Linux lsattr Command

The Linux lsattr command is used to display file attributes.

To change the attributes of a file or directory with chattr, you can use the lsattr command to query its attributes.

lsattr [-adlRvV][file or directory...]

Parameters:

-a 　Displays all files and directories, including those with names starting with ".", the current directory ".", and the parent directory "..".
-d 　Displays the directory name rather than its contents.
-l 　This parameter currently has no effect.
-R 　Recursively processes all files and subdirectories under the specified directory.
-v 　Displays the version of the file or directory.
-V 　Displays version information.

Use the chattr command to prevent a critical file in the system from being modified:
```
# chattr +i /etc/resolv.conf
```

Then, commands like mv /etc/resolv.conf will result in "Operation not permitted".

When editing the file with vim, it will prompt "W10: Warning: Changing a readonly file". To modify this file, the i attribute must be removed:

chattr -i /etc/resolv.conf

Use the lsattr command to display the file attributes:

# lsattr /etc/resolv.conf

The output will be:

----i-------- /etc/resolv.conf

Allow a file to only have data appended to it but not deleted, suitable for various log files:
```
# chattr +a /var/log/messages
```