> As you can see dumpargs_gcc receives "\127.0.0.127\foo.cxx" and dumpargs_cl
> receives "\\127.0.0.127\foo.cxx".
Interesting. I am confused, too.
(1) Native-only parameter passing:
execv(PROG, ARGV) -> MSVCRT -> line = M(ARGV) -> CreateProcess( PROG,
line, .. ) ->
MSVCRT -> CommandLineToArgvW( line ) -> argv, argc = M'( line ) ->
int main( int argc, char *argv[] )
http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
(2) POSIX compatibility wrapper (Cygwin):
execv(PROG, ARGV) -> Cygwin DLL -> prog = W(PROG), line = C(ARGV) ->
CreateProcess( prog, line, .. )
(a) PROG is a native program:
-> MSVCRT -> CommandLineToArgvW( line ) -> argc, argv = M'(
line ) -> int main( int argc, char *argv[] )
(b) PROG is another Cygwin-linked program:
-> Cygwin stub (crt0?) -> argc, argv = C'( line ) -> int main(
int argc, char *argv[] )
Thanks to your createprocess.c/dumpargs.c pair, I could figure the existing
Cygwin's parsing without looking into its source code. It turned to ignore the
escaping power of a bare (unquoted) backslash when it was followed by a double
quote, which is against both MSVC and Bash rules.
Here is my understanding of expansion features of Win32 (M), Bash (B) and
Cygwin (C) shown as a diagram, where "special character" means a dollar sign
[$], a double quote ["], another backslash [\], backquote [`] or a newline, as
explained in section 2.2.3 Double-Quotes of the Open Group's XCU document.
http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
Bare backslashes Bare backslashes Quoted backslashes Quoted
backslashes
not followed by a followed by a not followed by a followed
by a
double quote double quote special character special
character
MSVC regular protecting regular regular
Bash protecting protecting regular
protecting
Cygwin regular protecting regular
protecting
So I guess the confusion remains as to why (a) C != M and (b) C != B.#include <windows.h>
#include <stdio.h>
void runCommand(char * command) {
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory(&pi, sizeof(pi));
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
printf("\nCommand: %s\n", command);
CreateProcessA(NULL, command, NULL, NULL, TRUE, 0, NULL, NULL, &si, &pi);
WaitForSingleObject(pi.hProcess, INFINITE);
CloseHandle( pi.hProcess );
CloseHandle( pi.hThread );
fflush( stdout ); // insufficient when main() is called from
Cygwin bash; added setbuf()
fflush( stderr ); //
}
// [ "\\a\b" "c\\d" "\e\f" "\\\\g\\h" "QUOTED WORDS" WO\"RD \\a\b \\"a\b"
\\a\"b \\\\"a \\\\\" b" ]
// [ "\\a\b" "c\\d" "\e\f" "\\\\g\\h" "QUOTED WORDS" WO\"RD x" \\a\b \\"a\b"
\\a\"b x" \\\\"a \\\\\" b" ]
// The second line compensates Cygwin's interpretation of a bare (unquoted)
// backslash followed by a double quote as two separate characters.
#define COMMAND_ARGS " \"\\\\a\\b\" \"c\\\\d\"
\"\\e\\f\" \"\\\\\\\\g\\\\h\" \"QUOTED WORDS\" WO\\\"RD" \
" \\\\a\\b \\\\\"a\\b\" \\\\a\\\"b" \
" \\\\\\\\\"a \\\\\\\\\\\" b\" "
#define COMMAND_ARGS_CYGWIN_BARE_BACKSLASH_QUOTE " \"\\\\a\\b\" \"c\\\\d\"
\"\\e\\f\" \"\\\\\\\\g\\\\h\" \"QUOTED WORDS\" WO\\\"RD x\"" \
" \\\\a\\b \\\\\"a\\b\" \\\\a\\\"b x\"" \
" \\\\\\\\\"a \\\\\\\\\\\" b\" "
int main() {
setbuf( stdout, NULL ); // just flushing these files appears to be
insufficient
setbuf( stderr, NULL ); //
runCommand(".\\dumpargs_gcc.exe " COMMAND_ARGS_CYGWIN_BARE_BACKSLASH_QUOTE);
runCommand(".\\dumpargs_cl.exe " COMMAND_ARGS);
return 0;
}
$ ./createprocess_cl.exe
Command: .\dumpargs_gcc.exe "\\a\b" "c\\d" "\e\f" "\\\\g\\h" "QUOTED WORDS"
WO\"RD x" \\a\b \\"a\b" \\a\"b x" \\\\"a \\\\\" b"
./dumpargs_gcc
\a\b
c\d
\e\f
\\g\h
QUOTED WORDS
WO\RD x
\\a\b
\a\b
\a\b x
\\a \\" b
Command: .\dumpargs_cl.exe "\\a\b" "c\\d" "\e\f" "\\\\g\\h" "QUOTED WORDS"
WO\"RD \\a\b \\"a\b" \\a\"b \\\\"a \\\\\" b"
.\dumpargs_cl.exe
\\a\b
c\\d
\e\f
\\\\g\\h
QUOTED WORDS
WO"RD
\\a\b
\a\b
\\a"b
\\a \\" b
$ for w in "\\a\b" "c\\d" "\e\f" "\\\\g\\h" "QUOTED WORDS" WO\"RD \\a\b
\\"a\b" \\a\"b \\\\"a \\\\\" b" ; do echo "$w" ; done
\a\b
c\d
\e\f
\\g\h
QUOTED WORDS
WO"RD
\ab
\a\b
\a"b
\\a \\" b
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