You may try the following as a base for further development.
It selects all .txt files from the current directory.
The sfk tail command seems to have a bug
so it is not used like "+then tail" in this example,
but through a workaround with another run command.
------- file begin: doextract.sh --------
#!/bin/bash
sfk script doextract.sh -from begin $@
function skip_block.
