Can I disable a dataset from the command line

From Fmepedia

Q) Can I disable a dataset from the command line?

A) No. It's been filed as an enhancement request, so if you need to do this please contact support (http://www.safe.com/support/contact/form.php) and have them add your details to the PR. The more requesters, the quicker it will be implemented.

A workaround in the meantime would be to publish the 'Max Features to Read' option for each reader (see navigation pane > dataset > parameters > advanced - this needs FME2006-GB). Having done this you can specify either...

fme <workspace_name> --MAX_FEATURES_1=1 --MAX_FEATURES_2=99999999

or

fme <workspace_name> --MAX_FEATURES_1=99999999 --MAX_FEATURES_2=1

...depending on which dataset you wanted to read. I use 1 rather than 0 because I'm not sure this function works when set to zero.

Custom Transformer

Thanks to Jeff at Inser (http://www.inser.ch) in Switzerland for sending the Enabler Custom Transformer that lets you turn datasets on and off from either Workbench or the command line - the data does actually get read, but is discarded if the writer is set to 'false'.