That ought to work, almost. (I expect you need to double that backslash.) I suggest using .print to see what your actual submission to the shell meta-command is. As for the continuation prompt: I am with you on expecting that the primary prompt after that hairy piping means that it at least completed (even if it did not do quite what you wanted.) My suspicion would be that you may have exposed a bug in the shell's own input source switching logic. Later today, I will take a look at some less hairy equivalent meta-commands and see what is going on. > Isn't the parser completely reset after each line that it parses successfully? Yes, for meta-command input. But the input source switch and restore may have become confused. It bears investigation. Please feel welcome and encouraged to add more detail to the working/failing boundary on this.