SUBROUTINE: initial statement of a subroutine subprogram

• A subroutine subprogram is invoked in
  • a CALL statement
  • in the ALARM() function
  • in a callback from many HicEst functions.
• Unlike the FUNCTION procedure a subroutine does not return a particular value. It may return variable values only via the parameter list.
• The following are examples of subroutines and how to call them. The procedures differ in the scope of variables, either local or global
• ⇒ Programming (procedures)
• this by the way is a complete HicEst script

REAL :: var1=111.111, var2=222.222
CHARACTER
 MENU="hello world; good morning", selected_text*20
    CALL SUB_no_USE_no_ARG
    CALL SUB_with_USE
    CALL SUB_with_ARG( var1, var2^2, "hello world") ! parameter list with 3 actual arguments
    CALL SUB_with_ARG_and_USE( var1+var2 )
    ALARM(2.3, 5) ! calls F5 in 2.3 sec
    POP(Menu=MENU, SelTxt=selected_text) ! calls MENU from popup menu
 END

SUBROUTINE SUB_no_USE_no_ARG
    ! definitions are global
    WRITE(Messagebox, Name) var1, var2, var3
END       ! message box output: var1=111.111; var2=222.222; var3=0;

SUBROUTINE SUB_with_USE
 USE
 : var2        ! use a global variable
    ! with USE definitions are local
    var3 = 333.333 ! this is a local variable
    WRITE(Messagebox, Name) var1, var2, var3
 END       ! message box output: var1=0; var2=222.222; var3=333.333;

SUBROUTINE SUB_with_ARG(dummy1, dummy2, dummy3) ! 3 dummy arguments
 CHARACTER dummy3 ! string dummies must be defined
    ! with arguments definitions are local
    WRITE(Messagebox, Name) dummy1, dummy2, dummy3
 END       ! message box output: var1=111.111; dummy2=49382.61728; dummy3=hello world;

SUBROUTINE SUB_with_ARG_and_USE(dummy1)
 USE : var2
 USE SUB_with_USE : var3
    WRITE(Messagebox, Name) dummy1, var2, var3
 END       ! message box output: dummy1=333.333; var2=222.222; var3=333.333;

SUBROUTINE F5 ! alarm subroutine, also on toolbar
    time = TIME()/60/60/24 ! fractional day
    WRITE(Messagebox, Format="UHH:mm:SS") time
 END       ! message box output: 16:58:34

SUBROUTINE MENU ! example of a callback routine
    WRITE(Messagebox, Name) $$, selected_text
 END       ! message box output: $$=2; selected_text=good morning;