下载apue.3e后进入make，提示错误如下：
collect2: error: ld returned exit status
Makefile:: recipe for target 'badexit2' failed
make[]: *** [badexit2] Error
make[]: Leaving directory '/home/pi/Downloads/apue.3e/threads'
Makefile:: recipe for target 'all' failed
make: *** [all] Error
需要安装库：
sudo apt-get install libbsd-dev
然后：
cp ./include/apue.h /usr/include/cp ./lib/error.c /usr/includecp ./lib/libapue.a /usr/local/lib/
在apue.h最后加一行代码
#include "error.c"