Re: A finalized program

From	Richard Heathfield <rjh@cpax.org.uk>
Newsgroups	comp.lang.c
Subject	Re: A finalized program
References	<d93ca264-e41a-4f82-8c09-cd87731b2eed@googlegroups.com> <76d2dbff-c516-4e0e-8420-7a7914d7a8f4@googlegroups.com> <87lhcdgm3d.fsf@bsb.me.uk>
Message-ID	<SxAIx.423866$vg2.379766@fx34.am4> (permalink)
Organization	virginmedia.com
Date	2015-09-11 14:19 +0100

Show all headers | View raw

On 11/09/2015 13:46, Ben Bacarisse wrote:

<snip>

> Richard has said don't use scanf, but that's bad advice!!

Dem's fitin' woids! I'll see you in the playground at lunchtime.

> The correct
> advice is don't use scanf for complex things -- it *will* drive you mad.

That's certainly true...

> But for simple input tasks in beginners' programs it is ideal.

...but that isn't.

> He
> re-wrote your example using fgets and saying how easy it was.  He just
> had to write write a dozen or so lines of code to do what %[0-9] does!

Yes, but they were easy lines - easy to write, easy to read, easy to 
understand, and easy to get right. Surely you cannot have overlooked 
just how much grief scanf has caused just in this one thread?

> And he has to use cast, which he hates!

Actually, if I hate anything about casts, it is only that they are 
wrongly used. I could easily have avoided the cast, like this:

   unsigned char uc = d;
   if(isdigit(c))

but that would have been pointless. Casts are useful, provided one 
understands what they are for and when it is appropriate to use them.

> What's more, fgets has it's own
> problems which can confuse users in interactive programs.

Okay, that's worth talking about. What problems are those?

> In short, there are loads of interesting things to lean that you will
> use time and time again (command-line argument processing is one) but
> this isn't one of them!

Actually, I'd more or less agree with your main point that interactive 
programs on the teletype model are rare nowadays, *but* it's still handy 
to know how to do it, partly because there are times when you just want 
to hack out a quickie interactive program without going to all the 
hassle of a full-blown GUI app, but mostly because the skills you learn 
in doing so are transferable to file processing.

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
Sig line 4 vacant - apply within

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

Thread

A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-08 04:13 -0700
  Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-08 04:19 -0700
    Re: A finalized program fir <profesor.fir@gmail.com> - 2015-09-08 04:30 -0700
    Re: A finalized program Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-08 14:45 +0100
      Re: A finalized program Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-08 08:29 -0700
      Re: A finalized program Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-08 08:52 -0700
        Re: A finalized program Martin Shobe <martin.shobe@yahoo.com> - 2015-09-08 13:01 -0500
        Re: A finalized program Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-08 21:00 +0100
          Re: A finalized program Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-08 13:33 -0700
            Re: A finalized program Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-09 00:28 +0100
  Re: A finalized program Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-08 14:26 +0100
    Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-08 06:42 -0700
      Re: A finalized program Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-08 20:50 +0100
        Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 01:47 -0700
  Re: A finalized program jt@toerring.de (Jens Thoms Toerring) - 2015-09-08 13:41 +0000
    Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-10 01:31 -0700
      Re: A finalized program jt@toerring.de (Jens Thoms Toerring) - 2015-09-10 10:39 +0000
        Re: A finalized program David Thompson <dave.thompson2@verizon.net> - 2015-09-20 18:35 -0400
    Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-10 01:33 -0700
    Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-10 10:16 -0700
      Re: A finalized program bartekltg <bartekltg@gmail.com> - 2015-09-10 20:08 +0200
        Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 02:05 -0700
          Re: A finalized program Richard Heathfield <rjh@cpax.org.uk> - 2015-09-11 10:17 +0100
            Re: A finalized program Richard Heathfield <rjh@cpax.org.uk> - 2015-09-11 10:19 +0100
            Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 02:28 -0700
            Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 02:29 -0700
        Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 02:19 -0700
          Re: A finalized program Richard Heathfield <rjh@cpax.org.uk> - 2015-09-11 10:23 +0100
            Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 02:33 -0700
              Re: A finalized program Keith Thompson <kst-u@mib.org> - 2015-09-11 14:11 -0700
                Re: A finalized program jt@toerring.de (Jens Thoms Toerring) - 2015-09-11 21:39 +0000
          Re: A finalized program bartekltg <bartekltg@gmail.com> - 2015-09-11 12:49 +0200
      Re: A finalized program Richard Heathfield <rjh@cpax.org.uk> - 2015-09-10 23:31 +0100
        Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 02:15 -0700
      Re: A finalized program jt@toerring.de (Jens Thoms Toerring) - 2015-09-10 22:37 +0000
        Re: A finalized program Richard Heathfield <rjh@cpax.org.uk> - 2015-09-10 23:47 +0100
          Re: A finalized program jt@toerring.de (Jens Thoms Toerring) - 2015-09-11 10:18 +0000
        Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 01:07 -0700
        Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 02:14 -0700
          Re: A finalized program jt@toerring.de (Jens Thoms Toerring) - 2015-09-11 10:10 +0000
            Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 04:19 -0700
  Re: A finalized program Barry Schwarz <schwarzb@dqel.com> - 2015-09-08 15:53 -0700
  Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 04:27 -0700
    Re: A finalized program bartekltg <bartekltg@gmail.com> - 2015-09-11 14:05 +0200
  Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 04:42 -0700
    Re: A finalized program bartekltg <bartekltg@gmail.com> - 2015-09-11 14:15 +0200
      Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 05:50 -0700
        Re: A finalized program bartekltg <bartekltg@gmail.com> - 2015-09-11 15:00 +0200
      Re: A finalized program Alla _ <modelling.data@gmail.com> - 2015-09-11 05:50 -0700
    Re: A finalized program Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-11 13:46 +0100
      Re: A finalized program Richard Heathfield <rjh@cpax.org.uk> - 2015-09-11 14:19 +0100

csiph-web