Allows running an external program on the data. It will write out the incoming datatable into a temporary file which can be used as an input to an external tool. After the tool finishes the node will read in an output file the tool has (hopefully) created.
NOTE: Running an external executable takes the control out of our hands. There will be no progress, no failure message, exceptions will not be caught, it may even cause the entire KNIME platform to fail and you loose any unsaved data, etc. Especially, if a shell script (or .bat file) creates sub processes (by calling other programs), these sub processes will continue living even if the node gets canceled. Furthermore, their output will not be fetched, causing them (possibly) to block (not finishing their job) and to exist until you kill them off manually.
Highlighting will not work across this node. Colors are lost (the Color Manager node must be inserted in the flow to re-generate colors).
The output of the external tool is caught and can be seen in the node's views (the last 500 lines only, full output is logged to KNIME's log file - if the log level is set to DEBUG, which is the default).