I don’t generally forget the password for Wi-Fi networks I use, mainly because I use 1Password to store all secrets. But, I ran across the ability to retrieve the password, in plain text, from the OS X Keychain of an SSID I’ve previously connected with. Not a huge amount of utility to this but it’s interesting the capability exists.

Below are the various Bash commands needed to flush DNS on Mac OS X. There are several different versions of the commands depending on which version of OS X in use. Ensure you are selecting the command appropriate for your OS. HT to OSXDaily for additional explanations on what is happening under the covers.

Generating an SSH key without a password. For example, for passphraseless old school Hadoop clusters. This is generally done from within a users home directory such as /Users/username on Mac.