'/etc' is the nerve center of your system, it contains
all system related configuration files.
Some important subdirectories:
- This directory contains all the configuration files
for the X Window System, like 'XF86Config(-4)', the X server's configuration
file, 'fs/config', which controls the X font server, or 'xdm/' and 'xinit/'
which contain important initialization files.
- These directories contain scripts to be executed
on a regular basis by thecron
- That's the place where the desktop menu system can
be configured centrally.
- This directory is the home of the configuration files
for the Pluggable Authentication Modules.
- '/etc/postfix/' holds your 'postfix' configuration
- That's the place where your dial-up configuration files go to.
- This contains all the files necessary to control
services and configure runlevels.
- This is the nerve center of MSEC, LM's own security
- Files in this directory are automatically put into
every new user's home directory.
- This directory contains configuration files for the
boot process, like 'clock', which sets the time-zone, or 'keyboard' which
controls the keyboard map. The subdirectory 'network-scripts/' holds - among
others - configuration files for network interfaces ('ifcfg-*').
- Services controlled via xinetd put their configuration file here.
Some network configuration files in /etc
Some system configuration files in /etc
- '/etc/bashrc': 'System wide functions and aliases'
for the bash shell.
- '/etc/fstab': Configuration file for 'mount'.
- '/etc/group': This lists the configured user groups
and who belongs to them.
- '/etc/inittab': Tells
init how to handle
runlevels. Sets the default runlevel.
- '/etc/issue': This is your welcome screen.
- '/etc/ld.so.conf': Tells the Linux Loader/Linker
'ld' where to look for libraries.
- '/etc/lilo.conf': Configuration file for the Linux
boot loader LiLo.
- '/etc/motd': 'Message of the Day', displayed after
- '/etc/mtab': Lists all currently mounted
- '/etc/passwd': This is the 'old' password file, kept
- '/etc/printcap': Printer configuration ('capabilities')
- '/etc/profile': 'System wide environment and startup
programs' for the bash shell. Also have a look at the scripts collected in
- '/etc/shadow': The password file, used by the Pluggable
Authentication Modules (PAM). Passwords are stored in encrypted form.
- '/etc/sysctl.conf': Some security relevant settings.
- '/etc/syslog.conf': Where the log files go and what
messages are written to them.
- '/etc/updatedb.conf': Configures the database for
And many, many more. I suggest that you should browse
this directory, it will teach you a lot about your Linux system and how you
can customize it!
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'/home/$USER' (aka '~/') is your playground: everything's
at your command, you can write files, delete them, install programs etc.
Your home directory contains your personal configuration files, the so-called
dot files (their name is preceded by a dot). Personal configuration files
are usually 'hidden', if you want to see them, you either have to turn on
the appropriate option in your file manager or run 'ls' with the '-a' option.
If there is a conflict between personal and system-wide configuration files,
the settings in the personal file will prevail.
'/home' can get quite large (mine is about 400 MB) and can be used for storing
downloads, compiling, installing and running programs, your mail, your collection
of image or sound files etc.
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'/var' holds 'variable' data like spool directories
for mail and news, data bank data and log files.
- '/var/catman' caches formatted man-pages.
- '/var/db' stores data banks.
- '/var/lib' holds frequently changing data libraries
like the RPMdb or game scores.
- '/var/local' can contain local variable data (as
opposed to a remotely mounted '/var' partition).
- '/var/lock' holds lock files of some devices. These
lock files ensure that only one application may have access to a device at
- '/var/log' contains files, where the system and services
write log and error messages to. A good place to start with troubleshooting
- '/var/run' contains the process identification files (PIDs) of system
services. It is emptied on every boot.
- '/var/spool' holds spool files, for instance for
mail and printing (lpd). Spool files store data to be processed after the
job currently occupying a device is finished or the appropriate cron job
- '/var/tmp' ... well, guess ;-).
- '/var/www' is the home for public webserver files.
The /usr directory
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