Linux Privileges in depth introduction (to Be continued)

Rwxr-xr-x	Each of the three groups is a group of front (RWX) groups that represent the group (r-x) in the middle of the owner (user Group) (Group of user groups); the latter group (R-X) represents other groups (other)
WhoAmI	Show Current User
Useradd	option: -c comment specifies an annotated description. -d directory Specifies the home directory, and if this directory does not exist, use the-M option, You can create a home directory. -g user group specifies the user group to which the user belongs. -g user group, user group specifies the additional group to which the user belongs. -s shell file specifies the user's login shell. -u user number specifies the user's user number, and if the-o option is available, You can reuse the other user's identification number.
PASSWD	-l lock the password, that is, disable the account. -u password unlocked. -d make Account no password. -f force the user to change the password the next time they log on
groupadd	-g GID specifies a new group identification number for the user group. -o is used in conjunction with-G option, The new GID for the user group can be the same as the GID for the user group already in the system. -n new user Group change user group name to new name
linux Common file Permissions conclusion
File deletion principle and description	Delete the text actually delete the file name (the file name corresponding to the inode, such as the file name does not have the system mechanism to reclaim the inode, so that other new files can be used and its corresponding space)
Cat/etc/redhat-release	View system versions (version)

Linux Privileges in depth introduction (to Be continued)