4 // Fraunhofer Institute for Open Communication Systems (FOKUS)
5 // Competence Center NETwork research (NET), St. Augustin, GERMANY
6 // Stefan Bund <g0dil@berlios.de>
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 2 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the
20 // Free Software Foundation, Inc.,
21 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 \brief Parse public header */
29 /** \defgroup console_parser The parser
31 The console/config library defines a simple language used to interact with the console or to
32 configure the application. The parser is not concerned about interpreting commands or
33 arguments, checking that a command exists or managing directories. The parser just takes the
38 \section console_language The Language
40 The config/console language is used in configuration files and interactively at the
41 console. Some features of the language are more useful in config files, others at the
42 interactive console but the language is the same in both cases.
44 Let's start with a sample of the config/console language. The following is written as a
47 # My someserver configuration file
53 accept senf::log::Debug IMPORTANT;
54 accept server::ServerLog CRITICAL;
57 provide serverlog senf::log::FileTarget "/var/log/server.log";
59 reject senf::log::Debug senf::Console::Server NOTICE;
60 accept senf::log::Debug NOTICE;
61 accept server::ServerLog;
65 /server/stuffing (UDPPacket x"01 02 03 04");
66 /server/allow_hosts 10.1.2.3 # our internal server
67 10.2.3.4 10.4.3.5 # client workstations
70 /help/infoUrl "http://senf.j32.de/src/doc";
73 The interactive syntax is the same with some notes:
74 \li All commands must be complete on a single line. This includes grouping constructs which must
75 be closed on the same line they are opened.
76 \li The last ';' is optional. However, multiple commands may be entered on a single line when
77 they are separated by ';'.
78 \li An empty line on the interactive console will repeat the last command.
80 The language consists of a small number of syntactic entities:
82 \subsection console_special_chars Special characters
84 These are characters, which have a special meaning. Some are used internally, others are just
85 returned as punctuation tokens
88 <tr><td>/</td><td>path component separator</td></tr>
89 <tr><td>( )</td><td>argument grouping</td></tr>
90 <tr><td>{ }</td><td>directory grouping</td></tr>
91 <tr><td>;</td><td>command terminator</td></tr>
92 <tr><td>, =</td><td>punctuation tokens</td></tr>
95 \subsection console_basic Basic elements
97 A <b>word</b> is \e any sequence of consecutive characters which does not include any special
98 character. Examples for words are thus
101 jens@fokus.fraunhofer.de
106 The following are \e not valid words:
112 A <b>string literal</b> is just that: A double-quoted string (C/C++ style) possibly with
113 embedded escape chars:
119 A <b>hex-string literal</b> is used to represent binary data. It looks like a string which has
120 only hexadecimal bytes or whitespace as contents (comments and newlines are Ok when not read
121 from the interactive console)
129 A <b>token</b> is a \e word, \e string or \e hex-string, or a single special character (that's
130 true, any special character is allowed as a token). '(' and ')' must be properly nested.
132 A <b>path</b> is a sequence of \e words separated by '/' (and optional whitespace). A path may
133 have an optional initial and/or a terminating '/'.
140 \subsection console_statements Statements
142 There are several types of statements:
143 \li The bulk of all statements are \e path statements
144 \li There are some \e built-in statements which are mostly useful at the interactive console
145 \li A special form of statement is the <em>directory group</em>
147 A <b>path</b> statement consists of a (possibly relative) path followed by any number of
148 arguments and terminated with a ';' (or end-of-input)
150 /path/to/command arg1 "arg2" (complex=(1 2) another) ;
152 Every argument is either
153 \li A single word, string or hex-string
154 \li or a parenthesized list of tokens.
156 So above command has three arguments: 'arg1', 'arg2' (a single token each) and one argument with
157 the 7 tokens 'complex', '=', '(', '1', '2', ')', 'another'. The interpretation of the arguments
158 is completely up to the command.
160 A <b>built-in</b> statement is one of
163 <tr><td>\c cd \e path</td><td>Change current directory</td></tr>
164 <tr><td>\c ls [ \e path ]</td><td>List contents of \e path or current directory</td></tr>
165 <tr><td>\c exit</td><td>Exit interactive console</td></tr>
166 <tr><td>\c help [ \e path ]</td><td>Show help for \e path or current directory</td></tr>
169 A <b>directory group</b> statement is a block of statements all executed relatively to a fixed
177 At the beginning of the block, the current directory is saved and the directory is changed to
178 the given directory. All commands are executed and at the end of the block, the saved directory
181 \section console_parse_api The parser API
183 The senf::console::CommandParser is responsible for taking text input and turning it into a
184 sequence of senf::console::ParseCommandInfo structures. The structures are returned by passing
185 them successively to a callback function.
187 Every statement is returned as a senf::console::ParseCommandInfo instance. Directory groups are
188 handled specially: They are divided into two special built-in commands called PUSHD and POPD.
194 #include <boost/utility.hpp>
195 #include <boost/scoped_ptr.hpp>
196 #include <boost/range/iterator_range.hpp>
197 #include <boost/iterator/iterator_facade.hpp>
198 #include <boost/function.hpp>
199 #include "../Utils/safe_bool.hh"
201 //#include "Parse.mpp"
202 ///////////////////////////////hh.p////////////////////////////////////////
207 namespace detail { struct ParserAccess; }
209 /** \brief Single argument token
211 All command arguments are split into tokens by the parser. Each token is returned as an
214 \ingroup console_parser
221 PathSeparator = 0x0001, // '/'
222 ArgumentGroupOpen = 0x0002, // '('
223 ArgumentGroupClose = 0x0004, // ')'
224 DirectoryGroupOpen = 0x0008, // '{'
225 DirectoryGroupClose = 0x0010, // '}'
226 CommandTerminator = 0x0020, // ';'
227 OtherPunctuation = 0x0040,
228 BasicString = 0x0080,
234 ArgumentGrouper = ArgumentGroupOpen
235 | ArgumentGroupClose,
237 DirectoryGrouper = DirectoryGroupOpen
238 | DirectoryGroupClose,
240 Punctuation = DirectoryGroupOpen
241 | DirectoryGroupClose
249 SimpleArgument = Word
255 Token(TokenType type, std::string token);
257 std::string const & value() const; ///< String value of token
258 /**< This value is properly unquoted */
260 TokenType type() const; ///< Token type
262 bool is(unsigned tokens) const; ///< Check, whether tokens type matches \a tokens
263 /**< \a tokens is a bit-mask of token types to check. */
265 bool operator==(Token const & other) const;
266 bool operator!=(Token const & other) const;
275 std::ostream & operator<<(std::ostream & os, Token const & token);
279 Token PathSeparatorToken();
280 Token ArgumentGroupOpenToken();
281 Token ArgumentGroupCloseToken();
282 Token DirectoryGroupOpenToken();
283 Token DirectoryGroupCloseToken();
284 Token CommandTerminatorToken();
285 Token OtherPunctuationToken(std::string const & value);
286 Token BasicStringToken(std::string const & value);
287 Token HexStringToken(std::string const & value);
288 Token WordToken(std::string const & value);
290 /** \brief Single parsed console command
292 Every command parsed is returned in a ParseCommandInfo instance. This information is purely
293 taken from the parser, no semantic information is attached at this point, the config/console
294 node tree is not involved in any why. ParseCommandInfo consist of
296 \li the type of command: built-in or normal command represented by a possibly relative path
297 into the command tree.
299 \li the arguments. Every argument consists of a range of Token instances.
301 \ingroup console_parser
303 class ParseCommandInfo
305 typedef std::vector<Token> Tokens;
306 typedef std::vector<std::string> CommandPath;
309 class ArgumentIterator;
311 typedef CommandPath::const_iterator path_iterator;
312 typedef Tokens::const_iterator token_iterator;
313 typedef ArgumentIterator argument_iterator;
314 typedef Tokens::size_type size_type;
316 typedef boost::iterator_range<path_iterator> CommandPathRange;
317 typedef boost::iterator_range<argument_iterator> ArgumentsRange;
318 typedef boost::iterator_range<token_iterator> TokensRange;
320 enum BuiltinCommand { NoBuiltin,
328 BuiltinCommand builtin() const; ///< Command type
329 /**< \returns \c NoBuiltin, if the command is an ordinary
330 command, otherwise the id of the built-in command */
331 TokensRange commandPath() const; ///< Command path
332 /**< This is the path to the command if it is not a built-in
333 command. Every element of the returned range
334 constitutes one path element. If the first element is
335 empty, the path is an absolute path, otherwise it is
336 relative. If the last element is an empty string, the
337 path ends with a '/' char. */
338 ArgumentsRange arguments() const; ///< Command arguments
339 /**< The returned range contains one TokensRange for each
341 TokensRange tokens() const; ///< All argument tokens
342 /**< The returned range contains \e all argument tokens in a
343 single range not divided into separate arguments. */
348 void setBuiltin(BuiltinCommand builtin);
349 void setCommand(std::vector<Token> & commandPath);
350 void addToken(Token const & token);
354 std::vector<Token> commandPath_;
355 BuiltinCommand builtin_;
358 friend class detail::ParserAccess;
361 /** \brief Iterator parsing argument groups
363 This special iterator parses a token range returned by the parser into argument ranges. An
364 argument range is either a single token or it is a range of tokens enclosed in matching
365 parenthesis. The ParseCommandInfo::arguments() uses this iterator type. To recursively parse
366 complex arguments, you can however use this iterator to divide a multi-token argument into
367 further argument groups (e.g. to parse a list or vector of items).
369 This iterator is a bidirectional iterator \e not a random access iterator.
371 class ParseCommandInfo::ArgumentIterator
372 : public boost::iterator_facade< ParseCommandInfo::ArgumentIterator,
373 ParseCommandInfo::TokensRange,
374 boost::bidirectional_traversal_tag,
375 ParseCommandInfo::TokensRange >
379 explicit ArgumentIterator(ParseCommandInfo::TokensRange::iterator i);
382 reference dereference() const;
383 bool equal(ArgumentIterator const & other) const;
387 mutable ParseCommandInfo::TokensRange::iterator b_;
388 mutable ParseCommandInfo::TokensRange::iterator e_;
390 void setRange() const;
392 friend class boost::iterator_core_access;
393 friend class ParseCommandInfo;
396 /** \brief Syntax error parsing command arguments exception
398 All errors while parsing the arguments of a command must be signaled by throwing an instance
399 of SyntaxErrorException. This is important, so command overloading works.
401 struct SyntaxErrorException : public std::exception
403 explicit SyntaxErrorException(std::string const & msg = "");
404 virtual ~SyntaxErrorException() throw();
406 virtual char const * what() const throw();
407 std::string const & message() const;
410 std::string message_;
413 /** \brief Wrapper checking argument iterator access for validity
415 CheckedArgumentIteratorWrapper is a wrapper around a range of arguments parsed using the
416 ParseCommandInfo::ArgumentIterator. It is used to parse arguments either in a command
417 (registered with manual argument parsing) or when defining a custom parser.
419 void fn(std::ostream & out, senf::console::ParseCommandInfo command)
425 senf::console::CheckedArgumentIteratorWrapper arg (command.arguments());
426 senf::console::parse( *(arg++), arg1 );
427 senf::console::parse( *(arg++), arg2 );
434 To use the wrapper, you must ensure that:
435 \li You increment the iterator \e past all arguments you parse. The iterator must point to
436 the end of the range when parsing is complete.
437 \li The iterator wrapper is destroyed after parsing but before executing the command itself
440 Accessing a non-existent argument or failing to parse all arguments will raise a
441 senf::console::SyntaxErrorException.
443 \see \link console_arg_custom Example customer parser \endlink
445 class CheckedArgumentIteratorWrapper
446 : boost::noncopyable,
447 public boost::iterator_facade< CheckedArgumentIteratorWrapper,
448 ParseCommandInfo::TokensRange,
449 boost::forward_traversal_tag,
450 ParseCommandInfo::TokensRange >,
451 public senf::safe_bool<CheckedArgumentIteratorWrapper>
454 typedef boost::iterator_facade< CheckedArgumentIteratorWrapper,
455 ParseCommandInfo::TokensRange,
456 boost::forward_traversal_tag,
457 ParseCommandInfo::TokensRange > IteratorFacade;
460 explicit CheckedArgumentIteratorWrapper(
461 ParseCommandInfo::ArgumentsRange const & range,
462 std::string const & msg = "invalid number of arguments");
463 ///< Make wrapper from ArgumentsRange
464 /**< This constructs a wrapper from a
465 ParseCommandInfo::ArgumentsRange.
466 \param[in] range Range of arguments to parse
467 \param[in] msg Error message */
468 explicit CheckedArgumentIteratorWrapper(
469 ParseCommandInfo::TokensRange const & range,
470 std::string const & msg = "invalid number of arguments");
471 ///< Make wrapper from TokensRange
472 /**< This constructs a wrapper from a
473 ParseCommandInfo::TokensRange. The TokensRange is first
474 converted into an ParseCommandInfo::ArgumentsRange
475 which is then wrapped.
476 \param[in] range Range of tokens to parse
477 \param[in] msg Error message */
479 ~CheckedArgumentIteratorWrapper(); ///< Check, if all arguments are parsed
480 /**< The destructor validates, that all arguments are parsed
481 correctly when leaving the scope, in which the wrapper
482 is instantiated normally (not by an exception).
484 \warning This destructor will throw a
485 SyntaxErrorException, if not all arguments are parsed
486 and when no other exception is in progress. */
488 operator ParseCommandInfo::ArgumentIterator();
489 ///< Use wrapper as ParseCommandInfo::ArgumentIterator
491 bool boolean_test() const; ///< \c true, if more arguments are available
492 bool done() const; ///< \c true, if all arguments are parsed
494 void clear(); ///< Set range empty
495 /**< This call will point the current iterator to the end of
497 \post done() == \c true; */
499 bool operator==(ParseCommandInfo::ArgumentIterator const & other) const;
500 ///< Compare wrapper against ArgumentIterator
501 bool operator!=(ParseCommandInfo::ArgumentIterator const & other) const;
502 ///< Compare wrapper against ArgumentIterator
504 using IteratorFacade::operator++;
505 ParseCommandInfo::ArgumentIterator operator++(int);
508 reference dereference() const;
511 ParseCommandInfo::ArgumentIterator i_;
512 ParseCommandInfo::ArgumentIterator e_;
515 friend class boost::iterator_core_access;
518 /**< \brief Output ParseCommandInfo instance
519 \related ParseCommandInfo
521 std::ostream & operator<<(std::ostream & stream, ParseCommandInfo const & info);
523 /** \brief Parse commands
525 This class implements a parser for the console/config language. It supports parsing strings
526 as well as files. For every parsed command, a callback function is called.
528 \implementation The implementation is based on Boost.Spirit. See the file \ref Parse.ih for
529 the formal language grammar.
531 \implementation Parsing an arbitrary iostream is not supported since arbitrary streams are
532 not seekable. If this is needed, it can however be provided using stream iterators and
533 some special iterator adaptors from Boost.Spirit. However, the amount of backtracking
534 needs to be analyzed before this is viable.
536 \todo Implement more detailed error reporting and error recovery.
538 \ingroup console_parser
544 ///////////////////////////////////////////////////////////////////////////
547 typedef boost::function<void (ParseCommandInfo const &)> Callback;
549 ///////////////////////////////////////////////////////////////////////////
550 ///\name Structors and default members
557 ///////////////////////////////////////////////////////////////////////////
559 bool parse(std::string command, Callback cb); ///< Parse string
560 bool parseFile(std::string filename, Callback cb); ///< Parse file
561 /**< \throws SystemException if the file cannot be
569 boost::scoped_ptr<Impl> impl_;
574 ///////////////////////////////hh.e////////////////////////////////////////
576 //#include "Parse.ct"
577 //#include "Parse.cti"
584 // comment-column: 40
585 // c-file-style: "senf"
586 // indent-tabs-mode: nil
587 // ispell-local-dictionary: "american"
588 // compile-command: "scons -u test"