我正在寻找在我的简单c应用程序中使用pcre2,(我正在使用vs2015).
(我正在看各种正则表达式库,一般的感觉是pcre / pcre2是最灵活的)
(我正在看各种正则表达式库,一般的感觉是pcre / pcre2是最灵活的)
首先我从官方位置(http://sourceforge.net/projects/pcre/files/pcre2/10.20/)下载了pcre2并创建了一个非常简单的例子.
- #define PCRE2_CODE_UNIT_WIDTH 8
- #include <pcre2.h>
- ...
- PCRE2_SPTR subject = (PCRE2_SPTR)std::string("this is it").c_str();
- PCRE2_SPTR pattern = (PCRE2_SPTR)std::string("([a-z]+)|\\s").c_str();
- ...
- int errorcode;
- PCRE2_SIZE erroroffset;
- pcre2_code *re = pcre2_compile(pattern,PCRE2_ZERO_TERMINATED,PCRE2_ANCHORED | PCRE2_UTF,&errorcode,&erroroffset,NULL);
- ...
首先文件“pcre2.h”不存在,所以我将pcre2.h.generic重命名为pcre2.h
我猜我需要从源到项目包含一个或多个文件.
但我不愿意随意添加文件而不知道它们的作用.
有人可以给出一些简单的步骤来使用pcre2成功构建项目吗?
UPDATE
这不是一个导入库问题,pcre2.h没有附带librar(不是我在其发布位置可以看到的那个).
解决方法
如果你不介意使用包装器,这是我的:
JPCRE2
您需要根据要使用的字符串类(分别为std :: string,std :: wstring,std :: u16string,std :: u32string)选择基本字符类型(char,wchar_t,char16_t,char32_t):
- typedef jpcre2::select<char> jp;
- //Selecting char as the basic character type will require
- //8 bit PCRE2 library where char is 8 bit,//or 16 bit PCRE2 library where char is 16 bit,//or 32 bit PCRE2 library where char is 32 bit.
- //If char is not 8,16 or 32 bit,it's a compile error.
匹配示例:
检查字符串是否与模式匹配:
- if(jp::Regex("(\\d)|(\\w)").match("I am the subject"))
- std::cout<<"\nmatched";
- else
- std::cout<<"\nno match";
匹配所有并获得匹配计数:
- size_t count =
- jp::Regex("(\\d)|(\\w)","mi").match("I am the subject","g");
- // 'm' modifier enables multi-line mode for the regex
- // 'i' modifier makes the regex case insensitive
- // 'g' modifier enables global matching
获取编号的子字符串/捕获的组:
- jp::VecNum vec_num;
- count =
- jp::Regex("(\\w+)\\s*(\\d+)","im").initMatch()
- .setSubject("I am 23,I am digits 10")
- .setModifier("g")
- .setNumberedSubstringVector(&vec_num)
- .match();
- std::cout<<"\nTotal match of first match: "<<vec_num[0][0];
- std::cout<<"\nCaptrued group 1 of first match: "<<vec_num[0][1];
- std::cout<<"\nCaptrued group 2 of first match: "<<vec_num[0][2];
- std::cout<<"\nTotal match of second match: "<<vec_num[1][0];
- std::cout<<"\nCaptrued group 1 of second match: "<<vec_num[1][1];
- std::cout<<"\nCaptrued group 2 of second match: "<<vec_num[1][2];
获取命名的子串/捕获组:
- jp::VecNas vec_nas;
- count =
- jp::Regex("(?<word>\\w+)\\s*(?<digit>\\d+)","m")
- .initMatch()
- .setSubject("I am 23,I am digits 10")
- .setModifier("g")
- .setNamedSubstringVector(&vec_nas)
- .match();
- std::cout<<"\nCaptured group (word) of first match: "<<vec_nas[0]["word"];
- std::cout<<"\nCaptured group (digit) of first match: "<<vec_nas[0]["digit"];
- std::cout<<"\nCaptured group (word) of second match: "<<vec_nas[1]["word"];
- std::cout<<"\nCaptured group (digit) of second match: "<<vec_nas[1]["digit"];
迭代所有匹配和子串:
- //Iterating through numbered substring
- for(size_t i=0;i<vec_num.size();++i){
- //i=0 is the first match found,i=1 is the second and so forth
- for(size_t j=0;j<vec_num[i].size();++j){
- //j=0 is the capture group 0 i.e the total match
- //j=1 is the capture group 1 and so forth.
- std::cout<<"\n\t("<<j<<"): "<<vec_num[i][j]<<"\n";
- }
- }
替换/替换示例:
- std::cout<<"\n"<<
- ///replace all occurrences of a digit with @
- jp::Regex("\\d").replace("I am the subject string 44","@","g");
- ///swap two parts of a string
- std::cout<<"\n"<<
- jp::Regex("^([^\t]+)\t([^\t]+)$")
- .initReplace()
- .setSubject("I am the subject\tTo be swapped according to tab")
- .setReplaceWith("$2 $1")
- .replace();
替换为匹配评估器:
- jp::String callback1(const jp::NumSub& m,void*,void*){
- return "("+m[0]+")"; //m[0] is capture group 0,i.e total match (in each match)
- }
- int main(){
- jp::Regex re("(?<total>\\w+)","n");
- jp::RegexReplace rr(&re);
- String s3 = "I am ঋ আা a string 879879 fdsjkll ১ ২ ৩ ৪ অ আ ক খ গ ঘ আমার সোনার বাংলা";
- rr.setSubject(s3)
- .setPcre2Option(PCRE2_SUBSTITUTE_GLOBAL);
- std::cout<<"\n\n### 1\n"<<
- rr.nreplace(jp::MatchEvaluator(callback1));
- //nreplace() treats the returned string from the callback as literal,//while replace() will process the returned string
- //with pcre2_substitute()
- #if __cplusplus >= 201103L
- //example with lambda
- std::cout<<"\n\n### Lambda\n"<<
- rr.nreplace(
- jp::MatchEvaluator(
- [](const jp::NumSub& m1,const jp::MapNas& m2,void*){
- return "("+m1[0]+"/"+m2.at("total")+")";
- }
- ));
- #endif
- return 0;
- }
您可以阅读完整的文档here.