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
212 ArgumentToken instance.
214 \ingroup console_parser
220 PathSeparator = 0x0001,
221 ArgumentGroupOpen = 0x0002,
222 ArgumentGroupClose = 0x0004,
223 DirectoryGroupOpen = 0x0008,
224 DirectoryGroupClose = 0x0010,
225 CommandTerminator = 0x0020,
226 OtherPunctuation = 0x0040,
227 BasicString = 0x0080,
233 ArgumentGrouper = ArgumentGroupOpen
234 | ArgumentGroupClose,
236 DirectoryGrouper = DirectoryGroupOpen
237 | DirectoryGroupClose,
239 Punctuation = DirectoryGroupOpen
240 | DirectoryGroupClose
248 SimpleArgument = Word
253 std::string const & value() const; ///< String value of token
254 /**< This value is properly unquoted */
256 TokenType type() const; ///< Token type
258 bool is(unsigned tokens) const; ///< Check, whether tokens type matches \a tokens
259 /**< \a tokens is a bit-mask of token types to check. */
264 ArgumentToken(TokenType type, std::string token);
269 friend class detail::ParserAccess;
272 /** \brief Single parsed console command
274 Every command parsed is returned in a ParseCommandInfo instance. This information is purely
275 taken from the parser, no semantic information is attached at this point, the config/console
276 node tree is not involved in any why. ParseCommandInfo consist of
278 \li the type of command: built-in or normal command represented by a possibly relative path
279 into the command tree.
281 \li the arguments. Every argument consists of a range of ArgumentToken instances.
283 \ingroup console_parser
285 class ParseCommandInfo
287 typedef std::vector<ArgumentToken> Tokens;
288 typedef std::vector<std::string> CommandPath;
291 class ArgumentIterator;
293 typedef CommandPath::const_iterator path_iterator;
294 typedef Tokens::const_iterator token_iterator;
295 typedef ArgumentIterator argument_iterator;
296 typedef Tokens::size_type size_type;
298 typedef boost::iterator_range<path_iterator> CommandPathRange;
299 typedef boost::iterator_range<argument_iterator> ArgumentsRange;
300 typedef boost::iterator_range<token_iterator> TokensRange;
302 enum BuiltinCommand { NoBuiltin,
310 BuiltinCommand builtin() const; ///< Command type
311 /**< \returns \c NoBuiltin, if the command is an ordinary
312 command, otherwise the id of the built-in command */
313 CommandPathRange commandPath() const; ///< Command path
314 /**< This is the path to the command if it is not a built-in
315 command. Every element of the returned range
316 constitutes one path element. If the first element is
317 empty, the path is an absolute path, otherwise it is
318 relative. If the last element is an empty string, the
319 path ends with a '/' char. */
320 ArgumentsRange arguments() const; ///< Command arguments
321 /**< The returned range contains one TokensRange for each
323 TokensRange tokens() const; ///< All argument tokens
324 /**< The returned range contains \e all argument tokens in a
325 single range not divided into separate arguments. */
330 void setBuiltin(BuiltinCommand builtin);
331 void setCommand(std::vector<std::string> & commandPath);
332 void addToken(ArgumentToken const & token);
336 std::vector<std::string> commandPath_;
337 BuiltinCommand builtin_;
340 friend class detail::ParserAccess;
343 /** \brief Iterator parsing argument groups
345 This special iterator parses a token range returned by the parser into argument ranges. An
346 argument range is either a single token or it is a range of tokens enclosed in matching
347 parenthesis. The ParseCommandInfo::arguments() uses this iterator type. To recursively parse
348 complex arguments, you can however use this iterator to divide a multi-token argument into
349 further argument groups (e.g. to parse a list or vector of items).
351 This iterator is a bidirectional iterator \e not a random access iterator.
353 class ParseCommandInfo::ArgumentIterator
354 : public boost::iterator_facade< ParseCommandInfo::ArgumentIterator,
355 ParseCommandInfo::TokensRange,
356 boost::bidirectional_traversal_tag,
357 ParseCommandInfo::TokensRange >
361 explicit ArgumentIterator(ParseCommandInfo::TokensRange::iterator i);
364 reference dereference() const;
365 bool equal(ArgumentIterator const & other) const;
369 mutable ParseCommandInfo::TokensRange::iterator b_;
370 mutable ParseCommandInfo::TokensRange::iterator e_;
372 void setRange() const;
374 friend class boost::iterator_core_access;
375 friend class ParseCommandInfo;
378 /** \brief Syntax error parsing command arguments exception
380 All errors while parsing the arguments of a command must be signaled by throwing an instance
381 of SyntaxErrorException. This is important, so command overloading works.
383 struct SyntaxErrorException : public std::exception
385 explicit SyntaxErrorException(std::string const & msg = "");
386 virtual ~SyntaxErrorException() throw();
388 virtual char const * what() const throw();
389 std::string const & message() const;
392 std::string message_;
395 /** \brief Wrapper checking argument iterator access for validity
397 CheckedArgumentIteratorWrapper is a wrapper around a range of arguments parsed using the
398 ParseCommandInfo::ArgumentIterator. It is used to parse arguments either in a command
399 (registered with manual argument parsing) or when defining a custom parser.
401 void fn(std::ostream & out, senf::console::ParseCommandInfo command)
407 senf::console::CheckedArgumentIteratorWrapper arg (command.arguments());
408 senf::console::parse( *(arg++), arg1 );
409 senf::console::parse( *(arg++), arg2 );
416 To use the wrapper, you must ensure that:
417 \li You increment the iterator \e past all arguments you parse. The iterator must point to
418 the end of the range when parsing is complete.
419 \li The iterator wrapper is destroyed after parsing but before executing the command itself
422 Accessing a non-existent argument or failing to parse all arguments will raise a
423 senf::console::SyntaxErrorException.
425 \see \link console_arg_custom Example customer parser \endlink
427 class CheckedArgumentIteratorWrapper
428 : boost::noncopyable,
429 public boost::iterator_facade< CheckedArgumentIteratorWrapper,
430 ParseCommandInfo::TokensRange,
431 boost::forward_traversal_tag,
432 ParseCommandInfo::TokensRange >,
433 public senf::safe_bool<CheckedArgumentIteratorWrapper>
436 typedef boost::iterator_facade< CheckedArgumentIteratorWrapper,
437 ParseCommandInfo::TokensRange,
438 boost::forward_traversal_tag,
439 ParseCommandInfo::TokensRange > IteratorFacade;
442 explicit CheckedArgumentIteratorWrapper(
443 ParseCommandInfo::ArgumentsRange const & range,
444 std::string const & msg = "invalid number of arguments");
445 ///< Make wrapper from ArgumentsRange
446 /**< This constructs a wrapper from a
447 ParseCommandInfo::ArgumentsRange.
448 \param[in] range Range of arguments to parse
449 \param[in] msg Error message */
450 explicit CheckedArgumentIteratorWrapper(
451 ParseCommandInfo::TokensRange const & range,
452 std::string const & msg = "invalid number of arguments");
453 ///< Make wrapper from TokensRange
454 /**< This constructs a wrapper from a
455 ParseCommandInfo::TokensRange. The TokensRange is first
456 converted into an ParseCommandInfo::ArgumentsRange
457 which is then wrapped.
458 \param[in] range Range of tokens to parse
459 \param[in] msg Error message */
461 ~CheckedArgumentIteratorWrapper(); ///< Check, if all arguments are parsed
462 /**< The destructor validates, that all arguments are parsed
463 correctly when leaving the scope, in which the wrapper
464 is instantiated normally (not by an exception).
466 \warning This destructor will throw a
467 SyntaxErrorException, if not all arguments are parsed
468 and when no other exception is in progress. */
470 operator ParseCommandInfo::ArgumentIterator();
471 ///< Use wrapper as ParseCommandInfo::ArgumentIterator
473 bool boolean_test() const; ///< \c true, if more arguments are available
474 bool done() const; ///< \c true, if all arguments are parsed
476 void clear(); ///< Set range empty
477 /**< This call will point the current iterator to the end of
479 \post done() == \c true; */
481 bool operator==(ParseCommandInfo::ArgumentIterator const & other) const;
482 ///< Compare wrapper against ArgumentIterator
483 bool operator!=(ParseCommandInfo::ArgumentIterator const & other) const;
484 ///< Compare wrapper against ArgumentIterator
486 using IteratorFacade::operator++;
487 ParseCommandInfo::ArgumentIterator operator++(int);
490 reference dereference() const;
493 ParseCommandInfo::ArgumentIterator i_;
494 ParseCommandInfo::ArgumentIterator e_;
497 friend class boost::iterator_core_access;
500 /**< \brief Output ParseCommandInfo instance
501 \related ParseCommandInfo
503 std::ostream & operator<<(std::ostream & stream, ParseCommandInfo const & info);
505 /** \brief Parse commands
507 This class implements a parser for the console/config language. It supports parsing strings
508 as well as files. For every parsed command, a callback function is called.
510 \implementation The implementation is based on Boost.Spirit. See the file \ref Parse.ih for
511 the formal language grammar.
513 \implementation Parsing an arbitrary iostream is not supported since arbitrary streams are
514 not seekable. If this is needed, it can however be provided using stream iterators and
515 some special iterator adaptors from Boost.Spirit. However, the amount of backtracking
516 needs to be analyzed before this is viable.
518 \todo Implement more detailed error reporting and error recovery.
520 \ingroup console_parser
526 ///////////////////////////////////////////////////////////////////////////
529 typedef boost::function<void (ParseCommandInfo const &)> Callback;
531 ///////////////////////////////////////////////////////////////////////////
532 ///\name Structors and default members
539 ///////////////////////////////////////////////////////////////////////////
541 bool parse(std::string command, Callback cb); ///< Parse string
542 bool parseFile(std::string filename, Callback cb); ///< Parse file
543 /**< \throws SystemException if the file cannot be
551 boost::scoped_ptr<Impl> impl_;
556 ///////////////////////////////hh.e////////////////////////////////////////
558 //#include "Parse.ct"
559 //#include "Parse.cti"
566 // comment-column: 40
567 // c-file-style: "senf"
568 // indent-tabs-mode: nil
569 // ispell-local-dictionary: "american"
570 // compile-command: "scons -u test"