Linux Common commands

To get a good command, have a Linux system, and learn some Linux system knowledge, here are some examples:

root directory	The file system differs from window in that the root directory is/
Relative path, absolute path	Indicates absolute path/home/ken/xxx with/start does not start with/to indicate a relative path such as CD./cdir represents the Cdir directory under the current directory
Inode
Shell	Bash Tcsh zsh
Environment variables	Http://www.cnblogs.com/growup/archive/2011/07/02/2096142.html
Input and output redirection	Http://www.cnblogs.com/chengmo/archive/2010/10/20/1855805.html
Pipeline	Connect the output of one program directly to the input of another program

There is a list of UNIX commands on the wiki: http://zh.wikipedia.org/wiki/Template:Unix%E5%91%BD%E4%BB%A4

Because Linux and UNIX are compatible, you can refer to learning directly. Here are some of the commands that I commonly use, simply categorize and attach simple instructions:

File System command:

Pwd	Show Current working directory
Cd	Cd. To the current directory Cd.. To the parent directory CD ~ To user home directory CD/To root directory
Ls	List Directory Contents Study site: http://www.cnblogs.com/s7vens/archive/2011/12/01/2270426.html -a lists all files that contain the files that begin with the. file in Linux. The files that begin represent hidden files -A lists all files, not included. And.. -L Show more information -H human readable, and-l use the displayed size with units such as Ls-lh Cdir -I display Inode -s sort sorted by size -T Sort by time -R reverse and sort mates ls-sr xx means reverse ls–tr xxx in reverse chronological order of file size Example: LS */*.c lists all c files in the level two directory
chmod	Change file permissions, only the file owner and Superuser can modify the file or directory permissions. Study site: Http://zh.wikipedia.org/wiki/Chmod Use octal syntax to represent permissions: r=4 w=2 x=1–=0 rwx, 4+2+1=7 chmod 664 MyFile Modify the owner and other users within the group have read and write access to the file, and the other members of the group are only reading permissions To represent permissions in symbolic mode: User: U:user file owner g:group file owner Groups o:Others all other user A:all users, equivalent to Ugo Action: +: Add permissions for the specified user type-: Remove permissions for the specified user type = Set settings for the specified user rights, reset all permissions for the user type \ Permissions: r: Read W: Write X: Execute chmod ug+rw,o=r myfile chmod u=rwx,go= myfile
Cat	File content View
Cp	Copy CP file1 File2 CP *.c DIR0 CP./ken/* Dir1 Cp–r dir1 dir2 Copy a directory and any subdirectories and files it contains into another directory, like-R and-R Cp–i Overlay Tips Cp–f forcibly copied, covered by the way
Rm	Delete Rm–i file with hints Rm–f Mandatory Delete directory with write protection excepted Rm–r Deleting a directory recursively Xargs rm< filelist Bulk Delete Find. -name ' *.png '-print0 | xargs-0 RM
Mv	Move Rename -I interaction -F Mandatory -N does not overwrite existing files, so-I and-F are invalidated.
Touch	Change the file access modification time, create a new empty file Touch myfile file does not exist on new file, file exists on Change access and modification time to current time
Mkdir	New Catalog mkdir test1 -V Displays information each time a new directory is created -P Create a multilevel directory MKDIR–VP Test1/test2/test3

User environment:

Clear	Clear screen, equivalent to the CLS in Windows
Histrory	View history Commands
Su	SU User name Switch user
WhoAmI	Who the current user is, is useful when you are constantly converting an identity operating system. For example, just starting the user is Ken, after running the command Su Yan, identity becomes the Yan user, Su root after the identity becomes the super user This command comes in handy when you need to know which user you are currently working with.
Sudo	Run as Super User
passwd	Change Password
Exit	Exit
Env	Display shows all environment variables and values

Program:

Ps	To display a running process -L Long format -F Tree Format -a Show all user processes -R Running Process How many CPUs the%CPU process is using How much memory is being used by the%MEM process Memory address of the ADDR process C or CP CPU usage and scheduling information command* process name, including parameters (if any) NI Nice value F Mark PID Process ID PPID Parent Process ID PRI Process Priority RSS Real Memory usage S or STAT process status code Start or stime process startup time SZ Virtual Memory usage Time Total CPU Usage tt or TTY with process-related terminals UID or username of user process Owner Memory address of the event that the Wchan process waits for
Top	Dynamic Display Process
Kill	kill–9 20345 force kills 20345 process
Date	Display and set the system date and time
Time	Executing commands and timing
Aa.	Show Calendar

Find and edit:

Awk	The file is read line by row, with a space as the default delimiter will be sliced each row, cut the part of the various analytical processing. $ A represents all fields, representing the first domain, $n represents the nth field. The default Domain delimiter is the "blank key" or "[tab] key" Last-n 5 | awk ' {print '} ' shows the 1th column of last-n 5 execution results CAT/ETC/PASSWD |awk-f ': ' {print $} ' per line: separator
Head	Head-n file1 Display the first 10 lines of the file
Tail	tail–f file1 dynamic Monitor file growth Tail–n file1 display file after 10 lines
Wc	Displays the number of lines of the file in bytes file name. -C Count bytes. -L counts the number of rows. -M counts the number of characters. This flag cannot be used with the-C flag. -W count words. A word is defined as a string separated by a blank, a jump, or a newline character.
Vi	Study site: http://www.cnblogs.com/88999660/articles/1581524.html
Find	Find Files You can use the logical operators and, or, and not to correspond to –a-o! Find–name ' *.bak ' –o–name ' *.log ' Find it! –name ' File1 ' -group Specifying groups -user the specified user -empty finding a directory or file of size 0 Reference: http://blog.chinaunix.net/uid-20082146-id-83489.html
Grep	Http://www.cnblogs.com/end/archive/2012/02/21/2360965.htm
Whereis	Truncate the path to the front end of the provided file name parameter with the extension part of the backend and find out the special file with which the file name matches Lookups are primarily for locating targets in the path of an environment variable, and are typically used for program command location lookups
More	Split screen Display
Xargs	Convert a parameter list to a small segment to pass to another command Http://zh.wikipedia.org/wiki/Xargs

Other:

man	man ls view command manual
Shutdown	shutdown–r now restart shutdown  now shutdown
ping	ping xx.xx.xx.xx  Detect network Connectivity
ssh	Telnet, now log in more with the tools of SSH
netstat	http://www.cnblogs.com/g gjucheng/archive/2012/01/08/2316661.html
nohup	http://www.2cto.com/os/201301/185701.html