First Login System
The CentOS default image interface is GNOME.
Linux by default will provide 6 terminal to allow users to log in, the switch mode is CTRL+ALT+[F1-F6], the system will be named the six operating interface Tty1-tty6.
You can use the ' startx ' command in the terminal interface if you want to start the window interface.
executing commands in command-line mode Start execution Command
Command format: [-options] Parameter1 parameter2 ...
operation of the underlying command
Display date and time: Date
Show Calendar: Cal
Display calculator: BC
Important Hotkeys
TAB key
With command completion and file complement function.
Command completion: such as input: CA [tab] [tab], will be all the instructions to start with the CA display, as follows;
[[Email protected] ~]# CA [tab] [Tab]cacertdir_rehash CA-legacy Captoinfocache_check Calibrate_ppa Caribou-preferencescache_dump caller caseCache_metadata_ Size Canberra-boot catcache_repair Canberra-gtk-play Catchsegvcache_restore Cancel Catmancairo-sphinx cancel.cups Cal Capsh ~]# CA
File completion: For example input: Ls-al ~/.bash [tab] [tab], as follows:
ls -al ~/. Bash [tab] [Tab].bash_history . Bash_logout . Bash_profile . BASHRC LS -al ~/.bash
CTRL + C keys
Stops the current program.
online Help for man page and info page Mans Page
Input: Man date, shown as follows:
DATE (1) User Commands DATE (1) NAMEDate-Print or set the systemDateand TimeSynopsisDate[OPTION] ... [+FORMAT]Date[-u|--utc|--Universal] [MMDDHHMM[[CC]YY][.SS]] DESCRIPTION Display The current Time inchThe given FORMAT, or set the systemDate. Mandatory arguments toLongOptions are mandatory for Shortoptions too. -D,--Date=STRING Display TimeDescribed by STRING, not' Now'-F,--file=Datefile like--DateOnce forEach line of Datefile-i[timespec],--iso-8601[=Timespec] OutputDate/ Time inchIso8601Format. Timespec='Date' for Date...... Omitted after
The 1 in DATE (1) represents a command that can be used by a general user. Several commonly used numbers are as follows:
1: Commands or executables that a user can manipulate in a shell environment
5: Configuration file or format of some files
8: Administrative commands available to system administrators
After entering the command information page, you can do something with the following keys:
Space: down one page
Page DOWN: Flip one page
Page UP: Turn up one page
Home: Back to the first page
End: Back to the last page
/string: Find string down
? String: Find string up
N,n: Using the above two lookup string directives, you can use N to continue with the next query, N to continue with the previous query.
Q: End this man page.
Info Page
Similar to the use of the man instruction, the display method is different.
the correct method of shutting down the machine You can check the computer status before shutting down the machine
Who: View current online users
Netstat-a: Online Status of the network
Ps-aux: Viewing programs executed in the background
notifies the user of the shutdown time
Shutdown command
data synchronously written to disk: Sync
To speed up data reading, a lot of data is placed in memory and should be synchronized to disk before shutting down to perform sync instructions. The Shutdown/reboot/halt command performs a call to sync before shutting down the machine.
Customary shutdown command: shutdown
Restart, shutdown: Reboot,halt,poweroff
Toggle Execution Level: init
0: Turn off the machine
3: pure command line mode
5: Graphical interface mode included
6: Restart
5th first login and online Help man page