Re: what does # mean?

From	T <T@invalid.invalid>
Newsgroups	comp.lang.c
Subject	Re: what does # mean?
Date	2017-06-03 19:27 -0700
Organization	A noiseless patient Spider
Message-ID	<ogvr0h$8pm$1@dont-email.me> (permalink)
References	<ogtotj$r7b$1@dont-email.me> <lna85pm4yj.fsf@kst-u.example.com> <ogv7oi$i8n$3@dont-email.me> <lnwp8slcr8.fsf@kst-u.example.com>

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On 06/03/2017 07:15 PM, Keith Thompson wrote:
> T <T@invalid.invalid> writes:
>> On 06/03/2017 09:05 AM, Keith Thompson wrote:
>>> T <T@invalid.invalid> writes:
>>>> I don't understand C.  I am trying to find something
>>>> in some source code.  What does "#" mean as in
>>> [snip]
>>>
>>> You cannot learn C by asking about one feature at a time.  Find a
>>> decent C book or tutorial (and feel free to ask here for advice
>>> about finding one).
>>
>> I am not trying to learn C.  I am trying to find
>> a missing dependency.  I can read Perl, Pascal, Modula2.
>> I am lost when it comes to C.  Hopefully, when I
>> find what I am looking for, I won't have to read C
>> again for many years.  When it comes to C, there are
>> folks far better at it than me and I will leave it to them.
> 
> OK.  I've seen a number of questions (not necessarily here) where
> posters *seem* to be trying to learn C, or some other language,
> by asking about one tiny feature at a time -- analagous to someone
> trying to learn English by asking what "the" means.  It wasn't at all
> clear from your original question what you were trying to accomplish.
> 
> It would have helped us to help you if you had given a little more
> information about your goals in asking your question.  Some people
> run into something called an "X/Y problem", where they need to do X,
> assume that Y is the right approach, and then ask about Y.
> 
> You've probably gotten the information you need by now, but I'll
> summarize.
> 
> Many scripting languages use the '#' character to introduce an
> end-of-line commment.  C does not.  C comments are introduced by
> /* and terminated by */ (and may span multiple lines, or part of
> a line), or are introduce by // and run to the end of the line
> (inherited from BCPL via C++, and introduced to C by the 1999
> standard).
> 
> The # character at the beginning of a line (possibly preceded
> and/or followed by white space) usually introduces a preprocessor
> directive.  The preprocessor is a separate translation phase, run
> before syntactic analysis.  It performs conditional compilation (#if,
> #ifdef, #elif, #else, #endif), file inclusion (#include) and macro
> definition and expansion (#define).  (The preprocessor also has #
> and ## operators, but you probably don't need to worry about those.)
> 
> The preprocessor is described in definitive detail in section
> 6.10 of the current ISO C standard; the latest public draft is
> http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf
> 
> One more piece of advice.  You've gotten some particularly rude
> responses (mine was not *intended* to be among them).  This newsgroup
> is, unfortunately, infested with several trolls.  A lot of us
> use killfiles to avoid seeing their nonsense.  Replying to them,
> as we've found from long experience, is not useful, and further
> damages the group's signal-to-noise ratio.
> 

Hi Keith,

I was thinking that # was a comment mark.  I write in bash
and perl, where they are comment marks.  I was skipping over them.

I saw/am looking for a missing system call to an OS dependency.
 From what I can tell,

     HAVE_LIBNOTIFY7

Is loading a system decadency or a modules that call
a system dependency.

And

     $ rpm -qa \*notify\*
     libnotify-0.7.5-8.el7.x86_64

Has been a long running pain-in-my-ass.  Fedora is now
on 0.7.7.  I tried to rebuild Fedora's srpm, but I
landed in RPM hell.

Thank you for all the help, and point taken.

-T

Thread

what does # mean? T <T@invalid.invalid> - 2017-06-03 00:39 -0700
  Re: what does # mean? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-03 10:06 +0200
    Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 01:25 -0700
      Re: what does # mean? Leon Taylor <leontaylor476@gmail.com> - 2017-06-03 03:41 -0700
      Re: what does # mean? Keith Thompson <kst-u@mib.org> - 2017-06-03 09:03 -0700
        Re: what does # mean? bartc <bc@freeuk.com> - 2017-06-03 17:11 +0100
          Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 13:56 -0700
  Re: what does # mean? Jerry Stuckle <jstucklex@attglobal.net> - 2017-06-03 09:24 -0400
    Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 13:52 -0700
    Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 13:55 -0700
      Re: what does # mean? Jerry Stuckle <jstucklex@attglobal.net> - 2017-06-04 18:19 -0400
        Re: what does # mean? T <T@invalid.invalid> - 2017-06-05 01:54 -0700
  Re: what does # mean? Keith Thompson <kst-u@mib.org> - 2017-06-03 09:05 -0700
    Re: what does # mean? gazelle@shell.xmission.com (Kenny McCormack) - 2017-06-03 16:18 +0000
      Re: what does # mean? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-03 18:22 +0200
        Re: what does # mean? gazelle@shell.xmission.com (Kenny McCormack) - 2017-06-03 16:30 +0000
          Re: what does # mean? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-03 19:18 +0200
            Re: what does # mean? gazelle@shell.xmission.com (Kenny McCormack) - 2017-06-03 18:03 +0000
    Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 13:59 -0700
      Re: what does # mean? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-03 23:30 +0200
        Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 14:35 -0700
          Re: what does # mean? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-03 23:55 +0200
            Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 15:30 -0700
              Re: what does # mean? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-04 00:36 +0200
                Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 16:12 -0700
                Re: what does # mean? Ian Collins <ian-news@hotmail.com> - 2017-06-04 11:17 +1200
                Re: what does # mean? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-04 01:23 +0200
      Re: what does # mean? Keith Thompson <kst-u@mib.org> - 2017-06-03 19:15 -0700
        Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 19:27 -0700
          Re: what does # mean? Manfred <noname@invalid.add> - 2017-06-04 19:09 +0200
            Re: what does # mean? T <T@invalid.invalid> - 2017-06-05 01:56 -0700
          Re: what does # mean? Keith Thompson <kst-u@mib.org> - 2017-06-04 13:51 -0700
            Re: what does # mean? T <T@invalid.invalid> - 2017-06-05 01:57 -0700
  Re: what does # mean? James Kuyper <jameskuyper@verizon.net> - 2017-06-03 23:08 -0400
    Re: what does # mean? T <T@invalid.invalid> - 2017-06-03 20:53 -0700
      Re: what does # mean? John Bode <jfbode1029@gmail.com> - 2017-06-05 12:44 -0700
        Re: what does # mean? T <T@invalid.invalid> - 2017-06-05 14:52 -0700
  Re: what does # mean? T <T@invalid.invalid> - 2017-06-05 03:00 -0700

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