Linux Learning Notes < Two >--linux root file system and file directory management

Description of the directories in the file system:

/boot: System boot related files, such as kernel, INITRD, and Grub (bootloader)

/dev: Device files

Device files:

Block devices: Random access, data blocks, and so-called order, such as silver plate

Character Devices: Linear access, in characters, sequentially input/read one by one, such as keyboard, mouse, monitor

Device number: Main device number (major) and secondary device number (minor)

/etc: Configuration file

Home directory for users, the home directory of each user defaults to/home/username

/root: Administrator's home directory

/lib: library file, cannot be executed individually, smart is called

Static Library:. A is directly linked to the program and becomes part of the program by static compilation

Dynamic library:. So (Shared object) uses the time to load the dynamic library into memory for common use.

/lib/modules: Kernel module files

/media: mount point directory, mobile device, such as U-disk, CD-ROM, etc.

/MNT: mount point directory, additional temporary file system, such as a second hard drive

/OPT: The installation directory of third-party software, usually some optional software, all the data of the software is placed in this directory, to remove the software can be directly RM-RF

/PORC: Pseudo file system, kernel mapping file, kernel attribute function mapping, composing file

/sys: Pseudo file system, property mapping file related to hardware device

/tmp: Temp file,/var/tmp

/var: a variable file

/bin: Executable file, user command

/sbin: Managing Commands

/usr:universal shared Read-only System-level directory, equivalent to C:\windows in Windows

/usr/bin

/usr/sbin

/usr/lib

/usr/local: The installation directory of third-party software, usually some manually installed software, user-compiled software is automatically installed in this file system by default

/usr/local/bin

/usr/local/sbin

/usr/local/lib

File naming rules:

1. Length cannot exceed 255 characters
   

2. The file name cannot contain/characters

3. Strictly case-sensitive

Relative path: Find the path to a specific file as a starting point for your working directory

Absolute path: Find the path to the feature file from the root directory

Directory Management:

1. The previously mentioned LS CD pwd

2.mkdir: Create a new directory

-P: Overlay Create Directory

-v:verbose, displaying details after creating a directory

Pay special attention to the use of the {} symbol

MKDIR-PV/MNT/TEST/{X/A,B}

Created two directories for/mnt/test/x/a and/mnt/test/b

3.tree: Viewing the directory tree

Format: Tree Directory

4.rmdir: Delete Empty directory

-P (parents): Delete with parent directory, i.e. overlay Delete empty directory

5.install-d Directory: Creating directories

6.rm-r: Recursively Delete a directory

File Management:

1.touch: Create a file or change the timestamp of the file

-A: Modify access time

-M: Modify Modify Time

-T YYYYMMDDHHMMSS: Specify both access time and modify

-C: Do not create a new file

2.stat: View detailed information about a file or file system

Format: Stat file/directory

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3.file: View the encoding type of the file

Format: File files

Coding Standard: Ascii,gb18030,gbk,gb2312,unicode

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4.RM: Delete Files

-I: Display prompt information

-F: Forced deletion, different hints

-r: Recursively delete directory

To ensure that files are not deleted by mistake, the system has an RM alias of Rm-i

5.CP: Copying and moving files

Format: CP src dest

-R: Recursive replication, copy the contents of the source directory to the directory

-i:interactive, prompt before copying

-f:force, do not prompt when copying

-P: Preserve original properties for replication

-D: Copy the linked file, by default CP cannot copy the linked file directly

-A: Equivalent to-DRP, archive replication, often used for backup, does not change the properties of the file

CP Usage Rules:

When more than one parameter is present, the last parameter is dest, and the previous one is SRC

Directory must exist when dest is a directory

CP can only copy one file to a file

n Files +n directories to a directory

6.MV: Move files, can also be used to rename files and directories

Format: MV Src dest

-T dest SRC: For moving multiple source files into a directory

7.install: Copy files or set file permissions

-D directory: Creating directories

src dest: Copy files, permissions are modified by default to Rwxr-xr-x

-M xxxxxxxxx sre dest: Copy files and specify permissions for files

-T dest SRC: For copying multiple source files into a directory

Linux Learning Notes < Two >--linux root file system and file directory management