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Simple String Class Segmentation Fault

oatmeal678 (28)
I am doing a simple string class program using dynamic allocation and c-strings.
I can get everything to compile, but I get a segmentation fault.
the program starts
s1 = asdf
segemtation Fault
When I try to debug it shows:
Program received signal SIGSEGV, Segmentation fault.
__strcat_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S:296
296 movdqu (%rsi), %xmm1
(gdb) where
#0 __strcat_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S:296
#1 0x00000000004011d6 in MyString::operator+=(MyString const&) ()
#2 0x00000000004012f3 in operator>>(std::istream&, MyString&) ()
#3 0x0000000000401f2a in main ()
Header File:
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#ifndef MYSTRING_H
#define MYSTRING_H
#include <iostream>
using namespace std;

class MyString
{
  friend ostream& operator<< (ostream& , const MyString& );
  friend istream& operator>> (istream& , MyString& );
  friend istream& getline (istream& , MyString& , char delim = '\n');

  friend MyString operator+ (const MyString& , const MyString& );

  friend bool operator< (const MyString& , const MyString& );
  friend bool operator> (const MyString& , const MyString& );
  friend bool operator<=(const MyString& , const MyString& );
  friend bool operator>=(const MyString& , const MyString& );
  friend bool operator==(const MyString& , const MyString& );
  friend bool operator!=(const MyString& , const MyString& );

public:
  MyString();				// empty string
  MyString(const char* );		// conversion from c-string
  MyString(int );			// conversion from int
  ~MyString();				// destructor
  MyString(const MyString& );		// copy constructor
  MyString& operator=(const MyString& );   // assignment operator

  MyString& operator+=(const MyString& );  // concatenation/assignment

  // bracket operators to access char positions
  char& operator[] (unsigned int index);
  const char& operator[] (unsigned int index) const;

  // insert s into the string at position "index"
  MyString& insert(unsigned int index, const MyString& s);

  // find index of the first occurrence of s inside the string
  //  return the index, or -1 if not found
  int indexOf(const MyString& s) const;
  
  int getLength() const;		// return string length
  const char* getCString() const;	// return c-string equiv

  MyString substring(unsigned int , unsigned int ) const;
  MyString substring(unsigned int ) const;

private:

char * str;
int size;


};
#endif


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#include <iostream>
#include <cstring>
#include <cctype>
#include <iomanip>
#include "mystring.h"

MyString::MyString()
{
	size = 0;
	str = new char[size+1];
	str = NULL;
}                           

MyString::MyString(const char* s)
{
	
	size = strlen(s);
	str = new char[size+1];
	strcpy(str,s);
}               

MyString::MyString(int convert)
{
	int con = convert;
	int counter = 0;

	do	
	{
		con = con / 10;
		counter++;
	}while(con != 0);
	
	size = counter + 1;
	str = new char[size];
 	
	do	
	{
		str[counter - 1] = char((convert % 10) + 48);
		convert = convert / 10;
		counter--;
	}while(counter >= 1);
	str= '\0';
}                       

MyString::~MyString()
{
	delete [] str;
}                          

MyString::MyString(const MyString& second)
{
	
	size = second.size;
	str = new char[size+1];
	strcpy(str,second.str);

}

MyString& MyString::operator=(const MyString& second )
{
        
	if (this != &second)
        {
                delete []str;
		size = strlen(second.str);
                str = new char[size+1];
                strcpy(str,second.str);
		str[size]='\0';
        }
	
                return *this;
}

MyString& MyString::operator+=(const MyString& first)
{
   	size = size + first.size;
   	char  *temp = str;
   	str = new char[size+1];
   	strcpy(str,temp);
   	strcat(str,first.str);
   	delete  [] temp;
   	return  *this;
}

ostream& operator<< (ostream& os, const MyString& s)
{
	  
	os <<s.str;
	return os;
}

istream& operator>> (istream& is, MyString& s)
{

    	char c;

	while (is && isspace(is.peek()))
		is.ignore();

	s = ""; // Set the target to the empty string.
	while (is && !isspace(is.peek()))
	{
		is >> c;
		s += c;
	}

    return is;
}


istream& getline (istream& is, MyString& s, char delim)
{
	MyString String;
	char ch;
	is.get(ch);
	while (ch!= delim && !is.eof()) //check for end of file
	{
		String+=ch;
		is.get(ch);
	}
	s=String;
	return is;		
}

MyString operator+ (const MyString& first, const MyString& second)
{
	MyString s = first;
        s += second;
   	return  s; 
}

char& MyString::operator[] (unsigned int index)
{
	//assert aborts program with error message
	if(index>=0 && index < strlen(str))
	{
		cout << "Not Valid";
		
	}
	return str[index];
}

const char& MyString::operator[] (unsigned int index) const
{
	if(index>=0 && index < strlen(str))
	{
		cout << "Not Valid";
		
	}
	return str[index];
}

MyString& MyString::insert(unsigned int index, const MyString& s)
{
	if(index <= size)	
	{
		char* tempstring = new char[size + s.size];
		
		for(int i = 0; i < index; i++)
			tempstring[i] = str[i];

		for(int i = 0; i < s.size - 1; i++)
			tempstring[i + index] = s.str[i];

		for(int i = index + s.size - 1; i < size + s.size -2; i++)
			tempstring[i] = str[i - s.size +1];

		tempstring[size + s.size -2] = '\0';
		delete [] str;
		str = tempstring;
		size = size + s.size - 1;
	}
	else				
	{
		char* tempstring = new char[size + s.size - 1];

		for(int i = 0; i < size - 1; i++)
			tempstring[i] = str[i];

		for(int i = 0; i < s.size - 1; i++)
			tempstring[size - 1 + i] = s.str[i];

		tempstring[size + s.size - 2] = '\0';
		delete [] str;
		str = tempstring;
		size = size + s.size - 1;
	}
		return *this;  
}


int MyString::indexOf(const MyString& s) const
{
	if(size < s.size)	
		return -1;
	else if(size == s.size)	
	{
		int i = 0;

		while((str[i] == s.str[i]) && (str[i] != '\0'))
			i++;

		if(str[i] == '\0')
			return 0;
		else
			return -1;
	}
	else					
	{
		int index = 0;

		while(index < (size - s.size + 1))
		{	
			int j = 0;
			int k = 0;
			while((s[0] != str[index]) && (index < (size - s.size + 1)))
				index++;
		
			if(index == size - s.size + 1)
				return -1;
			else
			{
				k = index;
				while((s[j] == str[k]) && (s[j] != '\0'))
				{
					k++;
					j++;
				}

				if(s[j] == '\0')
					return index;
				else
					index++;
			}
		}
	}	
}

int MyString::getLength() const
{
	return size;
}

const char* MyString::getCString() const
{
	return str;
}

MyString MyString::substring(unsigned int index, unsigned int sz ) const
{
	MyString sub = substring(index);
	
	if(sub.size - 1 <= sz)
	{
		return sub;
	}
	else
	{
		char* tempstring = new char[sz + 1];
		
		for(int i = 0; i < sz; i++)
		{
			tempstring[i] = sub.str[i];
		}
		
		tempstring[sz] = '\0';
		delete [] sub.str;
		sub.str = tempstring;
		sub.size = sz + 1;
		return sub;
	}
}

MyString MyString::substring(unsigned int index) const
{
	MyString sub;
	int tempsize = size - index;
	
	if(tempsize <= 1)
	{
		sub.str = '\0';
		sub.size = 1;
	}
	else
	{
		char* tempstring = new char[tempsize];
		
		for(int i = 0; i < tempsize - 1; i++)
		{
			tempstring[i] = str[i + index];
		}
		
		tempstring[tempsize - 1] = '\0';	
		delete [] sub.str;
		sub.str = tempstring;
		sub.size = tempsize;
	}
	return sub;
}


bool operator< (const MyString& first, const MyString& second)
{
	return strcmp(first.str,second.str)<0;
}

bool operator> (const MyString& first, const MyString& second)
{
	return strcmp(first.str,second.str)>0;
}

bool operator<=(const MyString& first, const MyString& second)
{
	return strcmp(first.str,second.str)<=0;
}

bool operator>=(const MyString& first, const MyString& second)
{
	return strcmp(first.str,second.str)>=0;
}

bool operator==(const MyString& first, const MyString& second)
{
	return strcmp(first.str,second.str)==0;
}

bool operator!=(const MyString& first, const MyString& second)
{
	return strcmp(first.str,second.str)!=0;
}


oatmeal678 (28)
My driver Program
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#include <iostream>
using namespace std;

#include "mystring.h"

int main()
{
   MyString s1;
   MyString s2("Hello, World");
   MyString s3 = "Welcome to Florida, have a nice day";
   MyString s4 = 12345;

   cout << "s1 = " << s1 << '\n';
   cout << "s2 = " << s2 << '\n';
   cout << "s3 = " << s3 << '\n';
   cout << "s4 = " << s4 << '\n';
   cout << '\n';

   cout << "Making the calls:\n"
        << "\tcin >> s1\n"
        << "\tgetline(cin, s2, ',')\n"
        << "\tgetline(cin, s3)\n";
   cout << "Enter some sentences: ";
  
   cin >> s1;
   getline(cin,s2,',');
   getline(cin,s3);

   cout << "\nNew string values:\n";

   cout << "s1 = " << s1 << '\n';
   cout << "s2 = " << s2 << '\n';
   cout << "s3 = " << s3 << '\n';
   cout << "---------------------------\n";

// ----------------------------------

   s1 = "Dog";
   s2 = "Food";
   MyString result = s1 + s2;
   cout << "result = " << result << '\n';

   s1 += s2;
   cout << "s1 = " << s1 << endl;

   const MyString s5 = "The concatenation of the catapult is a catamaran";
   cout << "s5 = " << s5 << endl;
   cout << "s5.indexOf(\"cat\") returns " << s5.indexOf("cat") << '\n';
   cout << "s5.indexOf(\"dog\") returns " << s5.indexOf("dog") << '\n';

   cout << "s5.getLength() = " << s5.getLength() << '\n';

   cout << "s5[4] = " << s5[4] << '\n';
   cout << "s5[10] = " << s5[10] << '\n';
   cout << "s5[15] = " << s5[15] << '\n';
   cout << "s5[52] = ascii " << static_cast<int>(s5[52]) << '\n';

   cout << "s5.substring(10,16) = " << s5.substring(10,16) << '\n';
   cout << "s5.substring(23) = " << s5.substring(23) << '\n';

   cout << "-----------------------------\n";

   MyString words = "Greetings, Earthling";

   cout << "words = " << words << '\n';
   cout << "words.getLength() = " << words.getLength() << '\n';
   words[0] = 'K';
   words[4] = 'p';
   words[16] = 'z';

   cout << "words = " << words << '\n';

   words[25] = 'Q';
   cout << "words = " << words << '\n';

   words.insert(11, "Insane ");
   cout << "words = " << words << '\n';

   cout << "-----------------------------\n";

   MyString x = "apple", y = "apply";
   cout << "x = " << x << '\n';
   cout << "y = " << y << '\n';

   if (x < y)		cout << "x < y is true\n";
   if (x > y)		cout << "x > y is true\n";
   if (x <= y)		cout << "x <= y is true\n";
   if (x >= y)		cout << "x >= y is true\n";
   if (x == y)		cout << "x == y is true\n";
   if (x != y)		cout << "x != y is true\n";



}
Thomas1965 (4571)
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