This is really old, but still helpful

  1. Basic scan:

  2. Scan multiple addresses:

  3. Scan entire subnet looking for valid hosts. This quick scan will also grab MAC address and perform MAC lookup to help determine what the host is.

  4.   Discovery:  Before a scan nmap will attempt to send an ICMP echo request.  To not send the ICMP, :

  5. To do only a ping scan:

  6. Do an ARP Ping scan:

  7. Port Scanning options:  Performing a Fast scan:

  8. Scan only specific ports:

  9. Scan multiple ports:

  10. Scan ports by name (found in /etc/services)

  11. Scan all ports:

  12. Choose between TCP and/or UDP:

  13. What OS is the target running?

  14. If the OS is unknown, have nmap attempt to guess the OS

  15. Service version detection


I have no idea how or why this started happening however my monitors would go black after 15 seconds of idle.  No power settings or screensavers were causing it, nor did I see any helpful logs to help troubleshoot.  However somewhere/how the Energy Star features of my monitor got enabled and literally after 15 seconds of idle time the monitors would go black..

Simple fix:


This fixed the issue not only for the current logged in session but also after a reboot.

$# : Number of arguments passed via script

$0 : Name of the script

$@ : Names of arguments passed to the script at execution

$$ : Process ID associated with script

$OSTYPE : What’s the OS type?

$TERM :  What’s term is being used?

$USER : What’s the username that executed the script?

$HOSTNAME : What’s the hostname of the box that ran the script?

$LOGNAME :  What was the login username?

$LINENO : Current line # of the script

$RANDOM : Random #

$BASH_SOURCE :  What’s the bash source?

Example script:





This will create a folder for each month 01-12.  Inside each month folder will be 30 or 31 folders for each day of the month except for Feb. which will have only 28.  This can be changed to 29 if it happens to be a leap-year.