linux

1. / – Root

 Every single file and directory starts from the root directory.

 Only root user has write privilege under this directory.

 Please note that /root is root user’s home directory, which is not same as /.

4. /etc – Configuration Files

 Contains configuration files required by all programs.

 This also contains startup and shutdown shell scripts used to start/stop individual

programs.

 For example: /etc/resolv.conf, /etc/logrotate.conf

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2. /bin – User Binaries

 Contains binary executables.

 Common linux commands you need to use in single-user modes are located under this

directory.

 Commands used by all the users of the system are located here.

 For example: ps, ls, ping, grep, cp.

3. /sbin – System Binaries

 Just like /bin, /sbin also contains binary executables.

 But, the linux commands located under this directory are used typically by system

aministrator, for system maintenance purpose.

 For example: iptables, reboot, fdisk, ifconfig, swapon

5. /dev – Device Files

 Contains device files.

 These include terminal devices, usb, or any

7. /var – Variable Files

 var stands for variable files.

 Content of the files that are expected to grow can be found under this directory.

 This includes — system log files (/var/log); packages and database files (/var/lib); emails

(/var/mail); print queues (/var/spool); lock files (/var/lock); temp files needed across

reboots (/var/tmp);

8. /tmp – Temporary Files

 Directory that contains temporary files created by system and users.

 Files under this directory are deleted when system is rebooted.

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6. /proc – Process Information

 Contains information about system process.

 This is a pseudo filesystem contains information about running process. For example:

/proc/{pid} directory contains information about the process with that particular pid.

 This is a virtual filesystem with text information about system resources. For example:

/proc/uptime

9. /usr – User Programs

 Contains binaries, libraries, documentation, and source-code for second level programs.

 /usr/bin contains binary files for user programs. If you can’t find a user binary under /bin,

look under /usr/bin. For example: at, awk, cc, less, scp

 /usr/sbin contains binary files for system administrators. If you can’t find a system binary

under /sbin, look under /usr/sbin. For example: atd, cron, sshd, useradd, userdel

 /usr/lib contains libraries for /usr/bin and /usr/sbin

 /usr/local contains users programs that you install from source. For example, when you

install apache from source, it goes under /usr/local/apache2

10. /home – Home Directories

 Home directories for all users to store their personal files.

 For example: /home/john, /home/nikita

11. /boot – Boot Loader Files

 Contains boot loader related files.

 Kernel initrd, vmlinux, grub files are located under /boot

 For example: initrd.img-2.6.32-24-generic, vmlinuz-2.6.32-24-generic

12. /lib – System Libraries

 Contains library files that supports the binaries located under /bin and /sbin

 Library filenames are either ld* or lib*.so.*

 For example: ld-2.11.1.so, libncurses.so.5.7

13. /opt – Optional add-on Applications

 opt stands for optional.

 Contains add-on applications from individual vendors.

 add-on applications should be installed under either /opt/ or /opt/ sub-directory.

14. /mnt – Mount Directory

 Temporary mount directory where sysadmins can mount filesystems.

15. /media – Removable Media Devices

 Temporary mount directory for removable devices.

 For examples, /media/cdrom for CD-ROM; /media/floppy for floppy drives;

/media/cdrecorder for CD writer

16. /srv – Service Data

 srv stands for service.

 Contains server specific services related data.

 For example, /srv/cvs contains CVS related data

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