Common Linux configuration files

I./etc configuration file
/ETC/PASSWD user database, where the domain gives the user name, real name, home directory, encrypted password, and other information of the user

/etc/group is similar to/etc/passwd, but not the user but the group.

Configuration file for/etc/inittab Init

/etc/issue the output information before the logon prompt. Usually includes a short description of the system or a welcome message. The content is determined by the system administrator.

/ETC/MOTD is automatically output after successful login, the content is determined by the system administrator, and is often used to advertise information such as a warning about scheduled time off.

/etc/mtab the list of currently installed file systems. Initialized by scripts and updated automatically by the Mount command. Need a current

When you install a list of file systems, such as the DF Command, when Df–a, the information you see should be consistent with it.

/etc/shadow the shadow password file on the system on which the shadow password software is installed. The shadow password file will be in the/etc/passwd file

The encrypted password is moved to the/etc/shadow, and the latter is only readable by root. This makes it more difficult to decipher the password.

/etc/login.defs configuration file for the login command

/etc/profile,/etc/csh.login,/ETC/CSH.CSHRC logon or Startup Bourne or C

The file that is executed when shells. This allows the system administrator to establish a global default environment for all users
/etc/printcap similar to/etc/termcap, but for printers. syntax is different.

/etc/securetty confirm the security terminal, that is, which terminal allows root login. Typically only virtual consoles are listed, which makes it impossible

(at least difficult) to break into the system via modem or network and gain superuser privileges.

/etc/shells lists the trusted shells. The CHSH command allows the user to change the login shell within the scope specified in this file. Provide a

Machine FTP Service process FTPD Check that the user shell is listed in the/etc/shells

File, if the user is not allowed to log on.

/ETC/TERMCAP Terminal Performance database. Describes what "escape sequence" controls are used by different terminals. The escape sequence is not output directly when the program is written (this

Only work on a particular brand of terminal), instead, look for the correct sequence of work to be done from/etc/termcap. In this way, most of the

The program can run on most terminals.

/ETC/INPUTRC Input Device configuration file

/etc/default/useradd Adding a user's default information to a file

/etc/login.defs is the default attribute for user password information

/etc/skel Skeleton of user information

/sbin/nologin users who cannot log in

Log file for/var/log/message system

/etc/profile Global profiles can be added one line path= $PATH:/usr/local/mysql/bin can be used by the command of the software

Alias of the/ROOT/BASHRC command

/ETC/YUM.REPOS.D Configuring the local Yum source

/etc/httpd/conf/httpd.conf Configuring the configuration file for the HTTP service

/etc/fstab devices that are automatically loaded when the system starts (for configuring automatic mount devices)

/etc/selinux Secure Linux Settings

/etc/sysconfig/network can change hostname (hostname) and network card operating status

/etc/hosts change the hostname and IP address correspondence, note that the format is hostname.domain hostname localhost

Localhost.domian, the file must be modified when the hostname is modified

/etc/resolv.conf configurable DNS addresses, that is, the default search path for first DNS, second DNS, and DNS

/etc/sysconfig/networking/profiles/default contains several files that can be configured with hosts, network cards, DNS addresses, and

DNS Search Path, etc.

/etc/sysconfig/network-scripts/ifcfg-eth0 Configuring the NIC Eth0

/etc/rc.d/init.d/network Restart Restart Network

/ETC/RC.D/INIT.D startup scripts for placing almost all services

/etc/sysctl.conf Kernel parameter configuration file

/etc/sysconfig/i18n setting the system language and character types

/etc/crontab system-defined task schedules

/etc/anacrontab implementing a profile that checks for outdated and incomplete crontab tasks

/etc/rc.d/init.d/functions defining a configuration file for a feature

/etc/rc.d/rc.sysinit system Boot Settings configuration file

/etc/sysconfig/system-config-firewall Configure the firewall's trust port, and the firewall's working status. Graphical configuration of Fire protection

The wall of the archive file, specifically to save only the graphical interface of the Otherport inside the set of items, if the master configuration

There is a corresponding configuration entry for the file, it does not matter whether the configuration entry exists in it.

/etc/sysconfig/iptables Firewall master configuration file

/etc/sysconfig/system-config-securitylevel system security level files that are not covered in the firewall configuration

/etc/xinetd.conf XINETD's master configuration file

/etc/hosts.allow a license table for TCP

/etc/host.deny A deny table for TCP

/etc/squid/squid.conf Proxy Server (squid) configuration file

/etc/sysconfig/vncservers VNC Service configuration file

/etc/vsftpd/ftpusers for saving local user accounts (blacklists) that do not allow FTP logons

/etc/vsftpd/user_list more flexible user access control, but needs to be declared in the master configuration file

/etc/inetd.conf SWAT Configuration

/etc/dhcpd.conf configuration file for DHCP

/ETC/RC.D/INIT.D/DHCPD Stop Stop DHCP

/etc/access can control SendMail mail flow

/ETC/UDEV/RULES.D is a program that outputs hardware probe information to a device configuration file when the system is initialized.

Allows the user to define UDEV rules, thereby enabling the creation of device files using different device file names

Note:/etc/passwd Store user's account number

Slaceware:x:5000:5000:test User:/home/slackware:/bin/bash

NAME:PASSWD Location: UID:GID:CECOS (note):d iectory (home directory): Shell

Note:/etc/shadow Store user's password

Slaceware:$1$12345678$0me5n6odyoeawup7b5udm/:15355:0:99999:7:::

Name: Password After encryption: Time 1: Time 2: Time 3: Time 4: Time 5: Time 6: Reserved segment

Password after encryption: to $ separate, the first $ after is 1, stating that the encryption algorithm is MD5, the second $ after is added sail, the third $ after is added

The password

Time 1: The number of days since January 1, 1970 to the most recent modification

Time 2: Minimum age of password

Time 3: Maximum password age

Time 4: How many days before the password expires warning

Time 5: Number of days after password expiration user disabled

Time 6: How long the user has been disabled since January 1, 1970

Note:/etc/group the account of the storage group

slackware:x:5000:

NAME:PASSWD Location: GID: List of users of additional groups

Note: Interactive login users:

/etc/profile-->/etc/profile.d/*-->~/.bash_profile-->~/.BASHRC-->/ETC/BASHRC

Non-interactive logon:

~/.BASHRC-->/ETC/BASHRC-->.etc/profile.d/*

Second,/proc configuration file

/PROC/DMA Displays the DMA channel currently in use.

/proc/filesystems the file system of the core configuration.

/proc/interrupts shows the interrupts used, and how many of each there has been.

/proc/ioports the I/O port currently in use.

/proc/kcore System physical memory image. Exactly the same size as the physical memory, but does not actually occupy so much memory;

It's generated on the fly as programs access it.

(Remember: Unless you copy it somewhere, there's nothing in the/proc that takes up any disk space.) ）

/proc/kmsg the core output message. was also sent to the syslog

/proc/ksyms Core Symbol table

/proc/loadavg system "average load"; 3 indicators indicate the current workload of the system.

/proc/meminfo memory usage information, including physical memory and swap.

/proc/modules which core modules are currently loaded.

/proc/net Network protocol status information.

/proc/self to view the symbolic connection of the process directory of the/PROC program. When 2 processes view/proc

, the connection is different. This is primarily convenient for the program to get its own process directory.

Different states of the/proc/stat system, such as the number of page faults since the systems was booted.

/proc/uptime the length of time the system started.

/proc/cpuinfo processor information, such as type, manufacturer, model, and performance.

/proc/devices a list of device drivers for the currently running core configuration.

/proc/version Core version.

/proc/mdstat RAID Device Information

/proc/cmdline ro root=/dev/vol0/root rhgb quiet grub information

/proc/cpuinfo displaying information about the CPU

The/proc/cpuset CPU collection is used to show which CPUs the current process can apply to

/proc/filesystem types of file systems supported by the current system

/ETC/245/VM virtual memory information for a process with a process ID number of 245

/etc/245/kernel kernel information for process with process ID number 245

/proc/mounts all file Systems mounted

/proc/swaps Exchanging partition information

/proc/uptime Boot system Run time

/proc/sys (with Write permission) defines the value of the kernel parameter to define the functionality of the kernel

/proc/sys/kernel/hostname Host name settings

Iii./usr configuration file

/usr/bin a multitude of applications

/usr/doc Linux Documentation

/usr/include the header files required to develop and compile applications under Linux C

/usr/include/g++ the header of the C + + compiler

/usr/lib Common dynamic-link libraries and package profiles

Source code for/USR/SRC system software

/usr/src/linux the source code of the Linux kernel

/usr/local/bin Local Add-on command

/usr/local/lib local additions to the library

/usr/sbin programs reserved for the system administrator

/usr/share/fonts Font Files

/usr/share/doc various document files

/usr/share/man System manual Page

/usr/local/apache/man Defining the Man directory anthology

Iv. Other Directory configuration files

/dev/null the location of unused files, equivalent to the Recycle Bin, engulfing the device

/dev/zero initializing disk (spit 0)

/dev/random random number generator, entropy pool

/dev/urandom pseudo-random number generator, entropy pool. (Generate random numbers with software when the entropy pool is exhausted)

/var/spool/mail/root define mail settings send user as Root

/bin/bash system built-in script

/home/username User Quota file

/var/spool/cron/username user-defined task schedules

V. Directory structure:
/boot files for the bootstrap loader (LILO or grub). When the computer starts (if there are multiple operating systems,

It is possible to allow you to choose which operating system to start, these files are loaded first. This directory will also contain the Linux kernel (compressed file

Vmlinuz), but the Linux kernel can also exist elsewhere, as long as Lilo is configured and Lilo knows where the Linux kernel is.

/bin boot program (binary execution file) required for system startup, these files can be used by ordinary users

/dev represents the device file directory for the hardware component. LINUX devices are treated as files, so the hardware is abstracted and

To read-write, network sharing, and temporary loading into the file system. Under normal circumstances, the device will have a separate subdirectory. These devices

Content will appear in separate subdirectories. LINUX does not have a so-called driver.

/etc store various configuration files

/ETC/RC.D startup configuration files and scripts

/home User master directory with parameter settings files, personalization files, documents, data, EMAIL, cached data, etc.

/lib Standard Programming Library, also known as dynamic Link shared library, acts like a. dll file in Windows

/sbin the boot program (binary execution file) that is reserved for system administrators for system startup, and these files are not intended to be

Normal users (normal users can still use them, but to specify directories)

/tmp Common temporary file storage point, the directory will be automatically cleaned up

/root system Administrator's home directory

The/MNT system provides this directory to allow users to temporarily mount other file systems.

/lost+found This directory is usually empty, the system is not properly shut down and leave the "homeless" files (what is called under Windows. chk) right here.

/proc virtual directory, is the system memory mapping, can directly access the directory to obtain system information. The entire directory contains

Unreal file. They do not actually exist on the disk, and they do not occupy any space. (use Ls–l to display their size) when viewing

These files are actually accessing the information that exists in memory, which is used to access the system

/PROC/1 the directory of information about process 1. Each process has a directory named its process number under/proc.

/var Some large file overflow areas, such as log files for various services, contain files that have been changed during normal operation:

Spool files, record files, lock files, temporary files, and page format files

/var/spool mail, news, print queues, and other queue work directories. Each of the different spool have their own under the/var/spool

Subdirectories, for example, the user's mailbox in/var/spool/mail.

/opt optional applications, such as KDE under REDHAT 5.2 (REDHAT 6.0, KDE is placed in other

Xwindows application, the main executor is in the/usr/bin directory)

/usr The largest directory, the applications and files to be used almost all in this directory.

/home/var/usr/local are often separate partitions because they are often manipulated and prone to fragmentation.

/srv This directory holds data that needs to be extracted after some services are started

Common Linux configuration files