google gflag使用方法举例

 1 #include<iostream>
 2 #include<gflags/gflags.h>
 3 #include<string>
 4 #include<cstring>
 5 #include<cstdio>
 6 #include<cstdlib>
 7 
 8 using namespace std;
 9 using namespace google;
10 
11 static bool check( const char * flagname , google::int32  age )
12 {
13 
14     std::cout<<"the age "<< age <<std::ends;
15     if(age>16)
16     {
17         std::cout<<" is valid ~"<<std::endl;
18         return true;
19     }
20     std::cout<<" is invalid～"<<std::endl;
21     return false;
22 }
23 
24 DEFINE_string(username , "xijun.gong" , "the student of name");
25 DEFINE_int32(age , 14 , "the student of age");
26 DEFINE_double(grade , 89 ,"the student of grade");
27 
28 static const bool validate = google::RegisterFlagValidator(&FLAGS_age , &check);
29 int main(int argc, char** argv) {
30     google::SetVersionString("0.0.0.1");
31     google::SetUsageMessage("Usage: ./gflags");
32     google::ParseCommandLineFlags(&argc, &argv, true);
33     std::cout <<"Student Infomation: "<<std::endl;
34     std::cout << "username : " << FLAGS_username <<std::endl;
35         std::cout <<"age: " << FLAGS_age << std::endl;
36     std::cout <<"grade: "<< FLAGS_grade <<std::endl;
37     return 0;
38 }

g++ gflag.cc -o gflags -lgflags  -lpthread