..:: Common SSH Commands or Linux Shell Commands ::..
 
These are some basic linux commands I most commonly use when administering my linux shell. I work a lot remotely, so I use Putty or some secure SSH client. From a Linux desktop, you could use X-Terminal.
 
 


[indent]// wall : broadcasts a server wide message
wall "hi"
// ls : list files/directories in a directory, comparable to dir in windows/dos.
: shows all files (including ones that start with a period), directories, and details attributes for each file.
ls -al
// df : shows filesystem and usage
df
// cd : change directory · ·
: go to /usr/local/apache/ directory
cd /usr/local/apache: go to your home directory
cd ~: go to the last directory you were in
cd -
: go up a directory cat : print file contents to the screen
cd ..
// cat filename.txt : cat the contents of filename.txt to your screen
cat filename.txt
// tail : like cat, but only reads the end of the file
: see the last 20 (by default) lines of /var/log/messages
tail /var/log/messages
: watch the file continuously, while it\'s being updated
tail -f /var/log/messages: print the last 200 lines of the file to the screen
tail -200 /var/log/messages
// more : like cat, but opens the file one screen at a time rather than all at once
: browse through the userdomains file. hit to go to the next page, to quitmore /etc/userdomains
 
// pico : friendly, easy to use file editor
: edit the index page for the user\'s website.
pico /home/common/public_html/index.html(Your system may have "nano" which is a pico clone. In that case just replace "pico" with "nano" in the examples.)
 
// vi : another editor, tons of features, harder to use at first than pico
: edit the index page for the user\'s website.
vi /home/common/public_html/index.html
 
// grep : looks for patterns in files
: shows all matches of root in /etc/p***wd
grep root /etc/p***wd: shows all lines that do not match root
grep -v root /etc/p***wd
 
// touch : creates an empty file
: create an empty file called 404.html in the directory /home/common/public_html/
touch /home/common/public_html/404.html
// ln : create\'s "links" between files and directories
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.
 
// rm : delete a file
: deletes filename.txt, will more than likely ask if you really want to delete it
rm filename.txt: deletes filename.txt, will not ask for confirmation before deleting.
rm -f filename.txt: recursively deletes the directory tmp, and all files in it, including subdirectories.
rm -Rf tmp/ BE VERY CAREFULL WITH THIS COMMAND!!!
 
// last : shows who logged in and when
: shows only the last 20 logins
last -20: shows last 20 logins, with the hostname in the last field last -20 -a
// w : shows who is currently logged in and where they are logged in from.
w
// netstat : shows all current network connections.
: shows all connections to the server, the source and destination ips and ports.
netstat -an: shows routing table for all ips bound to the server.
netstat -rn
 
// 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 -crun top then type Shift + M to sort by memory usage or Shift + P to sort by CPU usage. Type "q" to quit.
 
// ps: 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).
: shows processes for a certain user
ps U username: shows all system processes
ps aux: shows all system processes like the above but organizes in a hierarchy that\'s very useful!
ps aux --forest
// file : attempts to guess what type of file a file is by looking at it\'s content.
: prints out a list of all files/directories in a directory
file *
// du : shows disk usage.
: 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.
du -sh *
 
// wc : word count
: tells how many lines are in filename.txt
wc -l filename.txt
// cp : copy a file
: copies filename to filename.backup
cp filename filename.backup: copies all files, retaining permissions form one directory to another.
cp -a /home/burst/new_design/* /home/common/public_html/
 
// kill: terminate a system process
: kill -9 (forceful) PID (process) number 431
kill -9 431Use top or ps ux to get system PIDs
 
 

[/indent]Feel free to comment or post more frequestly used shell commands

Another one that I find useful...

 cat /etc/passwd/

Will show you all the users on your *nix box and their home directories.

Is there a way to get all this in one message so that it can be printed out instead of a bunch of little messages I have to wade through. It would make life a lot easier for me.

THANK YOU
I just copied it all out to Tomboy notes for ease of access