A Simple Win32 Command-Line Parser

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Environment: VC6, WIN 9x

A Simple Win32 Command-Line Parser

I was disapointed when I first discovered that (non-console)
Win32 apps did not have argc and argv. This class is my solution.
CmdLineArgs is a subclass of STL vector. After instantiation, it
contains the command line args for your app.

argc – size()
argv – operator[]

Here’s an example of it’s use…

int main ()

{

    CmdLineArgs args;

    for (int i = 0; i < args.size(); i++)
        puts (args[i]);

    return 0;
}

Here’s a test run of the example code above…

C:>test.exe This “is” a “”test”” “of the parsing” alg”o”rithm.

C:Test.exe

This

is

a

“test”

of the parsing

alg”o”rithm.

The class…

class CmdLineArgs : public std::vector

{

public:

    CmdLineArgs ()

    {

        // Save local copy of the command line string, because

        // ParseCmdLine() modifies this string while parsing it.

        PSZ cmdline = GetCommandLine();

        m_cmdline = new char [strlen (cmdline) + 1];

        if (m_cmdline)

        {

            strcpy (m_cmdline, cmdline);

            ParseCmdLine();

        }

    }

    ~CmdLineArgs()

    {

        delete m_cmdline;

    }

private:

    PSZ m_cmdline; // the command line string
    ////////////////////////////////////////////////////////////////////////////////

    // Parse m_cmdline into individual tokens, which are delimited by spaces. If a

    // token begins with a quote, then that token is terminated by the next quote

    // followed immediately by a space or terminator.  This allows tokens to contain

    // spaces.

    // This input string:     This “is” a “”test”” “of the parsing” alg”o”rithm.

    // Produces these tokens: This, is, a, “test”, of the parsing, alg”o”rithm

    ////////////////////////////////////////////////////////////////////////////////

    void ParseCmdLine ()

    {

        enum { TERM  = ‘’,

               QUOTE = ‘”‘ };
        bool bInQuotes = false;

        PSZ pargs = m_cmdline;
        while (*pargs)

        {

            while (isspace (*pargs))        // skip leading whitespace

                pargs++;
            bInQuotes = (*pargs == QUOTE);  // see if this token is quoted
            if (bInQuotes)                  // skip leading quote

                pargs++;
            push_back (pargs);              // store position of current token
            // Find next token.

            // NOTE: Args are normally terminated by whitespace, unless the

            // arg is quoted.  That’s why we handle the two cases separately,

            // even though they are very similar.

            if (bInQuotes)

            {

                // find next quote followed by a space or terminator

                while (*pargs &&

                      !(*pargs == QUOTE && (isspace (pargs[1]) || pargs[1] == TERM)))

                    pargs++;

                if (*pargs)

                {

                    *pargs = TERM;  // terminate token

                    if (pargs[1])   // if quoted token not followed by a terminator

                        pargs += 2; // advance to next token

                }

            }

            else

            {

                // skip to next non-whitespace character

                while (*pargs && !isspace (*pargs))

                    pargs++;

                if (*pargs && isspace (*pargs)) // end of token

                {

                   *pargs = TERM;    // terminate token

                    pargs++;         // advance to next token or terminator

                }

            }

        } // while (*pargs)

    } // ParseCmdLine()

}; // class CmdLineArgs

Download demo project – 5 Kb