Re: scanf design

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From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: scanf design
Date	Mon, 12 Dec 2016 11:37:08 -0800
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"Bill Cunningham" <nospam@nspam.invalid> writes:
> "Malcolm McLean" <malcolm.mclean5@btinternet.com> wrote in message 
> news:96650663-827e-4f89-b78f-7b42a2516ef3@googlegroups.com...
[...]
>> But scanf is a bit unusual in that it returns a flexible number of
>> values of flexible type. So you see the & operator used heavily.
>> It's relatively rare to see the & operator used in most code.
>
> In the manual it speaks of "pointer arguments". Now a dumb ass like me isn't 
> going to be too sure of what that means. And it takes scanf(const char 
> *format,...) and the ellipsis. Variable arguments.
>
>     I know I am responding to you Malcom but this is for anyone to answer. 
> Is '&' not always used? it's all I've seen used. Very useful function.

Most scanf format specifies require a corresponding argument of some
specific pointer type.  Let's say it's FOO* (where FOO could be char,
int, double, or whatever).  One way to obtain the required value of type
FOO* is to apply the unary & operator to the name of an object of type
FOO.  There are other ways that don't require the use of unary &.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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scanf design "Bill Cuningham" <nospam@nspam.invalid> - 2016-12-11 16:42 -0500
  Re: scanf design Noob <root@127.0.0.1> - 2016-12-11 22:55 +0100
    Re: scanf design "Bill Cuningham" <nospam@nspam.invalid> - 2016-12-11 17:03 -0500
  Re: scanf design Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-11 22:05 +0000
  Re: scanf design Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-11 14:43 -0800
    Re: scanf design "Bill Cunningham" <nospam@nspam.invalid> - 2016-12-12 12:25 -0500
      Re: scanf design Keith Thompson <kst-u@mib.org> - 2016-12-12 11:15 -0800
        Re: scanf design Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-12 13:17 -0800
          Re: scanf design Keith Thompson <kst-u@mib.org> - 2016-12-12 14:02 -0800
            Re: scanf design Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-12 15:06 -0800
              Re: scanf design fir <profesor.fir@gmail.com> - 2016-12-12 15:58 -0800
                Re: scanf design fir <profesor.fir@gmail.com> - 2016-12-12 16:10 -0800
                Re: scanf design fir <profesor.fir@gmail.com> - 2016-12-12 16:10 -0800
                Re: scanf design fir <profesor.fir@gmail.com> - 2016-12-12 16:22 -0800
                Re: scanf design fir <profesor.fir@gmail.com> - 2016-12-15 07:30 -0800
                Re: scanf design fir <profesor.fir@gmail.com> - 2016-12-15 07:56 -0800
                Re: scanf design fir <profesor.fir@gmail.com> - 2016-12-15 08:21 -0800
    Re: scanf design "Bill Cunningham" <nospam@nspam.invalid> - 2016-12-12 13:18 -0500
      Re: scanf design Keith Thompson <kst-u@mib.org> - 2016-12-12 11:37 -0800

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