Re: Program to read csv file, store characters and numbers in separate arrays

From	Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups	comp.lang.c
Subject	Re: Program to read csv file, store characters and numbers in separate arrays
Date	2016-12-16 15:04 +0000
Organization	A noiseless patient Spider
Message-ID	<874m233ogi.fsf@bsb.me.uk> (permalink)
References	(7 earlier) <o30eii$q7r$1@dont-email.me> <e87be1fa-364e-4117-b4b0-7c81b89a3406@googlegroups.com> <o30j33$8po$1@dont-email.me> <87a8bw2iai.fsf@bsb.me.uk> <o30oks$rn1$1@dont-email.me>

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BartC <bc@freeuk.com> writes:

> On 16/12/2016 12:02, Ben Bacarisse wrote:
>
>> Well, should is a matter of opinion.  Here is at least one opinion about
>> what a CSV file is:
>>
>>    1.  Each record is located on a separate line, delimited by a line
>>        break (CRLF).  For example:
>>
>>        aaa,bbb,ccc CRLF
>>        zzz,yyy,xxx CRLF
>>
>> This is from RFC 4180 (don't worry, it does explain that fields can span
>> lines later on).
>
> Big mistake. Apparently leading and trailing spaces are also
> significant.

I'm not sure what the mistake is.  Can you explain?

> This means that a big chunk of a file spanning multiple lines
> containing English prose, or function of a programming language,
> counts as just one CSV field so long as there aren't any commas in
> there.

I know this is meant to explain the "big mistake" but I still don't see
it.

I don't think commas are really an issue since in every CSV format I've
seen fields with multiple lines have to be quoted.  But since there can
be two kind of "line" in a CSV file, it's possible that commas might
come into it, but I'm not sure that's what you mean.

For example, in a file with CRLF line endings, I can imagine a really
nasty CSV file with multi-line text whose line separator is LF:

  f1,f2,thisLFisLFfourLFlinesCRLF

(I don't know it any software either write this or reads it, but I can
imagine it being possible in some badly specified formats.)

> (And apparently a quoted field can still contain unadorned newline
> characters. So even fgets can only retrieve part of a field. Such
> characters should be escaped. Newline should be a higher level
> separator than comma.)

Yes.  You should not use fgets to read binary files.  You /can/, of
course, but I can't see the point other than give yourself a lot of
pain.

>> CSV files have no universally agreed separator (despite the name), no
>> universally agreed character encoding, no universally agreed line ending
>> and no universally agreed quoting scheme.  The only universally agreed
>> thing about them is that they are a pain in neck.
>
> If your program generates CSV then you can do it properly so that you
> can read your own files and make it more likely for them to be
> acceptable to other programs. But you might still have the headache of
> dealing with embedded special characters within a field.
>
>> The sound advice about file formats: "be generous in what your code
>> accepts and strict in what it generates"
>
> Oh, that's what I just repeated...

Yes, though I went on to say that it's almost impossible to do.  Your
"you can do it properly" makes it sound easy.

-- 
Ben.

Thread

Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-15 05:05 -0800
  Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 13:48 +0000
    Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-15 08:22 -0800
      Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 16:28 +0000
        Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-15 09:25 -0800
          Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 19:31 +0000
            Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 01:19 -0800
              Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 10:01 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 02:43 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 11:03 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 03:08 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays jameskuyper@verizon.net - 2016-12-18 03:32 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays Barry Schwarz <schwarzb@dqel.com> - 2016-12-16 17:09 -0800
            Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 01:25 -0800
              Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 10:11 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 02:45 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays Keith Thompson <kst-u@mib.org> - 2016-12-16 09:54 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 17:56 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-16 18:02 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 03:06 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 11:28 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-16 12:02 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 12:41 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays BartC <bc@freeuk.com> - 2016-12-16 13:40 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 14:03 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays BartC <bc@freeuk.com> - 2016-12-16 13:03 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-16 15:04 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays BartC <bc@freeuk.com> - 2016-12-16 15:26 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-16 17:01 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 04:18 -0800
  Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 14:12 +0000
    Re: Program to read csv file, store characters and numbers in separate arrays David Brown <david.brown@hesbynett.no> - 2016-12-15 16:14 +0100
      Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 15:37 +0000
        Re: Program to read csv file, store characters and numbers in separate arrays David Brown <david.brown@hesbynett.no> - 2016-12-15 23:20 +0100
          Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 23:27 +0000
            Re: Program to read csv file, store characters and numbers in separate arrays David Brown <david.brown@hesbynett.no> - 2016-12-16 12:10 +0100
              Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 11:43 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays David Brown <david.brown@hesbynett.no> - 2016-12-16 14:01 +0100
                Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 13:12 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays David Brown <david.brown@hesbynett.no> - 2016-12-16 14:57 +0100
      Re: Program to read csv file, store characters and numbers in separate arrays BartC <bc@freeuk.com> - 2016-12-15 16:30 +0000
        Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 16:36 +0000
          Re: Program to read csv file, store characters and numbers in separate arrays David Brown <david.brown@hesbynett.no> - 2016-12-15 23:29 +0100
    Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-15 08:26 -0800
      Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 16:33 +0000
    Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-15 08:32 -0800
      Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 16:37 +0000
      Re: Program to read csv file, store characters and numbers in separate arrays Keith Thompson <kst-u@mib.org> - 2016-12-15 12:17 -0800
        Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 01:33 -0800
    Re: Program to read csv file, store characters and numbers in separate arrays Keith Thompson <kst-u@mib.org> - 2016-12-15 12:23 -0800
      Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 20:39 +0000
    Re: Program to read csv file, store characters and numbers in separate arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-15 21:13 +0000
    Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 00:39 -0800
      Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 08:54 +0000
        Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 01:09 -0800
          Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 09:32 +0000
            Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 01:51 -0800
              Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 10:08 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-16 11:09 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 03:16 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 03:20 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays Keith Thompson <kst-u@mib.org> - 2016-12-16 09:48 -0800
                Re: Program to read csv file, store characters and numbers in separate arrays gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-16 17:55 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays raltbos@xs4all.nl (Richard Bos) - 2016-12-20 11:53 +0000
                Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 11:33 +0000
            Re: Program to read csv file, store characters and numbers in separate arrays Keith Thompson <kst-u@mib.org> - 2016-12-16 09:46 -0800
      Re: Program to read csv file, store characters and numbers in separate arrays "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-03 15:38 -0500
  Re: Program to read csv file, store characters and numbers in separate arrays Barry Schwarz <schwarzb@dqel.com> - 2016-12-15 12:36 -0800
    Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 01:44 -0800
      Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 10:04 +0000
        Re: Program to read csv file, store characters and numbers in separate arrays Alla _ <modelling.data@gmail.com> - 2016-12-16 03:14 -0800
          Re: Program to read csv file, store characters and numbers in separate arrays Richard Heathfield <rjh@cpax.org.uk> - 2016-12-16 11:46 +0000

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