Linux root file system detailed

ELF: The storage format for executable files

Executable, can link the file

File system:

Rootfs: Root file system

LS/

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

Vmlinux-2.6.18-308.el5

Initrd-2.6.18-308.el5.img

/dev: Device file, yellow, note: All devices are recognized as files

Device files, only access to data on the device

Block devices: Random access, accessed by block of data

Character Devices: Linear access, sequential access, per-character access, keyboard, mouse, monitor

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

Symbolic Link File:

Dvd,→hdc

Cdrom,→hdc

Cdrom-hdc,→hdc

Cdrw,→hdc

Cdrw-hdc,→hdc

Cdwriter,→hdc

Cdwriter-hdc,→hdc

/etc: Configuration file, plain text

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

/root: Administrator's home directory

/lib: library files and kernel module files,

Note: library files cannot be executed separately, there is no access to the program portal, can only be called

Library: Encapsulated function, directly call can

/lib/modules: Kernel module files

Static Library:. A

Dynamic libraries:. dll,.so (Shared object) share objects

Example: Program A is used in shared library A, stored in memory, program B is used in shared library A, directly in memory to use. Shared library A uses only one footprint in memory, greatly saving memory space.

Static library: Included in program a

/lost+found: Storage host suddenly power off, there is no time to save the file

/media: mount point directory, mobile device, U disk, CD,

/MNT: mount point directory, additional temporary file system, hard disk

Mount: Linux, you need to associate a device with a node under the root file system

/misc: Miscellaneous

/opt:optional, optional directory, installation directory for third-party programs

/proc: Pseudo file system, kernel mapping file, kernel properties

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

Modify the disk schedule queue, I/O scheduling queue, etc.

/tmp: Temp file, green, right t

All users can create their own temporary files, can only delete their own temporary files

/var: a variable file

/var/tmp: Temp File

PID: Process ID Number

/bin:binary, binaries, executables, user commands, related to system startup

/sbin:super, managing commands, related to system startup

/usr:universal shared read-only, globally shared read-only files, read-only files,

/usr/bin:

/usr/sbin:

/usr/lib:

/usr/local: Third-party Software installation directory

/usr/local/bin:

/usr/local/sbin:

/usr/local/lib:

Naming rules:

1. Strictly case-sensitive;

2. The length cannot exceed 255 characters;

3. Cannot use/when file name

Relative path:

Absolute path:

File Management

Directory Management

Ls

Cd

Pwd

mkdir: Creating an empty Directory

Run the program

Device Management

Software Management

Process Management

Network management

Linux root file system detailed