Advantages and disadvantages of 1.Linux:
Advantages:
A stable system
Free or little fee
Security, quick fixes for vulnerabilities
Multi-tasking, multi-user
Planning for users and users
Relatively non-resource-intensive systems
Suitable for embedded systems that require small cores
Integrated and versatile graphical user interface
Disadvantages:
Vendors with no specific support
Lack of game support
Lack of support for software
Lack of support for professional software
2. system catalog Files
/: root directory, containing all directory files for the entire Linux system
/boot: Store the files needed to start the Linux system, including kernel files, image files, boot menu configuration files
/deb: Storage of the Linux system of hard disk, keyboard, mouse, CD-ROM and other equipment files
/root: The host directory of the system administrator, which is the home directory of the root account
/bin: The most basic user command for placing the operating system
/sbin: The most basic command in Linux system, the general administrator user can have permission to execute.
/etc: A configuration file that stores Linux systems and various programs.
/var: some files, such as System log files, that often need to change in the storage system
/home: The default host directory for all ordinary users (family directory)
/lib: Save some shared library of functions.
/usr: contains many subdirectories to hold system commands and program information
/tmp: Store Some temporary files that are used during the operation of the system.
3. Some basic commands
echo $LANG See which languages are currently supported
Lang=en_us setting the currently supported languages
Date Displays dates
commands for displaying calendars: cal
Cal specified year//display calendar for the whole year
Cal Month Year
Use a simple calculator:
Using the BC command
+ Addition
-Subtraction
* Multiplication
/divisible
^ Index
% remainder
Quit command, leave calculator
10/100 How is 0, the integer used here is rounded. This is the default for the BC output integer only, if you want to output all decimals, then you have to execute scale=number, that number is the digits after the decimal point, for example;
The above reserved is 3 decimal places.
4. Basic Hotkey
The TAB key has the function of command completion, which prevents us from hitting the wrong command or file name.
CA [Tab][tab]
The commands at the beginning of all the CAs above are displayed, so what happens if you enter Ls-al ~/.bash with two tabs?
Filenames that begin with. Bash will be displayed in the directory below.
Summarize:
tab is appended to the first command of a sequence of commands, then "command completion";
tab is appended to the second command of a sequence of commands, then "file replenishment";
5.ctrl +c button, if you enter the wrong command or parameter under Linux, sometimes this command or program will run continuously under the system, this time can use CTRL + C, end the run, let the current program stop. Note, however, that this key combination can interrupt a running command, and if you are working on a more important command, don't rush to use this key combination.
6.ctrl+d, this key combination represents the end of the keyboard input (end of the file or end of input) meaning, but also can be used to replace the input of exit, such as directly from the text interface, you can directly use this key combination, equivalent to exit.
7. When command not found appears, it may be caused by the following:
This command does not exist, because the software is not installed, the solution is to install the software;
This command is in the same directory as the current user does not add it to the command search path, you can add the command to the path;
The order was wrong.
8.man PGE Online Help documentation
Man Date
After entering the man command, you can press the SPACEBAR to page down, you can press the Q button to leave the man's environment.
You see no in date (1), different numbers have different meanings:
1: Commands or executable files that the user can manipulate in the shell environment
2: System kernel callable function tool, etc.
3: Some common function functions and library function libraries, most of which are C library
4: Description of the device file, usually files in/dev
5: Configuration file or format of some files
6: Game Games
7: Conventions and protocols, such as Linux file system, network protocol, ASCII code and other instructions
8: Commands available to system administrators
9: Documents related to Kernel
One of the more important is 1,5,8
You can use a space to page down in the man page, or you can use page up or page down to page through. If you want to know some keywords, you can enter/word at any time to proactively find keywords. For example, enter/date to find all occurrences of the date. Home key to go to the first page,? String up query string string
9.info page, you can use the Man command in a Unix like system, but Linux provides an additional way of online query, that is, using the info command, some keys are used in the info page.
Page DOWN PAGE Down
Page UP pages up
tab moves between nodes, where nodes are usually displayed as "*"
Enter when the cursor is above the node, press ENTER to enter the node
B move the cursor to the first node of the info interface
E move the cursor to the last node in the info interface
N go to the next node
P go to the previous node
U Move up one layer
S (/) query in Infopage
H Display Help Menu
? Order List
Q end of this info page
The info page is a product that only exists on Linux, and is much more readable.
10. Other useful files can be viewed in the/usr/share/doc directory
11 Ultra-Simple text editor Nano
With the Nano file name, you can open a file or create a file for write operations.
Use of some key combinations in the Nano
Ctrl +g, get online Help
Ctrl+x leave the Namo software, if you modify the file will indicate whether you need to save
Ctrl+o Save the file, if you have permission, you can save the file
Ctrl+r read data from other files, you can paste the contents of a file into this file
Ctrl+w query string
CTRL + C explains the number of rows and columns at the current cursor location
Ctrl+_ can enter line numbers directly, allowing the cursor to move quickly to a row
Alt+y correction grammar function on or off (click on, click Off)
Alt+m can support the mouse to move the cursor function.
11. View the status of the system using the WHO command, if you want to view the network connection status, you can execute netstat-a this command
12. Synchronize data to a command on the hard disk: Sync
13. The usual shutdown command Shutdow need to be executed in root account, otherwise you need to enter the password
-T sec:-t after seconds, that is, after a few seconds the meaning of shutdown
-K: Don't really shut down, just send a warning message out
-R: Shut down immediately after the system service is stopped
-N: Shut down directly with shutdown function without the INIT program
-F: A disk check that forces a bypass of fsck after shutting down and powering on
-F: Force a magnetic check of fsck after system restart
-C: Cancels the contents of the Shutdow command already in progress
/sbin/shutdown-h ' I'll shutdown after mins ' tells you that this machine will shut down in 10 minutes and will be displayed in front of the current login screen.
Shutdown-h now shuts down immediately, where it is equivalent to the 0 state of time
Shutdown-h 20:25 system in today's 20:25 minutes shutdown, if you do this command 21:25, the next day shutdown
Shutdown-h 10 system automatically shuts down after 10 minutes
Shutdown-r now system restarts immediately
Shutdown-r +30 ' The system will reboot ' in another 30 minutes, and the following message is displayed to all online users
Shutdown-k now ' This system will reboot ' sends only the parameters of the warning letter, which does not shut down the computer
14. Restart, shutdown: Reboot,halt,poweroff
Reboot restart
Shutdown can be shut down after each service has been shut down according to the service that is currently started.
Halt can not ignore the current system conditions, the hardware shutdown of the special function.
Inti 0 can also be shut down
All right, this is the study summary, and then we'll take some notes later.
This article original, reprint please indicate from: http://blog.csdn.net/j903829182/article/details/39826855
Linux Learning One