MacOS –安装不带xcode的命令行工具
如果要（需要）在MacOS中安装命令行工具，并且不想安装完整的xCode：
1–启动终端
2–运行以下命令
xcode-select --install
安装将位于/Library/Developer/CommandLineTools/中，并将具有以下工具：
ar as asa bison BuildStrings c++ c89 c99 cc clang clang++ cmpdylib codesign_allocate CpMac cpp ctags ctf_insert DeRez dsymutil dwarfdump dyldinfo flex flex++ g++ gatherheaderdoc gcc gcov GetFileInfo git git-cvsserver git-receive-pack git-shell git-upload-archive git-upload-pack gm4 gnumake gperf hdxml2manxml headerdoc2html indent install_name_tool ld lex libtool lipo lldb lorder m4 make MergePef mig mkdep MvMac nasm ndisasm nm nmedit otool pagestuff projectInfo ranlib rebase redo_prebinding ResMerger resolveLinks Rez RezDet RezWack rpcgen segedit SetFile size SplitForks strings strip svn svnadmin svndumpfilter svnlook svnrdump svnserve svnsync svnversion unifdef unifdefall UnRezWack unwinddump what xml2man yacc