Linux umask command

Linux Command Encyclopedia

The Linux umask command specifies the default permission mask when creating files.

umask can be used to set the [permission mask]. The [permission mask] is composed of three octal digits. Subtracting the permission mask from the existing access permissions produces the default permissions when creating files.

Syntax

umask [-S][权限掩码]

Parameter description：

-S Displays the permission mask in text format.

Examples

Use the command "umask" to view the current permission mask, enter the following command:

$ umask                         #获取当前权限掩码 

After executing the above command, the output information is as follows:

0022

Next, use the command "mkdir" to create a directory, and use the command "ls" to get detailed information about that directory. Enter the following command:

$ mkdir test1                       #创建目录  
$ ls –d –l test1/                   #显示目录的详细信息  

After executing the above command, the detailed information of the newly created directory will be displayed, as follows:

drwxr-xr-x 2 rootlocal rootlocal 4096 2011-9-19 21:46 test1/ 

Note: In the output above, "drwxr-xr-x" = "777-022=755".

Linux Command Encyclopedia