Linux - Tree structure of files

They need your help

06:48 spyware treat (Viruses/security)
06:30 Install Web cam w/o cd (Hardware)
06:25 copy the files in the same format. (Windows)
06:22 data recovery (Hardware)
05:04 Use cells in different files IN excell (Office software)
19/08 test drive unlimed running error (Video games)

UNIX

Introduction to UNIX files

In UNIX systems any element is represented in the form of a file. All files are architectured around a single tree structure where the base, called the root, is written "/".

File types

UNIX systems define different file types:

Physical files, entered on the hard disk. This is a file in the generally understood sense of the word;
Directories are files (nodes) of the tree structure able to contain files or other directories. A directory contains at least a parent directory (written ..), relating to the directory at the higher level, and a current directory (written .), i.e. itself;
Links are special files enabling several names (links) to be associated to a single and same file. This system makes it possible to have several instances of the same file in several places in the tree structure without needing to copy it, which in particular helps to ensure maximum coherence and save on disk space. There are two types of links:
- Symbolic links representing virtual pointers (shortcuts) to the real files. In the event that a symbolic link is deleted, the file which it points to is not deleted. Symbolic links are created using the In -s command according to the following syntax:
```
ln -s name-of-real-file name-of-symbolic-link
```
- Physical links (also called hardlinks) represent an alternative name for a file. So, when a file has two physical links, the deletion of one or other of these links does not lead to the deletion of the file. More specifically, while there is at least one physical link remaining, the file is not deleted. On the other hand, when all physical links for the same file are deleted the file is too. Please note however, that it is only possible to create physical links within the single and same file system. Physical links are created using the In (without the option -n) command according to the following syntax:
```
ln name-of-real-file name-of-physical-link
```
Virtual files do not really exist because they only exist in the memory. These files, located in particular in the /proc directory contain information about the system (processor, memory, hard disks, processes, etc.);
The Device files located in the /dev/ directory relate to the system devices. This concept may be disconcerting for a new user for the first time.

The concept of mount points

Files in a UNIX system are organised into a single tree structure. It is however possible to have several partitions using a mechanism called mounting which makes it possible to connect a partition to a directory in the main tree structure. So, the fact of mounting a partition in the directory /mnt/partition makes all the files in the partition accessible from this directory, called the "mount point".

File hierarchy under Unix

To ensure compatibility and portability, UNIX systems comply with the FHS (File Hierarchy Standard) standard. The basic hierarchy of a Unix system is as follows:

/				the root, containing the main directories
	/bin			Contains the executables necessary for the system, used by all users.
	/boot			Contains the loading files for the kernel, including the bootstrap loader.
	/dev			Contains entry points for the devices.
	/etc			Contains the configuration files required for the administration of the system (files passwd, group, inittab, ld.so.conf, lilo.conf, etc.)
		/etc/X11		contains specific files for the configuration of X (contains XF86Config, for example)
	/home			Contains the users' personal directories. Insofar as the directories located under /home are intended to host the user files for the system, you are advised to dedicate a specific partition to the /boot directory in order to limit damage in the case of disk space saturation.
	/lib			Contains standard libraries shared between the system's different applications.
	/mnt			Makes it possible to host the mount points of temporary partitions (CD-Rom, floppy disk, etc.)
	/proc			Merges a collection of virtual files making it possible to obtain information about the system or processes being executed.
	/root			Root administrator's personal directory. The administrator's personal directory is located apart from the other personal directories because it is located in the root partition so as to be able to be loaded at the start, before the mounting of the /home partition.
	/sbin			Contains essential system executables (for example the command adduser).
	/tmp			contains temporary files
	/usr			Secondary hierarchy
		/usr/X11R6		this directory is reserved for system X version 11 release 6
		/usr/X386		used before by X version 5, this is a symbolic link to /usr/X11R6
		/usr/bin		contains the majority of binary files and user commands
		/usr/include		contains header files for the programs C and C++
		/usr/lib		contains most of the shared libraries for the system
		/usr/local		contains data relating to the programs installed on the local machine by the root
			/usr/local/bin	Binaries for local programs
			/usr/local/include	Local C and C++ header files
			/usr/local/lib	Shared local libraries
			/usr/local/sbin	Local system binaries
			/usr/local/share	Independent hierarchy
			/usr/local/src	Local source files
		/usr/sbin		contains binary files not essential for the system that are reserved for the system administrator
		/usr/share		reserved for non-dependent data of the architecture
		/usr/src		contains source code files
	/var			contains changeable data such as database files, logs, files for the print spooler or even waiting emails.

The file system UNIX system - Commands Batch File To delete folders Telnet script or batch file

Tips & Tricks relevant found in the knowledge base

24/01 14h48	Keeping different versions of a Word document in the same file	Word
24/01 14h43	I can't play a video file. What's wrong?	Video
16/01 10h37	What are Cookies?	Internet
16/01 10h39	How can I save web pages on my computer?	Internet
24/01 14h51	How do I change the margins in a Word doc?	Word

More tricks on « Unix Files »

Relevant topic found in the forum

30/04 03h22	Excel autofilter stops filtering	13
10/03 17h31	How disable or enable Simple File Sharing XP?	6
08/03 20h07	File descriptors???	2
04/03 17h58	Deleting Files from a Flash Drive	1
20/06 12h41	Files with date stamp	1

More discussions about « Unix Files »

Software found in the relevant downloads

	SoftPerfect File Recovery - SoftPerfect File Recovery is a free and useful tool to restore accidentally deleted files from hard and floppy disks, USB...	Category: Backup License: Freeware/gratuit
	PC Inspector File Recovery - PC INSPECTORâ�¢ File Recovery is a data recovery program that supports the FAT 12/16/32 and NTFS file systems. Finds...	Category: Backup License: Freeware/gratuit
	FileZilla Client - Possibilty to download a version compatible with Linux or MacOS <h2> </h2> FileZilla Client is a fast and reliable...	Category: FTP License: Open Source
	FileZilla Server - FileZilla Server is an FTP server supports FTP and FTP over SSL/TLS.	Category: FTP License: Open Source

More freeware about « Unix Files »