Linux operating system and common commands 1

Windows:

Dll:dynamic link library, dynamic link libraries

Linux:

. so:shared object, shared objects

Operating system:

Kernel: Kernel:

1. Process Management

2. Kernel Management

Library: Libraries, APIs

Shell: human-computer interface

Login

User name: User ID

Authentication mechanism: password, fingerprint, face recognition technology, Iris,

Authorized:

Audit:

Command:

Magic Numbers: Magic number, shebang, execution format

Ls:list, list, listing files/directories under the specified path

Blue indicates directory, green indicates execute permission

Directories: Files, path mappings

Path:

Absolute path:

Relative path:

Pwd:print working directory, print working directory

/: Top-level directory, root directory

Ls:

-L, long format, display file attributes: Total 10 bits

The 1th bit indicates the file type:

-: Normal file (f)

D: Catalog file

B: Block device files (blocks)

C: Character device file (character)

L: Symbolic Link files (symbolic link file)

P: Named pipe file (pipe)

S: Socket file (socket)

File permissions: 9-bit, every 3-bit group, each group: rwx (Read, write, execute)

Number of hard links to files

Owner of the file

Genus Group of files

File size (size), default unit is byte

Timestamp (timestamp): Last Modified Time

Time Visited: Access

Time Modified: Modify, File content changed

Changed time: change, filename, etc.

Meta Data: Attribute data for a file, metadata

Filename

-H: Do unit conversions

-a:all, hide the file with "." Beginning

. Represents the current directory

.. Indicates a parent directory

-A: Displays all files, not including "." and ".."

-D: Display the directory's own properties

-i:inode,index node, index node, display the index number of the file

-R: Show files in reverse order

-R: Recursive display, recursive, including displaying files in subdirectories

Cd:change Directory

~: Back to home directory

CD ~username: Enter the home directory of the specified user

CD-: Switch back and forth between the current directory and the previous directory

Command type:

Built-in command (shell built-in): Shell builtin

External command: There is an executable file corresponding to the command name in a path on the file system

Type: Shows which type the specified command belongs to

Environment variables: named memory space

PRINTENV: Print Environment variables

Path: Paths separated by colons

Hash: Hashes, key-value pairs, command cache paths

O (1)

Linux operating system and common commands 1