Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #395755

Re: is_binary_file()

From Michael S <already5chosen@yahoo.com>
Newsgroups comp.lang.c
Subject Re: is_binary_file()
Date 2025-12-10 11:21 +0200
Organization A noiseless patient Spider
Message-ID <20251210112132.00004083@yahoo.com> (permalink)
References <10gvvh8$1vv6e$1@dont-email.me> <10h2loi$1o59d$1@dont-email.me> <10ha4c3$kd3o$2@dont-email.me>

Show all headers | View raw

On Tue, 9 Dec 2025 16:29:39 -0500
James Kuyper <jameskuyper@alumni.caltech.edu> wrote:

> On 2025-12-06 20:37, James Kuyper wrote:
> ...
> > "Data read in from a text stream will necessarily compare equal to
> > the data that were earlier written out to that stream only if: the
> > data consist only of printing characters and the control characters
> > horizontal tab and new-line; no new-line character is immediately
> > preceded by space characters; and the last character is a new-line
> > character." (7.23.2p2).
> > 
> > I believe it therefore makes sense to consider something to be a
> > text file if it meets those requirements, and otherwise is a binary
> > file. Note that the last requirement implies that an empty file
> > cannot qualify as text - at a minimum, it must contain a new-line
> > character.
> > 
> > This implies the use of the isprint() function; the only other
> > characters you need to handle specifically are '\t', '\n', and ' '.
> > Since the result returned by isprint() is locale-dependent, the
> > program should, at least optionally, use setlocale().  
> 
> I just realized an annoying complication. Whatever
> implementation-specific method is used to indicate end-of-line can
> only be portably identified as such by opening the file in text mode
> and looking for the newline characters that it gets converted into.
> But because of 7.23.2p2, text mode cannot be relied upon for
> precisely the files we're trying to identify.

Does not sound like a problem. According to my understanding, wide
portability was never a part of the OP's spec.

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-06 01:05 +0000
  Re: is_binary_file() Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2025-12-06 01:41 +0000
    Re: is_binary_file() Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2025-12-06 02:00 +0000
      Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 17:40 +0000
      Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 11:35 +0000
        Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-10 15:07 +0000
          Re: is_binary_file() Michael S <already5chosen@yahoo.com> - 2025-12-10 19:00 +0200
            Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-10 17:18 +0000
              Re: is_binary_file() Richard Heathfield <rjh@cpax.org.uk> - 2025-12-10 19:42 +0000
                Re: is_binary_file() bart <bc@freeuk.com> - 2025-12-10 22:37 +0000
                Re: is_binary_file() Paul <nospam@needed.invalid> - 2025-12-10 22:35 -0500
                Re: is_binary_file() bart <bc@freeuk.com> - 2025-12-11 11:46 +0000
                Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-11 12:53 +0100
          Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 18:42 +0000
        Re: is_binary_file() Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2025-12-10 15:58 +0000
          Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 18:44 +0000
        Re: is_binary_file() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-12-10 12:46 -0500
          Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 18:45 +0000
        Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 18:41 +0000
          Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 20:57 +0000
            Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-10 22:07 +0000
              Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-11 01:09 +0000
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-11 12:33 +0000
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-12 19:25 +0000
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-12 22:54 +0000
                Re: is_binary_file() "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-12-12 15:33 -0800
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-13 00:20 +0000
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-13 02:32 +0000
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-16 00:26 +0000
                Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-16 17:24 +0100
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-17 03:19 +0000
                Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-17 07:57 +0100
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-17 19:35 +0000
                Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-18 08:44 +0100
                Re: is_binary_file() bart <bc@freeuk.com> - 2025-12-18 12:49 +0000
                Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-18 14:06 +0100
                Re: is_binary_file() gazelle@shell.xmission.com (Kenny McCormack) - 2025-12-18 13:17 +0000
                Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-18 16:03 +0100
  Re: is_binary_file() Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-12-05 17:42 -0800
    Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-06 17:37 +0000
      Re: is_binary_file() Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-12-06 16:05 -0800
      Re: is_binary_file() Louis Krupp <lkrupp@invalid.pssw.com.invalid> - 2025-12-07 03:43 -0700
        Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-07 16:47 +0000
        Re: is_binary_file() Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-12-27 03:18 +0000
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 17:46 +0000
  Re: is_binary_file() Kaz Kylheku <046-301-5902@kylheku.com> - 2025-12-06 02:42 +0000
    Re: is_binary_file() bart <bc@freeuk.com> - 2025-12-06 12:42 +0000
    Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-06 17:40 +0000
      Re: is_binary_file() Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2025-12-06 18:04 +0000
        Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-06 19:06 +0000
          Re: is_binary_file() Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2025-12-06 21:16 +0000
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 17:48 +0000
      Re: is_binary_file() Kaz Kylheku <046-301-5902@kylheku.com> - 2025-12-08 19:26 +0000
        Re: is_binary_file() Richard Heathfield <rjh@cpax.org.uk> - 2025-12-08 19:42 +0000
        Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-09 21:49 +0000
  Re: is_binary_file() Paul <nospam@needed.invalid> - 2025-12-06 03:14 -0500
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 17:56 +0000
      Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-08 20:16 +0000
        Re: is_binary_file() David Brown <david.brown@hesbynett.no> - 2025-12-09 09:03 +0100
          Re: is_binary_file() Richard Heathfield <rjh@cpax.org.uk> - 2025-12-09 09:43 +0000
            Re: is_binary_file() Richard Harnden <richard.nospam@gmail.invalid> - 2025-12-09 10:17 +0000
              Re: is_binary_file() Kaz Kylheku <046-301-5902@kylheku.com> - 2025-12-09 20:15 +0000
          Re: is_binary_file() tTh <tth@none.invalid> - 2025-12-09 12:22 +0100
            Re: is_binary_file() Paul <nospam@needed.invalid> - 2025-12-09 20:26 -0500
          Re: is_binary_file() Paul <nospam@needed.invalid> - 2025-12-09 06:38 -0500
            Re: is_binary_file() Michael S <already5chosen@yahoo.com> - 2025-12-09 17:31 +0200
            Re: is_binary_file() Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-12-28 02:49 +0000
    Re: is_binary_file() Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-12-28 00:12 +0000
      Re: is_binary_file() richard@cogsci.ed.ac.uk (Richard Tobin) - 2025-12-28 00:43 +0000
  Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-06 17:33 +0000
    Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-07 19:04 +0100
  Re: is_binary_file() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-12-06 20:37 -0500
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 18:02 +0000
    Re: is_binary_file() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-12-09 16:29 -0500
      Re: is_binary_file() Michael S <already5chosen@yahoo.com> - 2025-12-10 11:21 +0200
        Re: is_binary_file() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-12-10 12:48 -0500
      Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 11:38 +0000
  Re: is_binary_file() antispam@fricas.org (Waldek Hebisch) - 2025-12-07 03:43 +0000
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 18:04 +0000
      Re: is_binary_file() bart <bc@freeuk.com> - 2025-12-08 18:44 +0000
        Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-09 19:53 +0000
          Re: is_binary_file() Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-12-09 15:42 -0800
            Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 11:41 +0000
              Re: is_binary_file() Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-12-10 15:20 -0800
                Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-10 23:59 +0000
        Re: is_binary_file() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-12-09 16:23 -0500
  Re: is_binary_file() Richard Harnden <richard.nospam@gmail.invalid> - 2025-12-07 19:01 +0000
    Re: is_binary_file() Richard Heathfield <rjh@cpax.org.uk> - 2025-12-07 21:51 +0000
      Re: is_binary_file() Richard Harnden <richard.nospam@gmail.invalid> - 2025-12-07 22:49 +0000
      Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-08 13:51 +0100
        Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-08 16:04 +0000
          Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-08 19:27 +0100
        Re: is_binary_file() Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-12-27 05:51 +0000
          Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-29 16:06 +0100
            Re: is_binary_file() mjos_examine <m6502x64@gmail.com> - 2025-12-29 11:49 -0500
              Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-29 20:49 +0100
            Re: is_binary_file() Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-12-30 01:52 +0000
      Re: is_binary_file() scott@slp53.sl.home (Scott Lurndal) - 2025-12-08 16:02 +0000
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 18:07 +0000
    Re: is_binary_file() Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-12-27 03:13 +0000
      Re: is_binary_file() Paul <nospam@needed.invalid> - 2025-12-27 01:28 -0500
        Re: is_binary_file() Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-12-27 21:27 +0000
        Re: is_binary_file() antispam@fricas.org (Waldek Hebisch) - 2025-12-28 05:46 +0000
  Re: is_binary_file() "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-12-07 14:42 -0800
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-08 18:09 +0000
      Re: is_binary_file() "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-12-09 12:45 -0800
  Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-08 20:36 +0100
    Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-08 20:50 +0100
      Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-09 15:09 +0100
    Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-10 09:18 +0100
  Re: is_binary_file() Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-12-08 14:43 -0800
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-09 21:38 +0000
  Re: is_binary_file() Kaz Kylheku <046-301-5902@kylheku.com> - 2025-12-11 17:33 +0000
    Re: is_binary_file() Bonita Montero <Bonita.Montero@gmail.com> - 2025-12-11 19:10 +0100
    Re: is_binary_file() "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-12-11 14:56 -0800
    Re: is_binary_file() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-12-11 18:15 -0500
    Re: is_binary_file() Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-12-12 02:19 +0100
    Re: is_binary_file() Michael Sanders <porkchop@invalid.foo> - 2025-12-14 08:27 +0000
    Re: is_binary_file() Lynn McGuire <lynnmcguire5@gmail.com> - 2025-12-17 00:52 -0600

csiph-web