# # Chapter XIII centos # ## 1.centos installation and describes three ways to install the centos: - installed directly on the machine - dual system - installed linux on windows by virtualization software virtualization software: - VMware - VBox - mac bridge: gets the ip address of the same network segment with your windows machine net: do not get with the windows Kiki same network segment ip address requirements in the company centos password settings: - 12 and above - must contain uppercase purple, lowercase letters, numbers, special characters - three months or six months to replace weak passwords: passwords are easy to guess the linux user - root user - super administrator - has permission to fully operate the system - misuse of the system damage infinity - Do not use the root login -Common User - operating authority of the system is small - the damage is limited - requires ordinary user login terminal: - graphic terminal - virtual terminal F1- + Alt + Ctrl F6 - physical terminal - Equipment Terminal - serial terminal - pseudo-terminal - TTY See terminal remote connection tool - Xshell - PuTTY - SecureCRT interactive Interface: after starting the terminal, opened on a terminal device interfaces - the GUI graphics interface - the CLI - the shell - PowerShell the shell: a linux interface is used on the system, is used to user input is sent to the operating system to perform and put out the resulting output view supported by the system CAT shell / etc /shells switch the chsh shell - S shell view the current running echo $ SHELL shell # ## 2. command to view the ip address `` `Python ifconfig to view ip address ip addr ip A ` `` command prompt: `` `Python [root @ localhost ~] # # - super administrator $ normal user [user @ hostname directory] command prompt adjustment [root @ localhost ~] # font color permanent echo ' PS1 = "\ [\ E [1; 30; 35m \] [\ @ U \ H \ W is] \\ $ \ [\ E [0m \] " ' >> /etc/profile.d/ ps.sh ` `` Run directly enter commands after finishing - internal commands - after the installation, the system comes with command, is the internal command - to get help through the internal command list - external command - provided by third parties, in some places you can find the executable file directly - `` `Python of the type command to view the type of path which find command ` `` # ### 2.1 alias alias `` `Python a; oas listed directly in the system all the aliases alias cdetc = ' cd / etc ' set an alias unalias cdetc cancel alias # make permanent command # user user [root @ localhost ~] # echo" alias = cdetc 'cd / etc' ">> .bashrc # for all users take effect echo " Alias cdetc = 'cd / etc' " >>/ etc / bashrc `` ` execute the original command itself -" LS " - \ LS - ' LS ' difference between single and double quotation marks - "" You can print variable values directly - '' quotes what to write on what print date of the command `` `Python [root @ localhost ~] # date Mon CST 29 12:18:14 2019 Jul- [the root @ localhost ~] # DATE + F.% 2019-07-29 [the root @ localhost ~] # DATE +% H (24 hour) 12 is [the root @ localhost ~] # DATE +% I (12 hour) 12 is [the root @ localhost ~] # DATE Y +% . 19 [root@localhost ~]#date +%m 07 [root@localhost ~]#date +%d 29 [root@localhost ~]#date +%M 22 [root@localhost ~]#date +%S 25 [root@localhost ~]#date +%a Mon [root@localhost ~]#date +%A Monday [root@localhost ~]#date +%T 12:23:31 [root@localhost ~]#date +%y-%m-%d 19-07-29 [root@localhost ~]#%% Y-M- date +% D 2019-07-29 UNIX year [the root @ localhost ~] # date + time stamp% S 1,564,374,331 [the root @ localhost ~] # how many weeks of date +% W year 30 `` ` set the time zone: ` `` Python [root @ localhost ~] # timedatectl [root @ localhost ~] # timedatectl the sET-timeZone Asia / on Shanghai `` ` calendar ` `` Python CAL display the current month calendar CAL - the y-show year calendar CAL -y # display # calendar-year `` ` shutdown restart ` `` Python the shutdown default is off one minute after the shutdown -c cancel the shutdown - r restart the shutdown - now immediately reboot reboot reboot - the p-power off the init 6 reboot init 0 shutdown poweroff shutdown `` ` format of the command ` `` Python the Command [Options] [args ..] Options: Start or disable a these features short options: - a long option: - All parameters: the role of command, in general, is a directory, users, etc. Note: need separated by a space between multiple options and parameters and commands Ctrl + c to cancel the command performing a; plurality of spaced commands simultaneously performed using the \ terms of multi-line switching command to `