It would be handy to be able to specify the standard input instead of an input filename, and also to have the option to write to the standard output instead of to output.pdf or to a given filename.
I can do this from bash, somewhat awkwardly:
upstream-command | txt2pdf <(cat) -o >(cat) | downstream-command
but it could be nice to have the "-" in place of input or output filename, as in the 'a2ps' command.
-Bill