Turn from: http://www.cnblogs.com/JCSU/articles/2770249.html for learning reference only
First, the Linux directory structure
Do you want to know why some programs are located under/bin, or/sbin, or/usr/bin, or/usr/sbin directories? For example, the less command is located in the/usr/bin directory. Why not in/bin, or/sbin, or/usr/sbin directory? What is the difference between all these directories?
In this article, let's review the file system architecture of Linux and understand the meanings of the top-level directories.
Blue: Indicates directory
Cyan: Indicates a link
Black: Indicates file
1,/-root
Each file and directory starts with the root directory.
Only the root user has write permissions to the directory. Please note that/root is the root user's home directory, which is not the same as/.
2,/bin -user binary files
Contains a binary executable file.
In single-user mode, the common Linux commands you need to use are located in this directory. The commands used by all users of the system are set here.
For example: PS, ls, ping, grep, CP
3./sbin Directory-System binaries
Just like/bin,/sbin also contains binary executables.
However, Linux commands in this directory are usually used by system administrators to maintain the system. Example: Iptables, reboot, Fdisk, ifconfig, swapon commands
4./etc -configuration file
Contains the configuration files that are required for all programs.
It also contains startup and shutdown shell scripts for starting/stopping a single program. For example:/etc/resolv.conf,/etc/logrotate.conf
Hosts: The resolution of the device name (or domain name) to the IP address, equivalent to the local presence of DNS functionality. See:
5./Dev -device files
Contains device files.
These include terminal equipment, USB or any device connected to the system. For example:/dev/tty1,/dev/usbmon0
6./proc -Process information
Contains information about the system process.
This is a virtual file system that contains information about the processes that are running. For example: The/proc/{pid} directory contains information related to a specific PID.
This is a virtual file system in which system resources exist as textual information. Example:/proc/uptime
7./var -variable file
var represents a variable file.
This directory allows you to find files that may grow in content.
This includes-system log files (/var/log), Package and database files (/var/lib), e-mail (/var/mail), print queue (/var/spool), lock Files (/var/lock), multiple restarts of required temporary files (/var/tmp) ;
8./tmp -temp file
Contains system and user-created temporary files.
When the system restarts, the files in this directory will be deleted.
9./usr -user program
Source code that contains binaries, library files, documents, and level two programs.
The/usr/bin contains a binary file of the user program. If you can't find the user binaries in/bin, go to the/usr/bin directory to see. For example: At, awk, CC, less, SCP.
The/usr/sbin contains the system administrator's binaries. If you can't find the system binaries in/sbin, go to the/usr/sbin directory to see it. For example: ATD, Cron, sshd, Useradd, Userdel.
The/usr/lib contains the libraries used by/usr/bin and/usr/sbin.
The user program installed from the source is included in the/usr/local. For example, when you install Apache from the source, it will be in/usr/local/apache2.
10. /home Directory
All users use the home directory to store their personal files.
For example:/home/john,/home/nikita
11./boot -Boot loader file
Contains the boot loader-related files.
The kernel's initrd, vmlinux, and grub files are located under/boot.
For example: Initrd.img-2.6.32-24-generic, Vmlinuz-2.6.32-24-generic
12./lib -System Library
Contains library files that support binary files located under/bin and/sbin.
The library file is named ld* or lib*.so.*
Example: ld-2.11.1.so,libncurses.so.5.7
13,/opt -Optional add-on app
OPT stands for optional.
Contains additional applications from individual vendors.
Additional applications should be installed in subdirectories of/opt/or/opt/.
14,/mnt -Mount Directory
A temporary installation directory where the system administrator can mount the file system.
15./media -removable media device
A temporary directory that is used to mount removable devices.
For example, mount the CD-ROM/media/cdrom, mount the floppy disk drive/media/floppy;
16./srv -Service data
The SRV Representative service.
Contains data related to server-specific services.
For example,/srv/cvs contains CVS-related data.
Reference
Linux Filesystem Hierarchy
Source and pre-formatted versions available 1. Linux Filesystem Hierarchy
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- 1.1. Foreward
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- 1.2. The Root Directory
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- 1.3. /bin
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- 1.4./ Boot
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- 1.5./ Dev
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- 1.6. etc
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- 1.7. /Home
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- 1.8. /INITRD
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- 1.9. /lib
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- 1.10. /lost+found
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- 1.11. /media
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- 1.12. /mnt
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- 1.13. /opt
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- 1.14. /proc
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- 1.15. /root
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- 1.16. /sbin
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- 1.17./ usr
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- 1.18./ var
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- 1.19. /srv
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- 1.20./ tmp
Glossary A. UNIX System V signals B. Sources c. about the Author D. Contributors E. Disclaimer F. Donations G. Feedback H. GNU free documentation License
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- H.1. Preamble
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- H.2. Applicability and Definitions
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- H.3. Verbatim COPYING
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- H.4. COPYING in QUANTITY
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- H.5. Modifications
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- H.6. Combining DOCUMENTS
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- h.7. collections of DOCUMENTS
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- H.8. AGGREGATION with independent WORKS
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- H.9. translation
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- h.10. termination
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- h.11. Future revisions of this LICENSE
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- h.12. Addendum:how to use this License for your documents
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Ii. Common Commands
1. Command Help
2. Users
3. SHELL
4, display hard disk, partition, CPU, memory information
5. Network
6. Process
7. Documents
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1. Command Help
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[[Email protected] ~] #man PS
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2. Users
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$finger Username Display user username information
$who show current logged in user
$who am I
$su become the root user
$sudo command executes as the root user
$PASSWD Change your password
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3. SHELL
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$history Show command history under the current shell
$alias Show all the commands for the nickname
$alias new_command= ' command ' is called New_command
$env Show all the environment variables
$export var=value Set environment variable var to value
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4, display hard disk, partition, CPU, memory information
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$DF-LH Show the usage of all hard drives
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$du-sh * Displays the size of each directory and file in the current directory
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$mount Show all hard disk partition mounts
$mount partition path hangs on partition path
$umount Partition Uninstall partition
$sudo fdisk-l Show All the partitions
$sudo fdisk device to create a partitioned table for device (such as/DEV/SDC). After entering, select N, p, W
$sudo mkfs-t ext3 partition formatted partition patition (e.g./DEV/SDC1)
Modify the/etc/fstab to mount the partition automatically. Add Rows:
/DEV/SDC1 Path (mount point) ext3 defaults 0 0
$arch Display Schema
$cat/proc/cpuinfo Display CPU Information
$cat/proc/meminfo Display Memory information
$free Show Memory usage
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5. Network
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The $ifconfig displays the network interface and the corresponding IP address. Ifconfig can be used to set the network interface
$ifup eth0 running Eth0 interface
$ifdown eth0 Close the Eth0 interface
$iwconfig Show Wireless network interface
$route Show the routing table. The route can also be used to modify the routing table
$netstat Display the current network connection status
Send ping packets to address IP $ping IP
$traceroute IP Probe routing path to address IP
$dhclient send DHCP requests to the DHCP host for IP addresses and other setup information.
$host domain DNS query to find the IP
$host IP Reverse DNS Query
$wget URL uses wget to download the resource that the URL points to
$wget-m URL image download
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6. Process
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$top display process information and update it in real time
$ps shows the process under the current shell
$ps-lu username shows the process of user username
$ps-AJX Show All processes in a more complete format
$kill PID kills the PID process (PID is the process ID)
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7. Documents
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$touch filename If the file does not exist, create a blank file, or update the file read and modify times if the file exists.
$rm filename Delete files
$cp file1 file2 copy file1 to File2
$ls -l path displaying file and file-related information
$mkdir dir Create dir folder
$mkdir-P path recursively create paths to all folders on path
$rmdir dir & nbsp; Delete dir folder, dir must be an empty folder.
$rm-R dir Delete the Dir folder and all files it contains
$file filename file filename type description
$chown username:groupname filename The owner of the changed file is owner, and owns group
$ chmod 755 filename Change the permissions for a file to 755:owner r+w+x, group:r+x, others:r+x
$od-C filename display the file in ASCII characters /dt>
$cat filename Display file
$cat file1 file2 Connection displays file1 and File2
$head-1 filename Displays the first line of the file
$tail-5 filename Displays the fifth line of the file
$diff file1 file2 shows the difference between File1 and file2
$sort filename to sort the rows in the file and display
$sort-f filename is sorted regardless of case
$sort-u filename Sort, and remove duplicate rows
$uniq filename Displays the rows that are not duplicates in the file filename (the same content but not adjacent rows, not duplicates)
$WC the number of characters, words, and lines in the filename statistic file
$WC the number of rows in the-l filename statistic file
RPM: Linux directory structure and common commands