Re: Am I playing with fire? (calling RPG subproc from CL)

[Barbara Morris <bmorris@xxxxxxxxxx>]

AGlauser@xxxxxxxxxxxx wrote:
> This *seems* to work fine - my concern is the fact that my CL varibles are 
> *CHAR while my RPG parameters are expecting dates.  How safe is it to do 
> what I'm doing here?

In this case, it's quite safe because dates, times, and timestamps are 
pretty much string values at the parameter-passing level.

It wouldn't be safe to pass a character variable by value if the actual 
parameter was float or integer.

There are two types of parameters at the low level (a level way below 
RPG): scalar and aggregate.  Integer, float, and pointer are scalar; 
string types and DTZ types are aggregate*; I'm not sure about packed and 
zoned.  I don't know the exact mechanisms, but scalar parameters are 
passed by value differently from aggregate parameters, so you can't mix 
and match.

If you want to be really safe, you would create a wrapper procedure for 
CL to call, with character parameters, that you pass on to the real 
procedure using %DATE(parm).  Or the wrapper could pass the parameters 
by reference, and pass them on directly to the real procedure.

* With EXTPROC(*CWIDEN|*CNOWIDEN) single-char alpha and single-char 
unicode are handled as scalar.