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From: "Jeffrey R. Carter" <spam.jrcarter.not@acm.nospam.org>
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Subject: Re: Concatenating files
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mhamel_98@yahoo.com wrote:
> Hi Jeff, I don't have any resources available in front of me, but I
> always thought Direct_Io was essentially the same as Sequential_Io
> save for the additional ability of retrieving, or reading, the "nth"
> record without having to start from the beginning of the file.  Does
> Direct_Io allow editing, or writing, of said "nth" record without
> disrupting records written before or after?  Or, does Direct_Io allow
> writing to the "nth" place? in which case I would start writing my
> data starting at 2, for instance, then when complete, write the first,
> or header record.

Ada.Direct_IO is specified in ARM A.8.4:

http://www.adaic.org/standards/05rm/html/RM-A-8-4.html

It includes the operations

procedure Read (File : in     File_Type;
                 Item :    out Element_Type;
                 From : in     Positive_Count);
procedure Write(File : in File_Type;
                 Item : in  Element_Type;
                 To   : in Positive_Count);

You may read and write from any position in the file.

-- 
Jeff Carter
"Ada has made you lazy and careless. You can write programs in C that
are just as safe by the simple application of super-human diligence."
E. Robert Tisdale
72