// Copyright (c) 2005, Google Inc. // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // // Author: Sanjay Ghemawat // Support for PCRE_XXX modifiers added by Giuseppe Maxia, July 2005 #ifndef _PCRECPP_H #define _PCRECPP_H // C++ interface to the pcre regular-expression library. RE supports // Perl-style regular expressions (with extensions like \d, \w, \s, // ...). // // ----------------------------------------------------------------------- // REGEXP SYNTAX: // // This module is part of the pcre library and hence supports its syntax // for regular expressions. // // The syntax is pretty similar to Perl's. For those not familiar // with Perl's regular expressions, here are some examples of the most // commonly used extensions: // // "hello (\\w+) world" -- \w matches a "word" character // "version (\\d+)" -- \d matches a digit // "hello\\s+world" -- \s matches any whitespace character // "\\b(\\w+)\\b" -- \b matches empty string at a word boundary // "(?i)hello" -- (?i) turns on case-insensitive matching // "/\\*(.*?)\\*/" -- .*? matches . minimum no. of times possible // // ----------------------------------------------------------------------- // MATCHING INTERFACE: // // The "FullMatch" operation checks that supplied text matches a // supplied pattern exactly. // // Example: successful match // pcrecpp::RE re("h.*o"); // re.FullMatch("hello"); // // Example: unsuccessful match (requires full match): // pcrecpp::RE re("e"); // !re.FullMatch("hello"); // // Example: creating a temporary RE object: // pcrecpp::RE("h.*o").FullMatch("hello"); // // You can pass in a "const char*" or a "string" for "text". The // examples below tend to use a const char*. // // You can, as in the different examples above, store the RE object // explicitly in a variable or use a temporary RE object. The // examples below use one mode or the other arbitrarily. Either // could correctly be used for any of these examples. // // ----------------------------------------------------------------------- // MATCHING WITH SUB-STRING EXTRACTION: // // You can supply extra pointer arguments to extract matched subpieces. // // Example: extracts "ruby" into "s" and 1234 into "i" // int i; // string s; // pcrecpp::RE re("(\\w+):(\\d+)"); // re.FullMatch("ruby:1234", &s, &i); // // Example: does not try to extract any extra sub-patterns // re.FullMatch("ruby:1234", &s); // // Example: does not try to extract into NULL // re.FullMatch("ruby:1234", NULL, &i); // // Example: integer overflow causes failure // !re.FullMatch("ruby:1234567891234", NULL, &i); // // Example: fails because there aren't enough sub-patterns: // !pcrecpp::RE("\\w+:\\d+").FullMatch("ruby:1234", &s); // // Example: fails because string cannot be stored in integer // !pcrecpp::RE("(.*)").FullMatch("ruby", &i); // // The provided pointer arguments can be pointers to any scalar numeric // type, or one of // string (matched piece is copied to string) // StringPiece (StringPiece is mutated to point to matched piece) // T (where "bool T::ParseFrom(const char*, int)" exists) // NULL (the corresponding matched sub-pattern is not copied) // // CAVEAT: An optional sub-pattern that does not exist in the matched // string is assigned the empty string. Therefore, the following will // return false (because the empty string is not a valid number): // int number; // pcrecpp::RE::FullMatch("abc", "[a-z]+(\\d+)?", &number); // // ----------------------------------------------------------------------- // DO_MATCH // // The matching interface supports at most 16 arguments per call. // If you need more, consider using the more general interface // pcrecpp::RE::DoMatch(). See pcrecpp.h for the signature for DoMatch. // // ----------------------------------------------------------------------- // PARTIAL MATCHES // // You can use the "PartialMatch" operation when you want the pattern // to match any substring of the text. // // Example: simple search for a string: // pcrecpp::RE("ell").PartialMatch("hello"); // // Example: find first number in a string: // int number; // pcrecpp::RE re("(\\d+)"); // re.PartialMatch("x*100 + 20", &number); // assert(number == 100); // // ----------------------------------------------------------------------- // UTF-8 AND THE MATCHING INTERFACE: // // By default, pattern and text are plain text, one byte per character. // The UTF8 flag, passed to the constructor, causes both pattern // and string to be treated as UTF-8 text, still a byte stream but // potentially multiple bytes per character. In practice, the text // is likelier to be UTF-8 than the pattern, but the match returned // may depend on the UTF8 flag, so always use it when matching // UTF8 text. E.g., "." will match one byte normally but with UTF8 // set may match up to three bytes of a multi-byte character. // // Example: // pcrecpp::RE_Options options; // options.set_utf8(); // pcrecpp::RE re(utf8_pattern, options); // re.FullMatch(utf8_string); // // Example: using the convenience function UTF8(): // pcrecpp::RE re(utf8_pattern, pcrecpp::UTF8()); // re.FullMatch(utf8_string); // // NOTE: The UTF8 option is ignored if pcre was not configured with the // --enable-utf8 flag. // // ----------------------------------------------------------------------- // PASSING MODIFIERS TO THE REGULAR EXPRESSION ENGINE // // PCRE defines some modifiers to change the behavior of the regular // expression engine. // The C++ wrapper defines an auxiliary class, RE_Options, as a vehicle // to pass such modifiers to a RE class. // // Currently, the following modifiers are supported // // modifier description Perl corresponding // // PCRE_CASELESS case insensitive match /i // PCRE_MULTILINE multiple lines match /m // PCRE_DOTALL dot matches newlines /s // PCRE_DOLLAR_ENDONLY $ matches only at end N/A // PCRE_EXTRA strict escape parsing N/A // PCRE_EXTENDED ignore whitespaces /x // PCRE_UTF8 handles UTF8 chars built-in // PCRE_UNGREEDY reverses * and *? N/A // PCRE_NO_AUTO_CAPTURE disables matching parens N/A (*) // // (For a full account on how each modifier works, please check the // PCRE API reference manual). // // (*) Both Perl and PCRE allow non matching parentheses by means of the // "?:" modifier within the pattern itself. e.g. (?:ab|cd) does not // capture, while (ab|cd) does. // // For each modifier, there are two member functions whose name is made // out of the modifier in lowercase, without the "PCRE_" prefix. For // instance, PCRE_CASELESS is handled by // bool caseless(), // which returns true if the modifier is set, and // RE_Options & set_caseless(bool), // which sets or unsets the modifier. // // Moreover, PCRE_EXTRA_MATCH_LIMIT can be accessed through the // set_match_limit() and match_limit() member functions. // Setting match_limit to a non-zero value will limit the executation of // pcre to keep it from doing bad things like blowing the stack or taking // an eternity to return a result. A value of 5000 is good enough to stop // stack blowup in a 2MB thread stack. Setting match_limit to zero will // disable match limiting. Alternately, you can set match_limit_recursion() // which uses PCRE_EXTRA_MATCH_LIMIT_RECURSION to limit how much pcre // recurses. match_limit() caps the number of matches pcre does; // match_limit_recrusion() caps the depth of recursion. // // Normally, to pass one or more modifiers to a RE class, you declare // a RE_Options object, set the appropriate options, and pass this // object to a RE constructor. Example: // // RE_options opt; // opt.set_caseless(true); // // if (RE("HELLO", opt).PartialMatch("hello world")) ... // // RE_options has two constructors. The default constructor takes no // arguments and creates a set of flags that are off by default. // // The optional parameter 'option_flags' is to facilitate transfer // of legacy code from C programs. This lets you do // RE(pattern, RE_Options(PCRE_CASELESS|PCRE_MULTILINE)).PartialMatch(str); // // But new code is better off doing // RE(pattern, // RE_Options().set_caseless(true).set_multiline(true)).PartialMatch(str); // (See below) // // If you are going to pass one of the most used modifiers, there are some // convenience functions that return a RE_Options class with the // appropriate modifier already set: // CASELESS(), UTF8(), MULTILINE(), DOTALL(), EXTENDED() // // If you need to set several options at once, and you don't want to go // through the pains of declaring a RE_Options object and setting several // options, there is a parallel method that give you such ability on the // fly. You can concatenate several set_xxxxx member functions, since each // of them returns a reference to its class object. e.g.: to pass // PCRE_CASELESS, PCRE_EXTENDED, and PCRE_MULTILINE to a RE with one // statement, you may write // // RE(" ^ xyz \\s+ .* blah$", RE_Options() // .set_caseless(true) // .set_extended(true) // .set_multiline(true)).PartialMatch(sometext); // // ----------------------------------------------------------------------- // SCANNING TEXT INCREMENTALLY // // The "Consume" operation may be useful if you want to repeatedly // match regular expressions at the front of a string and skip over // them as they match. This requires use of the "StringPiece" type, // which represents a sub-range of a real string. Like RE, StringPiece // is defined in the pcrecpp namespace. // // Example: read lines of the form "var = value" from a string. // string contents = ...; // Fill string somehow // pcrecpp::StringPiece input(contents); // Wrap in a StringPiece // // string var; // int value; // pcrecpp::RE re("(\\w+) = (\\d+)\n"); // while (re.Consume(&input, &var, &value)) { // ...; // } // // Each successful call to "Consume" will set "var/value", and also // advance "input" so it points past the matched text. // // The "FindAndConsume" operation is similar to "Consume" but does not // anchor your match at the beginning of the string. For example, you // could extract all words from a string by repeatedly calling // pcrecpp::RE("(\\w+)").FindAndConsume(&input, &word) // // ----------------------------------------------------------------------- // PARSING HEX/OCTAL/C-RADIX NUMBERS // // By default, if you pass a pointer to a numeric value, the // corresponding text is interpreted as a base-10 number. You can // instead wrap the pointer with a call to one of the operators Hex(), // Octal(), or CRadix() to interpret the text in another base. The // CRadix operator interprets C-style "0" (base-8) and "0x" (base-16) // prefixes, but defaults to base-10. // // Example: // int a, b, c, d; // pcrecpp::RE re("(.*) (.*) (.*) (.*)"); // re.FullMatch("100 40 0100 0x40", // pcrecpp::Octal(&a), pcrecpp::Hex(&b), // pcrecpp::CRadix(&c), pcrecpp::CRadix(&d)); // will leave 64 in a, b, c, and d. // // ----------------------------------------------------------------------- // REPLACING PARTS OF STRINGS // // You can replace the first match of "pattern" in "str" with // "rewrite". Within "rewrite", backslash-escaped digits (\1 to \9) // can be used to insert text matching corresponding parenthesized // group from the pattern. \0 in "rewrite" refers to the entire // matching text. E.g., // // string s = "yabba dabba doo"; // pcrecpp::RE("b+").Replace("d", &s); // // will leave "s" containing "yada dabba doo". The result is true if // the pattern matches and a replacement occurs, or false otherwise. // // GlobalReplace() is like Replace(), except that it replaces all // occurrences of the pattern in the string with the rewrite. // Replacements are not subject to re-matching. E.g., // // string s = "yabba dabba doo"; // pcrecpp::RE("b+").GlobalReplace("d", &s); // // will leave "s" containing "yada dada doo". It returns the number // of replacements made. // // Extract() is like Replace(), except that if the pattern matches, // "rewrite" is copied into "out" (an additional argument) with // substitutions. The non-matching portions of "text" are ignored. // Returns true iff a match occurred and the extraction happened // successfully. If no match occurs, the string is left unaffected. #include <string> #include <pcre.h> #include <pcrecpparg.h> // defines the Arg class // This isn't technically needed here, but we include it // anyway so folks who include pcrecpp.h don't have to. #include <pcre_stringpiece.h> namespace pcrecpp { #define PCRE_SET_OR_CLEAR(b, o) \ if (b) all_options_ |= (o); else all_options_ &= ~(o); \ return *this #define PCRE_IS_SET(o) \ (all_options_ & o) == o /***** Compiling regular expressions: the RE class *****/ // RE_Options allow you to set options to be passed along to pcre, // along with other options we put on top of pcre. // Only 9 modifiers, plus match_limit and match_limit_recursion, // are supported now. class PCRECPP_EXP_DEFN RE_Options { public: // constructor RE_Options() : match_limit_(0), match_limit_recursion_(0), all_options_(0) {} // alternative constructor. // To facilitate transfer of legacy code from C programs // // This lets you do // RE(pattern, RE_Options(PCRE_CASELESS|PCRE_MULTILINE)).PartialMatch(str); // But new code is better off doing // RE(pattern, // RE_Options().set_caseless(true).set_multiline(true)).PartialMatch(str); RE_Options(int option_flags) : match_limit_(0), match_limit_recursion_(0), all_options_(option_flags) {} // we're fine with the default destructor, copy constructor, etc. // accessors and mutators int match_limit() const { return match_limit_; }; RE_Options &set_match_limit(int limit) { match_limit_ = limit; return *this; } int match_limit_recursion() const { return match_limit_recursion_; }; RE_Options &set_match_limit_recursion(int limit) { match_limit_recursion_ = limit; return *this; } bool caseless() const { return PCRE_IS_SET(PCRE_CASELESS); } RE_Options &set_caseless(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_CASELESS); } bool multiline() const { return PCRE_IS_SET(PCRE_MULTILINE); } RE_Options &set_multiline(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_MULTILINE); } bool dotall() const { return PCRE_IS_SET(PCRE_DOTALL); } RE_Options &set_dotall(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_DOTALL); } bool extended() const { return PCRE_IS_SET(PCRE_EXTENDED); } RE_Options &set_extended(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_EXTENDED); } bool dollar_endonly() const { return PCRE_IS_SET(PCRE_DOLLAR_ENDONLY); } RE_Options &set_dollar_endonly(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_DOLLAR_ENDONLY); } bool extra() const { return PCRE_IS_SET(PCRE_EXTRA); } RE_Options &set_extra(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_EXTRA); } bool ungreedy() const { return PCRE_IS_SET(PCRE_UNGREEDY); } RE_Options &set_ungreedy(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_UNGREEDY); } bool utf8() const { return PCRE_IS_SET(PCRE_UTF8); } RE_Options &set_utf8(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_UTF8); } bool no_auto_capture() const { return PCRE_IS_SET(PCRE_NO_AUTO_CAPTURE); } RE_Options &set_no_auto_capture(bool x) { PCRE_SET_OR_CLEAR(x, PCRE_NO_AUTO_CAPTURE); } RE_Options &set_all_options(int opt) { all_options_ = opt; return *this; } int all_options() const { return all_options_ ; } // TODO: add other pcre flags private: int match_limit_; int match_limit_recursion_; int all_options_; }; // These functions return some common RE_Options static inline RE_Options UTF8() { return RE_Options().set_utf8(true); } static inline RE_Options CASELESS() { return RE_Options().set_caseless(true); } static inline RE_Options MULTILINE() { return RE_Options().set_multiline(true); } static inline RE_Options DOTALL() { return RE_Options().set_dotall(true); } static inline RE_Options EXTENDED() { return RE_Options().set_extended(true); } // Interface for regular expression matching. Also corresponds to a // pre-compiled regular expression. An "RE" object is safe for // concurrent use by multiple threads. class PCRECPP_EXP_DEFN RE { public: // We provide implicit conversions from strings so that users can // pass in a string or a "const char*" wherever an "RE" is expected. RE(const string& pat) { Init(pat, NULL); } RE(const string& pat, const RE_Options& option) { Init(pat, &option); } RE(const char* pat) { Init(pat, NULL); } RE(const char* pat, const RE_Options& option) { Init(pat, &option); } RE(const unsigned char* pat) { Init(reinterpret_cast<const char*>(pat), NULL); } RE(const unsigned char* pat, const RE_Options& option) { Init(reinterpret_cast<const char*>(pat), &option); } // Copy constructor & assignment - note that these are expensive // because they recompile the expression. RE(const RE& re) { Init(re.pattern_, &re.options_); } const RE& operator=(const RE& re) { if (this != &re) { Cleanup(); // This is the code that originally came from Google // Init(re.pattern_.c_str(), &re.options_); // This is the replacement from Ari Pollak Init(re.pattern_, &re.options_); } return *this; } ~RE(); // The string specification for this RE. E.g. // RE re("ab*c?d+"); // re.pattern(); // "ab*c?d+" const string& pattern() const { return pattern_; } // If RE could not be created properly, returns an error string. // Else returns the empty string. const string& error() const { return *error_; } /***** The useful part: the matching interface *****/ // This is provided so one can do pattern.ReplaceAll() just as // easily as ReplaceAll(pattern-text, ....) bool FullMatch(const StringPiece& text, const Arg& ptr1 = no_arg, const Arg& ptr2 = no_arg, const Arg& ptr3 = no_arg, const Arg& ptr4 = no_arg, const Arg& ptr5 = no_arg, const Arg& ptr6 = no_arg, const Arg& ptr7 = no_arg, const Arg& ptr8 = no_arg, const Arg& ptr9 = no_arg, const Arg& ptr10 = no_arg, const Arg& ptr11 = no_arg, const Arg& ptr12 = no_arg, const Arg& ptr13 = no_arg, const Arg& ptr14 = no_arg, const Arg& ptr15 = no_arg, const Arg& ptr16 = no_arg) const; bool PartialMatch(const StringPiece& text, const Arg& ptr1 = no_arg, const Arg& ptr2 = no_arg, const Arg& ptr3 = no_arg, const Arg& ptr4 = no_arg, const Arg& ptr5 = no_arg, const Arg& ptr6 = no_arg, const Arg& ptr7 = no_arg, const Arg& ptr8 = no_arg, const Arg& ptr9 = no_arg, const Arg& ptr10 = no_arg, const Arg& ptr11 = no_arg, const Arg& ptr12 = no_arg, const Arg& ptr13 = no_arg, const Arg& ptr14 = no_arg, const Arg& ptr15 = no_arg, const Arg& ptr16 = no_arg) const; bool Consume(StringPiece* input, const Arg& ptr1 = no_arg, const Arg& ptr2 = no_arg, const Arg& ptr3 = no_arg, const Arg& ptr4 = no_arg, const Arg& ptr5 = no_arg, const Arg& ptr6 = no_arg, const Arg& ptr7 = no_arg, const Arg& ptr8 = no_arg, const Arg& ptr9 = no_arg, const Arg& ptr10 = no_arg, const Arg& ptr11 = no_arg, const Arg& ptr12 = no_arg, const Arg& ptr13 = no_arg, const Arg& ptr14 = no_arg, const Arg& ptr15 = no_arg, const Arg& ptr16 = no_arg) const; bool FindAndConsume(StringPiece* input, const Arg& ptr1 = no_arg, const Arg& ptr2 = no_arg, const Arg& ptr3 = no_arg, const Arg& ptr4 = no_arg, const Arg& ptr5 = no_arg, const Arg& ptr6 = no_arg, const Arg& ptr7 = no_arg, const Arg& ptr8 = no_arg, const Arg& ptr9 = no_arg, const Arg& ptr10 = no_arg, const Arg& ptr11 = no_arg, const Arg& ptr12 = no_arg, const Arg& ptr13 = no_arg, const Arg& ptr14 = no_arg, const Arg& ptr15 = no_arg, const Arg& ptr16 = no_arg) const; bool Replace(const StringPiece& rewrite, string *str) const; int GlobalReplace(const StringPiece& rewrite, string *str) const; bool Extract(const StringPiece &rewrite, const StringPiece &text, string *out) const; // Escapes all potentially meaningful regexp characters in // 'unquoted'. The returned string, used as a regular expression, // will exactly match the original string. For example, // 1.5-2.0? // may become: // 1\.5\-2\.0\? // Note QuoteMeta behaves the same as perl's QuoteMeta function, // *except* that it escapes the NUL character (\0) as backslash + 0, // rather than backslash + NUL. static string QuoteMeta(const StringPiece& unquoted); /***** Generic matching interface *****/ // Type of match (TODO: Should be restructured as part of RE_Options) enum Anchor { UNANCHORED, // No anchoring ANCHOR_START, // Anchor at start only ANCHOR_BOTH // Anchor at start and end }; // General matching routine. Stores the length of the match in // "*consumed" if successful. bool DoMatch(const StringPiece& text, Anchor anchor, int* consumed, const Arg* const* args, int n) const; // Return the number of capturing subpatterns, or -1 if the // regexp wasn't valid on construction. int NumberOfCapturingGroups() const; // The default value for an argument, to indicate the end of the argument // list. This must be used only in optional argument defaults. It should NOT // be passed explicitly. Some people have tried to use it like this: // // FullMatch(x, y, &z, no_arg, &w); // // This is a mistake, and will not work. static Arg no_arg; private: void Init(const string& pattern, const RE_Options* options); void Cleanup(); // Match against "text", filling in "vec" (up to "vecsize" * 2/3) with // pairs of integers for the beginning and end positions of matched // text. The first pair corresponds to the entire matched text; // subsequent pairs correspond, in order, to parentheses-captured // matches. Returns the number of pairs (one more than the number of // the last subpattern with a match) if matching was successful // and zero if the match failed. // I.e. for RE("(foo)|(bar)|(baz)") it will return 2, 3, and 4 when matching // against "foo", "bar", and "baz" respectively. // When matching RE("(foo)|hello") against "hello", it will return 1. // But the values for all subpattern are filled in into "vec". int TryMatch(const StringPiece& text, int startpos, Anchor anchor, bool empty_ok, int *vec, int vecsize) const; // Append the "rewrite" string, with backslash subsitutions from "text" // and "vec", to string "out". bool Rewrite(string *out, const StringPiece& rewrite, const StringPiece& text, int *vec, int veclen) const; // internal implementation for DoMatch bool DoMatchImpl(const StringPiece& text, Anchor anchor, int* consumed, const Arg* const args[], int n, int* vec, int vecsize) const; // Compile the regexp for the specified anchoring mode pcre* Compile(Anchor anchor); string pattern_; RE_Options options_; pcre* re_full_; // For full matches pcre* re_partial_; // For partial matches const string* error_; // Error indicator (or points to empty string) }; } // namespace pcrecpp #endif /* _PCRECPP_H */