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From: "David Allsopp" <dra27@cantab.net>
To: "'Peter Rosin'" <peda@lysator.liu.se>, <cygwin@cygwin.com>
References: <005c01d1a6e2$30270ba0$907522e0$@metastack.com> <CACoZoo1LObZ0zu9X5O6dV4cO4jN+GO28bdRbuDkTMdaKHXpVbQ@mail.gmail.com> <000101d1a76d$c37c6b80$4a754280$@metastack.com> <967954968.20160506172040@yandex.ru> <006301d1a834$6ccd1380$46673a80$@cantab.net> <6e1f2ba2-0c8e-4659-4c5a-d748e90c1ced@lysator.liu.se>
In-Reply-To: <6e1f2ba2-0c8e-4659-4c5a-d748e90c1ced@lysator.liu.se>
Subject: RE: Formatting command line arguments when starting a Cygwin process from a native process
Date: Mon, 9 May 2016 16:49:42 +0100
Message-ID: <008e01d1aa0a$67a9ef40$36fdcdc0$@cantab.net>
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Hi!

Peter Rosin wrote:
> I think cygwin emulates posix shell style command line parsing when
> invoked from a Win32 process (like you do). So, try single quotes:
> 
> commandLine = "callee.exe \"@\"te\"\n\"st fo@o bar\" \"baz baz '*'
> '\"\\'\"'";
> 
> I get this (w/o noglob):
> 
> argc = 7
> argv[0] = callee
> argv[1] = @te
> st
> argv[2] = fo@o
> argv[3] = bar baz
> argv[4] = baz
> argv[5] = *
> argv[6] = "'"

Yes, that seems to be approximately the way I arrived at too - my concern
with all the extra quoting is then hitting the Windows limit on command line
length (I'd like to avoid needing @response files as much as possible). So
with various experimenting, the slightly odd scheme I've come up with is
that if none of the arguments contain double-quote characters, then set
noglob and use the quoting mechanism previously described (so whitespace
within an argument or an @ at the beginning of an argument needing
double-quoting) and if a double-quote character appears in any of the
arguments, then don't set noglob and escape every argument with
double-quotes (to avoid globbing) - any double-quote characters within can
then be escaped with "'"'" (i.e. terminate the current quote string,
single-quote a double-quote and then resume a quote string!). Messy, but
that seems to be about the only way...


David 


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