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Useful Linux Commands - IV

  1. who : gets all the connections made to your account
  2. netstat –antp : to know all the process running on ports
  3. sudo /etc/init.d/network restart : restart networking on your linux box
  4. Understanding the init.d Directory – This directory has the control scripts for most of the services on our linux box. The start/stop/restart/reload/force-reload options can be used with any command found under this directory
    1. Most common Services controllable from this directory are: apache2, sshd, networking, ftpd, samba, mysql
    2. You can run any command using the following format: sudo /etc/init.d/<command> <option>
      1. where command can be apache2, sshd, networking etc
      2. and option can be start, stop, restart etc
    3. For ex: sudo /etc/init.d/networking restart Smile Simple!
  5. Refresh DNS Cache
    1. Ping your linux box using “ping <your_computer_name>” – Note down the IP Address shown
    2. Look at the contents of ifconfig file using “sudo /sbin/ifconfig” – Read the part labeled as inet addr:
    3. The two values noted down in step 1 and 2 should match. If they don’t then it means your DNS Cache is stale.
    4. Refresh the DNS Cache using “sudo /etc/init.d/nscd restart”
  6. uptime : This command tells you the current time, length of time the host has been running, numbers of users currently logged on, and the load averages for the past 1, 5, and 15 minutes.

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