Linux operating foundation and concept

Linux operating foundation and concept

The concept of the terminal

Usually we use Linux, not dealing directly with the system, but through an intermediate program called Shell to complete, in order to achieve graphical interface allows us to complete user input and display output in a window, Linux system also provides program (terminal) of a called terminal emulator. For example: terminator

Installation Terminal Layout: sudo apt-get install terminator shortcut: ctrl + alt + t open terminal

Shell

1, the difference is not usually bring different releases of the above-mentioned various terminal emulator on actual experience in a graphical interface, but this Shell (Shell). There are shells there, nuclear here refers to the UNIX / Linux kernel, Shell refers to the software (command parser) "available to users interface", similar to the command under DOS (command line) and later cmd. exe. Shell ordinary sense of the program is acceptable user input commands. The reason it is called Shell because it hides the details of the underlying operating system. KDE and GNOME graphical user interface under the same UNIX / Linux, sometimes called "virtual shell" or "graphical shell".

2, Shell is both user interaction interface under UNIX / Linux operating system, but also the control system of the scripting language. Of course this is also under the command of Windows is different from the line, although the command line also provides a very simple control statements. In the Windows operating system, some users never directly use Shell, but in the UNIX family of operating systems, Shell still control system startup, X11 and many other utilities to start the script interpreter.

3, in UNIX / Linux more popular common Shell have bash, sh, zsh, ksh, csh, etc., Ubuntu terminal used by default is bash, the default desktop environment is GNOME or Unity (GNOME-based)

Command-line operating experience

Input: Input of course, is to open the terminal, and then press the keyboard, and press Enter, the input format is a kind of general

Output: Output will return results you want, for example, you want to see what files, it will return the contents of the file. If only perform, fail to perform will tell you where wrong, if you do not succeed then the output will be, because linux philosophy is: no result is the best result

1) Important shortcuts:

Use the Tab key to a portion of the command completion, the Tab key is usually next to the letters Q, this technique to bring you the greatest benefit is that when you forget the full name of a command can be entered only its beginning and press Tab key you can get tips or help complete

Ctrl + c forcibly terminate the current program example: find /

Ctrl + d terminal keyboard input or exit end

Ctrl + z into the current program running in the background, back to the front desk for the command fg

Ctrl + a cursor to the first input line, the Home key corresponding to

Ctrl + e move the cursor to an input end of a line, corresponding to the End key

Ctrl + k Delete from the cursor position to the end of the line

Ait + Backspace delete one word forward

Shift + PgUp the terminal display scrolls up

Shift + PgOn terminal displays scroll down

2) learn to use the input command history

Direction on the keyboard keys ↑, restore command you entered before, you try a glance.

3) learn to use wildcards

Wildcards are a special statement, mainly with an asterisk (*) and question mark (?) For the string fuzzy matching (such as file name, parameter name). When looking for a folder, you can use it to replace one or more real characters; when the characters do not really know or do not bother to enter the full name, often using wildcards instead of one or more real characters.

4) learn to get help from the command line

In a Linux environment, if you encounter difficulties, you can use the man command, which is an abbreviation of Manual pages. Manual pages is a UNIX or UNIX-like operating system online software documentation prevalent form, including computer programs (including libraries and system calls), official standards and practices, and even abstract concepts. Users can call manual page by executing man command. Details You can use the following commands way to get a description and usage patterns: Format: man  <command_name> example: man man

Normally, man manual contents inside are in English, which requires that you have some basic English. Many man pages of content, involving all aspects of the use of Linux in the process. For ease of reference, man is subjected to a manual Volume (segmented) process, manual normally is divided into eight segments, as follows:

1. General Command

2. System Calls

3. The library functions, covering the C standard library

4. special file (usually in / dev device) and the driver

5. File Formats and Conventions

6. games and screensavers

7. Miscellaneous

8. The system commands and daemons

NAME (name) the name of the command or function, followed by a line introduction.

SYNOPSIS (summary) command for formal description of how it works, and what kind of command-line parameters required. For functions, the desired functions described parameters, and which header file contains definitions of the function.

DESCRIPTION (Description) Text command or function functions described.

EXAMPLESIf (Example) Some examples of commonly used.

(See) a list of related commands or functions SEE ALSO.