The following directories, or symbolic links to directories are required in /etc:
"/etc" opt |
"Host-specific system configuration" Configuration for /opt |
Tree 3.7.2.1
The following directories, or symbolic links to directories must be in /etc, if the corresponding subsystem is installed:
"/etc" X11 sgml |
"Host-specific system configuration" Configuration for the X Window System (optional) Configuration for SGML and XML (optional) |
Tree 3.7.3.2
The following files, or symbolic links to files, must be in /etc if the corresponding subsystem is installed:[footnote 5]
csh.login | Systemwide initialization file for C shell logins (optional) |
exports | NFS filesystem access control list (optional) |
fstab | Static information about filesystems (optional) |
ftpusers | FTP daemon user access control list (optional) |
gateways | File which lists gateways for routed (optional) |
gettydefs | Speed and terminal settings used by getty (optional) |
group | User group file (optional) |
host.conf | Resolver configuration file (optional) |
hosts | Static information about host names (optional) |
hosts.allow | Host access file for TCP wrappers (optional) |
hosts.deny | Host access file for TCP wrappers (optional) |
hosts.equiv | List of trusted hosts for rlogin, rsh, rcp (optional) |
hosts.lpd | List of trusted hosts for lpd (optional) |
inetd.conf | Configuration file for inetd (optional) |
inittab | Configuration file for init (optional) |
issue | Pre-login message and identification file (optional) |
ld.so.conf | List of extra directories to search for shared libraries (optional) |
motd | Post-login message of the day file (optional) |
mtab | Dynamic information about filesystems (optional) |
mtools.conf | Configuration file for mtools (optional) |
networks | Static information about network names (optional) |
passwd | The password file (optional) |
printcap | The lpd printer capability database (optional) |
profile | Systemwide initialization file for sh shell logins (optional) |
protocols | IP protocol listing (optional) |
resolv.conf | Resolver configuration file (optional) |
rpc | RPC protocol listing (optional) |
securetty | TTY access control for root login (optional) |
services | Port names for network services (optional) |
shells | Pathnames of valid login shells (optional) |
syslog.conf | Configuration file for syslogd (optional) |
Table 3.7.3.1
mtab does not fit the static nature of /etc: it is excepted for historical reasons.[footnote 6]
If a configuration file must reside in a different location in order for the package or system to function properly, it may be placed in a location other than /etc/opt/<package>.
Xconfig | The configuration file for early versions of XFree86 (optional) |
XF86Config | The configuration file for XFree86 versions 3 and 4 (optional) |
Xmodmap | Global X11 keyboard modification file (optional) |
Table 3.7.5.2.2
Subdirectories of /etc/X11 may include those for xdm and for any other programs (some window managers, for example) that need them.[footnote 7]
[4] The setup of command scripts invoked at boot time may resemble System V, BSD or other models. Further specification in this area may be added to a future version of this standard.
[5] Systems that use the shadow password suite will have additional configuration files in /etc (/etc/shadow and others) and programs in /usr/sbin (useradd, usermod, and others).
[6] On some Linux systems, this may be a symbolic link to /proc/mounts, in which case this exception is not required.
[7] /etc/X11/xdm holds the configuration files for xdm. These are most of the files previously found in /usr/lib/X11/xdm. Some local variable data for xdm is stored in /var/lib/xdm. We recommend that window managers with only one configuration file which is a default .*wmrc file must name it system.*wmrc (unless there is a widely-accepted alternative name) and not use a subdirectory. Any window manager subdirectories must be identically named to the actual window manager binary.