HP OpenVMS DCL Dictionary
F$CSID
Returns an identification number from an OpenVMS Cluster system and
updates the context symbol to point to the current position in the
system's cluster node list.
Format
F$CSID (context-symbol)
Return Value
A character string containing the system cluster identification number
in the system's list of clustered nodes. If the current system is not a
member of a cluster, the first return value is null. After the last
system cluster identification number is returned, the F$CSID function
returns a null string ("").
Arguments
context-symbol
Specifies a symbol that DCL uses to store a pointer into the system's
list of clustered nodes. The F$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
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$ 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
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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.
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