Query External Variable R←⎕XT Y

Y must be a simple character scalar or vector which is taken to be a variable name. R is a simple character vector containing the file reference of the external array associated with the variable named by Y, or the null vector if there is no associated external array.

Example

      ⎕XT'V'
EXT\ARRAY

      ⍴⎕XT'G'
0