参考1:http://www.mkyong.com/mac/how-to-install-gcc-compiler-on-mac-os-x/
参考2:http://blog.licess.org/how-to-install-command-line-tools-in-osx-10-9-mavericks/
1.安装命令:xcode-select --install
chendeiMac:~ chendaer$ xcode-select --install
2.安装完成:gcc -v 命令查看gcc的版本
chendeiMac:~ chendaer$ gcc -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix
chendeiMac:~ chendaer$