shell脚本基础(六)

bash脚本编程之与用户交互

脚本参数：脚本传递数

用户交互：通过键盘输入数据，从而完成变量赋值操作

read变量赋值

[root@Centos-7-24 opt]# read name

tom

[root@Centos-7-24 opt]#  echo $name

tom

       -p prompt  给个提示符

[root@Centos-7-24 opt]# echo -n "Enter a username"; read name

Enter a username tom     

[root@Centos-7-24 opt]# echo $name

tom

[root@Centos-7-24 opt]# read -p "Enter a username:" name

Enter a username:tom

[root@Centos-7-24 opt]# echo $name

tom

       -t timeout 指定时间内未输入将超时退出，变量赋值为空

[root@Centos-7-24 opt]# [ -z "$name" ] && name="obama"   --变量name为空时赋值obama

[root@Centos-7-24 opt]# echo $name

tom

[root@Centos-7-24 opt]# read -t 5 -p "Enter a username:" name 5秒之后将超时

Enter a username:tom

[root@Centos-7-24 opt]# [ -z "$name" ] && name="obama"

[root@Centos-7-24 opt]# echo $name

tom

例：

#!/bin/bash

#

read -p "Enter a username:" name

[ -z $name ] && echo "a username is needed!!!" && exit 2

read -p "Enter a passwd for $name,[password]:" passwd

[ -z $passwd ] && passwd="password"

 

if

   id $name &>/dev/null

then

   echo "$name is exists!!!"

else

   useradd $name

   echo "$passwd" |passwd $name --stdin

   echo "Add user $name is finished."

fi

bash -n 检查脚本语法错误

bash -x 显示脚本执行过程中错误的地方