Need some help understanding the RPM spec bit operator

[Jeff Johnson]

On Aug 12, 2010, at 3:12 PM, Mitko Haralanov wrote:

> Hi all,
> 
> I am having some trouble understanding how the RPM spec bit operator
> seems to work. The documentation that I have been able to find confirms
> my understanding of it but, in practice, it doesn't work that way.
> 
> In my spec file, I define a variable like this:
> %{!?debug: %global debug 0}
> %if %{debug}
> %define __strip /bin/true
> %endif
> 
> Later on I use that same variable like this:
> ./configure --prefix=%{_prefix} %{?debug: --enable-debug}
> 
> The rpmbuild command line can be called with "--define 'debug 1'" when
> compiling with debugging enabled of without that "--define" when
> compiling without debugging.
> 
> However, no matter what the value of the %{debug} variable is,
> "--enable-debug" is present on the ./configure command line. Why is
> that? I thought that the bit operator tests not only whether a variable
> is defined but also whether it's value is 0 or 1?
> 

The %{?foo} is an existence, not a value test.

The %{!?foo} is just the negation of the existence test, i.e. TRUE if foo does not exist.

So you've always defined %{debug} but sometimes with value 0.

Hint:
%if 0%{?debug}
...
%endif

is one way to map the existence test back to a value test.

hth

73 de Jeff
> -- 
> Mitko Haralanov					 mitko at qlogic.com
> Senior Software Engineer			     650.934.8064
> NSG InfiniBand Engineering		    http://www.qlogic.com
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