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

Groups > comp.lang.c > #111744

Re: How to determine if file is binary or text?

Show all headers | View raw

Some systems store binary and text files very differently, and have file-mode
flags which keep track of whether something is a binary or a text file.  They
may provide a system-specific means of accessing that information, but require
that files written as text be re-opened as text, and those written as binary be
re-opened as binary.

Other systems treat both kinds of files identically and do not keep track of
whether a file was opened with "w" or "wb" because they have no reason to care
about such things.

Finally, there are systems where certain operations on files are performed
somewhat differently based upon the mode used to open a file, but which
don't keep track of how files on disk are written.  Writing "Hello\n" to a
file in text mode on such a system might produce the exact same bit pattern
as writing "Hello\r\n" in binary mode.

The Standard can't require implementations to report whether something is
a text file or binary file because many implementations don't keep track
of such information.  It can't require implementations to allow text files
to be opened in binary mode, nor vice versa, because some systems treat
such files in ways that are fundamentally different.  The net effect is
that the Standard provides nothing beyond "hope for the best" semantics in
cases where one wants to open a file and doesn't know what mode was used
to create it.

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

Thread

How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-07 14:40 -0400
  Re: How to determine if file is binary or text? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 20:46 +0200
  Re: How to determine if file is binary or text? bartc <bc@freeuk.com> - 2017-06-07 19:58 +0100
  Re: How to determine if file is binary or text? scott@slp53.sl.home (Scott Lurndal) - 2017-06-07 19:05 +0000
  Re: How to determine if file is binary or text? supercat@casperkitty.com - 2017-06-07 12:10 -0700
  Re: How to determine if file is binary or text? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-06-07 16:25 -0400
  Re: How to determine if file is binary or text? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2017-06-07 21:44 +0000
    Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-07 18:14 -0400
      Re: How to determine if file is binary or text? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-08 00:23 +0200
        Re: How to determine if file is binary or text? Robert Wessel <robertwessel2@yahoo.com> - 2017-06-08 00:11 -0500
          Re: How to determine if file is binary or text? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-08 15:14 +0200
            Re: How to determine if file is binary or text? Robert Wessel <robertwessel2@yahoo.com> - 2017-06-08 11:06 -0500
          Re: How to determine if file is binary or text? raltbos@xs4all.nl (Richard Bos) - 2017-06-17 18:28 +0000
      Re: How to determine if file is binary or text? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-07 23:30 +0100
        Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-07 20:26 -0400
          Re: How to determine if file is binary or text? bartc <bc@freeuk.com> - 2017-06-08 01:30 +0100
            Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-07 23:50 -0400
              Re: How to determine if file is binary or text? mark.bluemel@gmail.com - 2017-06-08 02:13 -0700
                Re: How to determine if file is binary or text? mark.bluemel@gmail.com - 2017-06-08 04:05 -0700
                Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-08 09:21 -0400
                Re: How to determine if file is binary or text? Ike Naar <ike@iceland.freeshell.org> - 2017-06-08 14:19 +0000
                Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-08 12:07 -0400
                Re: How to determine if file is binary or text? scott@slp53.sl.home (Scott Lurndal) - 2017-06-08 16:14 +0000
                Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-08 12:37 -0400
                Re: How to determine if file is binary or text? scott@slp53.sl.home (Scott Lurndal) - 2017-06-08 16:54 +0000
                Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-08 13:14 -0400
                An old version of what??? (Was: How to determine if file is binary or text?) gazelle@shell.xmission.com (Kenny McCormack) - 2017-06-09 17:13 +0000
              Re: How to determine if file is binary or text? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-08 11:15 +0100
          Re: How to determine if file is binary or text? scott@slp53.sl.home (Scott Lurndal) - 2017-06-08 12:49 +0000
          Re: How to determine if file is binary or text? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2017-06-08 14:01 +0000
          Re: How to determine if file is binary or text? Michael Forsythe <forsythe@example.com> - 2017-06-08 15:33 +0000
            Re: How to determine if file is binary or text? DFS <nospam@dfs.com> - 2017-06-08 18:43 -0400
              Re: How to determine if file is binary or text? jak <please@nospam.tnx> - 2017-06-09 08:46 +0200
      Re: How to determine if file is binary or text? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-06-07 19:23 -0400
      Re: How to determine if file is binary or text? Barry Schwarz <schwarzb@dqel.com> - 2017-06-07 16:50 -0700
      Re: How to determine if file is binary or text? "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-06-08 15:51 +0200
  Re: How to determine if file is binary or text? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-06-07 17:17 -0600
    Re: How to determine if file is binary or text? Keith Thompson <kst-u@mib.org> - 2017-06-07 19:21 -0700
      Re: How to determine if file is binary or text? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-06-07 21:37 -0600
  Re: How to determine if file is binary or text? Noob <root@127.0.0.1> - 2017-06-08 08:40 +0200
  Re: How to determine if file is binary or text? gordonb.t9rom@burditt.org (Gordon Burditt) - 2017-06-08 12:03 -0500

csiph-web