Key Based Authentication for SSH

What is key based authentication for ssh?

keyKey based authentication for SSH is a way to connect remotely to another computer/server using an encrypted file you HAVE and an optional password you KNOW to unlock the file. Key based authentication has the advantage of being more secure and/or more convenient.


Password based authentication:
Logging in via password over SSH encrypts your password so it ends up looking like this:
..t-:p.%.E.{..E..X7.@.@.~....s..............NXP...{W..!8..;.eh9..N......#....q..1f...:...D9R0 zy
Because the password is encrypted, it won’t be seen in plain text over the wire which is good. If the password is short or simple enough, a hacker will be able to crack your password. Assuming the password is good enough, password based authentication’s strength comes from keeping that knowledge from others.

Key based authentication allows you to connect remotely using an encrypted file as a key instead of a password. Key based authentication gives you the option to Continue reading Key Based Authentication for SSH

Where Are the Default Mac OS X Icons

Where are the default Mac OS X Icons in .icns format?




How to get there:

you can get there several different ways.
1) Paste into Terminal

cd /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources; open .

2) Open Finder -> Select “Go” menu item -> Select “Go to Folder” -> Paste


3) Open Finder -> (Keyboard Shortcut) Shift + Command + G -> Paste


Become a power “pinger” in the Terminal


It is always fun to read the “man” pages in terminal and learn more about each command that I already use. I recently read the man page for ping and learned some cool stuff worthy of sharing.

Ping in specific time intervals

  • To ping at a time interval other than the default 1 second us the option flag of ‘-i [seconds to wait]’
  • Example: ping -i5
    • This command will send a ping to google every 5 seconds
    • Note: It appears that any interval below 1 second requires root privileges

Super Ping! aka “Flood ping”
Personally, I think super ping sounds way cooler than flood ping but the later provides a better description of what it does.

  • According to the “man” pages, a flood will send out pings as fast as they come back or 100 pings/sec. Which ever one is happening faster will be the rule that is followed.
  • Example: sudo ping -f
    • This command will print a period to the console for every packet sent and will delete a period for every packet received. The cumulative effect of this is as more packets are dropped you will see more and more periods accumulate on the screen giving you instant feed back on how fast packets are being dropped.
    • Note: Use this command very wisely and with caution as it taxes your network.
    • With my internet connection, pinging google, I was able to send off 6,000 pings in 10 seconds.

The terminal is a very powerful tool!



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Creative Commons License
Become a power “pinger” in the Terminal by Mike Grace is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.

The “man” pages were used for the information found in this post. You can find the ping man page by typing into a unix or linux terminal the command “man ping” or a copy of several operating system man pages can be found at

open files or directory from OS X terminal

Terminal loves Finder
Terminal loves Finder

In Mac OS X Terminal open the current folder in Finder by using the command ‘open .’ You can also open a file with its default application by using ‘open fileName.fileExtension’


If the current working directory in terminal is “/System/Library” then ‘open .’ would open “/System/Library” in finder.

‘open test.txt’ would open the text file “test.txt” in TextEdit.

‘open *’ would open all the files in the current directory with their default applications.

‘open *.jpg’ opens all jpg images in folder.

‘open [ABC]*.pdf’ opens all pdfs that start with an uppercase A, B, or C.

The possibilities and the power of the ‘open’ command in terminal are astounding. Learn even more about the command by using the command ‘man open’ or just ‘open’ and the terminal will display more information on that command and how it is used. If you use the ‘man open’ command spacebar will show the next page and ‘q’ will exit the manual.

The heart in the image was acquired from under the Creative Commons Attribution 2.5 Generic License

URL: Accessed: 2009-4-24. (Archived by WebCite® at

Creative Commons License
Open files or directory in Finder from OS X Terminal by Mike Grace is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.