<--Directory--
1. Theoretical knowledge
2. User and User group management
3. Source Package Installation
"Theoretical Knowledge"
I. User account Management
Aaa
A:authentication Certification-who are you?
A:authorization Authorization--What can you do?
A:audit Audit-What did you do?
Two. User Account UID Range command View ID root
0->root
1-499 System Users
>=500-General User
Four. passwd file format
Root:x:0:0:root:/root:/bin/bash
1 2 3 4 5 6 7
1. Name of the user account
2. Password-word or placeholder
3. UID number of user account
4. GID number of the basic group to which it belongs
5. User's full name
6. Host Directory
7. The path of the login shell program
Five. Shadow file format
Root:$1$8c2tu7sa$bdkquifwsz9ktvttn/etb0:16274:0:99999:7:::
1 2 3 4 5 6 7 8 9
1. Name of the user account
2. Encrypted password string
3. Last time the password was changed (number of days from January 1, 1940 to the most recent password Change day)
4. Minimum effective days of password, default 0 (using how many geniuses may change the password, 0 means you can change the password at any time)
5. Maximum valid number of days for passwords, default 99999 (valid for password use)
6. Number of warning days before password expires, default 7
7. Disable this user account for the number of days after the password expires
8. Account expiration time, default value is empty
9. Reserved fields (not used)
commands for viewing user-related password information
19. Group Management
Etc/group basic information for saving group accounts
-one row per group record: Split into 4 fields
Field 1 name of the group account
Field 2 Password placeholder x
GID number for Field 3 group accounts
Field 4 Member Users list for this group
Etc/gshadow Storage Group account management information
Field 1: Name of the group account
Field 2: Cipher string for encryption number
Field 3: List of administrators for this group
Field 4: List of member users for this group
Mail_dir/var/spool/mail
Pass_max_days 99999//password Maximum usage time
Pass_min_days 0//Minimum Password usage time
Pass_min_len 5//Minimum length of password
Pass_warn_age 7 //Password warning time
Uid_min 500
Uid_max 60000
Gid_min 500
Gid_max 60000
Create_home Yes
UMASK 077
Usergroups_enab Yes
Md5_crypt_enab Yes
Encrypt_method MD5
/etc/skel//New account template file
~/.bash_profile//execute on every login
~/BASHRC//Execute every time you enter a new bash environment
Global
/etc/bashrc
/etc/profile
"User and user group management"
Three. When creating a user, these files are affected by default
/ETC/PASSWD: Store user-related information
/etc/shadow: Store password-related information
/etc/group: Storage group membership related information
/etc/gshadow: Storage group password-related information
Chage-l root view Tom user password modification time or grep Root/etc/shadow
Chage ABC to modify the security settings of ABC
Useradd command
-Format useradd [options] ... User name
Common Command Options
-U Specify UID tag number
-D Specify the host directory, default to/home/user name
-e Specify the expiry time of the account
-g Specifies the base group (group name or GID) that belongs to
-g Specifies the attached group (group name or GID) attached
-M does not establish and initialize the Ruthenica home directory for the user
-S Specify user's login shell
VI, create a user
Create User Alice,uidj is 800, home directory is/home/sum, except in his own primary group, also in the Jack Group (additional group)
He does not have a usable shell (unable to log into the system)
Useradd-u 800-d/home/sum-g jack-s/sbin/nologin Alice
Vim Etc/logon. Press Tab
Nine. Set the password
1. Only root users can set passwords for other users
2. Ordinary users can only change their own password, and before changing their own password, to enter the old password
passwd Chitian
-Format: passwd [options] ... User Name Change Password: (passwd user name)
Common Command Options
-D: Clear the user's password so that it can log in without a password
-S: Check the status of the user account (whether locked)
-L: Lock user account
-U: Unlock user account
echo Password | passwd--stdin User Name
echo 111 | passwd--stdin Tom
Cases
Lock the Jack User
Passwd-l Jack.
View user Status
Passwd-s Jack.
Unlock Users
Passwd-u Jack.
10. Change user Information
Format: usermod [options] ... User name
Common Command Options
-L Change the login name of the user account
-u-d-g-g-S is the same as Useradd
Cases
1. Change Jack's login name to Slina
Usermod-l Slina Jack
4. Change the user's login shell
Usermod-s/sbin/nologin Slina (no login allowed)
Usermod-s/bin/bash Slina (login allowed)
11. Delete a user
1. Simply delete the user, Tom
Userdel Tom---just remove the user, the user's home directory still exists
2. Delete the user Tom at the same time, put Bob's home directory also deleted
Userdel-r Tom
Afternoon
Chage-m 1 Tom//Set Tom User password minimum usage time 1 days
Note (see Time with Chage-l)
CHAGE-M Tom//Set Tom User password up to 90 days maximum usage time
15. Set Password Policy
Grep-ve "^#|^$"/etc/login.defs (see the lines in the Login.defs file that do not start with a # number and are not blank lines)
Vim/etc/login.defs
16. Set user password expires on January 1, 2014
CHAGE-E 2019-1-1 Tom
17. Chage Syntax Format
Administrative Tools Chage Command
-Format chage [options] User name
Common Command Options
-l list Password expiration information
-e Specify the account expiration time Yyyy-mm-dd
-i specifies how many days to lock after a password expires
-m specifies the minimum number of days for a password
-m Specifies the maximum number of days for a password
Chage User Name change password directly
Force user account expires chage-d 0 username
18. ID command
1. Use the ID command directly to view information that is the current user
2.id User Name--View information for a specified user//id spaces
Id-u Tom Tom's UID
G GID
What groups are the G root root, and what are the ID numbers for those groups?
What groups the Gn root belongs to and what the group name is
Create a group
GROUPADD-G-HR//create Group ID number 1000
grep hr/etc/group//view Group
grep Hr/etc/gshadow
Usermod-ag hr Tom//a represents append, G for additional group
Gpasswd-a Bob HR//Add user Bob to the HR group
ID Bob
Go to vim Etc/group to find the appropriate group modification
gpasswd-d Bob HR//Remove Bob from the HR group
ID Bob
Gpasswd-m Bob,alice,jerry HR//Add multiple users to the HR group at once
grep HR Etc/group
Gpasswd-a Bob HR//Set up an HR group Administrator is Bob
Grep/hr/etc/gshadow
Usermod (-l-u-d-g-g-s) Property modification
Chage (-l-i-m-m-e) Security modification
passwd (-l-u-s-d) User
GPASSWD (-a-a-m-d) group
GPASSWD Market//Change Password
grep maket/etc/gshadow//view password
Gpasswd-r Market//Delete password
Market a directory has access rights, Tom users do not belong to the market group, you can not access this directory.
Tom can temporarily change his membership to the market to access the directory,
The group password is used to temporarily change the membership of the group
Su-tom
ID-GN See which group Tom belongs to
NEWGRP market temporarily add your own to the market group, you need to know the market password
ID-GN See which group you belong to again
exit from Market Group
Id-gn
Groupdel Tom Delete a group
Groups Tom See what groups users are in
Last. Related commands
Su-tom Switch to Tom User
LS ~ Current User home Directory
Ls-a ~tom or ls-a/home/tom Tom for the username this two command meaning for the designated home directory
Chsh-l view with what SH Linux with bash
"Source Package Installation"
Vim hello.c
#include <stdio.h>
int main (VIOD)
{
printf ("Hello world\n");
}
GCC hello.c//Generate a file a.out
./a.out//Execution a.out
Two. Install the relevant compilation environment
Yum install-y gcc gcc-c++
Three. Installing the Apache Web server
Tar jxf httpd.xxx.tar.bz
CD httpd-x.xx
Vim Install//view installation files
./configure--prefix=/usr/local/apache//Specify the installation directory
Make
Make Istall
Four. Start the Web server
Cd/usr/local/apache/bin
./apachectl Start
Firefox &//Open Firefox input into address 127.0.0.1
Web server's Web hosting directory is/usr/local/apache/htdocs
/configure the problem, install Gcc,gcc-c++,openssl-devel.
This article is from the "Wsyht blog" blog, make sure to keep this source http://wsyht2015.blog.51cto.com/9014030/1790246
5. User and User group management