Ubuntu - 没有这样的文件或目录 #include<string>

Question

i am trying to write a code like this: (not finished)

 #include"header.h"
 #include<stdlib>
 #include<stdio.h>
 #include<libpq-fe.h>
 #include<string>

 int main(){
  std::string pguser = "XYZ";
  std::string pgpassword = "XYZ";
  std::string pghost="XYZ";
  std::string pgdbname = "XYZ";
  int i;
  PGconn *conn;
  PGresult *res;

  connstr = "user=";
  connstr += pguser;
  connstr +="password=";
  connstr += pgpassword;
  connstr +="host=";
  connstr += pghost;
  connstr +="dbname=";
  connstr += pgdbname;   

  //DB-Login
  conn = db_login(const string &user, const string &password, const string        &host, const string &dbname);
  if(conn == true){
  printf("LOGIN SUCCESFULLY");
  }else{
     printf("LOGIN FAILED");
  }

  return 0;

  }

My Header.h

 #ifndef DB_H
 #define DB_H

 #include <string>

 using namespace std;

 int db_login(const string &user, const string &password, const string  &host, const string &dbname);
 #endif

I just wanted to test it (sudo gcc main.c header.h -o test) The Result i get is : No such file or directory #include string

I searched for an solution and tried it out but i get the same error. (also installed -> sudo apt-get install build-essential )

Please Help

Answer 1

You are writing C++ code, but trying to compile it as C - gcc is the C language front-end, so use g++ instead. Also rename your source files from .c to .cpp to get automatic support from make(1) .

Answer 2

#include<string> is C++ header. You are using C++ code in .c file, it is incorrect. Probably you should rename main.c to main.cpp and use g++ instead of gcc

Answer 3

For those who run into this question and use make instead of explicitly call gcc:

make VERBOSE=1

will indicate whether its gcc or g++