sudo apt-get install libbsd-dev
cd apue.3e
make
......
sudo cp ./include/apue.h /usr/include/
sudo cp ./lib/libapue.a /usr/local/lib/
cd apue.3e
make
......
sudo cp ./include/apue.h /usr/local/include/
sudo cp ./lib/libapue.a /usr/local/lib/
gcc filename.c -lapue