在c项目中使用pcre2

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<<"\n@R_897_10586@l 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<<"\n@R_897_10586@l 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 @R_897_10586@l 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 @R_897_10586@l match (in each match)
}
int main(){
    jp::regex re("(?<@R_897_10586@l>\\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("@R_897_10586@l")+")";
                    }
                ));
    #endif
    return 0;
}

您可以阅读完整的文档here.