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.@H_404_4@
#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@H_404_4@
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.@H_404_4@
有人可以给出一些简单的步骤来使用pcre2成功构建项目吗?@H_404_4@
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).@H_404_4@
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):@H_404_4@
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:@H_404_4@
检查字符串是否与模式匹配:@H_404_4@
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:@H_404_4@
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
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];
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:@H_404_4@
//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:@H_404_4@
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:@H_404_4@
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; }