C++ and design Pattern (Composite design Pattern )

HI All

i am new to C++ and design Pattern ... while implementing Composite
design Pattern
Facing Issue. Kindly help me Out.

[root@arnav test]# cat Filesystem.cc
# include <iostream>
# include <vector>
# include <string.h>
# include <sstream>
# include <ctime>
using namespace std;

#define PORTAGE_DIR "/home/test/"

# include <stdio.h>
#include <stdlib.h>
# include <dirent.h>
# include <sys/types.h>
# include <sys/stat.h>

///////////////////////////////////////////////////////
class Directory;

class AbsFile {
   string name;
   class Directory* parent;
protected:
   Directory* getParent() { return parent; }
public:
   AbsFile( string n, Directory* p ) : name( n ) { parent = p; }
   virtual ~AbsFile() { }

   string getName() { return name; }
   virtual void fileSystemCrawler ( string = "" ) = 0;
};

////////////////////////////////////////////////////////////////////

class File : public AbsFile {
    stringstream content;

public:
    File(string n, Directory * p) : AbsFile(n , p){ }
   ~File() { }

   /*virtual*/
   void fileSystemCrawler( string s = "") {
        struct stat crawl_stat;
        s = getName();

        if (s == "" || s == ".." || s ==".")
            return ;

        if (stat(s.c_str(), &crawl_stat) == 0 ) {
            cout<< " Filename " << s << " " << crawl_stat.st_size <<
endl;
        }
   }

};

////////////////////////////////////////////////////////////////////////////

class Directory : public AbsFile {
    string name;
public:
   Directory (string n, Directory * p = 0) : AbsFile(n, p) {
   }

   ~Directory() {
   }

   //////////////////////////////////////////////////////////////////////////
   int isdir(struct dirent **check_dirent) {
       struct stat check_stat = {0};

       if ( stat((*check_dirent)->d_name, &check_stat) == 0 ) {
          if( S_ISDIR(check_stat.st_mode) != 0 ) {
             if( strcmp( (*check_dirent)->d_name , "." ) != 0 ) {
                 if( strcmp( (*check_dirent)->d_name , ".." ) != 0 ) {
                    return 0;
                 }
             }
          }
       }

       return 1;
    }

    //////////////////////////////////////////////////////////////////////////

   /*virtual*/
   void fileSystemCrawler ( string s = "" ) {
       /* Holds info for the main portage directory. */
        DIR *master;
        struct dirent *master_dirent;
        struct stat master_stat;

       /* Holds info for the crawler which goes in every category
folder. */
        DIR *crawl;
        struct dirent *crawl_dirent;
        struct stat crawl_stat = {0};

        s = getName();

        if (chdir(s.c_str()) != 0)
            cout << "chdir() failed" << endl;

        system ("pwd");

        if ((master = opendir(s.c_str())) == (DIR *)0)
            cout << " opendir failed" << endl;

        if (s == "" || s == ".." || s ==".")
            return ;

        if (stat(s.c_str(), &crawl_stat) == 0 ) {
            cout<< " Directory " << s << " " << crawl_stat.st_size <<
endl;
        }

        while((master_dirent = readdir(master)) != 0 ) {
           if (stat(master_dirent->d_name, &master_stat) == 0 ) {
              string str = master_dirent->d_name;

              if (isdir(&master_dirent) == 0)
              {
                  Directory * ptr = new Directory (str,
getParent());
                  ptr->fileSystemCrawler(str);
                  delete ptr;
                  chdir("..");
               } else {
                  File * ptr = new File(str, getParent());
                  ptr->fileSystemCrawler(str);
                  delete ptr;
               }
            }
        }

        closedir(master);
   }

};

Directory* initialize() {
   Directory* root = new Directory( "/home/test/" );
   return root;
}

//////////////////////////////////////////////////////////////

int main( void ) {
   ////////// Composite, Proxy //////////
   Directory* root = initialize();
   root->fileSystemCrawler(); cout << '\n';

   delete root; cout << '\n';

   return 0;
}

===================================================

[root@arnav test]#
[root@arnav test]#
[root@arnav test]# ls
a.out Backup.cc Backup_File.cc Filesystem.cc intermediate.cc
test1 test2 test3
[root@arnav test]# ./a.out
/home/test
 Directory /home/test/ 4096
 Filename a.out 44683
 Filename Backup_File.cc 5015
 Filename Backup.cc 5027
 /home/test/test2
 opendir failed
Segmentation fault (core dumped)
[root@arnav test]#

Thanks
Pallav Singh