Pointer Wont Print out to Console

[alMarshy]

Hi I am trying to make a program that returns a substring of a string if it is found. The cout statement works but the pointer variable inside it prints no contents. I have ran the program with a debugger and the pointer variable definetely has contents.

Can anybody see why it wont print to the console:

#include<iostream>
#include<limits>

using namespace std;

void pause()
{
 cin.clear();
 cout<<"Press Enter to Quit: ";
 cin.ignore(numeric_limits<streamsize>::max(),'\n');     
}

char *createSubString(char *str,char *sub,int len);

int main()
{
 char mystr[80];
 char *sub;
 char mystr2[80]; 
 int len;
 
 cout<<"Enter a String: ";
 gets(mystr);
 len=strlen(mystr);
 
 cout<<"Enter a substring to search: ";
 gets(mystr2);
 
 sub=createSubString(mystr,mystr2,len);
 
 if(sub){
   cout<<"Substring Found: "<<sub<<endl; //SUB DOES NOT PRINT OUT
 }
 else{
   cout<<"Substring not Found!"<<endl;   
 }
 pause();   
 return 0;   
}

char *createSubString(char *str,char *sub,int len)
{
     char *start;
     char *ptr;
     char *ptr2;
     int count=0;
     
     while(count<len)
     {
      start=&str[count];           
      ptr2=start;
      ptr=sub;
      
      while(*ptr==*ptr2 && *ptr)
      {
        ptr2++;
        ptr++;                             
      }
      
      //if end of *ptr then above while loop must have found match
      //so return the match
      if(!*ptr)
      {
        cout<<ptr<<endl;       
        return ptr;       
      }
        
      count++;                 
     }
     //return 0 if no substring found
     return 0;
}

Any help much appreciated

[Albatross]

http://cplusplus.com/reference/string/string/
http://cplusplus.com/reference/string/string/find/
Perhaps using strings will help you a bit.

-Albatross

[alMarshy]

Thanks for the links. I am doing this exercise just to learn pointers.

Its okay anyhow I just figured out why it was happening. ptr was getting incremented inside the while loop so by the time I returned it it was not the full substring. I had to do this before I returned it.

 if(!*ptr)
      { 
        ptr=sub;             
        return ptr;       
      }