System.CommandLine

From Xojo Documentation

Read-Only Property (As String )
StringValue = aSystem.CommandLine

New in 5.5

Supported for all project types and targets.

This property contains the parameters passed to the application.

Notes

For example, if the application "Foo.exe" was executed with the call "Foo.exe a b c", then CommandLine would contain "Foo.exe a b c". This is valid for Windows, macOS, and Linux applications.