First, the user of the user group
[root@localhost ~]# ll /usr/sbin/user* -rwxr-x--- 1 root root 74544 2009-11-27 /usr/sbin/useradd -rwxr-x--- 1 root root 53676 2009-11-27 /usr/sbin/userdel -rws--x--x 1 root root 32780 2008-09-09 /usr/sbin/userhelper -rwsr-xr-x 1 root root 6728 2009-06-09 /usr/sbin/userisdnctl -rwxr-x--- 1 root root 74480 2009-11-27 /usr/sbin/usermod -rwsr-xr-x 1 root root 6820 2009-07-13 /usr/sbin/usernetctl [root@localhost ~]# ll /usr/sbin/group* -rwxr-x--- 1 root root 39120 2009-11-27 /usr/sbin/groupadd -rwxr-x--- 1 root root 30568 2009-11-27 /usr/sbin/groupdel -rwxr-x--- 1 root root 30256 2009-11-27 /usr/sbin/groupmod [root@localhost ~]#
1, adding users
[root@localhost ~]# useradd xiaodi [root@localhost ~]# id xiaodi uid=609(xiaodi) gid=611(xiaodi) groups=611(xiaodi) context=root:system_r:unconfined_t:SystemLow-SystemHigh [root@localhost ~]#
Create a regular user xiaodi, create the default user group xiaodi name, and set the main user group xiaodi, and create / home / xiaodi
2, delete users
[root@localhost home]# userdel xiaodi
[root@localhost home]# id xiaodi
id: xiaodi：无此用户
[root@localhost home]# cat /etc/passwd | grep xiaodi
[root@localhost home]# cat /etc/group | grep xiaodi
[root@localhost home]#
The group only because xiaodi xiaodi user, when the user deletes the group will check on his own, will be automatically deleted
3, re-create the user: xiaodi
[root @ localhost Home] # useradd Xiaodi Creating Mailbox File: file already exists useradd: Warning: This home directory already exists. Do not copy any files to it from skel directory. [Home the root @ localhost] # Xiaodi ID UID = 609 (Xiaodi) GID = 611 (Xiaodi) Groups = 611 (Xiaodi) = the root context: system_r: unconfined_t: SystemLow- SystemHigh [Home the root @ localhost] #
4, the analog switch user lost pattern
When the user login, style becomes -bash-4.2 $, you need to execute the command, copying the style format: cp /etc/skel/.* / home / xiaodi
5, to add a group to another user xiaodi bigdata
[root@localhost ~]# groupadd bigdata [root@localhost ~]# cat /etc/group |grep bigdata bigdata:x:612: [root@localhost ~]# usermod -a -G bigdata xiaodi [root@localhost ~]# id xiaodi uid=609(xiaodi) gid=611(xiaodi) groups=611(xiaodi),612(bigdata) context=root:system_r:unconfined_t:SystemLow-SystemHigh [root@localhost ~]#
6, the main modifications to bigdata group of xiaodi
[root@localhost ~]# usermod -a -G bigdata xiaodi [root@localhost ~]# id xiaodi uid=609(xiaodi) gid=611(xiaodi) groups=611(xiaodi),612(bigdata) context=root:system_r:unconfined_t:SystemLow-SystemHigh [root@localhost ~]# usermod --gid bigdata xiaodi [root@localhost ~]# id xiaodi uid=609(xiaodi) gid=612(bigdata) groups=612(bigdata) context=root:system_r:unconfined_t:SystemLow-SystemHigh [root@localhost ~]# usermod -a -G xiaodi xiaodi [root@localhost ~]# id xiaodi uid=609(xiaodi) gid=612(bigdata) groups=612(bigdata),611(xiaodi) context=root:system_r:unconfined_t:SystemLow-SystemHigh [root@localhost ~]#
7, set a password
[root@localhost ~]# passwd xiaodi Changing password for user xiaodi. New UNIX password: BAD PASSWORD: it is too simplistic/systematic Retype new UNIX password: passwd: all authentication tokens updated successfully. [root@localhost ~]#
8, the user switches
[root@localhost ~]# su - xiaodi
[xiaodi@localhost ~]$
Xiaodi su
su - Xiaodi
on behalf of switching the user's home directory, and the execution environment variable file
. Bash_profile file su xiaodi not be executed, su - xiaodi perform
.bashrc file su xiaodi execution, su - xiaodi perform
9, the average user to obtain maximum root privileges
vi /etc/sudoers
xiaodi ALL=(root) NOPASSWD:ALL
Two, sudo command
For ordinary users sometimes encounter: "ls: can not open directory:. Permission denied" question authority, indicating that the average user is currently running instruction root super administrator privileges, if for the average user, non to run this command, you can add keywords to sudo in front of the instruction.
Third, the user can not log passwd file
Fourth, the permissions rwx ------ chmod chown Case
Error: Permission denied
· Chmod -R 777 folder / file path
· chown -R User: a user group folder / file path
Permissions for the file or folder identification purposes: D represents Folder - l represents the file represented connector
as: rwx rx rx
R & lt: Read. 4
W: Write 2
X: execution. 1
: - no authority 0
7=rwx
3=wx
5=rx
The first group of users rwx 7 represents the root of the file or folder, performing read and write
the user set the root rx 5 represents a second group of files or folders, the read execution
rx 5 represents a third set of other groups of users belong to the file or folder permissions: read execution
d rwx r-x r-x 2 root root 6 Nov 16 22:15 xiaodi
chmod -R 777 folder / file path
chown -R user: a user group folder / file path
777 represents any of the users in the group have execute permissions to read and write
Example:
[root@localhost ~]# cd /tmp/ [root@localhost tmp]# ll 总计 108 drwx------ 3 linux linux 4096 11-10 22:04 gconfd-linux drwx------ 2 linux linux 4096 10-16 06:12 keyring-auFdRo drwx------ 2 linux linux 4096 10-16 06:01 keyring-AY1zU5 drwx------ 2 linux linux 4096 11-10 22:04 keyring-d9Zc9n drwx------ 2 linux linux 4096 11-01 05:06 keyring-Gg6isH drwx------ 2 linux linux 4096 10-23 00:45 keyring-GJV1cR drwx------ 2 linux linux 4096 10-15 21:34 keyring-O34ivV drwx------ 2 linux linux 4096 10-25 20:03 keyring-x5O2gc srwxrwxr-x 1 linux linux 0 11-10 22:04 mapping-linux drwx------ 2 linux linux 4096 11-22 00:22 orbit-linux -rw-rw-r-- 1 linux linux 5 11-22 01:22 scim-bridge-0.3.0.lockfile-500@localhost:0.0 srwxrwxr-x 1 linux linux 0 11-22 00:22 scim-bridge-0.3.0.socket-500@localhost:0.0 srw------- 1 linux linux 0 11-10 22:04 scim-helper-manager-socket-linux srw------- 1 linux linux 0 11-10 22:04 scim-panel-socket:0-linux srw------- 1 linux linux 0 11-10 22:04 scim-socket-frontend-linux drwx------ 2 linux linux 4096 11-10 22:04 ssh-uUAfXg5534 [root@localhost tmp]# echo "https://www.cnblogs.com/Raodi" >> rz.log [root@localhost tmp]# ll |grep rz -rw-r--r-- 1 root root 30 11-22 01:59 rz.log [root@localhost tmp]# su - xiaodi [xiaodi@localhost ~]$ cd /t tftpboot/ tmp/ [xiaodi@localhost ~]$ cd /tmp/ [xiaodi@localhost tmp]$ ll |grep rz -rw-r--r-- 1 root root 30 11-22 01:59 rz.log [xiaodi@localhost tmp]$ vi rz.log https://www.cnblogs.com/Raodi a ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ [xiaodi@localhost tmp]$ ll -a 总计 176 drwxrwxrwt 15 root root 4096 11-22 02:01 . drwxr-xr-x 24 root root 4096 11-10 22:04 .. drwxrwxrwt 2 root root 4096 11-10 22:04 .font-unix drwx------ 3 linux linux 4096 11-10 22:04 gconfd-linux -rw------- 1 linux linux 66 11-22 00:25 .gdmD7A9A0 srw-rw-rw- 1 root root 0 11-10 22:04 .gdm_socket drwxrwxrwt 2 root root 4096 11-10 22:04 .ICE-unix drwx------ 2 linux linux 4096 10-16 06:12 keyring-auFdRo drwx------ 2 linux linux 4096 10-16 06:01 keyring-AY1zU5 drwx------ 2 linux linux 4096 11-10 22:04 keyring-d9Zc9n drwx------ 2 linux linux 4096 11-01 05:06 keyring-Gg6isH drwx------ 2 linux linux 4096 10-23 00:45 keyring-GJV1cR drwx------ 2 linux linux 4096 10-15 21:34 keyring-O34ivV drwx------ 2 linux linux 4096 10-25 20:03 keyring-x5O2gc srwxrwxr-x 1 linux linux 0 11-10 22:04 mapping-linux drwx------ 2 linux linux 4096 11-22 00:22 orbit-linux -rw-r--r-- 1 root root 30 11-22 01:59 rz.log -rw-rw-r-- 1 linux linux 5 11-22 01:22 scim-bridge-0.3.0.lockfile-500@localhost:0.0 srwxrwxr-x 1 linux linux 0 11-22 00:22 scim-bridge-0.3.0.socket-500@localhost:0.0 srw------- 1 linux linux 0 11-10 22:04 scim-helper-manager-socket-linux srw------- 1 linux linux 0 11-10 22:04 scim-panel-socket:0-linux srw------- 1 linux linux 0 11-10 22:04 scim-socket-frontend-linux drwx------ 2 linux linux 4096 11-10 22:04 ssh-uUAfXg5534 -r--r--r-- 1 root root 11 11-10 22:04 .X0-lock drwxrwxrwt 2 root root 4096 11-10 22:04 .X11-unix [xiaodi@localhost tmp]$ su - 口令： [root@localhost ~]# cd /tmp/ [root@localhost tmp]# ll |grep rz -rw-r--r-- 1 root root 30 11-22 01:59 rz.log [root@localhost tmp]# chmod 646 rz.log [root@localhost tmp]# ll |grep rz -rw-r--rw- 1 root root 30 11-22 01:59 rz.log [root@localhost tmp]# chmod 644 rz.log [root@localhost tmp]# usermod -a -G root xiaodi [root@localhost tmp]# ll |grep rz -rw-r--r-- 1 root root 30 11-22 01:59 rz.log [root@localhost tmp]# chmod 664 rz.log [root@localhost tmp]# ll |grep rz -rw-rw-r-- 1 root root 30 11-22 01:59 rz.log [root@localhost tmp]# usermod -a -G root xiaodi [root@localhost tmp]# ll |grep rz -rw-rw-r-- 1 root root 30 11-22 01:59 rz.log [root@localhost tmp]# su - xiaodi [xiaodi@localhost ~]$ cd /tmp/ [xiaodi@localhost tmp]$ ll |grep rz -rw-rw-r-- 1 root root 30 11-22 01:59 rz.log [xiaodi@localhost tmp]$ echo "sads">>rz.log [xiaodi@localhost tmp]$ cat rz.log https://www.cnblogs.com/Raodi sads [xiaodi@localhost tmp]$
ctrl + x / z will produce swp ll -a file can be deleted .rz.log.swp
Five other command
1, view the file size
[xiaodi@localhost tmp]$ ll |grep rz -rw-rw-r-- 1 root root 35 11-22 02:05 rz.log [xiaodi@localhost tmp]$ du -sh rz.log 8.0K rz.log [xiaodi@localhost tmp]$
2, View Folder Size
[root@localhost ~]# cd /tmp/ [root@localhost tmp]# ll |grep rz.log -rw-rw-r-- 1 root root 35 11-22 02:05 rz.log [root@localhost tmp]# mkdir bs [root@localhost tmp]# mv rz.log bs/ [root@localhost tmp]# du -sh bs/ 16K bs/ [root@localhost tmp]#
3. Search find
history history
ps -ef see the process
top system case
[root@localhost tmp]# cd /usr/local/ [root@localhost local]# mkdir xxxhadoopxxx [root@localhost local]# mkdir hadoop [root@localhost local]# find / -name '*hadoop*' /usr/local/xxxhadoopxxx /usr/local/hadoop find: /proc/fs/vmblock/mountPoint: 没有那个文件或目录 [root@localhost local]# find /usr/local -name '*hadoop*' /usr/local/xxxhadoopxxx /usr/local/hadoop [root@localhost local]#
* Represents the fuzzy matches