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From: Frank Buss <fb@frank-buss.de>
Newsgroups: comp.lang.ada
Subject: Re: quiz for Sequential_IO Read
Date: Sun, 3 Sep 2017 22:10:25 +0200
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Date: 2017-09-03T22:10:25+02:00
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On 09/03/2017 07:28 PM, J-P. Rosen wrote:
> Le 03/09/2017 à 13:01, Frank Buss a écrit :
>> The content of test.txt is just the ASCII string "hello":
> If it is a text file, it is not appropriate for Sequential_IO which
> requires a binary file.

It was just an example, and I posted the binary content of the file for 
clarification as well.

> In every language, the format of a binary file is known only to the
> compiler (I remember having been warned about this when I learned
> FORTRAN - a long time ago); the purpose of these files is to save data,
> then reread them from the same program, or at least the same language
> with the same compiler.

This is nonsense. There are a lot of binary file specifications and of 
course it should be possible to read and write these files, independent 
of the programming language or the compiler. Imagine files like PNG 
would only work, if you write/read them with a program, which was 
compiled with exact the same compiler.

> It may happen that the compiler just outputs the raw binary
> representation, but you have absolutely no guarantee about that.

Any programming language implementation which doesn't provide exact 
binary input/output is unusable. It might be fine for some rare cases, 
where you need it only in the same program that the binary 
representation doesn't matter (e.g. temporary cache files etc.), but 
usually you want to have control over the format and you want to know 
the format.

-- 
Frank Buss, http://www.frank-buss.de
electronics and more: http://www.youtube.com/user/frankbuss