LINUX shell 脚本攻略

       好吧，我们还是看书吧....

       echo Hello world ! 等价于 echo 'Hello world !' 但是不等价于echo "Hello world !"(!放在双引号里边的时候需要转义\)

       简单的判断例子

       

#!/bin/bash
if [ $UID ne 0 ];then
 echo Non root user.Please run as root.
else
 echo "Root user"
fi

      ....

      休息一会继续

       继续

#!/bin/bash
start=$(data +%s)
commands;
statements;
end=$(data +%s)
differenc=$((end - start))
echo Time taken to execute commands is $difference seconds.