From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,17f674692867d416 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII Path: g2news1.google.com!news4.google.com!news2.google.com!goblin2!goblin3!goblin.stu.neva.ru!bolzen.all.de!newsfeed.ision.net!newsfeed2.easynews.net!ision!news.belwue.de!newsfeed.arcor.de!newsspool3.arcor-online.net!news.arcor.de.POSTED!not-for-mail From: "Dmitry A. Kazakov" Subject: Re: Atomic file creation Newsgroups: comp.lang.ada User-Agent: 40tude_Dialog/2.0.15.1 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Reply-To: mailbox@dmitry-kazakov.de Organization: cbb software GmbH References: <0s2thh.3cd.ln@hunter.axlog.fr> Date: Tue, 5 Jan 2010 00:00:02 +0100 Message-ID: <10977h71ld839$.z6uro0qivqy$.dlg@40tude.net> NNTP-Posting-Date: 05 Jan 2010 00:00:02 CET NNTP-Posting-Host: ee3659d6.newsspool3.arcor-online.net X-Trace: DXC=^2k@U1NZ;UW5TOT9_N5iGMH7@f_DJ4>mk4\ZP[ X-Complaints-To: usenet-abuse@arcor.de Xref: g2news1.google.com comp.lang.ada:8601 Date: 2010-01-05T00:00:02+01:00 List-Id: On Mon, 4 Jan 2010 14:38:00 -0800 (PST), Ludovic Brenta wrote: > Jean-Pierre Rosen wrote: >> vlc a �crit : >> >>> On Jan 4, 4:52 pm, Jean-Pierre Rosen wrote: >>>> Maybe because temporary files have no names ;-) >> >>>> Kidding appart, in the old time when people still knew how to write >>>> operating systems, the notion of temporary file was supported by the OS, >>>> and those files had really no name (as opposed to a junk name in /var/tmp). >> >>> Well, they have names, are stored in in /tmp/ and still exist after >>> the call of Ada.Text_IO.Close in line 5. I actually checked this :-) >> >> I presume you are using some elementary OS like Unix, that fakes >> temporary files short of having true ones... But the implementation is >> free to behave as if they were true temporary files. This protects your >> portability (to VMS for example, sigh of nostalgia...) > > http://www.circa.ufl.edu/handouts/vms/tempfile.html > > suggests that (1) not all users of VMS know about nameless temporary > files No don't think so. This feature existed already in RSX-11. I remember frequently used it. > and (2) VMS does allow one to create named temporary files. > > Also I am wondering how VMS allows programs to communicate by means of > nameless temporary files (e.g. program A writes a large amount of data > in a new file and tells program B to process it and then delete the > file). Are the file names replaced with some kind of handle? Unnamed temporary files were used as a storage. It was especially important under RSX-11, which was 16-bit. For example the compiler could store its between-the-passes stuff in such files. You didn't care to delete the file, because it was done by the OS, even if the program crashed. Memory mapped files were supposed to supersede temporal files. But UNIX slashed further evolution of the operating systems design... > PS. VMS may be "non-elementary" but it is proprietary, ergo they have > something to hide, ergo I don't want it on *my* computer :) Huh, I don't well remember VMS before it became OpenVMS, but RSX-11 was 100% open source, even though that term didn't existed then. All kernel and drivers sources (in MACRO-11) were available. BTW, I still remember how much impressed me the quality and style of the kernel code. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de