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Re: Convert string to C expression syntax

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On 2013-08-01, Keith Thompson <kst-u@mib.org> wrote:
> Barry Schwarz <schwarzb@dqel.com> writes:
> [...]
>> If you want to check whether the string has a certain value, you would
>> use strcmp or strncmp in the condition of your if statement. Something
>> along the lines of 
>>      if (!strcmp(argv[1], "ABC")
>>           {/* equal code */}
>>      else
>>           {/* optional not equal code */}
>
> To be clear (since the OP may not be aware of it), strcmp() returns a
> value less than, equal to, or greater than 0 if the first argument is
> respectively than, equal to, or greater than the right argument.
>
> So (!strcmp(argv[1], "ABC") is true if the string pointed to by argv[1]
> is equal to "ABC".  If you treat the result of strcmp() as a boolean,
> it's true of the strings are unequal, false if they're equal.
>
> Personally, I prefer to be more explicit; I'd write:
>
>     if (strcmp(argv[1], "ABC") != 0) ...
>
> but you'll commonly see the !strcmp() form in C code.

Your preferred code does the opposite of the original code.
-- 
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Convert string to C expression syntax nilay <nilaybhatt@gmail.com> - 2013-07-30 21:58 -0500
  Re: Convert string to C expression syntax James Kuyper <jameskuyper@verizon.net> - 2013-07-31 21:22 -0500
  Re: Convert string to C expression syntax Barry Schwarz <schwarzb@dqel.com> - 2013-07-31 21:22 -0500
    Re: Convert string to C expression syntax Keith Thompson <kst-u@mib.org> - 2013-08-01 12:58 -0500
      Re: Convert string to C expression syntax Ike Naar <ike@ukato.freeshell.org> - 2013-08-01 21:05 -0500
        Re: Convert string to C expression syntax Keith Thompson <kst-u@mib.org> - 2013-08-02 18:34 -0500
  Re: Convert string to C expression syntax gordonb.uvkjx@burditt.org (Gordon Burditt) - 2013-07-31 21:22 -0500
  Re: Convert string to C expression syntax Roberto Waltman <usenet@rwaltman.com> - 2013-08-05 11:24 -0500
  Re: Convert string to C expression syntax malcolm.mclean5@btinternet.com - 2013-09-02 04:09 -0500
  Re: Convert string to C expression syntax "Paul D. DeRocco" <pderocco@ix.netcom.com> - 2013-09-06 23:25 -0500
    Re: Convert string to C expression syntax James Kuyper <jameskuyper@verizon.net> - 2013-09-11 17:27 -0500
      Re: Convert string to C expression syntax "Paul D. DeRocco" <pderocco@ix.netcom.com> - 2013-09-12 11:34 -0500
      Re: Convert string to C expression syntax Francis Glassborow <francis.glassborow@btinternet.com> - 2013-09-12 11:38 -0500
  Re: Convert string to C expression syntax Nitin Tripathi <2nitintr@gmail.com> - 2013-09-11 17:31 -0500

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