getpot.h

linux下实现视频播放的播放器

    _apriori_argv.push_back(std::string("Empty"));
    __parse_argument_vector(_apriori_argv);
}

inline
GetPot::GetPot(const int argc_, char ** argv_, 
	       const char* FieldSeparator /* =0x0 */)     
    // leave 'char**' non-const to honor less capable compilers ... 
{
    // TODO: Ponder over the problem when the argument list is of size = 0.
    //       This is 'sabotage', but it can still occur if the user specifies
    //       it himself.
    assert(argc_ >= 1);
    __basic_initialization();

    // if specified -> overwrite default string
    if( FieldSeparator ) _field_separator = std::string(FieldSeparator);

    // -- make an internal copy of the argument list:
    STRING_VECTOR _apriori_argv;
    // -- for the sake of clarity: we do want to include the first argument in the argument vector !
    //    it will not be a nominus argument, though. This gives us a minimun vector size of one
    //    which facilitates error checking in many functions. Also the user will be able to
    //    retrieve the name of his application by "get[0]"
    _apriori_argv.push_back(std::string(argv_[0]));
    int i=1;
    for(; i<argc_; ++i) {
	std::string tmp(argv_[i]);   // recall the problem with temporaries,
	_apriori_argv.push_back(tmp);       // reference counting in arguement lists ...
    }
    __parse_argument_vector(_apriori_argv);
}


inline
GetPot::GetPot(const char* FileName,
	       const char* CommentStart  /* = 0x0 */, const char* CommentEnd /* = 0x0 */,
	       const char* FieldSeparator/* = 0x0 */)     
{
    __basic_initialization();

    // if specified -> overwrite default strings
    if( CommentStart )   _comment_start = std::string(CommentStart);
    if( CommentEnd )     _comment_end   = std::string(CommentEnd);
    if( FieldSeparator ) _field_separator = FieldSeparator;
    
    STRING_VECTOR _apriori_argv;
    // -- file name is element of argument vector, however, it is not parsed for
    //    variable assignments or nominuses.
    _apriori_argv.push_back(std::string(FileName));

    STRING_VECTOR args = __read_in_file(FileName);
    _apriori_argv.insert(_apriori_argv.begin()+1, args.begin(), args.end());
    __parse_argument_vector(_apriori_argv);
}

inline
GetPot::GetPot(const GetPot& That)
{ GetPot::operator=(That); }

inline
GetPot::~GetPot()
{ 
    // may be some return strings had to be created, delete now !
    victorate(char*, __internal_string_container, it)
	delete [] *it;	
}

inline GetPot&
GetPot::operator=(const GetPot& That)
{
    if (&That == this) return *this;

    _comment_start  = That._comment_start;
    _comment_end    = That._comment_end;
    argv            = That.argv;
    variables       = That.variables;
    prefix          = That.prefix;

    cursor          = That.cursor;
    nominus_cursor  = That.nominus_cursor;
    search_failed_f = That.search_failed_f;

    idx_nominus     = That.idx_nominus;
    search_loop_f   = That.search_loop_f;

    return *this;
}


inline void
GetPot::absorb(const GetPot& That)
{
    if (&That == this) return;

    STRING_VECTOR  __tmp(That.argv);

    __tmp.erase(__tmp.begin());

    __parse_argument_vector(__tmp);
}

inline void    
GetPot::clear_requests()
{
    _requested_arguments.erase(_requested_arguments.begin(), _requested_arguments.end());
    _requested_variables.erase(_requested_variables.begin(), _requested_variables.end());
    _requested_sections.erase(_requested_sections.begin(), _requested_sections.end());
}

inline void
GetPot::__parse_argument_vector(const STRING_VECTOR& ARGV)
{
    if( ARGV.size() == 0 ) return;

    // build internal databases:
    //   1) array with no-minus arguments (usually used as filenames)
    //   2) variable assignments:
    //             'variable name' '=' number | string
    STRING_VECTOR                 section_stack;
    STRING_VECTOR::const_iterator it = ARGV.begin();


    section = "";

    // -- do not parse the first argument, so that it is not interpreted a s a nominus or so.
    argv.push_back(*it);
    ++it;

    // -- loop over remaining arguments
    unsigned i=1;
    for(; it != ARGV.end(); ++it, ++i) {
	std::string arg = *it;

	if( arg.length() == 0 ) continue;

	// -- [section] labels
	if( arg.length() > 1 && arg[0] == '[' && arg[arg.length()-1] == ']' ) {

	    // (*) sections are considered 'requested arguments'
	    if( __request_recording_f ) _requested_arguments.push_back(arg);
	    
	    const std::string Name = __DBE_expand_string(arg.substr(1, arg.length()-2));
	    section = __process_section_label(Name, section_stack);
	    // new section --> append to list of sections
	    if( find(section_list.begin(), section_list.end(), section) == section_list.end() )
		if( section.length() != 0 ) section_list.push_back(section);
	    argv.push_back(arg);
	}
	else {
	    arg = section + __DBE_expand_string(arg);
	    argv.push_back(arg);
	}

	// -- separate array for nominus arguments
	if( arg[0] != '-' ) idx_nominus.push_back(unsigned(i));

	// -- variables: does arg contain a '=' operator ?
	const char* p = arg.c_str();
	for(; *p ; p++) {
	    if( *p == '=' ) {
		// (*) record for later ufo detection
		//     arguments carriying variables are always treated as 'requested' arguments. 
		//     as a whole! That is 'x=4712' is  considered a requested argument.
		//
		//     unrequested variables have to be detected with the ufo-variable
		//     detection routine.
		if( __request_recording_f ) _requested_arguments.push_back(arg);

		// set terminating 'zero' to treat first part as single string
		// => arg (from start to 'p') = Name of variable
		//    p+1     (until terminating zero) = value of variable
		char* o = (char*)p++;
		*o = '\0';                       // set temporary terminating zero
		// __set_variable(...) 
		// calls __find_variable(...) which registers the search
		// temporarily disable this
		const bool tmp = __request_recording_f;
		__request_recording_f = false;
		__set_variable(arg.c_str(), p);  // v-name = c_str() bis 'p', value = rest
		__request_recording_f = tmp;
		*o = '=';                        // reset the original '='
		break;
	    }
	}
    }
}


inline STRING_VECTOR
GetPot::__read_in_file(const char* FileName)
{
    std::ifstream  i(FileName);
    if( ! i ) return STRING_VECTOR();
    // argv[0] == the filename of the file that was read in
    return __read_in_stream(i);
}

inline STRING_VECTOR
GetPot::__read_in_stream(std::istream& istr)
{
    STRING_VECTOR  brute_tokens;
    while(istr) {
	__skip_whitespace(istr);
	const std::string Token = __get_next_token(istr);
	if( Token.length() == 0 || Token[0] == EOF) break;
	brute_tokens.push_back(Token);
    }

    // -- reduce expressions of token1'='token2 to a single
    //    string 'token1=token2'
    // -- copy everything into 'argv'
    // -- arguments preceded by something like '[' name ']' (section)
    //    produce a second copy of each argument with a prefix '[name]argument'
    unsigned i1 = 0;
    unsigned i2 = 1;
    unsigned i3 = 2;

    STRING_VECTOR  arglist;
    while( i1 < brute_tokens.size() ) {
	const std::string& SRef = brute_tokens[i1];
	// 1) concatinate 'abcdef' '=' 'efgasdef' to 'abcdef=efgasdef'
	// note: java.lang.String: substring(a,b) = from a to b-1
	//        C++ string:      substr(a,b)    = from a to a + b
	if( i2 < brute_tokens.size() && brute_tokens[i2] == "=" ) {
	    if( i3 >= brute_tokens.size() )
		arglist.push_back(brute_tokens[i1] + brute_tokens[i2]);
	    else
		arglist.push_back(brute_tokens[i1] + brute_tokens[i2] + brute_tokens[i3]);
	    i1 = i3+1; i2 = i3+2; i3 = i3+3;
	    continue;
	}
	else {
	    arglist.push_back(SRef);
	    i1=i2; i2=i3; i3++;
	}
    }
    return arglist;
}

inline void
GetPot::__skip_whitespace(std::istream& istr)
{	
	bool found = false;
	do
	{
		int c = istr.peek();
		found = isspace(c);
		while ((isspace(c)) && (istr))
			c = istr.get();
		if (found)
			istr.unget();
		c = istr.peek();
		found = _comment_start.find(char(c)) != std::string::npos;
		if (found)
		{
			while (((_comment_end.find(c) == std::string::npos)) && (istr))
				c = istr.get();
		}
		if (found)
			istr.unget();		
	}
	while (found);
}

inline const std::string
GetPot::__get_next_token(std::istream& istr)
    // get next concatinates string token. consider quotes that embrace
    // whitespaces
{
    std::string token;
    int    tmp = 0;
    int    last_letter = 0;
    while(1+1 == 2) {
	last_letter = tmp; tmp = istr.get();
	if( tmp == EOF
	    || ((tmp == ' ' || tmp == '\t' || tmp == '\n') && last_letter != '\\') ) {
	    return token;
	}
	else if( tmp == '\'' && last_letter != '\\' ) {
	    // QUOTES: un-backslashed quotes => it's a string
	    token += __get_string(istr);
	    continue;
	}
	else if( tmp == '{' && last_letter == '$') {
	    token += '{' + __get_until_closing_bracket(istr);
	    continue;
	}
	else if( tmp == '$' && last_letter == '\\') {
	    token += tmp; tmp = 0;  //  so that last_letter will become = 0, not '$';
	    continue;
	}
	else if( tmp == '\\' && last_letter != '\\')
	    continue;              // don't append un-backslashed backslashes
	token += tmp;
    }
}

inline const std::string
GetPot::__get_string(std::istream& istr)
    // parse input until next matching '
{
    std::string str;
    int    tmp = 0;
    int    last_letter = 0;
    while(1 + 1 == 2) {
	last_letter = tmp; tmp = istr.get();
	if( tmp == EOF)  return str;
	// un-backslashed quotes => it's the end of the string
	else if( tmp == '\'' && last_letter != '\\')  return str;
	else if( tmp == '\\' && last_letter != '\\')  continue; // don't append

	str += tmp;
    }
}

inline const std::string
GetPot::__get_until_closing_bracket(std::istream& istr)
    // parse input until next matching }
{
    std::string str = "";
    int    tmp = 0;
    int    last_letter = 0;
    int    brackets = 1;
    while(1 + 1 == 2) {
	last_letter = tmp; tmp = istr.get();
	if( tmp == EOF) return str;
	else if( tmp == '{' && last_letter == '$') brackets += 1;
	else if( tmp == '}') {
	    brackets -= 1;
	    // un-backslashed brackets => it's the end of the string
	    if( brackets == 0) return str + '}';
	    else if( tmp == '\\' && last_letter != '\\')
		continue;  // do not append an unbackslashed backslash
	}
	str += tmp;
    }
}

inline std::string
GetPot::__process_section_label(const std::string& Section,
				STRING_VECTOR& section_stack)
{
    std::string sname = Section;
    //  1) subsection of actual section ('./' prefix)
    if( sname.length() >= 2 && sname.substr(0, 2) == "./" ) {
	sname = sname.substr(2);
    }
    //  2) subsection of parent section ('../' prefix)
    else if( sname.length() >= 3 && sname.substr(0, 3) == "../" ) {
	do {
	    if( section_stack.end() != section_stack.begin() )
		section_stack.pop_back();
	    sname = sname.substr(3);
	} while( sname.substr(0, 3) == "../" );
    }
    // 3) subsection of the root-section
    else {
	section_stack.erase(section_stack.begin(), section_stack.end());
	// [] => back to root section
    }

    if( sname != "" ) {
	// parse section name for 'slashes'
	unsigned i=0;
	while( i < sname.length() ) {
	    if( sname[i] == '/' ) {
		section_stack.push_back(sname.substr(0,i));
		if( i+1 < sname.length()-1 )
		    sname = sname.substr(i+1);
		i = 0;
	    }
	    else
		++i;
	}
	section_stack.push_back(sname);
    }
    std::string section = "";
    if( section_stack.size() != 0 ) {
	victorate(std::string, section_stack, it)
	    section += *it + "/";
    }
    return section;
}