><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN819"
HREF="#AEN819"
><SPAN
CLASS="footnote"
>[10]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>If you want to find out a user's home directory, you should use the
<TT
CLASS="FILENAME"
>getpwent(3)</TT
> library function rather than relying
on <TT
CLASS="FILENAME"
>/etc/passwd</TT
> because user information may be
stored remotely using systems such as NIS.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN826"
HREF="#AEN826"
><SPAN
CLASS="footnote"
>[11]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>It is recommended that apart from autosave and lock files programs
should refrain from creating non dot files or directories in a home
directory without user intervention.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN836"
HREF="#AEN836"
><SPAN
CLASS="footnote"
>[12]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>Shared libraries that are only necessary for binaries in
<TT
CLASS="FILENAME"
>/usr</TT
> (such as any X Window binaries) must not be
in <TT
CLASS="FILENAME"
>/lib</TT
>. Only the shared libraries required to
run binaries in <TT
CLASS="FILENAME"
>/bin</TT
> and
<TT
CLASS="FILENAME"
>/sbin</TT
> may be here. In particular, the library
<TT
CLASS="FILENAME"
>libm.so.*</TT
> may also be placed in
<TT
CLASS="FILENAME"
>/usr/lib</TT
> if it is not required by anything in
<TT
CLASS="FILENAME"
>/bin</TT
> or <TT
CLASS="FILENAME"
>/sbin</TT
>.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN866"
HREF="#AEN866"
><SPAN
CLASS="footnote"
>[13]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>The usual placement of this binary is <TT
CLASS="FILENAME"
>/usr/bin/cpp</TT
>.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN890"
HREF="#AEN890"
><SPAN
CLASS="footnote"
>[14]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>This is commonly used for 64-bit or 32-bit support on
systems which support multiple binary formats, but require libraries
of the same name. In this case, <TT
CLASS="FILENAME"
>/lib32</TT
> and
<TT
CLASS="FILENAME"
>/lib64</TT
> might be the library directories, and
<TT
CLASS="FILENAME"
>/lib</TT
> a symlink to one of them.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN900"
HREF="#AEN900"
><SPAN
CLASS="footnote"
>[15]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
><TT
CLASS="FILENAME"
>/lib<qual>/cpp</TT
> is still permitted: this
allows the case where <TT
CLASS="FILENAME"
>/lib</TT
> and
<TT
CLASS="FILENAME"
>/lib<qual></TT
> are the same (one is a symbolic
link to the other). </P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN947"
HREF="#AEN947"
><SPAN
CLASS="footnote"
>[16]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>A compliant implementation with two CDROM drives might have
<TT
CLASS="FILENAME"
>/media/cdrom0</TT
> and
<TT
CLASS="FILENAME"
>/media/cdrom1</TT
> with
<TT
CLASS="FILENAME"
>/media/cdrom</TT
> a symlink to either of these.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN1037"
HREF="#AEN1037"
><SPAN
CLASS="footnote"
>[17]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>If the home directory of the root account is not
stored on the root partition it will be necessary to make certain it
will default to <TT
CLASS="FILENAME"
>/</TT
> if it can not be
located.</P
><P
>We recommend against using the root account for tasks that can be
performed as an unprivileged user, and that it be used solely for system
administration. For this reason, we recommend that subdirectories for
mail and other applications not appear in the root account's home
directory, and that mail for administration roles such as root,
postmaster, and webmaster be forwarded to an appropriate user.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN1051"
HREF="#AEN1051"
><SPAN
CLASS="footnote"
>[18]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>Originally, <TT
CLASS="FILENAME"
>/sbin</TT
> binaries were kept in
<TT
CLASS="FILENAME"
>/etc</TT
>. </P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN1058"
HREF="#AEN1058"
><SPAN
CLASS="footnote"
>[19]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>Deciding what things go into
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>"sbin"</I
></SPAN
> directories is simple: if a normal (not a
system administrator) user will ever run it directly, then it must be
placed in one of the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>"bin"</I
></SPAN
> directories. Ordinary
users should not have to place any of the <TT
CLASS="FILENAME"
>sbin</TT
>
directories in their path.</P
><P
>For example, files such as <B
CLASS="COMMAND"
>chfn</B
> which users
only occasionally use must still be placed in
<TT
CLASS="FILENAME"
>/usr/bin</TT
>. <B
CLASS="COMMAND"
>ping</B
>, although it
is absolutely necessary for root (network recovery and diagnosis) is
often used by users and must live in <TT
CLASS="FILENAME"
>/bin</TT
> for
that reason.</P
><P
>We recommend that users have read and execute permission for
everything in <TT
CLASS="FILENAME"
>/sbin</TT
> except, perhaps, certain
setuid and setgid programs. The division between
<TT
CLASS="FILENAME"
>/bin</TT
> and <TT
CLASS="FILENAME"
>/sbin</TT
> was not
created for security reasons or to prevent users from seeing the
operating system, but to provide a good partition between binaries
that everyone uses and ones that are primarily used for administration
tasks. There is no inherent security advantage in making
<TT
CLASS="FILENAME"
>/sbin</TT
> off-limits for users. </P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN1192"
HREF="#AEN1192"
><SPAN
CLASS="footnote"
>[20]</SPAN
></A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>This is particularly important as these areas will often contain both
files initially installed by the distributor, and those added by the