Files System Directories “Hierarchy”

"In this article I will explain what’s files system directories also it know as Hierarchy.

This article will be really helpful for beginners to know what’s the purpose of each directory and command inside Hierarchy.

So let’s begin,"

Directory	Description
bin	Essential command binaries
boot	Static files of the boot loader
dev	Device files
etc	Host-specific system configuration
lib	Essential shared libraries and kernel modules
media	Mount point for removeable media
mnt	Mount point for mounting a filesystem temporarily
opt	Add-on application software packages
sbin	Essential system binaries
srv	Data for services provided by this system
tmp	Temporary files
usr	Secondary hierarchy
var	Variable data

1. bin

/bin contains commands that may be used by both the system administrator and by users, but which are required when no other filesystems are mounted (e.g. in single user mode). It may also contain commands which are used indirectly by scripts.

2. boot

/boot This directory contains everything required for the boot process except configuration files not needed at boot time and the map installer. Thus /boot stores data that is used before the kernel begins executing user-mode programs. This may include saved master boot sectors and sector map files.

3. dev

The /dev directory is the location of special or device files.

Devices treated like files to read and write it

Example:

• /dev/cdrom
• /dev/hda for first hard driver IDE

If it is possible that devices in /dev will need to be manually created, /dev must contain a command named MAKEDEV, which can create devices as needed. It may also contain a MAKEDEV.local for any local devices.

If required, MAKEDEV must have provisions for creating any device that may be found on the system, not just those that a particular implementation installs.

4. etc

The /etc hierarchy contains configuration files. A “configuration file” is a local file used to control the operation of a program; it must be static and cannot be an executable binary.

It can be edited by hand : ex:

• /etc/fstab
• /et

No binaries may be located under /etc.

The following directories, or symbolic links to directories are required in /etc:

Directory	Description
opt	Configuration for /opt
X11	Configuration for the X Window system (optional)
sgml	Configuration for SGML (optional)
xml	Configuration for XML (optional)