Generate zlib library on Ubuntu

1. download zlib source from http://zlib.net/

2. tar zxf zlib-1.2.7.tar.gz

3. cd zlib-1.2.7

4. ./configure

5. make

6. Generate library:

libz.a

libz.so
libz.so.1
libz.so.1.2.7

7. Copy the above 4 libraries to /usr/lib

8. export $PATH=$PATH:/zlib-1.2.7