c++: argv contains some spaces

Question

I want to pass only ONE parameter containing some spaces to my function main. Here is an example:

string param = "{\"abc\" \"de\"}"; // the string is {"abc" "de"}
boost::replace_all(param, "\"", "\\\""); // now it becomes: {\"abc\" \"de\"}
boost::replace_all(param, " ", "\\40");  // now it becomes: {\"abc\"\40\"de\"}

ShellExecute(GetDesktopWindow(), "open", "myMainTest.exe", param.c_str(), "", SW_SHOWNORMAL); // execute my function main in another project

// in the function main of myMainTest.exe

cout<<argv[1];

I got this result:

{"abc"\40"de"}

It means that the double quote is OK but the space is not.

Answer 1

IMHO, this is directly tied to the way windows processes its command line. Arguments are normally splitted on spaces with the exception that strings enclosed in double quotes (") are processed as a single parameter after removing quotes.

But it is far from the way Unix-like shells processes input! No simple and direct way to escape a quote itself. But as your quotes are balanced it will work. Here is the actual string that you must pass to ShellExecute: "{\"abc\" \"def\"}". Now only remains how to write that is C++ source:

string param = "\"{\\\"abc\\\" \\\"def\\\"}\"";
ShellExecute(GetDesktopWindow(), "open", "myMainTest.exe", param.c_str(), "", SW_SHOWNORMAL);

And myMainTest.exe should see only single parameter: {"abc" "def"}