^$GLOBAL

nspace

This optional parameter allows you to specify a structured system variable in another namespace by using an extended SSVN reference. You can specify the namespace name either explicitly, as a quoted string literal or as a variable, or by specifying an implied namespace. Namespace names are not case-sensitive. You can use either bracket syntax ["USER"] or environment syntax |"USER"|. No spaces are allowed before or after the nspace delimiters.

You can test whether a namespace is defined by using the following method:

   WRITE ##class(%SYS.Namespace).Exists("USER"),!  ; an existing namespace
   WRITE ##class(%SYS.Namespace).Exists("LOSER")   ; a non-existent namespace

You can use the $NAMESPACE special variable to determine the current namespace, and the ZNSPACE command to change the current namespace.

global_name

An expression that evaluates to a string containing an unsubscripted global name.

As an Argument to $DATA

^$GLOBAL as an argument to $DATA returns an integer value that signifies whether the global name you specify exists as a ^$GLOBAL node. The integer values that $DATA can return are shown in the following table.

The following example test for the existence of a global variable in the user’s default namespace.

   KILL ^GBL
   WRITE $DATA(^$GLOBAL("^GBL"))

returns 0.

The following example test for the existence of a global variable in the SAMPLES namespace.

   SET ^GBL(1)="TEST"
   WRITE $DATA(^$|"SAMPLES"|GLOBAL("^GBL"))

returns 10.

   SET ^GBL(1)="TEST"
   WRITE $DATA(^$||GLOBAL("^GBL"))

As an Argument to $ORDER

$ORDER(^$|nspace|GLOBAL( global_name),direction)

^$GLOBAL as an argument to $ORDER returns the next or previous global name in collating sequence to the global name you specify. If no such global name node exists in ^$GLOBAL, $ORDER returns a null string.

The direction argument specifies whether to return the next or the previous global name. If you do not provide a direction argument, Caché returns the next global name in collating sequence to the one you specify. For further details, refer to the $ORDER function.

The following subroutine searches the user’s default namespace and stores the global names in a local array named GLOBAL.

GLOB   
  SET NAME=""
  WRITE !,"The following globals are in ",$ZNSPACE
  FOR I=1:1 {
    SET NAME=$ORDER(^$GLOBAL(NAME))
    WRITE !,NAME
    QUIT:NAME=""
    SET GLOBAL(I)=NAME
  }
  WRITE !,"All done"
  QUIT

As an Argument to $QUERY

^$GLOBAL as an argument to $QUERY returns the next global name in collating sequence to the global name you specify. If no such global name exists as a node in ^$GLOBAL, $QUERY returns a null string.

In the following example, three globals (^GBL1, ^GBL2 and ^GBL3) are present in the USER namespace.

  NEW $NAMESPACE
  SET $NAMESPACE="USER"
  SET (^GBL1,^GBL2,^GBL3)="TEST"
  NEW $NAMESPACE
  SET $NAMESPACE="%SYS"
  WRITE $QUERY(^$|"USER"|GLOBAL("^GBL1")),!
  WRITE $QUERY(^$|"USER"|GLOBAL("^GBL2"))
  NEW $NAMESPACE
  SET $NAMESPACE="USER"
  KILL ^GBL1,^GBL2,^GBL3

The first WRITE returns ^$|"USER"|GLOBAL("^GBL2")

The second WRITE returns ^$|"USER"|GLOBAL("^GBL3")