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RE: Pointer math (merging ifs files)



Sender: michael@xxxxxxxxxxxxxxxxxx

memcpy() is a C function that can be called from RPG as a procedure.

> -------- Original Message --------
> Subject: Re: Pointer math (merging ifs files)
> From: Frank.Kolmann@xxxxxxxxxx
> Date: Wed, March 16, 2005 1:18 am
> To: ftpapi@xxxxxxxxxxxxx
> 
> Sender: Frank.Kolmann@xxxxxxxxxx
> 
> 
> 
> 
> 
> Please excuse my stupid question, as I dont know what memcpy is.
> Is it an API   and  does it have the 16M limit of user spaces.
> 
> Frank Kolmann
> 
> 
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> 
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>                                                                                                                                        
>                       Scott Klement                                                                                                    
>                       <sk@xxxxxxxxxxxxx        To:       ftpapi@xxxxxxxxxxxxx                                                          
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>                       Sent by:                 Subject:  Re: Pointer math (merging ifs files)                                          
>                       owner-ftpapi@xxxx                                                                                                
>                       e.ods.net                                                                                                        
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>                       16/03/2005 11:43                                                                                                 
>                       AM                                                                                                               
>                       Please respond to                                                                                                
>                       ftpapi                                                                                                           
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> Sender: Scott Klement <sk@xxxxxxxxxxxxxxxx>
> 
> 
> > memcpy(u_data: s_data: st_size_s)
> > memcpy(u_data + st_size_s: p_data: st_size_p)
> > memcpy(u_data + st_size_s + st_size_p: e_data: st_size_e)
> 
> Hmmm... if you do that, you'll have to allocate memory to s_data, p_data,
> and e_data, read the data into that memory, and then copy it to the user
> space.  It would work, but you'd have two copies of everything in memory
> at once, and you'd have to spend extra CPU cycles copying the memory.
> 
> So, it would work, but I wonder why you wouldn't just read it into the
> user space directly?
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