2016-1-29 Linux Basic Learning 1

linux Basic principles:
1. A small program consisting of a single purpose, combined with a small program to complete complex tasks
2. All documents
3. Avoid capturing user interfaces as much as possible
4. The configuration file is saved in plain text format

GUI interface
CLI interface:
     Command prompt: prompt, bash (shell)
         #:root
        $: normal user
     command:
Command format:
     Command    options     parameters
            Options: (Modify command execution mode)
         Short options:-< br>              Multiple options can be combined:-a -b -c-ab
         Long options:--word
           Parameters: Object of command
          
Password:
1, use 4 kinds characters wrongly written characters of at least 3 kinds of
2, long enough, greater than 7 bits
3, use random string
4, Periodic replacement
5, cycle period large enough            
Passwad: Change Password

prompt, command prompt [[email protected]~]#
Command:
Magic Number: Magic Numbers (special characters, such as "! ”：#！ /bin/bash).

Common Commands 1

Ls
/: Root, view a few file directories
-L: Long format
File type: the
-: Normal file (f)
D: Catalog file
B: Block devices (blocks)
C: Character device file (character)
L: Symbol device files (symbolic link file)
P: Command pipe file (pipe)
S: Socket file (socket)
File permissions: 9-bit, per three-bit set
Each group: rwx (Read, Write, execute) (for example: rw-means can read, can write, cannot be executed)
Number of hard links to files
The owner of the file (ower)
Genus Group of files
File size (size), in bytes
Timestamp (timestamp): The last time the file was modified
Access: Access
Modified: Modify file content changed
Change: Change,metadata metadata, file attributes changed

-H: Do unit conversions
-A: Show hidden files starting with.
. Represents the current directory
.. Represents the parent directory
-A also shows hidden files (but does not contain. and. File

-D: Display the directory's own properties
-I: Displays the index node number of the file (Inode:index node)
-R: Show files in reverse order
-R: Recursive display

Cd:change Directory
CD/A directory, you can switch to that directory
CD does not add any directory, back to home directory (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

This article is from the "11160930" blog, please be sure to keep this source http://11170930.blog.51cto.com/11160930/1739698

2016-1-29 Linux Basic Learning 1