======== User management ========
Add users: adduser or useeradd Command system will also create user main directories in / home directory at the same time: userDel [-r] -r parameter deletes the user, while deleting user home directories and main All files in the catalog. Password Modification: Passwd [username] If the username is empty, modify the current user account password to view the file content: Similar to the Type command under DOS Cat example: CAT / etc / passwd / etc / passwd file field Explanation: Record : Jear: x: 504: 504 :: / Home / Jear: / bin / bash From left to right, each field is used: Separate the username username Password password, encrypted password. If you appear as X, the password is stored in the / etc / shadow file, and the ID of the User ID user is made, and the UidGroup ID user group identification code is simply referred to as the gidcomment account. Command / etc / shadow files executed after the Command user log in can only be browsed by root.
