The role and content of Linux directories

1) root directory "/"
   
The root directory is located at the top level of the directory structure, denoted by a slash (/), similar to the "C: \" of the Windows operating system, and contains all the directories and files in the Fedora operating system.

2)/bin
   
/bin
a directory, also known as a binary directory, contains binary images of important Linux commands used by system administrators and ordinary users. This directory contains a variety of executable files, as well as symbolic connections to some executables. Common commands are:CP, DMESG, kill, Login, rm, ping, CHOMD, bash, cat, echo, ls, Mail, vi and so on.

3)/boot
/ Boot
The directory holds the system core file and the files that must be read at startup, including the binary image of the Linux kernel.

4)/dev
/ Dev
The directory holds the files of external device code, which are special, in fact they point to the peripheral devices represented, such as the terminal, disk drives, optical drives, printers, and so on. You can access these external devices, with no distinction between accessing a file or a directory. If the subdirectory under this directory/dev/cdrom represents the optical drive directory, the subdirectory/dev/console represents the console; Subdirectories/DEV/FD represents a floppy disk drive, a subdirectory/DEV/HD represents a partition on the hard drive, lp0 represents a printer, ttyS0 represents a serial device for a system, and a DSP represents a system's speaker device. For example, in the system, type "CD/dev/cdrom ", you can see the files in the CD-ROM; type" Cd/dev/mouse "to see the relevant files of the mouse.

/cdromThis directory is empty when you just installed the system, you can hang the optical drive file system in this directory, for example "Mount/dev/cdrom/cdrom ".

5)/etc
/ etc
The directory is the center of the entire Linux system and contains all the configuration files for system administration and maintenance, such as dhcpd.conf, host.conf, logrotate.conf, Man.config, mke2fs.conf, Modprobe.conf, resolv.conf, sysctl.conf, syslog.conf (or rsyslog.conf), xinetd.conf, and yum.conf, and other configuration files are located in separate subdirectories. It is often important to take care to back up the critical configuration files in this directory so that you need to be able to recover the system quickly . Files that are used to store the system's configuration files and specific hosts. For example, record the name of the user accountpassword file, the shadow of the projection passwordfiles and so on. The directory does not contain any binaries, and all files in that directory are used primarily by administrators, and the normal user has read access only. The directory also contains some network configuration files, file systems,x System configuration file, device configuration information, set user information, and so on.
/ETC/CRON.D
used to store the configuration and control files used by the Cron process to schedule the running background process. Other directories include four directories, such as Cron.hourly, cron.daily, cron.weekly, and cron.monthly, defined by the/etc/crontab file.
   
/etc/cups is used to store various configuration files used by the Universal Unix Printing system (commom UNIX Printing system,cups).
   
/etc/default files are used to provide variables and their default values used by some tool software, such as the Useradd program.
/etc/httpd
the root directory of the Apache configuration file. Apache is a general-purpose, high-performance HTTP server and the most popular Web server in the world. Apache uses a modular design approach that supports runtime dynamic module selection, virtual hosting, and dynamic adjustment of the number of service processes.
   
The/ETC/INIT.D is used to store script files that need to be executed by the INIT scheduler when entering the appropriate run level. In Fedora
Linux system, this is just a symbolic link file, the actual directory should be/ETC/RC.D/INIT.D.
/ETC/IPSEC.Dused to store the configuration files used by Ipsee, and so on.
/ETC/KDE contains some KDE initialization files and KDM configuration files.
/etc/pkiused to store various keys, such as keys for installing packages.
The/ETC/PPP is used to store PPP scripts and configuration files.
/ETC/PROFILE.D is used to store secondary initialization files such as/etc/profile, such as lang.sh script files.
/ETC/RC.DThe script file that is used to store access to the appropriate run level is executed by the INIT process scheduler. It contains subdirectories such as INIT.D and RCN.D (where n is 0, 1, 2, 3, 4, 5, and 6, indicating the operating level of the system).
/etc/sambathe root directory of the Samba configuration file. Samba is a generic term for web-sharing software, and the SMB protocol implemented in Linux systems allows Linux systems to provide file and print sharing services for Windows systems.
/etc/security Basic Security control files stored by the user, including registration control files, control access control files, and resource restriction control files.
/etc/selinux SELinux (Security enhanced Linux, by the national securityAgency) led the development of the GPL project, which has a flexible and mandatory access control structure designed to improve the security of Linux systems, provide robust security assurances, and defend against unknown attacks, allegedly equivalent to B1 level military security performance. than Ms
NT so-called C2 is much higher. By applying selinux, you can mitigate the disaster caused by malicious attacks or malware, and provide high security for information that requires high confidentiality and integrity. ) The root directory of the configuration file.
/etc/skelIt contains default initialization files such as. bash_logout,. Bash_profile,. BASHRC,. Emacs,. KDE,. ZSHRC, and so on. each time a new user is added, the system will copy some of the initialization files to the user's home directory . Note: The above files are hidden files. (That is, "." File name at the beginning)
   
/etc/sshThis directory contains the system configuration process, as well as the various configuration files that need to be used during the system boot process, and also the root directory of the various background service process configuration files maintained by Chkconfig. For example, the clock file contains the system's time zone settings, the keyboard file contains the type definition of the keyboard, and the init file contains the parameter definitions used by the system boot process.
   
/etc/tomcat5 Tomcat root directory
/etc/vsftpdcontains configuration files for the FTP server, including important files such as vsftpd.conf, Ftpusers, and User_list.
/etc/xinetd.dIt contains the configuration files that are used by all traditional network services that are controlled by the XINETD service process, especially those that include network applications such as Telnet. In the Linux system, the original inetd has been replaced by a more powerful xinetd service process, and the original inetd.conf configuration file is replaced by a series of separate configuration files in the Xinetd.d directory.
   
/etc/yum contains the configuration files used by the Yum Software Update Tool.
   
/ETC/YUM.REPOS.D contains the configuration files for each software warehouse.

6)/lib
/lib
The directory where the necessary runtime libraries are located, mainly the programming language libraries. Typical Linux operating systems include C, C + +, and Fortran.the library file. Applications developed in these languages can use these programming language library files. This enables software developers to take advantage of pre-written and test-ready functions. The library file contains the standard C library/lib/libc.so.*, the math library libm.so.*, the shared dynamic link library/lib/ld/so, and other shared libraries used in the directory/bin and/sbin. The core module of the/lib/modules directory storage System, some modular parts of the system does not need to compile the kernel of the core ontology, to avoid the large size of the body resulting in reduced efficiency.

7)/lost+found
This directory holds all files that are not associated with any other directory. In the event of a system error or a problem, Fedora automatically scans the disk drive, corrects the error, and if a missing or faulty fragment is found, convert the fragments to a file for further processing by the administrator.

8)/mnt
This directory is the default file system temporary mount point, which is a common installation point that can temporarily install any file system or remote resources. The system administrator executes Mount
command to complete the load job. In the system, this directory contains the mount points of the optical drive, disk, and floppy drive.

9)/proc
   
the root directory of the process file system proc, where some files correspond to a running process and can be used to access the address space of the current process. It is a very special virtual file system, which does not contain "actual" files, but can be used to refer to the system information of the current running system, such as CPU, memory, run time, software configuration, and hardware configuration information, which is generated in memory by the system itself.
   
/proc/net The files represent the status and statistics of various network protocols, such as TCP, UDP, and ARP, respectively.
/proc/sysThis directory contains not only a variety of system information, but also the system kernel and TCP/IP network tunable parameters. The kernel subdirectory contains tunable parameters for shared memory and Message Queuing, and the net subdirectory contains various tunable parameters of TCP/IP. For example, the Shmmax file contains the maximum shared memory definition for the system, and if you use the Echosomevalue >
/proc/sys/kernel/shmmax "command, you can directly modify the kernel parameters of the running system without rebooting the system. This is prudent, and some files may contain multiple values, or different types of values, so be sure to clarify the meaning and actual values of the parameters before modifying them. In order to use custom system tunable parameters each time you start the system, you can set up a sysctl.conf profile or write your own shell startup script.

)/opt
   
/opt
The directory is used to install the add-on package, and the user calls the package program under directory/opt/package_name/bin, Package_name is the name of the installation package.

One )/root

The root directory of Superuser root (on Linux systems, the slash character "/" is the entire system roots, not the Superuser's home directory.) )

/sbin)
directories/sbin,/usr/sbin, and/usr/local/sbin store the programs that are executed when the directory starts the system, such as administrative tools, application software, and common root user rights commands. Include Getty, init, update

The role and content of Linux directories