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);
278 Token PathSeparatorToken();
279 Token ArgumentGroupOpenToken();
280 Token ArgumentGroupCloseToken();
281 Token DirectoryGroupOpenToken();
282 Token DirectoryGroupCloseToken();
283 Token CommandTerminatorToken();
284 Token OtherPunctuationToken(std::string const & value);
285 Token BasicStringToken(std::string const & value);
286 Token HexStringToken(std::string const & value);
287 Token WordToken(std::string const & value);
289 /** \brief Single parsed console command
291 Every command parsed is returned in a ParseCommandInfo instance. This information is purely
292 taken from the parser, no semantic information is attached at this point, the config/console
293 node tree is not involved in any why. ParseCommandInfo consist of
295 \li the type of command: built-in or normal command represented by a possibly relative path
296 into the command tree.
298 \li the arguments. Every argument consists of a range of Token instances.
300 \ingroup console_parser
302 class ParseCommandInfo
304 typedef std::vector<Token> Tokens;
305 typedef std::vector<std::string> CommandPath;
308 class ArgumentIterator;
310 typedef CommandPath::const_iterator path_iterator;
311 typedef Tokens::const_iterator token_iterator;
312 typedef ArgumentIterator argument_iterator;
313 typedef Tokens::size_type size_type;
315 typedef boost::iterator_range<path_iterator> CommandPathRange;
316 typedef boost::iterator_range<argument_iterator> ArgumentsRange;
317 typedef boost::iterator_range<token_iterator> TokensRange;
319 enum BuiltinCommand { NoBuiltin,
329 BuiltinCommand builtin() const; ///< Command type
330 /**< \returns \c NoBuiltin, if the command is an ordinary
331 command, otherwise the id of the built-in command */
332 TokensRange commandPath() const; ///< Command path
333 /**< This is the path to the command if it is not a built-in
334 command. Every element of the returned range
335 constitutes one path element. If the first element is
336 empty, the path is an absolute path, otherwise it is
337 relative. If the last element is an empty string, the
338 path ends with a '/' char. */
339 ArgumentsRange arguments() const; ///< Command arguments
340 /**< The returned range contains one TokensRange for each
342 TokensRange tokens() const; ///< All argument tokens
343 /**< The returned range contains \e all argument tokens in a
344 single range not divided into separate arguments. */
348 void builtin(BuiltinCommand builtin);
349 void command(std::vector<Token> & commandPath);
351 void addToken(Token const & token);
358 std::vector<Token> commandPath_;
359 BuiltinCommand builtin_;
363 /** \brief Iterator parsing argument groups
365 This special iterator parses a token range returned by the parser into argument ranges. An
366 argument range is either a single token or it is a range of tokens enclosed in matching
367 parenthesis. The ParseCommandInfo::arguments() uses this iterator type. To recursively parse
368 complex arguments, you can however use this iterator to divide a multi-token argument into
369 further argument groups (e.g. to parse a list or vector of items).
371 This iterator is a bidirectional iterator \e not a random access iterator.
373 class ParseCommandInfo::ArgumentIterator
374 : public boost::iterator_facade< ParseCommandInfo::ArgumentIterator,
375 ParseCommandInfo::TokensRange,
376 boost::bidirectional_traversal_tag,
377 ParseCommandInfo::TokensRange >
381 explicit ArgumentIterator(ParseCommandInfo::TokensRange::iterator i);
384 reference dereference() const;
385 bool equal(ArgumentIterator const & other) const;
389 mutable ParseCommandInfo::TokensRange::iterator b_;
390 mutable ParseCommandInfo::TokensRange::iterator e_;
392 void setRange() const;
394 friend class boost::iterator_core_access;
395 friend class ParseCommandInfo;
398 /** \brief Syntax error parsing command arguments exception
400 All errors while parsing the arguments of a command must be signaled by throwing an instance
401 of SyntaxErrorException. This is important, so command overloading works.
403 struct SyntaxErrorException : public std::exception
405 explicit SyntaxErrorException(std::string const & msg = "");
406 virtual ~SyntaxErrorException() throw();
408 virtual char const * what() const throw();
409 std::string const & message() const;
412 std::string message_;
415 /** \brief Wrapper checking argument iterator access for validity
417 CheckedArgumentIteratorWrapper is a wrapper around a range of arguments parsed using the
418 ParseCommandInfo::ArgumentIterator. It is used to parse arguments either in a command
419 (registered with manual argument parsing) or when defining a custom parser.
421 void fn(std::ostream & out, senf::console::ParseCommandInfo command)
427 senf::console::CheckedArgumentIteratorWrapper arg (command.arguments());
428 senf::console::parse( *(arg++), arg1 );
429 senf::console::parse( *(arg++), arg2 );
436 To use the wrapper, you must ensure that:
437 \li You increment the iterator \e past all arguments you parse. The iterator must point to
438 the end of the range when parsing is complete.
439 \li The iterator wrapper is destroyed after parsing but before executing the command itself
442 Accessing a non-existent argument or failing to parse all arguments will raise a
443 senf::console::SyntaxErrorException.
445 \see \link console_arg_custom Example customer parser \endlink
447 class CheckedArgumentIteratorWrapper
448 : boost::noncopyable,
449 public boost::iterator_facade< CheckedArgumentIteratorWrapper,
450 ParseCommandInfo::TokensRange,
451 boost::forward_traversal_tag,
452 ParseCommandInfo::TokensRange >,
453 public senf::safe_bool<CheckedArgumentIteratorWrapper>
456 typedef boost::iterator_facade< CheckedArgumentIteratorWrapper,
457 ParseCommandInfo::TokensRange,
458 boost::forward_traversal_tag,
459 ParseCommandInfo::TokensRange > IteratorFacade;
462 explicit CheckedArgumentIteratorWrapper(
463 ParseCommandInfo::ArgumentsRange const & range,
464 std::string const & msg = "invalid number of arguments");
465 ///< Make wrapper from ArgumentsRange
466 /**< This constructs a wrapper from a
467 ParseCommandInfo::ArgumentsRange.
468 \param[in] range Range of arguments to parse
469 \param[in] msg Error message */
470 explicit CheckedArgumentIteratorWrapper(
471 ParseCommandInfo::TokensRange const & range,
472 std::string const & msg = "invalid number of arguments");
473 ///< Make wrapper from TokensRange
474 /**< This constructs a wrapper from a
475 ParseCommandInfo::TokensRange. The TokensRange is first
476 converted into an ParseCommandInfo::ArgumentsRange
477 which is then wrapped.
478 \param[in] range Range of tokens to parse
479 \param[in] msg Error message */
481 ~CheckedArgumentIteratorWrapper(); ///< Check, if all arguments are parsed
482 /**< The destructor validates, that all arguments are parsed
483 correctly when leaving the scope, in which the wrapper
484 is instantiated normally (not by an exception).
486 \warning This destructor will throw a
487 SyntaxErrorException, if not all arguments are parsed
488 and when no other exception is in progress. */
490 operator ParseCommandInfo::ArgumentIterator();
491 ///< Use wrapper as ParseCommandInfo::ArgumentIterator
493 bool boolean_test() const; ///< \c true, if more arguments are available
494 bool done() const; ///< \c true, if all arguments are parsed
496 void clear(); ///< Set range empty
497 /**< This call will point the current iterator to the end of
499 \post done() == \c true; */
501 bool operator==(ParseCommandInfo::ArgumentIterator const & other) const;
502 ///< Compare wrapper against ArgumentIterator
503 bool operator!=(ParseCommandInfo::ArgumentIterator const & other) const;
504 ///< Compare wrapper against ArgumentIterator
506 using IteratorFacade::operator++;
507 ParseCommandInfo::ArgumentIterator operator++(int);
510 reference dereference() const;
513 ParseCommandInfo::ArgumentIterator i_;
514 ParseCommandInfo::ArgumentIterator e_;
517 friend class boost::iterator_core_access;
520 /**< \brief Output ParseCommandInfo instance
521 \related ParseCommandInfo
523 std::ostream & operator<<(std::ostream & stream, ParseCommandInfo const & info);
525 /** \brief Parse commands
527 This class implements a parser for the console/config language. It supports parsing strings
528 as well as files. For every parsed command, a callback function is called.
530 \implementation The implementation is based on Boost.Spirit. See the file \ref Parse.ih for
531 the formal language grammar.
533 \implementation Parsing an arbitrary iostream is not supported since arbitrary streams are
534 not seekable. If this is needed, it can however be provided using stream iterators and
535 some special iterator adaptors from Boost.Spirit. However, the amount of backtracking
536 needs to be analyzed before this is viable.
538 \todo Implement more detailed error reporting and error recovery.
540 \ingroup console_parser
546 ///////////////////////////////////////////////////////////////////////////
549 typedef boost::function<void (ParseCommandInfo const &)> Callback;
551 ///////////////////////////////////////////////////////////////////////////
552 ///\name Structors and default members
559 ///////////////////////////////////////////////////////////////////////////
561 bool parse(std::string command, Callback cb); ///< Parse string
562 bool parseFile(std::string filename, Callback cb); ///< Parse file
563 /**< \throws SystemException if the file cannot be
566 bool parseArguments(std::string arguments, ParseCommandInfo & info);
573 boost::scoped_ptr<Impl> impl_;
578 ///////////////////////////////hh.e////////////////////////////////////////
580 //#include "Parse.ct"
581 //#include "Parse.cti"
588 // comment-column: 40
589 // c-file-style: "senf"
590 // indent-tabs-mode: nil
591 // ispell-local-dictionary: "american"
592 // compile-command: "scons -u test"