Usage of linux UMASK

In linux, UMASK is generally used to grant permissions to a directory or file when you create a directory or file. Here we need to explain two points: 1. For the directory, the x permission indicates that the directory can be accessed, so there is no problem with the initial assignment of this permission; 2. the permissions on file x represent execution, which is too risky. Therefore, the initial permission assignment must be removed from the permissions on file x. www.2cto.com [root @ www ~] # What are the four letters of umask0022? First of all, the above four numbers indicate the permissions to be assigned for initialization and discard. (For the corresponding file, the x permission must be discarded by default even if it is not described as discarding.) The first 0 represents the suid permission to discard; the second 0 indicates that the owner of the current file/directory has not discarded any permissions (except for file x permissions ); the third 2 indicates that the user group of the current file/directory has discarded w permissions (if it is a file, its x permissions are also discarded ); the third 2 represents that other users in this file/directory can only use r and x (except for files ). According to www.2cto.com, If you create a new file, the permission is-wr-w -- that is: 644. If you create a new directory, the permission is: dwrxw-xw-x is: 755 if you want to modify the unask familiarity, go directly to [root @ www ~]. # Umask 002 understand it!