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From: wayne@ultra.com (Wayne Hathaway)
Newsgroups: comp.lang.c
Subject: Re: #define DEBUG... (using printf for debugging)
Summary: careful of them if/else matchings!
Message-ID: <1990May4.212815.11565@ultra.com>
Date: 4 May 90 21:28:15 GMT
References: <11290@hoptoad.uucp> <40628@cornell.UUCP> <7377@crdgw1.crd.ge.com> <1990May4.161910.1353@cs.columbia.edu>
Reply-To: wayne@ultra.com (Wayne Hathaway)
Distribution: usa
Organization: Ultra Network Technologies
Lines: 36

travis@cs.columbia.edu (Travis Lee Winfrey) suggests:

  # ifdef DEBUG
  #       define dprintf(dlevel,printfargs)  if (dlevel <= DEBUG ) \
                                                  printf printfargs  
  # else /* DEBUG */
  #       define dprintf(a,b)
  # endif /* DEBUG */

A good idea, and one which I also use (slightly more generalized, of
course; I just can't resist getting too damn fancy for my own good!).


I do have one nit, though:  I would suggest defining "dprintf" as:

    define dprintf(dlevel,printfargs)  if (dlevel > DEBUG) ; \
                                       else printf printfargs

Why?  Consider the following:

        if ( <some_strange_situation> )
            dprintf(1, ("oh no! just had some strange situation\n"));
        else
            <regular_processing>;


You see, I just HATE programs that stop working when you turn on the
DEBUG flag!  :-)

wayne

  Wayne Hathaway            
  Ultra Network Technologies     domain: wayne@Ultra.COM
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