From:	kagel AT quasar DOT bloomberg DOT com
Date:	Tue, 22 Oct 1996 10:39:01 -0400
Message-Id:	<9610221439.AA04555@quasar.bloomberg.com >
To:	R DOT G DOT Morgan AT ncl DOT ac DOT uk
Cc:	djgpp AT delorie DOT com
In-Reply-To:	<54fgop$eoe@whitbeck.ncl.ac.uk> (R.G.Morgan@ncl.ac.uk)
Subject:	Re: Laugh at my mistakes (Errors you wish you're mother told you about)
Reply-To:	kagel AT dg1 DOT bloomberg DOT com

   Errors-To: postmaster AT bloomberg DOT com
   From: "R.G. Morgan" <R DOT G DOT Morgan AT ncl DOT ac DOT uk>
   Newsgroups: comp.os.msdos.djgpp
   Date: 21 Oct 1996 09:46:01 GMT
   Organization: University of Newcastle upon Tyne
   Lines: 32
   Distribution: world
   Nntp-Posting-Host: glen7.ncl.ac.uk
   Dj-Gateway: from newsgroup comp.os.msdos.djgpp
   Content-Type: text
   Content-Length: 897



     I've been programming C for a little while now,  and have more or less completed
   my first non-trivial program.  During this process I tore out (metaphorically)
   much hair due to these mistakes:

      1)   int i;
	   for (i = 0; i < SOME_NUMBER; i++);
	     {
		....
	     }

     I wonder why that loop only executes once?

      2) 	FILE *fp;   /* far, far away */
	   ...
	   fflush(NULL);

     intended to flush all streams, an uninitialised FILE pointer causes a SYSSEG
   on execution.

      3)	#include <somefile.c>

     Of course I meant .h,  but with hundreds of "previously defined" errors spraying
   out of gcc, this took some time to spot.

     In all these cases the compiler (rightly) generated no warning.  My question
   is,  does anyone else know of any similar mistakes I might make so that I 
   recognise them when the errors start to flow ?

OH tons!

How about:
	i=3;
	if (i = 0)
	   ...
	else
	   printf("Why doesn't this ever execute?\n");

Or:

	done=0;
	while(done=0) {
	  if (!read(.....))
	    done = 1;
	  ....
	  printf( "When will it ever end?  Done = %d.\n", done );
        }
	printf( "Never gets here!\n");

Just for starters.  Welcome to 'C'.  Have fun!

-- 
Art S. Kagel, kagel AT quasar DOT bloomberg DOT com

A proverb is no proverb to you 'till life has illustrated it.  -- John Keats

- Raw text -