Linux file system directories

  ================================
 Linux file system directories.
 ================================

 / Begin start (that is, the root of the system).
 / boot Contains kernel image files and modules loaded at boot
         system.
 / home Contains the user's home directories.
 / sbin Contains administration commands and commands used
     	   privileged user.
 / dev Contains device files, such as a printer terminal.
 / etc Contains configuration and other important system files.
 / bin Contains important user commands and utilities.
 / lib Contains important shared libraries and modules.
  	   kernels.
 / mnt Contains directories for mounting file systems temporarily.
	   drives used, such as CDs and floppy disks.
 / opt Contains added applications (for example, in some
	   distributions include KDE).
 / proc Process Directory — resident in memory directory
	   files containing system information.
 / tmp Contains temporary files.
 / usr Contains files and commands used by the system.  (more will be 
         in details).
 / var Contains constantly changing files, for example mail files
	   boxes.

 =========================
 Subdirectories of the / usr directory
 =========================

 / usr / bin Contains most user commands and utilities.
 / usr / sbin Contains not the most important administrative applications.
 / usr / lib Contains libraries for applications, programming languages, 
              desktops, etc.
 / usr / game Contains games and tutorials.
 / usr / includes Contains C programming language header files (.h)
 / usr / local Directory for software installed
		  on the local machine (all that is installed
		  by user).
 / usr / share Contains architecturally independent data, shared
		  for various systems.  For example, these include
		  electronic documentation pages such as Man and
		  info.
 / usr / src Contains the source code, including the kernel source code.
 / usr / X11R6 Contains applications and libraries for the X Window System
		  (version 11, revision 6)

 =========================
 Subdirectories of the / var directory
 =========================

 / var / account Contains a log of processes.
 / var / cache Contains cached application data for man pages,
		  proxy server data, fonts and specific data
		  for applications.
 / var / crash Contains system crash dumps.
 / var / games Contains game data.
 / var / lib Contains files with state-specific information
		  applications.
 / var / local Used for changing program data
		  installed in the / usr / local directory.
 / var / lock Contains lock files to determine
		  is a particular file currently in use or
		  program.
 / var / log Contains log files such as / var / log / messages, in
		  which stores all kernel and system messages
		  programs.
 / var / mail Contains user mailbox files.
 / var / opt Contains frequently changing application data
		  installed in the / opt directory.
 / var / run Contains files with information about working in the system
		  processes. 
 / var / spool Buffer directories for applications, such as data
		  email, news, print queuing, and
		  cron and al.
 / var / tmp Contains temporary files that should be saved
		  between system overloads.
 / var / yp Contains Network Information Service (NIS) data files.

 ==================================
 Subdirectories and files in the / proc directory
 ==================================

 / proc / pid This directory is available for each process (pid -
			 this is the process number).  For example, process with pid 1
			 corresponds to the directory / proc / 1.
 / proc / cpuinfo Information about the central processor: its type,
			 manufacturer, model, performance, etc.
 / proc / device List of device drivers configured 
			 for use at the moment
			 the core.
 / proc / dma Currently used direct channels
			 memory access (DMA).
 / proc / filesystems Kernel file systems.
 / proc / interrupts Used interrupts.
 / proc / ioports Used I / O ports.
 / proc / kcore Contains the image (dump) of the physical memory of the system.
 / proc / kmsg Messages generated by the kernel.
 / proc / ksyms Symbol table for the kernel.
 / proc / loadavg System load.
 / proc / meminfo Memory usage information.
 / proc / modules List of currently loaded kernel modules.
 / proc / net Information about the status of network protocols.
 / proc / stst System statistics, including such
			 parameters like the number of failed calls to
			 pages.
 / proc / uptime System time