Tee command usage example

tee​ ​ command ​​ Used to read standard input data , Output content to screen , At the same time save it as a file , And can be saved to multiple files .

How to use tee

​​tee​​​ The most basic usage is to display the output and save the content to a file . The following example uses ​​free​​​ ​ command ​​​ Display system memory usage information , And use ​​tee​​ The command outputs information to the screen , And save to file mem.txt in .

Log in and copy

       

        [[email protected] ~]# free -h | tee mem.txt
        
              total        used        free      shared  buff/cache   available
        
Mem:           1.8G        164M        1.2G        9.6M        387M        1.5G
        
Swap:          2.0G          0B        2.0G
       
       

        
1.
        
2.
        
3.
        
4.
       

You can have a look mem.txt file , You can see that the output has been saved to mem.txt Inside the .

Write to multiple files

​​tee​​ Multiple files can be written , Separate each file with a space .

Log in and copy

       

        [[email protected] ~]# free -h | tee mem1.txt mem2.txt mem3.txt
        
              total        used        free      shared  buff/cache   available
        
Mem:           1.8G        165M        1.2G        9.6M        389M        1.5G
        
Swap:          2.0G          0B        2.0G
       
       

        
1.
        
2.
        
3.
        
4.
       

Add content at the bottom of the existing file

The following example uses options ​​-a​​ Add content at the bottom of the file , Don't cover the original content .

Log in and copy

       

        [[email protected] ~]# free -h | tee -a mem.txt
        
              total        used        free      shared  buff/cache   available
        
Mem:           1.8G        165M        1.2G        9.6M        389M        1.5G
        
Swap:          2.0G          0B        2.0G
       
       

        
1.
        
2.
        
3.
        
4.
       

You can see , stay mem.txt New content is added at the bottom of the file .

If you don't want to output on the screen , have access to ​​>​​​ Standard output symbol , Redirect to ​​/dev/null​​ in ：

Log in and copy

       

        [[email protected] ~]# free -h | tee -a mem.txt > /dev/null
       
       

        
1.
       

summary

tee Command is used to read standard input data , Output content to screen , At the same time save it as a file , And can be saved to multiple files .