netcat [...] -e program nc [...] -e program
Is supposed to run
program as a server (as far as its stdin and stdout are concerned).
netcat on Mac OS X does not seem to have this
Why is that and is there a way to enable it?
It looks like you found one of many netcat-rewrites floating around the net. The One True Netcat uses -e to specify IPSEC parameters. Chances are you found a version that someone modified, or wrote from scratch, which is different than what most others call netcat.
You'll have to find the source for that version and compile it. If you don't want to do that, it may be possible to do some tricks with redirection and/or a wrapper to set up the FDs properly before exec()ing a program.
I don't have the
edit: Karmic has the