Introduction and calculation of Umask value in VSFTPD

Add the Local_umask and Anon_umask values in the previous article. In a Linux system, when we create the default permissions for files. How do I change this default permission? There are local_umask items in the VSFTPD configuration: local_umask=022 First, we need to figure out what Umask is. When we create a file, we always have a default permission, so how does this permission come from? That's what Umask did. Umask set the user to create the default permissions of the file, it and chmod effect just the opposite, Umask set is the permission "complement", and chmod set is the file permission code. Umask values are generally set in/etc/profile, $ [Home]/.bash_profile, or $[home]/.profile. How to calculate the Umask value. The Umask command allows you to set the default mode at the time the file was created, and there is a number in the corresponding Umask value for each type of user (file owner, same group user, other user). For a file, the maximum value for this number is 6. The system does not allow you to give permission to execute a text file when it is created, and you must use the chmod command to add this permission after creation. The directory allows you to set execution permissions so that the number of umask can be up to 7 for the directory. The general form of the command is: Umask nnn where nnn is Umask 000–777. We just have to remember that Umask is "taking" the appropriate bits from the right. The table below is a comparison of the umask values and permissions: Umask file directory —————————— —— 0 6 7 1 6 6 2 4 5 3 4 4 4 2 3 5 2 2 6 0,------—————————— —— Linux file system: R:4 ( Read) W:2 (write) x:1 (execute) such as: Umask value is 022, the default directory permissions are 755, the default file permissions are 644. Multi-point Example: If the configured Umask value is 000, the default directory permissions are 777, and the default file permissions are 666 if the configured umask value is 047, the default directory permissions are 730, and the default file permissions are 620 is it very simple? This article in Sina Blog address is: http:/ /blog.sina.com.cn/s/blog_49fd52cf0100nekk.html