To match the different policies for Unix-like systems and Windows, and different policies used on different Unix-like systems, the folders containing configuration files and plugins are different on different platforms. We indicate the location of the top-level folders under which configuration files and plugins are stored here, giving them placeholder names independent of their actual location, and use those names later when giving the location of the folders for configuration files and plugins.
A list of the folders Wireshark actually uses can be found under the Folders tab in the dialog box shown when you select About Wireshark from the Help menu.
%APPDATA% is the personal application data folder, e.g.: C:\Users\username\AppData\Roaming\Wireshark (details can be found at: Section B.5.1, “Windows profiles”).
WIRESHARK is the Wireshark program folder, e.g.: C:\Program Files\Wireshark.
$XDG_CONFIG_HOME is the folder for user-specific configuration files. It’s usually $HOME/.config, where $HOME is the user’s home folder, which is usually something such as $HOME/username, or /Users/username on macOS.
If you are using macOS and you are running a copy of Wireshark
installed as an application bundle, APPDIR is the top-level directory
of the Wireshark application bundle, which will typically be
/Applications/Wireshark.app. Otherwise, INSTALLDIR is the top-level
directory under which reside the subdirectories in which components of
Wireshark are installed. This will typically be
/usr if Wireshark is
bundled with the system (for example, provided as a package with a Linux
distribution) and /usr/local if, for example, you’ve build Wireshark
from source and installed it.