echo命令你真的会用了么？

echo命令你真的会用了么？

1. 简单使用

• 输出后接字符串
• 输出变量值

3. 常遇问题

• echo 一个变量之后，失去了换行符。
  解决办法： 将 echo $var 替换成 echo "$var" 接口
  示例如下：

[root@server4 shells]# cat log.txt 
2 this is a test
3 Are you like awk
This's a test
10 There are orange,apple,mongo
[root@server4 shells]# res=`cat log.txt`
[root@server4 shells]# echo $res
2 this is a test 3 Are you like awk This's a test 10 There are orange,apple,mongo
[root@server4 shells]# echo "$res"
2 this is a test
3 Are you like awk
This's a test
10 There are orange,apple,mongo