><HR><H2
CLASS="SECTION"
><A
NAME="TMPTEMPORARYFILES"
>/tmp : Temporary files</A
></H2
><DIV
CLASS="SECTION"
><H3
CLASS="SECTION"
><A
NAME="PURPOSE17"
>Purpose</A
></H3
><P
>The <TT
CLASS="FILENAME"
>/tmp</TT
> directory must be made available
for programs that require temporary files.</P
><P
>Programs must not assume that any files or directories in
<TT
CLASS="FILENAME"
>/tmp</TT
> are preserved between invocations of the
program.</P
><DIV
CLASS="TIP"
><P
></P
><TABLE
CLASS="TIP"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="tip.gif"
HSPACE="5"
ALT="Tip"></TD
><TH
ALIGN="LEFT"
VALIGN="CENTER"
><B
>Rationale</B
></TH
></TR
><TR
><TD
> </TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>IEEE standard P1003.2 (POSIX, part 2) makes requirements that
are similar to the above section.</P
><P
>Although data stored in <TT
CLASS="FILENAME"
>/tmp</TT
> may be deleted
in a site-specific manner, it is recommended that files and
directories located in <TT
CLASS="FILENAME"
>/tmp</TT
> be deleted whenever
the system is booted.</P
><P
>FHS added this recommendation on the basis of historical
precedent and common practice, but did not make it a requirement
because system administration is not within the scope of this
standard. </P
></TD
></TR
></TABLE
></DIV
></DIV
></DIV
></DIV
><DIV
CLASS="CHAPTER"
><HR><H1
><A
NAME="THEUSRHIERARCHY"
></A
>Chapter 4. The /usr Hierarchy</H1
><DIV
CLASS="SECTION"
><H2
CLASS="SECTION"
><A
NAME="PURPOSE18"
>Purpose</A
></H2
><P
><TT
CLASS="FILENAME"
>/usr</TT
> is the second major section of the
filesystem. <TT
CLASS="FILENAME"
>/usr</TT
> is shareable, read-only data.
That means that <TT
CLASS="FILENAME"
>/usr</TT
> should be shareable between
various FHS-compliant hosts and must not be written to. Any
information that is host-specific or varies with time is stored
elsewhere.</P
><P
>Large software packages must not use a direct subdirectory under
the <TT
CLASS="FILENAME"
>/usr</TT
> hierarchy.</P
></DIV
><DIV
CLASS="SECTION"
><HR><H2
CLASS="SECTION"
><A
NAME="REQUIREMENTS9"
>Requirements</A
></H2
><P
>The following directories, or symbolic links to directories, are
required in <TT
CLASS="FILENAME"
>/usr</TT
>.</P
><DIV
CLASS="INFORMALTABLE"
><P
></P
><A
NAME="AEN1223"
></A
><TABLE
BORDER="0"
FRAME="void"
CLASS="CALSTABLE"
><COL><COL><THEAD
><TR
><TH
>Directory</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="FILENAME"
>bin</TT
></TD
><TD
>Most user commands</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>include</TT
></TD
><TD
>Header files included by C programs</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>lib</TT
></TD
><TD
>Libraries</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>local</TT
></TD
><TD
>Local hierarchy (empty after main installation)</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>sbin</TT
></TD
><TD
>Non-vital system binaries</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>share</TT
></TD
><TD
>Architecture-independent data</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="SECTION"
><HR><H2
CLASS="SECTION"
><A
NAME="SPECIFICOPTIONS9"
>Specific Options</A
></H2
><DIV
CLASS="INFORMALTABLE"
><P
></P
><A
NAME="AEN1256"
></A
><TABLE
BORDER="0"
FRAME="void"
CLASS="CALSTABLE"
><COL><COL><THEAD
><TR
><TH
>Directory</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="FILENAME"
>X11R6</TT
></TD
><TD
>XWindow System, version 11 release 6 (optional)</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>games</TT
></TD
><TD
>Games and educational binaries (optional)</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>lib<qual></TT
></TD
><TD
>Alternate Format Libraries (optional)</TD
></TR
><TR
><TD
><TT
CLASS="FILENAME"
>src</TT
></TD
><TD
>Source code (optional)</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
><P
>An exception is made for the X Window System because of
considerable precedent and widely-accepted practice.</P
><P
>The following symbolic links to directories may be present. This
possibility is based on the need to preserve compatibility with older
systems until all implementations can be assumed to use the
<TT
CLASS="FILENAME"
>/var</TT
> hierarchy.</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SCREEN"
> /usr/spool -> /var/spool
/usr/tmp -> /var/tmp
/usr/spool/locks -> /var/lock</PRE
></TD
></TR
></TABLE
><P
>Once a system no longer requires any one of the above symbolic links,
the link may be removed, if desired.</P
></DIV
><DIV
CLASS="SECTION"
><HR><H2
CLASS="SECTION"
><A
NAME="USRX11R6XWINDOWSYSTEMVERSION11REL"
>/usr/X11R6 : X Window System, Version 11 Release 6 (optional)</A
></H2
><DIV
CLASS="SECTION"
><H3
CLASS="SECTION"
><A
NAME="PURPOSE19"
>Purpose</A
></H3
><P
>This hierarchy is reserved for the X Window System, version 11
release 6, and related files.</P
><P
>To simplify matters and make XFree86 more compatible with the X
Window System on other systems, the following symbolic links must be
present if <TT
CLASS="FILENAME"
>/usr/X11R6</TT
> exists:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SCREEN"
> /usr/bin/X11 -> /usr/X11R6/bin
/usr/lib/X11 -> /usr/X11R6/lib/X11
/usr/include/X11 -> /usr/X11R6/include/X11</PRE
></TD
></TR
></TABLE
><P
>In general, software must not be installed or managed via the above
symbolic links. They are intended for utilization by users only. The
difficulty is related to the release version of the X Window System —
in transitional periods, it is impossible to know what release of X11 is
in use.</P
></DIV
><DIV
CLASS="SECTION"
><HR><H3
CLASS="SECTION"
><A
NAME="SPECIFICOPTIONS10"
>Specific Options</A
></H3
><P
>Host-specific data in <TT
CLASS="FILENAME"
>/usr/X11R6/lib/X11</TT
> should be interpreted
as a demonstration file. Applications requiring information about the
current host must reference a configuration file in <TT
CLASS="FILENAME"
>/etc/X11</TT
>,
which may be linked to a file in <TT
CLASS="FILENAME"
>/usr/X11R6/lib</TT
>.
<A
NAME="AEN1299"
HREF="#FTN.AEN1299"
><SPAN
CLASS="footnote"
>[21]</SPAN
></A
></P
></DIV
></DIV
><DIV
CLASS="SECTION"
><HR><H2
CLASS="SECTION"
><A
NAME="USRBINMOSTUSERCOMMANDS"