Re: fseek under IBM MVS

From	glen herrmannsfeldt <gah@ugcs.caltech.edu>
Newsgroups	comp.lang.c
Subject	Re: fseek under IBM MVS
Date	2014-12-15 21:33 +0000
Organization	Aioe.org NNTP Server
Message-ID	<m6nk2e$9vs$2@speranza.aioe.org> (permalink)
References	<m6kumm$sfe$1@speranza.aioe.org> <36760209-5dbc-417b-85bb-17993bbe5900@googlegroups.com>

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John Bode <jfbode1029@gmail.com> wrote:

(snip)

> What "some people" are repeating is that there are some (admittedly old
> or oddball) systems where fseek()/ftell won't give you the correct size
> of a file's contents to the nearest byte, and that you shouldn't rely
> on the idiom working everywhere all the time.  
 
> If you're not working on those oddball filesystems, it's not an issue.
 
> If you're porting code from MPE/iX to HP-UX, it can be.  

On the PDP-10 systems files are specified in the number
of 36 bit words that they contain.  To complicate C, text files
are stored with five 7-bit ASCII characters per word. In core,
C stores four 9 bit characters per word.
 
> I still say that file size is a function of the file system, so you should
> use system-specific functions (stat() or fstat() on POSIX systems, for
> example) to query the filesystem directly, rather than using the 
> fseek/ftell idiom.  

-- glen

Thread

fseek under IBM MVS jacob navia <jacob@spamsink.net> - 2014-12-14 22:16 +0100
  Re: fseek under IBM MVS glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-15 01:12 +0000
    Re: fseek under IBM MVS jacob navia <jacob@spamsink.net> - 2014-12-15 09:13 +0100
      Re: fseek under IBM MVS glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-15 09:22 +0000
  Re: fseek under IBM MVS Kaz Kylheku <kaz@kylheku.com> - 2014-12-15 16:26 +0000
    Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-17 09:58 +0000
      Re: fseek under IBM MVS BartC <bc@freeuk.com> - 2014-12-17 11:29 +0000
  Re: fseek under IBM MVS John Bode <jfbode1029@gmail.com> - 2014-12-15 10:35 -0800
    Re: fseek under IBM MVS glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-15 21:33 +0000
      Re: fseek under IBM MVS jacob navia <jacob@spamsink.net> - 2014-12-15 23:45 +0100
        Re: fseek under IBM MVS Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2014-12-15 17:56 -0500
          Re: fseek under IBM MVS Kaz Kylheku <kaz@kylheku.com> - 2014-12-15 23:05 +0000
          Re: fseek under IBM MVS BartC <bc@freeuk.com> - 2014-12-15 23:19 +0000
            Re: fseek under IBM MVS Keith Thompson <kst-u@mib.org> - 2014-12-15 16:36 -0800
            Re: fseek under IBM MVS Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2014-12-15 20:42 -0500
          Re: fseek under IBM MVS jacob navia <jacob@spamsink.net> - 2014-12-16 01:00 +0100
        Re: fseek under IBM MVS glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-16 01:09 +0000
          Re: (OT) fseek under IBM MVS Vincenzo Mercuri <nomail@yahoo.it> - 2014-12-16 09:11 +0100
        Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-17 10:06 +0000
          Re: fseek under IBM MVS jacob navia <jacob@spamsink.net> - 2014-12-17 11:33 +0100
            Re: fseek under IBM MVS John Bode <jfbode1029@gmail.com> - 2014-12-17 08:48 -0800
              Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-17 17:26 +0000
              Re: fseek under IBM MVS jacob navia <jacob@spamsink.net> - 2014-12-17 19:46 +0100
                Re: fseek under IBM MVS Richard Heathfield <invalid@see.sig.invalid> - 2014-12-17 19:28 +0000
                Re: fseek under IBM MVS jacob navia <jacob@spamsink.net> - 2014-12-17 21:38 +0100
                Re: fseek under IBM MVS Richard Heathfield <invalid@see.sig.invalid> - 2014-12-17 21:05 +0000
                Re: fseek under IBM MVS Ian Collins <ian-news@hotmail.com> - 2014-12-18 11:37 +1300
                Re: fseek under IBM MVS John Bode <jfbode1029@gmail.com> - 2014-12-17 12:43 -0800
        Re: fseek under IBM MVS fir <profesor.fir@gmail.com> - 2014-12-19 08:35 -0800
          Re: fseek under IBM MVS BartC <bc@freeuk.com> - 2014-12-19 16:51 +0000
          Re: fseek under IBM MVS Robert Wessel <robertwessel2@yahoo.com> - 2014-12-19 16:36 -0600
    Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-17 10:05 +0000
      Re: fseek under IBM MVS Keith Thompson <kst-u@mib.org> - 2014-12-17 09:05 -0800
        Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-17 17:29 +0000
          Re: fseek under IBM MVS John Bode <jfbode1029@gmail.com> - 2014-12-17 12:55 -0800
            Re: fseek under IBM MVS John Bode <jfbode1029@gmail.com> - 2014-12-17 15:02 -0800
              Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-17 23:37 +0000
                Re: fseek under IBM MVS Keith Thompson <kst-u@mib.org> - 2014-12-17 16:11 -0800
                Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-18 12:06 +0000
                Re: fseek under IBM MVS James Kuyper <jameskuyper@verizon.net> - 2014-12-18 11:44 -0500
                Re: fseek under IBM MVS Keith Thompson <kst-u@mib.org> - 2014-12-18 11:03 -0800
                Re: fseek under IBM MVS raltbos@xs4all.nl (Richard Bos) - 2014-12-19 11:31 +0000
                Re: fseek under IBM MVS James Kuyper <jameskuyper@verizon.net> - 2014-12-19 08:03 -0500
                Re: fseek under IBM MVS Keith Thompson <kst-u@mib.org> - 2014-12-19 08:08 -0800
                Re: fseek under IBM MVS James Kuyper <jameskuyper@verizon.net> - 2014-12-19 11:30 -0500
              Re: fseek under IBM MVS Keith Thompson <kst-u@mib.org> - 2014-12-17 15:56 -0800
              Re: fseek under IBM MVS Ian Collins <ian-news@hotmail.com> - 2014-12-21 21:37 +1300
        Re: fseek under IBM MVS glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-17 21:59 +0000
          Re: fseek under IBM MVS Keith Thompson <kst-u@mib.org> - 2014-12-17 14:33 -0800
          Re: fseek under IBM MVS "Charles Richmond" <numerist@aquaporin4.com> - 2014-12-18 16:06 -0600
  Re: fseek under IBM MVS Siri Crews <chine.bleu@yahoo.com> - 2014-12-17 04:20 -0800

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