Windows Command Line

Test Cases for command line parsing

Commandline	arg1	arg2	arg3
"abc" d e	abc	d	e
a\\\b d"e f"g h	a\\\b	de fg	h
a\\\"b c d	a\"b	c	d
a\\\\"b c" d e	a\\b c	d	e
c:\a_dir\ "\sp ace\"	c:\a_dir\	\sp ace\
"a ""b"" c"	a "b" c
"""a b c"""	"a b c"
"a"" b c	a" b c
a "b" c	a	b	c
a "b c" "d e	a	b c	d e
a \"b\" c	a	"b"	c

Sources:

• [http://msdn.microsoft.com/en-us/library/17w5ykft%28v=vs.85%29.aspx]
• [http://blogs.msdn.com/b/twistylittlepassagesallalike/archive/2011/04/23/everyone-quotes-arguments-the-wrong-way.aspx]
• Good detail here [http://stackoverflow.com/questions/4094699/how-does-the-windows-command-interpreter-cmd-exe-parse-scripts]

Command line parsing - generic processes

The above apply to generic arguments to a process where that process uses C run-time via CommandLineToArgv() to split the command line into argc & argv's. In particular console applications, which use ANSI*, get parameters via int main( int argc, char * argv[] ) such as used by openscad.com

* see here for ANSI v's Unicode, basically "The main and WinMain functions cannot return Unicode strings".

Commandline	argc @	argv[1]	argv[2]	argv[3]
c:\nospaces\prog.exe p1 p2	c:\nospaces\prog.exe	p1	p2
"c:\spa ces\prog.exe" "p 1" p 2	"c:\spa ces\prog.exe"	p 1	p	2
aprog "c:\dir w spaces\"	aprog	c:\dir w spaces\
(note " in the third line above is not an escaped double-quote, it is the closing quote of a pair)

@ Note "By convention, argv[0] is the command with which the program is invoked. However, it is possible to spawn a process using CreateProcess and if you use both the first and second arguments (lpApplicationName and lpCommandLine), argv[0] may not be the executable name; use GetModuleFileName to retrieve the executable name, and its fully-qualified path."

Command line via _popen (ie via cmd.exe)

openscad.com uses _popen to run openscad.exe with the reconstructed command line via the windows command interpreter, hence cmd.exe parses the command line BEFORE it gets to CommandLineToArgv(), this is where parameters with special characters need to be enclosed in a pair of double-quotes as they are meaningful to cmd.exe. From here the special characters are:

& < > [ ] { } ^ = ; ! ' + , ` ~ [space] [tab]

Double-quote is not a special character in itself, a " (only, without any of the above) in a parameter does not need to be enclosed in a pair of double-quotes, but needs to be escaped, either with a backslash (\"), or another double-quote ("").