Re: %if

["Jeff Johnson" <n3npq jbj gmail com>]

On 12/16/06, Marcus Habermehl (BMH1980) <bmh1980de yahoo de> wrote:
> And this is the code from my /etc/rpm/macros file.
>
> %ifdef %{prefix}
>     %_prefix            %{prefix}
> %else
>     %_prefix            /usr
> %endif

If in /etc/rpm/macros, existence tests are tricky, recursion on macros
needs to be avoided.

Your example looks like
    %_prefix  %{?prefix}%{!?prefix:/usr}
in /etc/rpm/macros.

In a spec file, the above would look like
   %define _prefix  %{?prefix}%{!?prefix:/usr}
of (arguably more readable but using %if)

   %if %{?prefix:1}0
       %define _prefix            %{prefix}
   %else
       %define _prefix            /usr
   %endif

Note that %prefix is set as a side effect of Prefix: parsing, just
like Name: sets %name, Version sets %version, etc, etc.

73 de Jeff