Lionel, > I'd like to make some kind of substitution like in a > shell, i.e. having: > "${tool} -o ${target} -L${libpath} -l${lib} ${source}" > > with an env like this: > env = { > "tool" => "gcc", > "target" => "hello.exe", > "libpath" => "/usr/lib", > "lib" => "somelib", > "source" => "hello.c" > } > > it should give: > "gcc -o hello.exe -L/usr/lib -lsomelib hello.c" If there any problem with simply: "#{env['tool']} -o #{env['target']} -L#{env['libpath']} -l#{env['lib']} #{env['source']}" I hope this helps. - Warren Brown