Is application running ?

In post-DOS Oss it’s possible running multiple applications, even multiple instance of same application simultaneously. Sometime running multiple instance of same application may cause unpredictable results. So requires impeding, For this purpose HMG offers SET MULTIPLE ON | OFF [WARNING] command which impedes (OFF) or allow (ON) attempts to run multiple instances of the application with optional warning for both situation.

Sometime may be requires decide to allowing at run time. In this case you need know either a running instance exist or not before allowing or impeding.

IsAppRunning() function is for help this situation.

#include <hmg.ch>

PROCEDURE Main()

   LOCAL cCurrApp := HB_ProgName()
   
   IF IsAppRunning( cCurrApp )
      MsgSTop( cCurrApp + CRLF + CRLF +;
               "Application is running already !", "Error")
   ELSE
      
      DEFINE WINDOW frmIsAppRunTest ;
         ROW 0 ;
         COL 0 ;
         WIDTH 650 ;
         HEIGHT 450 ;
         TITLE "Testing 'IsAppRunning()' function" ;
         ON INIT MsgInfo( cCurrApp + CRLF + CRLF + ;
                          "Application is running for first time !",;
                          "No problem") ;
         MAIN
      
         ON KEY ESCAPE ACTION ThisWindow.Release
      END WINDOW // frmIsAppRunTest

      frmIsAppRunTest.Center()

      frmIsAppRunTest.Activate()
   ENDIF
   
RETURN // IsAppRunTest.Main()      

*-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.

PROCEDURE IsAppRunning(;
                        cAppName )

   LOCAL aProcess := EnumProcessesID(),;      // --> return array { nProcessID1, nProcessID2, ... }      
         nInstance := 0,;
         n1ProcID,;
         lRVal := .F.
         
   FOR EACH n1ProcID IN aProcess 
      IF cAppName == GetProcessFullName( n1ProcID ) 
         IF ++nInstance > 1
            lRVal := .T.
            EXIT 
         ENDIF   
      ENDIF                                      
   NEXT n1ProcID
   
RETURN lRVal // IsAppRunning()

*-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.