2.Linux Configuration Files
/dev/MAKEDEV The /dev/MAKEDEV file is a script written by the system administrator that creates local only device files or links such as device files for a non-standard device driver.
/etc/aliases Where the user's name is matched to a nickname for email.
/etc/crontab Lists commands and times to run them for the cron deamon.
/etc/filesystems Can be used to set the filesystem probe order when
filesystems are mounted with the auto option. The nodev parameter is specified for filesystems that are not really locally mounted systems such as proc, devpts, and nfs systems.
/etc/fstab Lists the filesystems mounted automatically a startup by the mount -a command (in /etc/rc or equivalent startup file).
/etc/group Similar to /etc/passwd but for groups rather than users. /etc/groups May contain passwords that let a user join a group.
/etc/gshadow Used to hold the group password and group Administrator password information for shadow passwords.
/etc/host.conf Specifies how host names are resolved.
/etc/hosts List hosts for name lookup use that are locally required.
/etc/inittab Configuration file for init, controls startup run levels, determines scripts to start with.
/etc/issue Output by getty before the login prompt. Description or welcoming message.
/etc/issue.net Output for network logins with LINUX version
/etc/login.defs Sets user login features on systems with shadow passwords.
/etc/logrotate.conf Configures the logrotate program used for managing logfiles.
/etc/mtab A list of currently mounted file systems. Setup by boot scripts and updated by the mount command.
/etc/named.conf Used for domain name servers.
/etc/nsswitch.conf Name service switch configuration file.
/etc/passwd The user database with fields giving the username, real name, home directory, encrypted password and other information about each user.
/etc/printcap A configuration files for printers.
/etc/protocols Describes DARPA internet protocols available from the TCP/IP subsystem. Maps protocol ID numbers to protocol names.
/etc/rc or /etc/rc.d or /etc/rc?.d Scripts or directories of scripts to run at startup or when changing run level.
/etc/rc.d/rc0.d Contains files used to control run level 0. Usually these files are softlink files.
/etc/rc.d/rc1.d Contains files to control run level 1. Scripts beginning with an S are for start, K for kill.
/etc/rc.d/rc.sysinit Init runs this when it starts.
/etc/resolv.conf configures the name resolver, specifying the address of your name server and your domain name.
/etc/securetty Identifies secure terminals from which root is allowed to log in.
/etc/services Lists the network services that the system supports.
/etc/shadow Shadow password file on systems with shadow password software installed. Shadow passwords move the encrypted password files from /etc/passwd to /etc/ shadow which can only be read by root.
/etc/shells Lists trusted shells. The chsh command allows users to change their login shell to shells listed only in this file.
/etc/skel/.profile can be used by administrator to set the editor Environment variable to some editor that is friendly to new users.
/etc/sudoers A list of users with special privileges along with the Commands they can execute.
/etc/sysconfig/amd Used to configure the auto mount daemon.
/etc/sysconfig/clock Used to configure the system clock to Universal or local time and set some other clock parameters.
/etc/sysconfig/i18n Controls the system font settings.
/etc/sysconfig/init This file is used to set some terminal characteristics and environment variables.
/etc/sysconfig/keyboard Used to configure the keyboard.
/etc/sysconfig/mouse This file is used to configure the mouse.
/etc/sysconfig/network-scripts/ifcfg-interface Defines a network interface.
/etc/sysconfig/pcmcia Used to configure pcmcia network cards.
/etc/X11/XF86Config The configuration file for the X server.
/etc/syslog.conf Configuration file for the syslogd daemon.
/etc/termcap The terminal capability database. Describes by what"escape sequences" various terminals can be controlled. See terminfo, termcap, curs_termcap man pages.
$HOME/.bashrc User aliases, path modifier, and functions.
$HOME/.bash_profile Users environment stuff and startup programs.
$HOME/.bash_ logout User actions to be done at logout.
/proc/cpuinfo Information about the processor such as its type, make and performance.
/proc/devices A list of devices configured into the currently running kernel.
/proc/dma Shows which DMA channels are being used at the moment.
/proc/filesystems Files systems that are configured into the kernel. The file used to detect filesystems if the
/etc/filesystems does not exist.
/proc/ioports Shows which I/O ports are in use at the moment.
/proc/interrupts Shows which interrupts are in use and how many of each there have been.
/proc/kcore An image of the physical memory of the system.
/proc/kmsg Messages output by the kernel. These are also routed to syslog.
/proc/ksyms Symbol table for the kernel.
/proc/meminfo Information about memory usage, both physical and swap.
/proc/modules Which kernel modules are currently loaded.
/proc/mounts Contains information on filesystems currently mounted, similar to /etc/mtab
/proc/net Contains status information about network protocols.
/proc/self A symbolic link to the process directory of the program that is looking at /proc. When 2 process look at proc, they get different links.
/proc/stat Various statistics about the system such as the number of page faults since the system was booted.
/proc/uptime The time the system has been up.
/proc/version The kernel version.
/var/log/lastlog Used by finger to tell when a user was last logged in.
/var/log/wtmp Binary info on users that have been logged on. The last command uses this info.
/var/run/utmp Contains information about users currently logged in.Who and w commands use this file.
/var/named/* Files used by domain name server. Placed here optionally, but this is the normal location.
/var/log/lastlog Contains information about the last time a login was done on the system. Works with lastb(1).
/var/log/messages The main system message log file.
/var/spool/mail Where mailboxes are usually stored.
