AuroraRuntime/Source/Processes/ArgvQuote.cpp

/*
 * Copyright(C) 2011 - Daniel Colascione, Microsoft Corporation
 * Public domain or equiv implied license
 * Microsoft gave their engineer permission to publish this reference code in his advisory article on MSDN/TechNet operated by MS
 * Stolen by commies and rebranded as GPL before -> https://fossies.org/linux/calibre/bypy/windows/portable.cpp
 * 
 * CmdLine subsystem uses CommandLineToArgvW to parse commandline strings from Windows, just like **most** (not all) apps and crts in Windows land
 * Unix programs merely passthrough unmodified strings using execv
 * 
 */
#include <Source/RuntimeInternal.hpp>
#include "ArgvQuote.hpp"

void
ArgvQuote(
    const AuString &argument,
    AuString &outputString,
    bool force
)
{
    //
    // Unless we're told otherwise, don't quote unless we actually
    // need to do so --- hopefully avoid problems if programs won't
    // parse quotes properly
    //
    
    if (!force &&
        argument.size() &&
        argument.find_first_of(" \t\n\v\"") == argument.npos)
    {
        outputString.append(argument);
        return;
    }
 
    outputString.push_back('"');
    
    for (auto itr = argument.begin() ; ; ++itr)
    {
        unsigned slashes = 0;
    
        while (itr != argument.end() && *itr == '\\')
        {
            ++itr;
            ++slashes;
        }
    
        if (itr == argument.end())
        {
            
            //
            // Escape all backslashes, but let the terminating
            // double quotation mark we add below be interpreted
            // as a metacharacter.
            //
            
            outputString.append(slashes * 2, '\\');
            break;
        }
        else if (*itr == '"')
        {

            //
            // Escape all backslashes and the following
            // double quotation mark.
            //
            
            outputString.append(slashes * 2 + 1, '\\');
            outputString.push_back(*itr);
        }
        else
        {
            
            //
            // Backslashes aren't special here.
            //
            
            if (AuString(" \t\n\v").find(*itr) != AuString::npos)
            {
                outputString.append(slashes, '\\');
            }

            outputString.push_back(*itr);
        }
    }
    
    outputString.push_back('"');
}