// Copyright (c) 2005, Google Inc.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// * 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
// * Neither the name of Google Inc. nor the names of its
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// 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
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// 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
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// (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
// C++ interface to the pcre regular-expression library. RE supports
// Perl-style regular expressions (with extensions like \d, \w, \s,
// -----------------------------------------------------------------------
// 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
// -----------------------------------------------------------------------
// 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):
// !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"
// 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
// 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):
// pcrecpp::RE::FullMatch("abc", "[a-z]+(\\d+)?", &number);
// -----------------------------------------------------------------------
// 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.
// -----------------------------------------------------------------------
// 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:
// 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.
// pcrecpp::RE_Options options;
// 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
// -----------------------------------------------------------------------
// PASSING MODIFIERS TO THE REGULAR EXPRESSION ENGINE
// PCRE defines some modifiers to change the behavior of the regular
// 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
// 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:
// 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_Options().set_caseless(true).set_multiline(true)).PartialMatch(str);
// 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_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
// 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.
// 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
// 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
// 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 <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>
#define PCRE_SET_OR_CLEAR(b, o) \
if (b) all_options_ |= (o); else all_options_ &= ~(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,
class PCRECPP_EXP_DEFN RE_Options {
RE_Options() : match_limit_(0), match_limit_recursion_(0), all_options_(0) {}
// alternative constructor.
// To facilitate transfer of legacy code from C programs
// RE(pattern, RE_Options(PCRE_CASELESS|PCRE_MULTILINE)).PartialMatch(str);
// But new code is better off doing
// 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) {
int match_limit_recursion() const { return match_limit_recursion_; };
RE_Options &set_match_limit_recursion(int limit) {
match_limit_recursion_ = limit;
return PCRE_IS_SET(PCRE_CASELESS);
RE_Options &set_caseless(bool x) {
PCRE_SET_OR_CLEAR(x, PCRE_CASELESS);
return PCRE_IS_SET(PCRE_MULTILINE);
RE_Options &set_multiline(bool x) {
PCRE_SET_OR_CLEAR(x, PCRE_MULTILINE);
return PCRE_IS_SET(PCRE_DOTALL);
RE_Options &set_dotall(bool x) {
PCRE_SET_OR_CLEAR(x, PCRE_DOTALL);
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);
return PCRE_IS_SET(PCRE_EXTRA);
RE_Options &set_extra(bool x) {
PCRE_SET_OR_CLEAR(x, PCRE_EXTRA);
return PCRE_IS_SET(PCRE_UNGREEDY);
RE_Options &set_ungreedy(bool x) {
PCRE_SET_OR_CLEAR(x, PCRE_UNGREEDY);
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) {
int all_options() const {
// TODO: add other pcre flags
int match_limit_recursion_;
// 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 {
// 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);
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
