Change in 'cygstart' functionality?

Nem W Schlecht
Tue Sep 13 19:05:00 GMT 2016

On Tue, Sep 13, 2016 at 12:44 PM, Ken Brown <> wrote:
> On 9/13/2016 10:50 AM, Nem W Schlecht wrote:
>> Hello all,
>> So, I used to be able to do this in Cygwin to open a chat session (in
>> my case, With Skype for Business aka S4B):
>>     cygstart ""
>> But I noticed recently that this now fails with:
>>     Unable to start 'sip': The specified file was not
>> found.
>> I have no idea why the colon ":" is getting converted into an a UTF
>> F038 character.  I'm also unsure of when this stopped working, since I
>> don't use it all that often.
> There's no code in cygstart to recognize the SIP protocol.  (It wouldn't be
> hard to add such code, as was done a few years ago for "mailto:". See line
> 598 of cygstart.c in the sources for the cygutils package.)
> So cygstart treats "" as a file name.  The funny Unicode
> character you see comes from Cygwin's translation to allow ":" as part of a
> file name.  See

Thanks for the excellent breakdown, Ken.  Makes sense with the colon
":".  Still not sure why it did work a couple months ago and now
doesn't.  I was under the assumption that 'cygstart' was a very basic
program that just passed whatever it was passed on to Windows to
handle - similar to "Start-Process" in Powershell, or well, just like
double-clicking on something on the Desktop.

My 'cygstart's last mod time is Nov 24, 2015 and this was definitely
working *after* that time, so something else changed.  It's like
'cygstart' is assuming this is a file and trying to do something smart
that way rather than just letting Windows handle it (as it would
*need* to do if this were indeed a Cygwin path).  Again, when I add in
the extra slashes, S4B *does* get the SIP request.  Without the
slashes, something in Cygwin is assuming this is a filesystem call.

I'll take a look at the 'cygstart' code and see if (with my lowly
programming skills) I can suggest a patch.  :)

Nem W Schlecht
"Perl did the magic. I just waved the wand."

Problem reports:
Unsubscribe info:

More information about the Cygwin mailing list