The chattr and lsattr of basic Linux commands

The 1.chattr command is used to change file properties:

chattr command:chattr [ -rvv ] [ mode ]  Files ... The [mode] section is composed of +-= and [Asacddiijsttu] characters, which are used to control the properties of the file. -R: Recursive processing, all files and subdirectories under the instruction directory are processed together with the; -v< version number;: Sets the file or directory version;  -v: Displays the instruction execution process; +< properties;: Opens the file or directory for that property; <: Close the Item property of the file or directory;=< property;: Specifies the property of the file or directory. S: HDD I/O sync option, similar to sync. A: Append, after setting this parameter, can only add data to the file, not delete, more for the server log file security, only root can set this property. C: Compresse, set whether the file is compressed and then stored. An automatic decompression operation is required for reading. D: No dump, the setting file cannot be the backup target of the dump program. I: The settings file cannot be deleted, renamed, linked, and cannot be written or added. The I parameter is a great help for file   system security settings. J: Journal, this parameter is set so that when the file system is:data=ordered  by the mount parameter or  data=writeback  hung   loaded, the file will be recorded first (in Journal )。 If the filesystem parameter is set to  data=journal, the parameter is automatically invalidated. S: Delete files or directories confidentially, that is, the hard disk space is fully recovered. U: In contrast to S, when set to U, the data content actually exists in the disk and can be used for undeletion. A and I are commonly used in the various parameter options. The A option enforces that only non-removable, multi-log system security settings can be added. While I is a more stringent security setting, only superuser  (root)   or a process with cap_linux_immutable processing power (identity) can apply this option. 

Chattr +i/etc/fstab #不能改动chattr +a/var/log/messages #让某个文件只能往里面追加数据, but cannot be deleted, applicable to various log files

2.lsattr command to view hidden properties of a file

lsattr [-RVADV] [files ...]  # rmdir hahah/rmdir:failed to remove ' hahah/': Operation not permitted# lsattr-d hahah/#进行查看----i----------- hahah/

This article is from the "Hello World" blog, so be sure to keep this source http://nxyboy.blog.51cto.com/10511646/1937491

Chattr and lsattr of basic Linux commands