Shell.ExecuteModes

From Xojo Documentation

Enumeration
[[Shell]].ExecuteModes

New in 2019r2

Specifies the types of modes in which the shell can execute.

Values

Enum Description
Synchronous (Default) The shell executes its command and returns the result in the Result property when the script has finished running. Synchronous shells block the main UI thread, even when they are in a thread themselves. For long-running shell processes, use one of the other shell modes instead.
Asynchronous The shell executes its command and returns data via the DataAvailable event. It does not wait for a command to finish before executing the next command. An asynchronous shell script can run in the background. You'll need to make sure the Shell instance does not go out of scope while you are waiting for operations to complete.
Interactive The script can display a prompt and the user can interact with the shell script while it is running. Data can be sent to a running shell session with the Write method and data is returned via the DataAvailable event. Refer the interactive shell Example included with your installation (Advanced/Shell). You'll need to make sure the Shell instance does not go out of scope while you are waiting for operations to complete.