Change the UID in linux

Example of changing the UID application in linux: 1. Add newuser2 to the staff group # usermod-G staff newuser2. Change newuser's username to newuser1 # usermod-l newuser1 newuser 3. Lock account newuser1 # usermod-L newuser1 4 unlock newuser1 # usermod-U newuser1 function description: modify a user account. Syntax: usermod [-LU] [-c <>] [-d <>] [-e <>] [-f <>] [-g <>] [-G <>] [-l <>] [-s] [-u] [User Account] supplementary instructions: usermod can be used to modify user account settings. Parameter:-c <> modify the remarks of the user account. -D logon directory <modify the directory when the user logs in. -E <> modify the validity period of the account. -F <> If the password expires, the account is closed for several days. -G <> modify the group to which the user belongs. -G <> modify the additional group to which the user belongs. -L <> modify the account name. -L lock the user password to make it invalid. -S: Modify the shell used after user login. -U: Modify the user ID. -U unlocks the password.