Learn how to simulate a multi-dimensional array in bash using an associate array with clever use of the hash key. Bash 4 only provides one-dimensional indexed and associative array variables.
Manage multiple ssh private keys and configure ssh to map different private keys to different hosts automatically by using ~/.ssh/config configuration file
Explains how to retrieve the WM_CLASS property of a window on Linux and also how to manually define the WM_CLASS property in desktop files using StartupWMClass field.