From: Rob Biedenharn <Rob@...>
Date: 2009-09-03T01:30:48+09:00
Subject: Re: regex issue confusing


On Sep 2, 2009, at 10:50 AM, Brian Candler wrote:

> You may find \b useful: it means "match a word boundary" without
> actually consuming any characters. Your example starts with \s (match
> one space), so it wouldn't match #include right at the beginning of  
> the
> file.
>
> But if I remember my C right, the #include has to be at the start of a
> line anyway. So perhaps you want:
>
>>> line = "#include <stdio.h>"
> => "#include <stdio.h>"
>>> line[/^\s*#include\s*["<]([^">]+)/, 1]
> => "stdio.h"
>
> HTH,
>
> Brian.
> -- 


And if you are trying to examine/process C code (and headers), the #  
must be at the start of the line, but the preprocessor keyword can be  
separated from the # by optional white space. For example:

#ifndef MAXCHAR			/* bytes to try to read in at once */
# ifdef i386
#  define MAXCHAR 65536		/* might be too big for some systems/devices */
# else
#  define MAXCHAR 32768
# endif
#endif


-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com