linux判斷root使用者

linux判斷root使用者 linux 中，如何判斷目前使用者是否是root  呢？ 判斷目前使用者是否是root   www.2cto.com  Shell代碼  Java代碼  #---------------------------- root user check ---------------------start       if [ `id -u` -ne 0 ]; then          echo "Please re-run ${this_file} as root."          exit 1       fi       #---------------------------- root user check ---------------------end          if [ x"$USER" = x"" ];then          if  id |grep "^uid=0(root)">/dev/null ;then              :           else              echo "Please rerun `basename $0` as root ."              exit 1           fi       else          if [ ! x"$USER" = x"root" ];then              echo "Please rerun `basename $0` as root ."              exit 1           fi       fi               #=============== check current user start ================       if [ ! $USER = root  ];then          echo "Please rerun this script as root ."          exit 1       fi       #=============== check current user end ================               #!/bin/sh       if  id |grep "^uid=0(root)">/dev/null ;then          echo is  root       else          echo not  root       fi                check_user(){           if [ $UID -ne 0 ];then              echo "Current user is not ROOT."              echo "Please rerun the installer as Root user."              exit 11           fi       }