Comment 6 for bug 544935

   -q secs quit after EOF on stdin and delay of secs (-1 to not quit)

Default value is 0, i.e. as soon as stdin EOF's, it terminates. When you're using printf, it EOF's before the remote server manages to send back a response. netcat-traditional happens to default to -1. Each of -1, 0, and X>0 as default values all have their individual idiosyncracies. You just happen to have hit one of the idiosyncracies that come with a default of 0.

If you depend on a specific behaviour, you should be specifically asking for said behaviour rather than relying on default values. Nevertheless, Hardy, Intrepid, Jaunty, Karmic, and now Lucid have all been released with this default behaviour. We are not going to issue an SRU that changes this behaviour, since people may have scripts that rely on it, and not breaking existing setups is always going to be more important than catering for new uses.

Whether this is even a bug is debatable. The docs could certainly point out that the default is 0, but as long as they're not lying and saying it's some other value, I consider it a wishlist request.

Oh, and Lars.. Comments such as #3 is not going to get you anything other than a rude gesture. It'd be helpful if you'd keep such comments to yourself.