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tutorials:unix_commands [2016/03/27 21:13]
Richard.Randriatoamanana@ec-nantes.fr
tutorials:unix_commands [2016/03/27 21:27] (current)
Richard.Randriatoamanana@ec-nantes.fr [Common Linux Shell Commands]
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 chmod 755  #Usually for CGI scripts</​code>​ chmod 755  #Usually for CGI scripts</​code>​
  
 +===chown=== ​
 +Changes file ownership permissions
  
-chown: changes file ownership permissions +The set of 2 go in this order from left to right: ​**USER - GROUP**<code bash> 
-The set of 2 go in this order from left to right: +chown root myfile.txt ​      # Changes the owner of the file to root 
-USER - GROUP+chown root.root myfile.txt ​ # Changes the owner and group of the file to root</​code>​
  
-chown root myfile.txt : Changes ​the owner of the file to root +===tail=== 
-chown root.root myfile.txt : Changes ​the owner and group of the file to root+Like ''​cat'',​ but only reads the end of the file.<code bash> 
 +tail /​var/​log/​messages ​     # see the last 20 (by default) lines of /​var/​log/​messages  
 +tail -f /​var/​log/​messages ​  # watch the file continuously,​ while it's being updated ​ 
 +tail -200 /​var/​log/​messages # print the last 200 lines of the file to the screen</​code>​
  
 +===more/​less===
 +like cat, but opens the file one screen at a time rather than all at once<​code bash>
 +more /​etc/​userdomains # browse through the userdomains file. hit Space to go to the next page, q to quit</​code>​
  
-tail : like cat, but only reads the end of the file +===vi=== 
-tail /var/log/messages : see the last 20 (by default) lines of /var/​log/​messages  +<code bash>​vi ​/home/burst/public_html/index.html # edit the index page for the user'​s ​website</code>
-tail -f /​var/​log/​messages : watch the file continuously,​ while it'​s ​being updated  +
-tail -200 /var/​log/​messages : print the last 200 lines of the file to the screen+
  
-more : like catbut opens the file one screen at a time rather than all at once  +While in the vi program you can use the following useful commandsyou will need to hit SHIFT + : to go into command mode<​code bash> 
-more /​etc/​userdomains ​browse through ​the userdomains ​file. hit Space to go to the next page, q to quit +:q! # This force quits the file without saving and exits vi 
 +:w  # This writes ​the file to disk, saves it 
 +:wq # This saves the file to disk and exists vi 
 +:LINENUMBER : EG :25 # Takes you to line 25 within ​the file 
 +:$ # Takes you to the last line of the file 
 +:0 # Takes you to the first line of the file</​code>​
  
-pico friendly, easy to use file editor  +  * [[http://www.tutorialspoint.com/unix/unix-vi-editor.htm]] 
-pico /home/burst/public_html/index.html edit the index page for the user's website+  * [[http://​www.openvim.com|interactive tutorial]]
  
-File Editing with VI commands +===grep=== 
-vi : another editor, tons of features, harder to use at first than pico  +Looks for patterns in files <code bash> 
-vi /home/burst/public_html/index.html : edit the index page for the user's website. ​ +grep root /etc/passwd ​   # shows all matches of root in /etc/passwd 
-Whie in the vi program you can use the following useful commands, you will need to hit SHIFT + : to go into command mode+grep -v root /etc/passwd # shows all lines that do not match root</​code>​
  
-:q! : This force quits the file without saving and exits vi +===ln=== ​ 
-:w : This writes the file to disk, saves it +Create'​s "​links"​ between files and directories<​code bash> 
-:wq : This saves the file to disk and exists vi +ln -s /​usr/​local/​apache/​conf/​httpd.conf /​etc/​httpd.conf # Now you can edit /​etc/​httpd.conf rather than the original. changes will affect ​the original, however ​you can delete ​the link and it will not delete ​the original.</​code>​
-:LINENUMBER : EG :25 : Takes you to line 25 within ​the file +
-:$ : Takes you to the last line of the file +
-:0 : Takes you to the first line of the file+
  
-grep : looks for patterns ​in files  +===last=== 
-grep root /etc/passwd : shows all matches of root in /etc/passwd +Shows who logged ​in and when<​code bas> 
-grep -v root /etc/passwd : shows all lines that do not match root +last -20    # shows only the last 20 logins ​ 
 +last -20 -a # shows last 20 logins, with the hostname in the last field </code>
  
-ln : create'​s "​links"​ between files and directories +===w=== 
-ln -s /usr/​local/​apache/​conf/​httpd.conf /​etc/​httpd.conf : Now you can edit /​etc/​httpd.conf rather than the original. changes will affect the orginal, however you can delete the link and it will not delete the original. ​+shows who is currently logged in and where they are logged in from. 
 +<code bash>who # This also shows who is on the server in an shell</code>
  
-last : shows who logged in and when +===netstat=== 
-last -20 : shows only the last 20 logins ​ +shows all current network connections. 
-last -20 -a : shows last 20 logins, with the hostname in the last field +<code bash> 
 +netstat ​-an # shows all connections to the server, the source and destination ips and ports. 
 +netstat ​-rn # shows routing table for all ips bound to the server.</​code>​
  
-w : shows who is currently logged in and where they are logged in from. +===top=== 
-who : This also shows who is on the server in an shell. +shows live system processes in a nice table, memory information,​ uptime and other useful info. This is excellent for managing your system processes, resources and ensure everything is working fine and your server isn't bogged down.
- +
-netstat : shows all current network connections. +
-netstat -an : shows all connections to the server, the source and destination ips and ports. +
-netstat -rn : shows routing table for all ips bound to the server. +
- +
-top : shows live system processes in a nice table, memory information,​ uptime and other useful info. This is excellent for managing your system processes, resources and ensure everything is working fine and your server isn't bogged down.+
 top then type Shift + M to sort by memory usage or Shift + P to sort by CPU usage top then type Shift + M to sort by memory usage or Shift + P to sort by CPU usage
  
-psps is short for process status, which is similar to the top command. It's used to show currently running processes and their PID. +===ps=== 
-A process ID is a unique number that identifies a process, with that you can kill or terminate a running program on your server (see kill command). +//ps// is short for process status, which is similar to the top command. It's used to show currently running processes and their PID. A process ID is a unique number that identifies a process, with that you can kill or terminate a running program on your server (see kill command).<code bash> 
-ps U username ​shows processes for a certain user +ps U username ​shows processes for a certain user 
-ps aux shows all system processes +ps aux shows all system processes 
-ps aux --forest ​shows all system processes like the above but organizes in a hierarchy that's very useful!+ps aux --forest ​shows all system processes like the above but organizes in a hierarchy that's very useful!</​code>​
  
-touch : create ​an empty file  +===touch===  
-touch /​home/​burst/​public_html/​404.html ​create an empty file called 404.html in the directory /​home/​burst/​public_html/ ​+creates ​an empty file <code bash> 
 +touch /​home/​burst/​public_html/​404.html ​create an empty file called 404.html in the directory /​home/​burst/​public_html/ ​</​code>​
  
-file attempts to guess what type of file a file is by looking at it's content.  +===file=== 
-file * prints out a list of all files/​directories in a directory ​+attempts to guess what type of file a file is by looking at it's content.  
 +<code bash>file * prints out a list of all files/​directories in a directory</​code>​
  
-du shows disk usage.  +===du===  
-du -sh shows a summary, in human-readble form, of total disk space used in the current directory, including subdirectories. +shows disk usage.<code bash> 
-du -sh * same thing, but for each file and directory. helpful when finding large files taking up space. ​+du -sh shows a summary, in human-readble form, of total disk space used in the current directory, including subdirectories. 
 +du -sh * same thing, but for each file and directory. helpful when finding large files taking up space. ​</​code>​
  
-wc word count +===wc=== 
-wc -l filename.txt ​tells how many lines are in filename.txt ​+word count 
 +<code bash>wc -l filename.txt ​tells how many lines are in filename.txt</​code>​
  
-cp copy a file  +===cp===  
-cp filename filename.backup ​copies filename to filename.backup +copy a file <code bash> 
-cp -a /​home/​burst/​new_design/​* /​home/​burst/​public_html/ ​copies all files, retaining permissions form one directory to another.  +cp filename filename.backup ​copies filename to filename.backup 
-cp -av * ../​newdir ​Copies all files and directories recurrsively in the current directory INTO newdir+cp -a /​home/​burst/​new_design/​* /​home/​burst/​public_html/ ​copies all files, retaining permissions form one directory to another.  
 +cp -av * ../​newdir ​Copies all files and directories recurrsively in the current directory INTO newdir</​code>​
  
-mv : Move a file command +===mv=== 
-mv oldfilename newfilename ​Move a file or directory from oldfilename to newfilename+move a file command<code bash> 
 +mv -v oldfilename newfilename ​Move a file or directory from oldfilename to newfilename ​in a verbose mode</​code>​
  
-rm delete a file +===rm===  
-rm filename.txt ​deletes filename.txt,​ will more than likely ask if you really want to delete it +delete a file 
-rm -filename.txt ​deletes filename.txt,​ will not ask for confirmation before deleting. +<code bash>rm -vi filename.txt ​deletes filename.txt,​ will more than likely ask if you really want to delete it 
-rm -rf tmp/ recursively deletes the directory tmp, and all files in it, including subdirectories. BE VERY CAREFULL WITH THIS COMMAND!!! ​+rm -fv filename.txt ​deletes filename.txt,​ will not ask for confirmation before deleting. 
 +rm -rfv tmp/ recursively deletes the directory tmp, and all files in it, including subdirectories. ​ 
 +             # ​BE VERY CAREFULL WITH THIS COMMAND!!!</​code>​
  
-TAR: Creating ​and Extracting .tar.gz and .tar files +===tar===  
-tar -zxvf file.tar.gz ​Extracts the file +creating ​and Extracting .tar.gz and .tar files<code bash> 
-tar -xvf file.tar ​Extracts the file +tar -zxvf file.tar.gz ​        # Extracts the file that have been compressed 
-tar -cf archive.tar contents/ ​Takes everything from contents/ and puts it into archive.tar +tar -xvf file.tar ​            # Extracts the file 
-gzip -d filename.gz ​Decompress the file, extract it+tar -cf archive.tar contents/ ​Takes everything from contents/ and puts it into archive.tar 
 +gzip -d filename.gz ​          # Decompress the file, extract it</​code>​
tutorials/unix_commands.1459106034.txt.gz · Last modified: 2016/03/27 21:13 by Richard.Randriatoamanana@ec-nantes.fr