Zhangminghui-linux Common Catalogue-1

"The command is not for remembering, practice!" Practice! Practice! The more you practice, the more it becomes your instinct to react.

/ETC/PASSWD store the relevant properties for each user

Add User

[email protected]/]# useradd XWJ

To set a password for a XWJ user

1, [[email protected] ~]# passwd XWJ

2, [[email protected] ~]# echo "xwj123456" |passwd--stdin XWJ

Switch to normal user

[email protected] ~]# SU-XWJ

[Email protected] ~]$ tail-1/etc/passwd

User: Password: User id: Group ID: Description: Home directory: Login Shell

Note Switch User: Su-user name

The difference between Su and Su-:

The former only switches the root identity, but the shell environment is still a normal user's shell, and the user and the shell environment to switch to root identity. After the SU switch to the root user, PWD, found that the working directory is still the normal user's working directory;

With the Su-command switch, the working directory becomes the working directory of root. You should use the Su-command.

/etc/shells viewing the system's available shells

/etc/selinux/config SELinux configuration file

Beginners should turn off selinux to interfere with the learning environment, not easy to troubleshoot problems

Ways to turn off SELINUX: replace selinux=enforcing with selinux=disabled

Replace with SED

[Email protected] ~]# sed-i "S#selinux=enforcing#selinux=disabled#g"/etc/selinux/config

Method One: see if the parameters are modified

[Email protected] ~]# Cat/etc/selinux/config

Method Two:

[[email protected] ~]# grep "selinux=disabled"/etc/selinux/config

Using grep to filter out the desired result line, the file has changed

Precautions:

1. To back up the files before modifying them

2, sed first without parameter I, to see if it is the result of their own

3, plus parameter-I, to achieve the modification of the file

Change the profile to take effect only when the system or service is started, and use the command to close SELinuximmediately

View the status of SELinux

[Email protected] ~]# Getenforce

Setting The status of SELinux

[Email protected] ~]# Setenforce 0

/etc/inittab Linux system operating level

# 0-halt (do not set Initdefault to this) shutdown

# 1-single User mode single users (password loss can be used)

# 2-multiuser, without NFS (the same as 3, if you don't have networking) multiuser, no Network file system

# 3-full Multiuser mode complete multi-user model

# 4-unused reserved runlevel

# 5-x11 Desktop

# 6-reboot (do not set Initdefault to this) reboot

1, 3, 5 commonly used

Set the run level of a file

Shutdown

Shutdown-h now

Halt

Init 0

Restart

Reboot

Shutdown-r

Init 6

"Linux commands to be remembered in use"

Zhangminghui-linux Common Catalogue-1