[wxWidgets.git] / src / common / cmdline.cpp

///////////////////////////////////////////////////////////////////////////////
// Name:        common/cmdline.cpp
// Purpose:     wxCmdLineParser implementation
// Author:      Vadim Zeitlin
// Modified by:
// Created:     05.01.00
// RCS-ID:      $Id$
// Copyright:   (c) 2000 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
// Licence:     wxWindows license
///////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#ifdef __GNUG__
    #pragma implementation "cmdline.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#include "wx/cmdline.h"

#if wxUSE_CMDLINE_PARSER

#ifndef WX_PRECOMP
    #include "wx/string.h"
    #include "wx/log.h"
    #include "wx/intl.h"
    #include "wx/app.h"
    #include "wx/dynarray.h"
    #include "wx/filefn.h"
#endif //WX_PRECOMP

#include <ctype.h>

#include "wx/datetime.h"
#include "wx/msgout.h"

// ----------------------------------------------------------------------------
// private functions
// ----------------------------------------------------------------------------

static wxString GetTypeName(wxCmdLineParamType type);

static wxString GetOptionName(const wxChar *p, const wxChar *allowedChars);

static wxString GetShortOptionName(const wxChar *p);

static wxString GetLongOptionName(const wxChar *p);

// ----------------------------------------------------------------------------
// private structs
// ----------------------------------------------------------------------------

// an internal representation of an option
struct wxCmdLineOption
{
    wxCmdLineOption(wxCmdLineEntryType k,
                    const wxString& shrt,
                    const wxString& lng,
                    const wxString& desc,
                    wxCmdLineParamType typ,
                    int fl)
    {
        wxASSERT_MSG( !shrt.empty() || !lng.empty(),
                      _T("option should have at least one name") );

        wxASSERT_MSG
            (
                GetShortOptionName(shrt).Len() == shrt.Len(),
                wxT("Short option contains invalid characters")
            );

        wxASSERT_MSG
            (
                GetLongOptionName(lng).Len() == lng.Len(),
                wxT("Long option contains invalid characters")
            );

        kind = k;

        shortName = shrt;
        longName = lng;
        description = desc;

        type = typ;
        flags = fl;

        m_hasVal = FALSE;
    }

    // can't use union easily here, so just store all possible data fields, we
    // don't waste much (might still use union later if the number of supported
    // types increases, so always use the accessor functions and don't access
    // the fields directly!)

    void Check(wxCmdLineParamType WXUNUSED_UNLESS_DEBUG(typ)) const
    {
        wxASSERT_MSG( type == typ, _T("type mismatch in wxCmdLineOption") );
    }

    long GetLongVal() const
        { Check(wxCMD_LINE_VAL_NUMBER); return m_longVal; }
    const wxString& GetStrVal() const
        { Check(wxCMD_LINE_VAL_STRING); return m_strVal;  }
    const wxDateTime& GetDateVal() const
        { Check(wxCMD_LINE_VAL_DATE);   return m_dateVal; }

    void SetLongVal(long val)
        { Check(wxCMD_LINE_VAL_NUMBER); m_longVal = val; m_hasVal = TRUE; }
    void SetStrVal(const wxString& val)
        { Check(wxCMD_LINE_VAL_STRING); m_strVal = val; m_hasVal = TRUE; }
    void SetDateVal(const wxDateTime val)
        { Check(wxCMD_LINE_VAL_DATE); m_dateVal = val; m_hasVal = TRUE; }

    void SetHasValue(bool hasValue = TRUE) { m_hasVal = hasValue; }
    bool HasValue() const { return m_hasVal; }

public:
    wxCmdLineEntryType kind;
    wxString shortName,
             longName,
             description;
    wxCmdLineParamType type;
    int flags;

private:
    bool m_hasVal;

    long m_longVal;
    wxString m_strVal;
    wxDateTime m_dateVal;
};

struct wxCmdLineParam
{
    wxCmdLineParam(const wxString& desc,
                   wxCmdLineParamType typ,
                   int fl)
        : description(desc)
    {
        type = typ;
        flags = fl;
    }

    wxString description;
    wxCmdLineParamType type;
    int flags;
};

WX_DECLARE_OBJARRAY(wxCmdLineOption, wxArrayOptions);
WX_DECLARE_OBJARRAY(wxCmdLineParam, wxArrayParams);

#include "wx/arrimpl.cpp"

WX_DEFINE_OBJARRAY(wxArrayOptions);
WX_DEFINE_OBJARRAY(wxArrayParams);

// the parser internal state
struct wxCmdLineParserData
{
    // options
    wxString m_switchChars;     // characters which may start an option
    bool m_enableLongOptions;   // TRUE if long options are enabled
    wxString m_logo;            // some extra text to show in Usage()

    // cmd line data
    wxArrayString m_arguments;  // == argv, argc == m_arguments.GetCount()
    wxArrayOptions m_options;   // all possible options and switchrs
    wxArrayParams m_paramDesc;  // description of all possible params
    wxArrayString m_parameters; // all params found

    // methods
    wxCmdLineParserData();
    void SetArguments(int argc, wxChar **argv);
    void SetArguments(const wxString& cmdline);

    int FindOption(const wxString& name);
    int FindOptionByLongName(const wxString& name);
};

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// wxCmdLineParserData
// ----------------------------------------------------------------------------

wxCmdLineParserData::wxCmdLineParserData()
{
    m_enableLongOptions = TRUE;
#ifdef __UNIX_LIKE__
    m_switchChars = _T("-");
#else // !Unix
    m_switchChars = _T("/-");
#endif
}

void wxCmdLineParserData::SetArguments(int argc, wxChar **argv)
{
    m_arguments.Empty();

    for ( int n = 0; n < argc; n++ )
    {
        m_arguments.Add(argv[n]);
    }
}

void wxCmdLineParserData::SetArguments(const wxString& cmdLine)
{
    m_arguments.Empty();

    m_arguments.Add(wxTheApp->GetAppName());

    wxArrayString args = wxCmdLineParser::ConvertStringToArgs(cmdLine);

    WX_APPEND_ARRAY(m_arguments, args);
}

int wxCmdLineParserData::FindOption(const wxString& name)
{
    if ( !name.empty() )
    {
        size_t count = m_options.GetCount();
        for ( size_t n = 0; n < count; n++ )
        {
            if ( m_options[n].shortName == name )
            {
                // found
                return n;
            }
        }
    }

    return wxNOT_FOUND;
}

int wxCmdLineParserData::FindOptionByLongName(const wxString& name)
{
    size_t count = m_options.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        if ( m_options[n].longName == name )
        {
            // found
            return n;
        }
    }

    return wxNOT_FOUND;
}

// ----------------------------------------------------------------------------
// construction and destruction
// ----------------------------------------------------------------------------

void wxCmdLineParser::Init()
{
    m_data = new wxCmdLineParserData;
}

void wxCmdLineParser::SetCmdLine(int argc, wxChar **argv)
{
    m_data->SetArguments(argc, argv);
}

void wxCmdLineParser::SetCmdLine(const wxString& cmdline)
{
    m_data->SetArguments(cmdline);
}

wxCmdLineParser::~wxCmdLineParser()
{
    delete m_data;
}

// ----------------------------------------------------------------------------
// options
// ----------------------------------------------------------------------------

void wxCmdLineParser::SetSwitchChars(const wxString& switchChars)
{
    m_data->m_switchChars = switchChars;
}

void wxCmdLineParser::EnableLongOptions(bool enable)
{
    m_data->m_enableLongOptions = enable;
}

bool wxCmdLineParser::AreLongOptionsEnabled()
{
    return m_data->m_enableLongOptions;
}

void wxCmdLineParser::SetLogo(const wxString& logo)
{
    m_data->m_logo = logo;
}

// ----------------------------------------------------------------------------
// command line construction
// ----------------------------------------------------------------------------

void wxCmdLineParser::SetDesc(const wxCmdLineEntryDesc *desc)
{
    for ( ;; desc++ )
    {
        switch ( desc->kind )
        {
            case wxCMD_LINE_SWITCH:
                AddSwitch(desc->shortName, desc->longName, desc->description,
                          desc->flags);
                break;

            case wxCMD_LINE_OPTION:
                AddOption(desc->shortName, desc->longName, desc->description,
                          desc->type, desc->flags);
                break;

            case wxCMD_LINE_PARAM:
                AddParam(desc->description, desc->type, desc->flags);
                break;

            default:
                wxFAIL_MSG( _T("unknown command line entry type") );
                // still fall through

            case wxCMD_LINE_NONE:
                return;
        }
    }
}

void wxCmdLineParser::AddSwitch(const wxString& shortName,
                                const wxString& longName,
                                const wxString& desc,
                                int flags)
{
    wxASSERT_MSG( m_data->FindOption(shortName) == wxNOT_FOUND,
                  _T("duplicate switch") );

    wxCmdLineOption *option = new wxCmdLineOption(wxCMD_LINE_SWITCH,
                                                  shortName, longName, desc,
                                                  wxCMD_LINE_VAL_NONE, flags);

    m_data->m_options.Add(option);
}

void wxCmdLineParser::AddOption(const wxString& shortName,
                                const wxString& longName,
                                const wxString& desc,
                                wxCmdLineParamType type,
                                int flags)
{
    wxASSERT_MSG( m_data->FindOption(shortName) == wxNOT_FOUND,
                  _T("duplicate option") );

    wxCmdLineOption *option = new wxCmdLineOption(wxCMD_LINE_OPTION,
                                                  shortName, longName, desc,
                                                  type, flags);

    m_data->m_options.Add(option);
}

void wxCmdLineParser::AddParam(const wxString& desc,
                               wxCmdLineParamType type,
                               int flags)
{
    // do some consistency checks: a required parameter can't follow an
    // optional one and nothing should follow a parameter with MULTIPLE flag
#ifdef __WXDEBUG__
    if ( !m_data->m_paramDesc.IsEmpty() )
    {
        wxCmdLineParam& param = m_data->m_paramDesc.Last();

        wxASSERT_MSG( !(param.flags & wxCMD_LINE_PARAM_MULTIPLE),
                      _T("all parameters after the one with wxCMD_LINE_PARAM_MULTIPLE style will be ignored") );

        if ( !(flags & wxCMD_LINE_PARAM_OPTIONAL) )
        {
            wxASSERT_MSG( !(param.flags & wxCMD_LINE_PARAM_OPTIONAL),
                          _T("a required parameter can't follow an optional one") );
        }
    }
#endif // Debug

    wxCmdLineParam *param = new wxCmdLineParam(desc, type, flags);

    m_data->m_paramDesc.Add(param);
}

// ----------------------------------------------------------------------------
// access to parse command line
// ----------------------------------------------------------------------------

bool wxCmdLineParser::Found(const wxString& name) const
{
    int i = m_data->FindOption(name);
    if ( i == wxNOT_FOUND )
        i = m_data->FindOptionByLongName(name);

    wxCHECK_MSG( i != wxNOT_FOUND, FALSE, _T("unknown switch") );

    wxCmdLineOption& opt = m_data->m_options[(size_t)i];
    if ( !opt.HasValue() )
        return FALSE;

    return TRUE;
}

bool wxCmdLineParser::Found(const wxString& name, wxString *value) const
{
    int i = m_data->FindOption(name);
    if ( i == wxNOT_FOUND )
        i = m_data->FindOptionByLongName(name);

    wxCHECK_MSG( i != wxNOT_FOUND, FALSE, _T("unknown option") );

    wxCmdLineOption& opt = m_data->m_options[(size_t)i];
    if ( !opt.HasValue() )
        return FALSE;

    wxCHECK_MSG( value, FALSE, _T("NULL pointer in wxCmdLineOption::Found") );

    *value = opt.GetStrVal();

    return TRUE;
}

bool wxCmdLineParser::Found(const wxString& name, long *value) const
{
    int i = m_data->FindOption(name);
    if ( i == wxNOT_FOUND )
        i = m_data->FindOptionByLongName(name);

    wxCHECK_MSG( i != wxNOT_FOUND, FALSE, _T("unknown option") );

    wxCmdLineOption& opt = m_data->m_options[(size_t)i];
    if ( !opt.HasValue() )
        return FALSE;

    wxCHECK_MSG( value, FALSE, _T("NULL pointer in wxCmdLineOption::Found") );

    *value = opt.GetLongVal();

    return TRUE;
}

bool wxCmdLineParser::Found(const wxString& name, wxDateTime *value) const
{
    int i = m_data->FindOption(name);
    if ( i == wxNOT_FOUND )
        i = m_data->FindOptionByLongName(name);

    wxCHECK_MSG( i != wxNOT_FOUND, FALSE, _T("unknown option") );

    wxCmdLineOption& opt = m_data->m_options[(size_t)i];
    if ( !opt.HasValue() )
        return FALSE;

    wxCHECK_MSG( value, FALSE, _T("NULL pointer in wxCmdLineOption::Found") );

    *value = opt.GetDateVal();

    return TRUE;
}

size_t wxCmdLineParser::GetParamCount() const
{
    return m_data->m_parameters.GetCount();
}

wxString wxCmdLineParser::GetParam(size_t n) const
{
    wxCHECK_MSG( n < GetParamCount(), wxEmptyString, _T("invalid param index") );

    return m_data->m_parameters[n];
}

// Resets switches and options
void wxCmdLineParser::Reset()
{
    for ( size_t i = 0; i < m_data->m_options.Count(); i++ )
    {
        wxCmdLineOption& opt = m_data->m_options[i];
        opt.SetHasValue(FALSE);
    }
}


// ----------------------------------------------------------------------------
// the real work is done here
// ----------------------------------------------------------------------------

int wxCmdLineParser::Parse(bool showUsage)
{
    bool maybeOption = TRUE;    // can the following arg be an option?
    bool ok = TRUE;             // TRUE until an error is detected
    bool helpRequested = FALSE; // TRUE if "-h" was given
    bool hadRepeatableParam = FALSE; // TRUE if found param with MULTIPLE flag

    size_t currentParam = 0;    // the index in m_paramDesc

    size_t countParam = m_data->m_paramDesc.GetCount();
    wxString errorMsg;

    Reset();

    // parse everything
    wxString arg;
    size_t count = m_data->m_arguments.GetCount();
    for ( size_t n = 1; ok && (n < count); n++ )    // 0 is program name
    {
        arg = m_data->m_arguments[n];

        // special case: "--" should be discarded and all following arguments
        // should be considered as parameters, even if they start with '-' and
        // not like options (this is POSIX-like)
        if ( arg == _T("--") )
        {
            maybeOption = FALSE;

            continue;
        }

        // empty argument or just '-' is not an option but a parameter
        if ( maybeOption && arg.length() > 1 &&
                wxStrchr(m_data->m_switchChars, arg[0u]) )
        {
            bool isLong;
            wxString name;
            int optInd = wxNOT_FOUND;   // init to suppress warnings

            // an option or a switch: find whether it's a long or a short one
            if ( arg[0u] == _T('-') && arg[1u] == _T('-') )
            {
                // a long one
                isLong = TRUE;

                // Skip leading "--"
                const wxChar *p = arg.c_str() + 2;

                bool longOptionsEnabled = AreLongOptionsEnabled();

                name = GetLongOptionName(p);

                if (longOptionsEnabled)
                {
                    optInd = m_data->FindOptionByLongName(name);
                    if ( optInd == wxNOT_FOUND )
                    {
                        errorMsg << wxString::Format(_("Unknown long option '%s'"), name.c_str()) << "\n";
                    }
                }
                else
                {
                    optInd = wxNOT_FOUND; // Sanity check

                    // Print the argument including leading "--"
                    name.Prepend( wxT("--") );
                    errorMsg << wxString::Format(_("Unknown option '%s'"), name.c_str()) << "\n";
                }

            }
            else
            {
                isLong = FALSE;

                // a short one: as they can be cumulated, we try to find the
                // longest substring which is a valid option
                const wxChar *p = arg.c_str() + 1;

                name = GetShortOptionName(p);

                size_t len = name.length();
                do
                {
                    if ( len == 0 )
                    {
                        // we couldn't find a valid option name in the
                        // beginning of this string
                        errorMsg << wxString::Format(_("Unknown option '%s'"), name.c_str()) << "\n";

                        break;
                    }
                    else
                    {
                        optInd = m_data->FindOption(name.Left(len));

                        // will try with one character less the next time
                        len--;
                    }
                }
                while ( optInd == wxNOT_FOUND );

                len++;  // compensates extra len-- above
                if ( (optInd != wxNOT_FOUND) && (len != name.length()) )
                {
                    // first of all, the option name is only part of this
                    // string
                    name = name.Left(len);

                    // our option is only part of this argument, there is
                    // something else in it - it is either the value of this
                    // option or other switches if it is a switch
                    if ( m_data->m_options[(size_t)optInd].kind
                            == wxCMD_LINE_SWITCH )
                    {
                        // pretend that all the rest of the argument is the
                        // next argument, in fact
                        wxString arg2 = arg[0u];
                        arg2 += arg.Mid(len + 1); // +1 for leading '-'

                        m_data->m_arguments.Insert(arg2, n + 1);
                        count++;
                    }
                    //else: it's our value, we'll deal with it below
                }
            }

            if ( optInd == wxNOT_FOUND )
            {
                ok = FALSE;

                continue;   // will break, in fact
            }

            wxCmdLineOption& opt = m_data->m_options[(size_t)optInd];
            if ( opt.kind == wxCMD_LINE_SWITCH )
            {
                // nothing more to do
                opt.SetHasValue();

                if ( opt.flags & wxCMD_LINE_OPTION_HELP )
                {
                    helpRequested = TRUE;

                    // it's not an error, but we still stop here
                    ok = FALSE;
                }
            }
            else
            {
                // get the value

                // +1 for leading '-'
                const wxChar *p = arg.c_str() + 1 + name.length();
                if ( isLong )
                {
                    p++;    // for another leading '-'

                    if ( *p++ != _T('=') )
                    {
                        errorMsg << wxString::Format(_("Option '%s' requires a value, '=' expected."), name.c_str()) << "\n";

                        ok = FALSE;
                    }
                }
                else
                {
                    switch ( *p )
                    {
                        case _T('='):
                        case _T(':'):
                            // the value follows
                            p++;
                            break;

                        case 0:
                            // the value is in the next argument
                            if ( ++n == count )
                            {
                                // ... but there is none
                                errorMsg << wxString::Format(_("Option '%s' requires a value."),
                                                             name.c_str()) << "\n";

                                ok = FALSE;
                            }
                            else
                            {
                                // ... take it from there
                                p = m_data->m_arguments[n].c_str();
                            }
                            break;

                        default:
                            // the value is right here: this may be legal or
                            // not depending on the option style
                            if ( opt.flags & wxCMD_LINE_NEEDS_SEPARATOR )
                            {
                                errorMsg << wxString::Format(_("Separator expected after the option '%s'."),
                                                             name.c_str()) << "\n";

                                ok = FALSE;
                            }
                    }
                }

                if ( ok )
                {
                    wxString value = p;
                    switch ( opt.type )
                    {
                        default:
                            wxFAIL_MSG( _T("unknown option type") );
                            // still fall through

                        case wxCMD_LINE_VAL_STRING:
                            opt.SetStrVal(value);
                            break;

                        case wxCMD_LINE_VAL_NUMBER:
                            {
                                long val;
                                if ( value.ToLong(&val) )
                                {
                                    opt.SetLongVal(val);
                                }
                                else
                                {
                                    errorMsg << wxString::Format(_("'%s' is not a correct numeric value for option '%s'."),
                                                                 value.c_str(), name.c_str()) << "\n";

                                    ok = FALSE;
                                }
                            }
                            break;

                        case wxCMD_LINE_VAL_DATE:
                            {
                                wxDateTime dt;
                                const wxChar *res = dt.ParseDate(value);
                                if ( !res || *res )
                                {
                                    errorMsg << wxString::Format(_("Option '%s': '%s' cannot be converted to a date."),
                                                                 name.c_str(), value.c_str()) << "\n";

                                    ok = FALSE;
                                }
                                else
                                {
                                    opt.SetDateVal(dt);
                                }
                            }
                            break;
                    }
                }
            }
        }
        else
        {
            // a parameter
            if ( currentParam < countParam )
            {
                wxCmdLineParam& param = m_data->m_paramDesc[currentParam];

                // TODO check the param type

                m_data->m_parameters.Add(arg);

                if ( !(param.flags & wxCMD_LINE_PARAM_MULTIPLE) )
                {
                    currentParam++;
                }
                else
                {
                    wxASSERT_MSG( currentParam == countParam - 1,
                                  _T("all parameters after the one with wxCMD_LINE_PARAM_MULTIPLE style are ignored") );

                    // remember that we did have this last repeatable parameter
                    hadRepeatableParam = TRUE;
                }
            }
            else
            {
                errorMsg << wxString::Format(_("Unexpected parameter '%s'"), arg.c_str()) << "\n";

                ok = FALSE;
            }
        }
    }

    // verify that all mandatory options were given
    if ( ok )
    {
        size_t countOpt = m_data->m_options.GetCount();
        for ( size_t n = 0; ok && (n < countOpt); n++ )
        {
            wxCmdLineOption& opt = m_data->m_options[n];
            if ( (opt.flags & wxCMD_LINE_OPTION_MANDATORY) && !opt.HasValue() )
            {
                wxString optName;
                if ( !opt.longName )
                {
                    optName = opt.shortName;
                }
                else
                {
                    if ( AreLongOptionsEnabled() )
                    {
                        optName.Printf( _("%s (or %s)"),
                                        opt.shortName.c_str(),
                                        opt.longName.c_str() );
                    }
                    else
                    {
                        optName.Printf( wxT("%s"),
                                        opt.shortName.c_str() );
                    }
                }

                errorMsg << wxString::Format(_("The value for the option '%s' must be specified."),
                                             optName.c_str()) << "\n";

                ok = FALSE;
            }
        }

        for ( ; ok && (currentParam < countParam); currentParam++ )
        {
            wxCmdLineParam& param = m_data->m_paramDesc[currentParam];
            if ( (currentParam == countParam - 1) &&
                 (param.flags & wxCMD_LINE_PARAM_MULTIPLE) &&
                 hadRepeatableParam )
            {
                // special case: currentParam wasn't incremented, but we did
                // have it, so don't give error
                continue;
            }

            if ( !(param.flags & wxCMD_LINE_PARAM_OPTIONAL) )
            {
                errorMsg << wxString::Format(_("The required parameter '%s' was not specified."),
                                             param.description.c_str()) << "\n";

                ok = FALSE;
            }
        }
    }

    // if there was an error during parsing the command line, show this error
    // and also the usage message if it had been requested
    if ( !ok && (!errorMsg.empty() || (helpRequested && showUsage)) )
    {
        wxMessageOutput* msgOut = wxMessageOutput::Get();
        if ( msgOut )
        {
            wxString usage;
            if ( showUsage )
                usage = GetUsageString();

            msgOut->Printf( wxT("%s%s"), usage.c_str(), errorMsg.c_str() );
        }
        else
        {
            wxFAIL_MSG( _T("no wxMessageOutput object?") );
        }
    }

    return ok ? 0 : helpRequested ? -1 : 1;
}

// ----------------------------------------------------------------------------
// give the usage message
// ----------------------------------------------------------------------------

void wxCmdLineParser::Usage()
{
    wxMessageOutput* msgOut = wxMessageOutput::Get();
    if ( msgOut )
    {
        msgOut->Printf( wxT("%s"), GetUsageString().c_str() );
    }
    else
    {
        wxFAIL_MSG( _T("no wxMessageOutput object?") );
    }
}

wxString wxCmdLineParser::GetUsageString()
{
    wxString appname = wxTheApp->GetAppName();
    if ( !appname )
    {
        wxCHECK_MSG( !m_data->m_arguments.IsEmpty(), wxEmptyString,
                     _T("no program name") );

        appname = wxFileNameFromPath(m_data->m_arguments[0]);
        wxStripExtension(appname);
    }

    // we construct the brief cmd line desc on the fly, but not the detailed
    // help message below because we want to align the options descriptions
    // and for this we must first know the longest one of them
    wxString usage;
    wxArrayString namesOptions, descOptions;

    if ( !m_data->m_logo.empty() )
    {
        usage << m_data->m_logo << _T('\n');
    }

    usage << wxString::Format(_("Usage: %s"), appname.c_str());

    // the switch char is usually '-' but this can be changed with
    // SetSwitchChars() and then the first one of possible chars is used
    wxChar chSwitch = !m_data->m_switchChars ? _T('-')
                                             : m_data->m_switchChars[0u];

    bool areLongOptionsEnabled = AreLongOptionsEnabled();
    size_t n, count = m_data->m_options.GetCount();
    for ( n = 0; n < count; n++ )
    {
        wxCmdLineOption& opt = m_data->m_options[n];

        usage << _T(' ');
        if ( !(opt.flags & wxCMD_LINE_OPTION_MANDATORY) )
        {
            usage << _T('[');
        }

        if ( !opt.shortName.empty() )
        {
            usage << chSwitch << opt.shortName;
        }
        else if ( areLongOptionsEnabled && !opt.longName.empty() )
        {
            usage << _T("--") << opt.longName;
        }
        else
        {
            if (!opt.longName.empty())
            {
                wxFAIL_MSG( wxT("option with only a long name while long ")
                    wxT("options are disabled") );
            }
            else
            {
                wxFAIL_MSG( _T("option without neither short nor long name") );
            }
        }

        wxString option;

        if ( !opt.shortName.empty() )
        {
            option << _T("  ") << chSwitch << opt.shortName;
        }

        if ( areLongOptionsEnabled && !opt.longName.empty() )
        {
            option << (option.empty() ? _T("  ") : _T(", "))
                   << _T("--") << opt.longName;
        }

        if ( opt.kind != wxCMD_LINE_SWITCH )
        {
            wxString val;
            val << _T('<') << GetTypeName(opt.type) << _T('>');
            usage << _T(' ') << val;
            option << (!opt.longName ? _T(':') : _T('=')) << val;
        }

        if ( !(opt.flags & wxCMD_LINE_OPTION_MANDATORY) )
        {
            usage << _T(']');
        }

        namesOptions.Add(option);
        descOptions.Add(opt.description);
    }

    count = m_data->m_paramDesc.GetCount();
    for ( n = 0; n < count; n++ )
    {
        wxCmdLineParam& param = m_data->m_paramDesc[n];

        usage << _T(' ');
        if ( param.flags & wxCMD_LINE_PARAM_OPTIONAL )
        {
            usage << _T('[');
        }

        usage << param.description;

        if ( param.flags & wxCMD_LINE_PARAM_MULTIPLE )
        {
            usage << _T("...");
        }

        if ( param.flags & wxCMD_LINE_PARAM_OPTIONAL )
        {
            usage << _T(']');
        }
    }

    usage << _T('\n');

    // now construct the detailed help message
    size_t len, lenMax = 0;
    count = namesOptions.GetCount();
    for ( n = 0; n < count; n++ )
    {
        len = namesOptions[n].length();
        if ( len > lenMax )
            lenMax = len;
    }

    for ( n = 0; n < count; n++ )
    {
        len = namesOptions[n].length();
        usage << namesOptions[n]
              << wxString(_T(' '), lenMax - len) << _T('\t')
              << descOptions[n]
              << _T('\n');
    }

    return usage;
}

// ----------------------------------------------------------------------------
// private functions
// ----------------------------------------------------------------------------

static wxString GetTypeName(wxCmdLineParamType type)
{
    wxString s;
    switch ( type )
    {
        default:
            wxFAIL_MSG( _T("unknown option type") );
            // still fall through

        case wxCMD_LINE_VAL_STRING:
            s = _("str");
            break;

        case wxCMD_LINE_VAL_NUMBER:
            s = _("num");
            break;

        case wxCMD_LINE_VAL_DATE:
            s = _("date");
            break;
    }

    return s;
}

/*
Returns a string which is equal to the string pointed to by p, but up to the
point where p contains an character that's not allowed.
Allowable characters are letters and numbers, and characters pointed to by
the parameter allowedChars.

For example, if p points to "abcde-@-_", and allowedChars is "-_",
this function returns "abcde-".
*/
static wxString GetOptionName(const wxChar *p,
    const wxChar *allowedChars)
{
    wxString argName;

    while ( *p && (wxIsalnum(*p) || wxStrchr(allowedChars, *p)) )
    {
        argName += *p++;
    }

    return argName;
}

// Besides alphanumeric characters, short and long options can
// have other characters.

// A short option additionally can have these
#define wxCMD_LINE_CHARS_ALLOWED_BY_SHORT_OPTION wxT("_?")

// A long option can have the same characters as a short option and a '-'.
#define wxCMD_LINE_CHARS_ALLOWED_BY_LONG_OPTION \
    wxCMD_LINE_CHARS_ALLOWED_BY_SHORT_OPTION wxT("-")

static wxString GetShortOptionName(const wxChar *p)
{
    return GetOptionName(p, wxCMD_LINE_CHARS_ALLOWED_BY_SHORT_OPTION);
}

static wxString GetLongOptionName(const wxChar *p)
{
    return GetOptionName(p, wxCMD_LINE_CHARS_ALLOWED_BY_LONG_OPTION);
}

#endif // wxUSE_CMDLINE_PARSER

// ----------------------------------------------------------------------------
// global functions
// ----------------------------------------------------------------------------

/*
   This function is mainly used under Windows (as under Unix we always get the
   command line arguments as argc/argv anyhow) and so it tries to handle the
   Windows path names (separated by backslashes) correctly. For this it only
   considers that a backslash may be used to escape another backslash (but
   normally this is _not_ needed) or a quote but nothing else.

   In particular, to pass a single argument containing a space to the program
   it should be quoted:

   myprog.exe foo bar       -> argc = 3, argv[1] = "foo", argv[2] = "bar"
   myprog.exe "foo bar"     -> argc = 2, argv[1] = "foo bar"

   To pass an argument containing spaces and quotes, the latter should be
   escaped with a backslash:

   myprog.exe "foo \"bar\"" -> argc = 2, argv[1] = "foo "bar""

   This hopefully matches the conventions used by Explorer/command line
   interpreter under Windows. If not, this function should be fixed.
 */

/* static */
wxArrayString wxCmdLineParser::ConvertStringToArgs(const wxChar *p)
{
    wxArrayString args;

    wxString arg;
    arg.reserve(1024);

    bool isInsideQuotes = FALSE;
    for ( ;; )
    {
        // skip white space
        while ( *p == _T(' ') || *p == _T('\t') )
            p++;

        // anything left?
        if ( *p == _T('\0') )
            break;

        // parse this parameter
        arg.clear();
        for ( ;; p++ )
        {
            // do we have a (lone) backslash?
            bool isQuotedByBS = FALSE;
            while ( *p == _T('\\') )
            {
                p++;

                // if we have 2 backslashes in a row, output one
                // unless it looks like a UNC path \\machine\dir\file.ext
                if ( isQuotedByBS || arg.Len() == 0 )
                {
                    arg += _T('\\');
                    isQuotedByBS = FALSE;
                }
                else // the next char is quoted
                {
                    isQuotedByBS = TRUE;
                }
            }

            bool skipChar = FALSE,
                 endParam = FALSE;
            switch ( *p )
            {
                case _T('"'):
                    if ( !isQuotedByBS )
                    {
                        // don't put the quote itself in the arg
                        skipChar = TRUE;

                        isInsideQuotes = !isInsideQuotes;
                    }
                    //else: insert a literal quote

                    break;

                case _T(' '):
                case _T('\t'):
                    // we intentionally don't check for preceding backslash
                    // here as if we allowed it to be used to escape spaces the
                    // cmd line of the form "foo.exe a:\ c:\bar" wouldn't be
                    // parsed correctly
                    if ( isInsideQuotes )
                    {
                        // preserve it, skip endParam below
                        break;
                    }
                    //else: fall through

                case _T('\0'):
                    endParam = TRUE;
                    break;

                default:
                    if ( isQuotedByBS )
                    {
                        // ignore backslash before an ordinary character - this
                        // is needed to properly handle the file names under
                        // Windows appearing in the command line
                        arg += _T('\\');
                    }
            }

            // end of argument?
            if ( endParam )
                break;

            // otherwise copy this char to arg
            if ( !skipChar )
            {
                arg += *p;
            }
        }

        args.Add(arg);
    }

    return args;
}