View source for F$CSID()

'''F$CSID''' is a [[Lexical functions|lexical function]] that 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. 

=Syntax=

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. 

=Examples=

 $ 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. 
 
[[Category:Lexical Functions]]