Manpage gensky (and others?) with unicode dash characters

Hi @Greg_Ward ,

I copied the commands from gensky and found out it couldnt run, whereas if I type the same command manually it works well.

I found out that the command in the manpages contains a unicode dash (-) that my radiance won’t accept if I copy it.

The ascii character 45 is a “regular” dash whereas the one copied from the man page gives me \u8722 dash.

Not sure if the “bad” dash came from the comments in code, the man page to html translater and not sure if this happens in other manpages either.

you can try yourself and copy this line gensky 7 4 14:30EDT +s −a 42 −o 89 from GENSKY into View non-printable unicode characters and inspect the dashes.

Hi Mathias,

Wow, I didn’t realize that groff was doing this, but each dash was replaced with “−” in the HTML. I don’t even remember when these man pages were last updated, but perhaps it’s time to redo them, and make a pass with sed to eliminate this substitution.

Thanks for pointing it out!

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Can you help me with the route you took to get to this manual page? Was it from a google search, or did you navigate through links on or I normally expect folks to find the PDF man pages at, not the outdated pages on (They both need updating, to be honest.)


Hi Greg,

I usually google “radiance rtrace” etc, and usually pick the html results over the pdf ones as they feel more lightweight than to download and open acrobat reader (in my case…).
In many cases the old comes first.

OK, makes sense. I’m not even sure where these pages are linked these days, or how Google’s web crawler is finding them, but I’ve updated the man pages there. The index page is still out of date, and I’m waiting for our admin to put the new one with the new tools on there. Hopefully, by tomorrow or Wednesday.


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The man pages tend to come up first for me as well, and sometimes the equivalent pages on don’t show up in my search results at all. I’m not sure if this is relevant to Google’s rankings or not, but the pages are html, which might push them higher in the search results. Personally, I prefer html to pdf.

Thanks for the additional feedback. I’ve updated the index now as well as the man pages, so Google’s crawler should find the new entries the same way it found the old ones.