Returns an identification number from an OpenVMS Cluster system and updates the context symbol to point to the current position in the system's cluster node list.

Format

F$CSID (context-symbol)

Return Value

Arguments

context-symbol

Specifies a symbol that DCL uses to store a pointer into the system's list of clustered nodes. The F$CSID function uses this pointer to return a cluster identification number.

Specify the context-symbol argument by using a symbol. The first time you use the F$CSID function, use a symbol that is either undefined or equated to the null string.

If the context-symbol argument is undefined or equated to a null string, the F$CSID function returns the cluster identification number of the first system in the system's cluster node list. Subsequent calls to the F$CSID function will return the cluster identification number of the rest of the nodes in the cluster.

Description

The F$CSID function returns a cluster identification number, and updates the context symbol to point to the current position in the system's cluster node list.

If the current system is not a member of a cluster, the first return value is null.

You can use the F$CSID function to obtain all of the cluster identification numbers on the system. For each cluster identification returned, the F$GETSYI function can be used to obtain information about the particular system.

Once the context-symbol argument is initialized by the first call, each subsequent F$CSID function call returns the cluster identification number of another node in the cluster. (Note that the cluster identification numbers are returned in random order.) After the cluster identification number of the last system in the list is returned, the F$CSID function returns a null string.

Example

$ IF F$GETSYI("CLUSTER_MEMBER") .EQS. "FALSE" THEN GOTO NOT_CLUSTER 
$ CONTEXT = "" 
$START: 
$   id = F$CSID (CONTEXT) 
$   IF id .EQS. "" THEN EXIT 
$   nodename = F$GETSYI ("NODENAME",,id) 
$   WRITE SYS$OUTPUT nodename 
$   GOTO start 
$NOT_CLUSTER: 
$ WRITE SYS$OUTPUT "Not a member of a cluster." 
$ EXIT 
 
      

This command procedure uses the F$CSID function to display a list of cluster system names. The assignment statement declares the symbol CONTEXT, which is used as the context-symbol argument for the F$CSID function. Because CONTEXT is equated to a null string, the F$CSID function will return the first cluster identification number in the cluster node list.

If the F$CSID function returns a null value, then the command procedure either is at the end of the list, or is attempting this operation on a nonclustered node. The call to F$GETSYI checks whether the current node is a member of a cluster. The command procedure will exit on this condition.

If the F$CSID function does not return a null value, then the command procedure uses the identification number as the third argument to the F$GETSYI function to obtain the name of the system. The name is then displayed using the WRITE command.