[With apologies if threading is broken; I erroneously thought as the list was not subscriber-only that replies would use reply-all and so wasn't subscribed]
On Thu, May 5, 2016 at 06:47 PM, Erik Soderquist wrote: > On Thu, May 5, 2016 at 11:24 AM, David Allsopp wrote: > > > > I am trying to work out the precise details for character escaping > > when starting a Cygwin process from a native (i.e. non-Cygwin) Windows > process. > <snip> > > For example: > > > > argv[0] = "foo" > > argv[1] = "bar baz" > > > > then the resulting command line string should be: > > > > lpCommandLine = "foo bar\" \"baz" > > If I recall correctly, Windows cmd.exe uses the carrot (^) as the general > escape from shell character, so > > C:\cygwin64\bin>.\echo.exe -e ^"hello\nworld^" > hello > world > > works. Indeed - but I'm not using cmd, or any shell for that matter (that's actually the point) - I am in a native Win32 process invoking a Cygwin process directly using the Windows API's CreateProcess call. As it happens, the program I have already has the arguments for the Cygwin process in an array, but Windows internally requires a single command line string (which is not in any related to Cmd). > However, I've found Windows's interpretation to be inconsistent, so often > have to play with it to find what the "right combination" is for a > particular instance. > > I find echoing the parameters to a temporary text file and then using the > file as input to be more reliable and easier to troubleshoot, and it > breaks apart whether it is Windows cli inconsistencies or receiving > program issues very nicely with the text file content as an intermediary This is an OK tack, but I don't wish to do this by experimentation and get caught out later by a case I didn't think of, so what I'm trying to determine is *exactly* how the Cygwin DLL processes the command line via its source code so that I can present it with my argv array converted to a single command line and be certain that the Cygwin will recover the same argv DLL. My reading of the relevant sources suggests that with globbing disabled, backslash escape sequences are *never* interpreted (since the quote function returns early - dcrt0.cc, line 171). If there is no way of encoding the double quote character, then perhaps I have to run with globbing enabled but ensure that the globify function will never actually expand anything - but as that's a lot of work, I was wondering if I was missing something with the simpler "noglob" case. David -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple