/sbin - This directory contains
all the binaries that are essential to the working of the system. These
include system administration as well as maintenance and hardware
configuration programs. Find lilo, fdisk, init, ifconfig etc here.
These are the essential programs that are required by all the users.
Another directory that contains system binaries is /usr/sbin. This
directory contains other binaries of use to the system administrator.
This is where you will find the network daemons for your system along
with other binaries that only the system administrator has access to,
but which are not required for system maintenance, repair etc.
/bin - In contrast to /sbin,
the bin directory contains several useful commands that are used by
both the system administrator as well as
non-privileged users. This directory usually contains the shells like
bash, csh etc. as well as much used commands like cp, mv, rm, cat, ls.
There also is /usr/bin, which contains other user binaries. These
binaries on the other hand are not essential for the user. The binaries
in /bin however, a user cannot do without.
/boot - This directory contains
the system.map file as well as the Linux kernel. Lilo places the boot
sector backups in this directory.
/dev - This is a very
interesting directory that highlights one important characteristic of
the Linux filesystem - everything is a file or a directory. Look
through this directory and you should see hda1, hda2 etc, which
represent the various partitions on the first master drive of the
system. /dev/cdrom and /dev/fd0 represent your CDROM drive and your
floppy drive. This may seem strange but it will make sense if you
compare the characteristics of files to that of your hardware. Both can
be read from and written to. Take /dev/dsp, for instance. This file
represents your speaker device. So any data written to this file will
be re-directed to your speaker. Try 'cat /etc/lilo.conf > /dev/dsp'
and you should hear some sound on the speaker. That's the sound of your
lilo.conf file! Similarly, sending data to and reading from /dev/ttyS0
( COM 1 ) will allow you to
communicate with a device attached there - your modem.
/etc - This directory contains
all the configuration files for your system. Your lilo.conf file lies
in this directory as does hosts, resolv.conf and fstab. Under this
directory will be X11 sub-directory which contains the configuration
files for X. More importantly, the /etc/rc.d directory contains the
system startup scripts. This is a good directory to backup often. It
will definitely save you a lot of re-configuration later if you
re-install or lose your current installation.
/home - Linux is a
multi-user environment so each user is also assigned a specific
directory which is accessible only to them and the system
administrator. These are the user home directories, which can be found
under /home/username. This directory also contains the user specificsettings for programs like IRC, X etc.
/lib - This contains all the
shared libraries that are required by system programs. Windows
equivalent to a shared library would be a DLL file.
/lost+found - Linux should
always go through a proper shutdown. Sometimes your system might crash
or a power failure might take the machine down. Either way, at the next
boot, a lengthy filesystem check using fsck will be done. Fsck will go
through the system and try to recover any corrupt files that it finds.
The result of this recovery operation will be placed in this directory.
The files recovered are not likely to be complete or make much sense
but there always is a chance that something worthwhile isrecovered.
/mnt - This is a generic
mount point under which you mount your filesystems or devices. Mounting
is the process by which you make a filesystem available to the system.
After mounting your files will be accessible under the mount-point.
This directory usually contains mount points or sub-directories where
you mount your floppy and your CD. You can also create additional
mount-points here if you want. There is no limitation to creating a
mount-point anywhere on your system but convention says thatyou do not litter your file system with mount-points.
/opt - This directory
contains all the software and add-on packages that are not part of the
default installation. Generally you will find KDE and StarOffice here.
Again, this directory is not used very often as it'smostly a standard in Unix installations.
/proc - This is a special directory on your system. We have a more detailed article on this one
here.
/root - We talked about user
home directories earlier and well this one is the home directory of the
user root. This is not to be confused with the system root, which is
directory at the highest level in the filesystem.
/tmp - This directory contains
mostly files that are required temporarily. Many programs use this to
create lock files and for temporary storage of data. On some systems,
this directory is cleared out at boot or at shutdown.
/usr - This is one of the
most important directories in the system as it contains all the user
binaries. X and its supporting libraries can be found here. User
programs like telnet, ftp etc are also placed here. /usr/doc contains
useful system documentation. /usr/src/linux contains thesource code for the Linux kernel.
/var - This directory
contains spooling data like mail and also the output from the printer
daemon. The system logs are also kept here in
/var/log/messages. You will also find the database for BIND in /var/named and for NIS in /var/yp.
reference:
http://www.freeos.com/articles/3102
http://www.pathname.com/fhs/