How to pass parameters to a windows application

Andy Koppe
Tue Aug 3 11:26:00 GMT 2010

On 2 August 2010 12:56, Jason Pyeron wrote:
>> 'cygstart'.
> It does not play nice with unc paths. Starting by cmd.exe /c start path does.
> Suggestions?
> jpyeron@phoenix /projects/cdnetdb/private/fxiao/cdnet
> $ cygstart .
> jpyeron@phoenix /projects/cdnetdb/private/fxiao/cdnet
> $ cygstart //host67/inst
> Unable to start '\\?\UNC\host67\inst': There is no application associated with
> the given file name extension.

It's a bug.

Cygstart uses cygwin_conv_path to convert to a Windows path, which
produces UNC paths for network paths. Trouble is, the ShellExecute
API, which is used to do the actual opening, doesn't appear to support
UNC paths.

Cygpath already turns '\\?\UNC\' at the start of a path into plain ol
'\\' (unless the resulting path would be longer than MAX_PATH, in
which case the UNC path is mandatory). Mintty does the same thing when
a file is opened with Ctrl+click.

So cygstart would need to do the same. And mkshortcut too (because the
APIs involved in creating shortcuts have trouble with long paths too).
Basically, any program that passes a path converted with
cygwin_conv_path to Windows APIs might have this issue.

Therefore I'm wondering whether it wouldn't be better to address this
once and for all in cygwin_conv_path itself by doing what cygpath
does: assuming the resulting path fits into MAX_PATH, drop "\\?\" from
all long paths and turn "UNC\" into "\\".


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