol (output)
- 32-bit integer, by reference. A number identifying the protocol
module with which the socket is associated: The only protocol available
to user processes is: 4 = TCP.
- socketkind (output)
- 32-bit integer, by reference. A number which identifies the
socket's type: 3 = call.
- result (output)
- 32-bit integer, by reference. The error code returned; zero if no
error.
Description
The IPCLOOKUP intrinsic is used to gain access to a named socket.
When supplied with the socket's name, it returns a destination descriptor that
the calling process can use in order to connect to and send messages to that
socket. It is important to synchronize the naming and lookup of sockets so
that the naming occurs before the lookup. If these two events are occurring
concurrently, you can repeat the IPCLOOKUP call, checking the result
parameter after each call, until the call is successful. If the result value
is 37 ("NAME NOT FOUND"), the socket has not yet been given the name. The
following Pascal program fragment illustrates this idea:
socketname := 'RAINBOW';
location := 'SOMEWHERE';
result := 0;
repeat
IPCLOOKUP (socketname, 7, location, 9, ,
destdesc, , , result);
until result<>37;
if result<>0 then ERRORPROCEDURE;
The only required parameters in the IPCLOOKUP intrinsic are
socketname, nlen, and destdesc.
This intrinsic is option variable. Condition codes returned by this intrinsic
are:
- CCE — Succeeded.
- CCL — Failed.
- CCG — Not returned by this intrinsic.
This intrinsic cannot be called in split stack mode.
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