Linux Basic content

In Linux, there are three basic file types:

1) Common documents

Normal files are data streams in bytes, including text files, source files, executable files, and so on. There is no difference between text and binary for Linux, and the interpretation of ordinary files is done by the application that handles the file.

2) Catalogue

Directories can contain normal files and special files, and directories are equivalent to folders in Windows and Mac OS.

3) device files

Some of the tutorials called special files are a meaning. Linux and external devices (such as optical drives, printers, terminals, modern, etc.) are communicated through a file called a device file. The way the Linux input and output to an external device is the same as the input and output to a file. Before Linux communicates with an external device, the device must first have a device file present.

For example, each terminal has its own device files for Linux to write data (appearing on the terminal screen) and read data (the user enters through the keyboard).

by Ls-l The files listed, each line begins with a, d,-or L, which represent the file type:

prefix	Description
-	Normal file. such as text files, binary executables, source code, and so on.
B	Block device files. The hard disk can use block device files.
C	Character device files. The hard disk can also use character device files.
D	Catalog files. Directories can contain files and other directories.
L	Symbolic links (soft links). You can link any normal file, similar to a shortcut in Windows.
P	Named pipes. Pipelines are a communication mechanism between processes.
S	A socket for interprocess communication.

Metacharacters is a character that has a special meaning. and? are meta characters:

• * can match 0 or more of any character;
• ? Match one character

For example:

$ls Ch*.doc

You can display all files that begin with CH and end with. Doc.

Cat View Content Command View file contents $ cat filename;

WC Statistics Content command statistics file characters and other information $WC filename;

• First column: Total number of rows in a file
• Second column: number of words
• Column three: The number of bytes in a file, that is, the size of the file
• Fourth column: File name

cp Copy File command $CP source_file destination_file;

mv Rename file command $mv old_file new_file;

mkdir Create directory command: $mkdir dirname

Point number (.)

A point number (.) Represents the current directory, two point numbers (..) Represents an ancestor directory (parent directory).

Linux Basic content