User management is done under the root user 1, the configuration file path: Save user information files:/etc/passwd Save password file:/etc/shadow Save user Group files:/etc/group Save User group password file:/etc/gshadow user profile:/ETC/DEFAULT/USERADD2, viewing user information: cat/etc/passwd[[email protected] hjp]# cat /etc/passwdroot:x:0:0:root:/root:/bin/bashbin:x:1:1:bin:/bin:/sbin/nologindaemon:x : 2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologinlp:x:4:7:lp:/var/spool/lpd:/sbin/ nologinsync:x:5:0:sync:/sbin:/bin/syncshutdown:x:6:0:shutdown:/sbin:/sbin/shutdownhalt:x:7:0:halt:/sbin:/sbin/ HALTMAIL:X:8:12:MAIL:/VAR/SPOOL/MAIL:/SBIN/NOLOGINOPERATOR:X:11:0:OPERATOR:/ROOT:/SBIN/NOLOGINGAMES:X:12:100: games:/usr/games:/sbin/nologinftp:x:14:50:ftp user:/var/ftp:/sbin/nologinnobody:x:99:99:nobody:/:/sbin/ NOLOGINAVAHI-AUTOIPD:X:170:170:AVAHI IPV4LL STACK:/VAR/LIB/AVAHI-AUTOIPD:/SBIN/NOLOGINDBUS:X:81:81: System message bus:/:/sbin/nologinpolkitd:x:999:998:user for polkitd:/:/sbin/nologintss:x : 59:59:ACCOUNT USED BY THE TROUSERS PACKAGE TO SANDBOX THE TCSD daemon:/dev/null:/sbin/nologinavahi:x:70:70:avahi mdns/dns-sd stack:/var/run/avahi-daemon:/ Sbin/nologinpostfix:x:89:89::/var/spool/postfix:/sbin/nologinchrony:x:998:997::/var/lib/chrony:/sbin/nologinsshd:x:74:74:privilege-separated ssh:/var/empty/sshd:/sbin/nologinhjp:x:1000:1000:hjp:/home/hjp:/bin/bash last user Hjp,id starting from 1000, analyzing hjp:x : 1000:1000:hjp:/home/hjp:/bin/bash separated by colon, Hjp: username x: Password placeholder 1000: User id &NB Sp 1000: User group id HJP: Description information for users &N Bsp /HOME/HJP: Home directory &N Bsp /bin/bash:shell, which exists for the purpose of protecting the operating system, exists on the kernel, provides an instruction interface for users to interact with the system, and bash can be compatible with Linux and Unix3, Useradd TestUser Add user testuser, use cat/etc/passwd to view one more user testuser TESTUSER:X:1001:1001: :/home/testuser:/bin/bash4, passwd testuser Add/Modify TESTuser Password 5, userdel testuser Delete user testuser (and do not delete the user home directory, switch to the home folder, ll command can view) 6, Userdel-r testuser Delete User testuser and its home directory 7, usermod-l testuser1 testuser Modify testuser user's login name is TESTUSER1,CAT/ETC/PASSWD View user information for testuser1:x:1001:1001::/home/testuser:/bin/bash (just change the user name) changed the username and changed the password by passwd TestUser1 8, modify the new user TestUser1 home directory (1), Root user Create folder under Home directory TestUser1 mkdir testuser1 (2), change TestUser1 folder belongs to user and user group chown Testuser1:testuser TestUser1 (there are no newly created user groups, so the previous user groups are used) (3), Edit Modify user Information TestUser1 the user points to the home directory  VI/ETC/PASSWD Enter Modify the user to point to the home directory as TestUser1 (in general mode, I means inserting after the cursor, shift+ ZZ Save and exit shortcut keys) (4), copy testuser folder under Config file (hidden file) to TestUser1  CD testuser Enter, ll-a enter, CP. Bash_profile. BASHRC. /testuser1 Enter (copy only these two profiles), switch to TestUser1 folder view (5), modify the TestUser1 folder under the configuration fileUsers and user groups  LL-A view configuration files, Chown testuser1:testuser. bash* Enter, ll-a view file information changed (TestUser folder and its sub-files can be deleted) (6), exit the current user, test login can 9, usermod-g Testuserg testuser Modify testuser users belong to the user group TESTUSERG10, usermod-g Testuserg,root testuser Modify testuser user belongs to Testuserg and root two user groups groups Directive View Group 11, usermod-d/home/ TestUser1 testuser Modify testuser User home directory is under the Home Folder TestUser1 folder (this folder should have a configuration file, log on to normal) (through 8 and 9 see some changes can be modified by the command) 12 , Groupadd TESTG Add user group TESTG13, Groupdel testg Delete user group TESTG14, groupmod directives for modifying user groups
User management of Linux learning
