Re: Line read from csv file with fgets has two characters before the terminating one

From	Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups	comp.lang.c
Subject	Re: Line read from csv file with fgets has two characters before the terminating one
Date	2016-12-17 02:48 +0000
Organization	A noiseless patient Spider
Message-ID	<87a8bvz2x3.fsf@bsb.me.uk> (permalink)
References	(8 earlier) <o2u8df$42d$1@dont-email.me> <87lgvg39i4.fsf@bsb.me.uk> <o30isq$81f$1@dont-email.me> <87shpn25ea.fsf@bsb.me.uk> <o31oie$gfm$1@dont-email.me>

Show all headers | View raw

BartC <bc@freeuk.com> writes:

> On 16/12/2016 16:41, Ben Bacarisse wrote:
>> BartC <bc@freeuk.com> writes:
>
>>> You're trying to merge interactive and file input again.
>>
>> No, I was just suggesting you avoid an infinite loop.
>>
>> But doesn't writing the prompt to stdout merge the interactive IO with
>> the file IO?  I prefer the output to be separated from the prompts.
>
> How do you separate the two types of output on a console?

That's up to the system (and the user), but the program has to do the
ground work by prompting to stderr rather than stdout.

>>> I tried to
>>> use code that was portable.
>>
>> It's more portable to test for EOF as you can't be sure the system won't
>> have a way for the user to accidentally close the input.  Anyway, it was
>> only a suggestion.
>
> Testing for EOF would make sense if the user inadvertently redirected
> console input to come from a file.

Or inadvertently closed the stdin stream.

> Then if there are more blocks in
> the dumped file than there are newline characters in the file,
> eventually the latter will only return EOF and no more Enters.

Yes, and without an EOF check the program will not end.  It's not a
common problem but the fix is so trivial it seems churlish to keep
arguing against using it.

> But this would be getting a long way from the kind of pause()
> functions I was using last century which waited for the next key press
> or mouse click. It would be going backwards.

There's not need to go back -- you can keep using if you like.  But if
you are going to do the pause the way you wrote it, it's better to
include an EOF test.

But the modern way is to write utilities that combine well together.  I
want to chose how to page through a program's output.  I don't wany you
do decide what facilities I get for that.  You don't even try to get the
page size right for my terminal.  My preferred pager is configured to
work as I like, and it has features that should not be duplicated in
every program on my system.

> Anyway it would be harmless. The user eventually presses Ctrl C or
> Ctrl Break to come out of it. If EOF was checked for, the dumped
> output would just stream past anyway.
>
>
>>> But they might be able to spot how to do that themselves.
>>
>> How would you suggest?  I know how to on my Linux system, but it's not
>> obvious to beginners, and at least one obvious attempt will provoke the
>> infinite loop you don't want to avoid.
>
> You just take out the lines that wait for a response.

Ah, this is a utility designed for people who will edit C source code to
alter their tool's behaviour.  I missed that.  That's usually considered
a fragile way to configure utilities.  (I'm joking, it's considered
bonkers!)

I'd edit the source to (a) not prompt, (b) not wait, and (c) not insist
on a file name.  Then I would not need to edit it again because I would
then have a dump utility that inter-works with my other tools in a
useful way.

-- 
Ben.

Thread

Line read from csv file with fgets has two characters before the terminating one Alla _ <modelling.data@gmail.com> - 2016-12-14 00:04 -0800
  Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-14 11:10 +0000
    Re: Line read from csv file with fgets has two characters before the terminating one Alla _ <modelling.data@gmail.com> - 2016-12-14 23:50 -0800
      Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 08:52 +0000
        Re: Line read from csv file with fgets has two characters before the terminating one Alla _ <modelling.data@gmail.com> - 2016-12-15 00:58 -0800
          Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 09:09 +0000
            Re: Line read from csv file with fgets has two characters before the terminating one Alla _ <modelling.data@gmail.com> - 2016-12-15 04:23 -0800
              Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 12:50 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-15 14:14 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 14:42 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Keith Thompson <kst-u@mib.org> - 2016-12-15 09:49 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-15 17:58 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-15 18:22 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Keith Thompson <kst-u@mib.org> - 2016-12-15 11:51 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-15 20:35 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Keith Thompson <kst-u@mib.org> - 2016-12-15 12:58 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-15 13:11 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-16 02:14 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-16 11:25 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-16 16:41 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-16 22:08 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-17 02:48 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-17 11:54 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-17 15:33 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one supercat@casperkitty.com - 2016-12-17 08:27 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-17 17:25 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-17 09:53 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-17 18:21 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one supercat@casperkitty.com - 2016-12-17 10:30 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-17 22:39 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-17 14:51 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one BartC <bc@freeuk.com> - 2016-12-17 23:12 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one supercat@casperkitty.com - 2016-12-18 08:37 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Keith Thompson <kst-u@mib.org> - 2016-12-18 13:14 -0800
            Re: Line read from csv file with fgets has two characters before the terminating one Geoff <geoff@invalid.invalid> - 2016-12-15 15:03 -0800
              Re: Line read from csv file with fgets has two characters before the terminating one Keith Thompson <kst-u@mib.org> - 2016-12-15 15:29 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Geoff <geoff@invalid.invalid> - 2016-12-15 20:48 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Keith Thompson <kst-u@mib.org> - 2016-12-15 22:58 -0800
                OSX line endings (Was: Line read from csv file with fgets has two characters before the terminating one) gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-16 10:22 +0000
                Re: OSX line endings (Was: Line read from csv file with fgets has two characters before the terminating one) Geoff <geoff@invalid.invalid> - 2016-12-16 07:29 -0800
                Making OSX's boot drive case-sensitve (Was: OSX line endings (Was: Line read from csv file with fgets has two characters before the terminating one)) gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-17 10:06 +0000
                Re: Making OSX's boot drive case-sensitve (Was: OSX line endings (Was: Line read from csv file with fgets has two characters before the terminating one)) Geoff <geoff@invalid.invalid> - 2016-12-17 12:39 -0800
                Re: Making OSX's boot drive case-sensitve (Was: OSX line endings (Was: Line read from csv file with fgets has two characters before the terminating one)) gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-18 13:54 +0000
                Re: Making OSX's boot drive case-sensitve (Was: OSX line endings (Was: Line read from csv file with fgets has two characters before the terminating one)) Geoff <geoff@invalid.invalid> - 2016-12-18 17:57 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Geoff <geoff@invalid.invalid> - 2016-12-16 07:12 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Keith Thompson <kst-u@mib.org> - 2016-12-16 12:02 -0800
              Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 23:29 +0000
              Re: Line read from csv file with fgets has two characters before the terminating one Alla _ <modelling.data@gmail.com> - 2016-12-16 02:37 -0800
                Re: Line read from csv file with fgets has two characters before the terminating one Geoff <geoff@invalid.invalid> - 2016-12-16 07:51 -0800
          Re: Line read from csv file with fgets has two characters before the terminating one Manfred <noname@invalid.add> - 2016-12-15 12:22 +0100
            Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 11:29 +0000
              Re: Line read from csv file with fgets has two characters before the terminating one Melzzzzz <Melzzzzz@zzzzz.com> - 2016-12-15 12:40 +0100
                Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 12:00 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one Melzzzzz <mel@zzzzz.com> - 2016-12-15 13:09 +0100
                Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 12:43 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one "James R. Kuyper" <jameskuyper@verizon.net> - 2016-12-15 09:18 -0500
                Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 14:49 +0000
                Re: Line read from csv file with fgets has two characters before the terminating one "James R. Kuyper" <jameskuyper@verizon.net> - 2016-12-15 10:34 -0500
              Re: Line read from csv file with fgets has two characters before the terminating one Manfred <noname@invalid.add> - 2016-12-15 16:34 +0100
    Re: Line read from csv file with fgets has two characters before the terminating one Alla _ <modelling.data@gmail.com> - 2016-12-15 00:22 -0800
      Re: Line read from csv file with fgets has two characters before the terminating one Richard Heathfield <rjh@cpax.org.uk> - 2016-12-15 09:04 +0000
  Re: Line read from csv file with fgets has two characters before the terminating one mark.bluemel@gmail.com - 2016-12-14 03:38 -0800

csiph-web