CentOS 7 Shell腳本編程第十講 read命令簡單介紹

本講內容主要講解read命令。經過學習咱們已經知道如何查詢Bash內置命令幫助。首先查看read命令幫助文檔。

[root@promote ~]# man read
[root@promote ~]# 
[root@promote ~]# info read | less
[root@promote ~]#

read 經常使用參數有-p 、-t、和-s。

下文代碼將分別演示簡單用法。

#-p 等待用戶輸入內容
[root@promote ~]# read -p "please input name: " name
please input name: www

#-t 設置等待時間，默認秒
[root@promote ~]# cat testreadv1.0.sh 
#!/bin/bash
if read -t 5 -p "please input name: " name
then
    echo "name is : $name"
else
    echo "input error..."
fi
exit 0
[root@promote ~]# cat testreadv1.0.sh 
#!/bin/bash
if read -t 5 -p "please input name: " name
then
    echo "name is : $name"
else
    echo -e "\ninput error..."
fi
exit 0
[root@promote ~]# bash testreadv1.0.sh 
please input name: www
name is : www
#第二次等待5秒未輸入內容
[root@promote ~]# bash testreadv1.0.sh 
please input name: www
input error...
#思考問題：如何清除錯誤輸出內容到下一行，本次操做實際輸入www未按回車鍵
[root@promote ~]# www


#-s 不前臺顯示輸入內容
[root@promote ~]# cat testreadv1.1.sh 
#!/bin/bash
read  -s  -p "please input password:" passwd
echo -e "\npassword is :$passwd"
exit 0
[root@promote ~]# 
[root@promote ~]# bash testreadv1.1.sh 
please input password:
 password is :www
[root@promote ~]#