The user-written USER routine allows your program to take control
    during a DECTPU editing session (for example, to leave the editor
    temporarily and perform a calculation).

    Format

      USER  integer ,stringin ,stringout

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

    Longword condition value.

2  –  Arguments

 integer

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    First parameter to the built-in procedure CALL_USER. This is an
    input-only parameter and must not be modified.

 stringin

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    Second parameter to the built-in procedure CALL_USER. This is an
    input-only parameter and must not be modified.

 stringout

    OpenVMS usage:char_string
    type:         character string
    access:       modify
    mechanism:    by descriptor
    Return value for the built-in procedure CALL_USER. Your program
    should fill in this descriptor with a dynamic string allocated by
    the string routines (such as LIB$SGET1_DD) provided by the Run-
    Time Library. The DECTPU editor frees this string when necessary.

3  –  Description

    This user-written routine is invoked by the DECTPU built-in
    procedure CALL_USER. The built-in procedure CALL_USER passes
    three parameters to this routine. These parameters are then
    passed to the appropriate part of your application to be used
    as specified. (For example, they can be used as operands in a
    calculation within a Fortran program.) Using the string routines
    provided by the Run-Time Library, your application fills in the
    stringout parameter in the call-user routine, which returns the
    stringout value to the built-in procedure CALL_USER.

    The description of the built-in procedure CALL_USER in the DEC
    Text Processing Utility Reference Manual shows an example of a
    BASIC program that is a call-user routine.