Issue the WHO command

Issue the WHO command and echo back the response.

/* REXX */                                                
rc=isfcalls('ON')                                         
     /* Issue the WHO command */                          
Address SDSF "ISFEXEC WHO"                                
     /* The responses are returned in the isfresp stem */ 
do ix=1 to isfresp.0                                      
  Say "isfresp."ix "is:" isfresp.ix                       
end 
rc=isfcalls('OFF')   
exit