Linux file permissions

The core of Linux security system is the user account, each person who accesses the Linux system should have the assigned, unique user account,

/ETC/PASSWD contains several information related to Linux users;; As follows:

User name: User password: uid:gid: Comment field: Home directory: default shell;;

Observing the/etc/passwd file we found that the account password is x, not that all account passwords are the same (x), but that they all use a shadow file to store the password information in their location/etc/shadow;

Useradd is a way to add new users; which Useradd//view its location, and properties

　　　　

Userdel by default, only the information in the/etc/passwd is deleted, and the files that the user owns in the system are not deleted;

The-r parameter deletes the user's home home directory and mail directory;

To modify your account information:

Usermod Edit user account information

passwd Modifying an existing user password

CHPASSWD Batch modification user password;;

Linux file permissions