#define pathToFolers "name_prjct"

~/projects/name_prjct/

#define pathToFolers "/home/$USER/projects/name_prjct/"

#ifndef APATH
#define APATH  /home/user1
#endif

#define pathToFolers  "APATH/projects/name_prjct/"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main()
{
    char *home = getenv("HOME");
    char *path, *dir = "/projects/name_prjct/";

    path = (char *)malloc(strlen(home) + strlen(dir) + 1); 
    strcpy(path, home);
    strcpy(path + strlen(home), dir);

    printf("path = '%s'\n", path);
}

#include<iostream>
#include<string>
#include<stdlib.h>
using namespace std;

int main(){
  auto path=getenv("HOME")+"/projects/name_prjct/"s;
  cout<<path<<'\n';
  }