Does the exec task pass the integration properties via the command line?
No. The integration properties are only available as environment variables. As there is no way of knowing the way in which the external program expects these properties to be formatted as command line arguments, environment variables are a simple, common medium for making these values accessible. To pass these environment variables into an external program, have the exec task call a batch file instead that will pick up the environment variables, format them and pass them as command line arguments to the external program. Using built in shell commands In Windows use cmd.exe as the executable, and pass the wanted command as an argument, preceded with /c. This allows to execute del *.* and the like.
