Install google test in my ubuntu 12.04

At first, I installed gtest by command:  sudo apt-get install libgtest-dev  .
Everything seemed well.
But when doing a test for my example.cpp by gtest, I got tons of error:
             undefined reference to `testing::internal: XXXX'
I guessed that I should give some arguments to g++ like -Ldir  -ldir.
But failure still occurs.

Noticed that all errors were linker error.
So I check if there were sth wrong with the libs and headers of gtest.
I went to check the .h in the /usr/include, everything still looked right.
But I found nothing about libgtest in /usr/lib,   /lib and /usr/local/lib.

Tthe following site told me why no lib were installed in my machine.
         http://askubuntu.com/questions/145887
And the comprehensive explanation could be found in google test FAQ.
         http://code.google.com/p/googletest/wiki/FAQ
         Why is it not recommended to install a pre-compiled copy of Google test? 

So I had two choices:
Build a static lib from the souce file by myself.
Or compile Google test together with your project.

To build the static lib:
cd /tmp 
mkdir .build 
cd .build 
sudo cmake -DCMAKE_BUILD_TYPE=RELEASE /usr/src/gtest/ 
sudo make 
sudo mv libg* /usr/lib/

After building, libgtest.a and libgtest_main.a had been in /usr/lib.
Tried compiling my test.cpp by command "g++ test.cpp -lgtest" again.
Errors still occurred but they were new types of errors .
        undefined reference to `pthread_XXXX`

Changed the compilation command to "g++ test.cpp -lgtest -lpthread" and
Succeeded!!!


But still I don't know how to use gtest without the pre-compiled lib.


reference:
http://www.thebigblob.com/getting-started-with-google-test-on-ubuntu/
http://askubuntu.com/questions/145887
http://code.google.com/p/googletest/wiki/FAQ