Rcpp First Compilation trouble

Rcpp First Compilation trouble

I recently downloaded the 2013 Rcpp book off amazon to learn how to use
C++ with my R code better and I'm trying the first compilation example
with the first fibonacci recursion function and wrapper to see if I can do
it. I'm on Ubuntu with the latest R.
First my C++:
/* Cpp based recurive function */
int fibonacci(const int x){
if(x == 0) return(0);
if(x == 1) return(1);
return(fibonacci(x - 1) + fibonacci(x - 2));
}
/* Wrapper */
extern "C" SEXP fibWrapper(SEXP xs) {
int x = Rcpp::as<int>(xs);
int fib = fibonacci(x);
return(Rcpp::wrap(fib));
}
Then I start sh and type in:
PKG_CXXFLAGS=`Rscript -e 'Rcpp:::CxxFlags()'`
PKG_LIBS=`Rscript -e 'Rcpp:::LdFlags()'`
R CMD SHLIB Fibonacci.cpp
But I get:
g++ -I/usr/share/R/include -DNDEBUG -fpic -O3 -pipe -g -c
Fibonacci.cpp -o Fibonacci.o
Fibbonacci.cpp:10:12: error: 'SEXP' does not name a type
make: *** [Fibonacci.o] Error 1
I figure maybe I need the include directive in my C++ code, so I do it
again, but this time with #include<Rcpp.h> at the top of the C++ file, and
do the same commands in sh again, but still no joy:
g++ -I/usr/share/R/include -DNDEBUG -fpic -O3 -pipe -g -c
Fibonacci.cpp -o Fibonacci.o
Fibonacci.cpp:1:18: fatal error: Rcpp.h: No such file or directory
compilation terminated.
make: *** [Fibbonacci.o] Error 1
What have I done wrong? If I query the values I've set in sh:
$PKG_CXXFLAGS
sh: 9: -I/local/yrq12edu/R/x86_64-pc-linux-gnu-library/3.0/Rcpp/include:
not found
$PKG_LIBS
sh: 10: -L/local/yrq12edu/R/x86_64-pc-linux-gnu-library/3.0/Rcpp/lib: not
found
But I think the not found messages are just because of the -L flag since
the files are there if I cd to the directory.
Thanks, Ben.