The /usr
directory is the main application-storage directory. The binary files in
this directory are not required for system start-up or maintenance, so the
/usr
hierarchy may be, and often is, located on a
separate file system. Because of its (usually) large size,
/usr
has its own hierarchy of sub-directories. We will
mention just a few:
/usr/X11R6
:
the entire X Window System hierarchy. All binaries and libraries
required for the operation of X (including the X
servers) must be located here. The
/usr/X11R6/lib/X11
directory contains all aspects
of X's configuration which do not vary from one computer to
another. Specific configurations for each computer should go in
/etc/X11
.
/usr/bin
:
contains the majority of the system's binaries.
Any binary program which isn't necessary for the
maintenance of the system and isn't a system administration program
must be located in this directory. The only exceptions are programs
you compile and install yourself, which must be located in
/usr/local
.
/usr/lib
: contains all the
necessary libraries to run programs located in
/usr/bin
and
/usr/sbin
. There is also a
/usr/lib/X11
symbolic link pointing to
/usr/X11R6/lib/X11
, the directory which
contains the X Window System libraries (but only if X is
installed)[3].
/usr/local
:
this is where you must install any applications you compile from
source. The installation program should create the necessary
hierarchy.
/usr/share
:
this directory contains all read-only, architecture-independent data
required by applications in /usr
. Among other
things, you will find zone and location information
(zoneinfo
and
locale
).
Let's also mention the
/usr/share/doc
and
/usr/share/man
directories, which respectively
contain application documentation and the system's manual pages.
[3] Please note that Mandriva Linux now uses Xorg instead of X Window System as the default X Window system.