STL 正则表达式 提取、替换

提取

regex_search:

//传入文件全路径，返回账户下的相对路径,截取部分符合条件的字符串返回
gchar *getlocaladdress(gchar *file_path)
{
	//icase: case insensitive 不区分大小写
	//匹配 xxx@xxx.xxx 的内容
    std::regex r(".*@[[:alnum:]]+\\.[[:alpha:]]+/(.*)", std::regex::icase);
    std::smatch results;
    std::string str = std::string(file_path);
    if(std::regex_search(str, results, r))
    {
        gchar *str = g_strdup(results.str(1).c_str());
        return str;
    }
    return NULL;
}

替换

regexp_replace:

#include <iostream>
#include <string>
#include <regex>

using namespace std;

int main()
{
    string local_path("INBOX/hello");
    string str("/home/sxd/.local/share/imap.163.com/24678@163.com/INBOX/.backup_mark");
    regex r("(.*[[:alnum:]]+@[[:alnum:]]+\\.com/)(.*)", std::regex::icase);
    string fmt = "$1" + local_path; //$1表示regex中第一个（）的内容
    cout << regex_replace(str, r, fmt) << endl;
    return 0;
}

读取文件、提取并写入文件

#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <regex>


using namespace std;

int main(int argc, char **argv)
{
    ifstream in(argv[1]);
    ofstream out(argv[2]);
    vector<string> vs;
    vector<string> outvs;
    while(in) {
        string tmpstr;
        getline(in, tmpstr);
        vs.push_back(tmpstr);
    }

    regex r(".*\\[Debug\\ \\ \\](.*)");
    for(const string &s :vs) {
        smatch result;
        if(regex_match(s, result, r)) {
            outvs.push_back(result.str(1));
        }
    }
    for(auto s:outvs) {
        out << s << endl;
    }
    return 0;
}