Thread: Help with my XOR routine..

I know that this topic has been covered a million times already, but i went through all the XOR topics on the site without figuring out what i am doing wrong in my own program?

I've attached the main program file to my post, the XOR function is defined in it's own file:

Code:

/* Source file for the XOR routine */

/* Include the function prototype */
#include "xor.h"

/* XOR-funtion declaration */
std::string XOR(std::string line, std::string key)
{
		unsigned int i = 0, j = 0;					
		std::size_t l_length, k_length;				
		std::string e_line;		
					
	l_length = line.length();
	k_length = key.length();
	
	for(;i < l_length; i++, j++)					
	{
		e_line[i] = line[i] ^ key[j];				
		
		if(j == k_length)							
		{
			j = 0;
		}
	}

	/* Return the encrypted line */
	return e_line;
}

Removed most of my comments since the forums are screwing up indentation.


I compile my project from the command line like this:
"g++ -omain.exe -Wall -pedantic xor.cpp main.cpp"

But when i run the program, nothing happens after i enter the key, i don't get any output to the outputfile, and the program just closes. Where in my code is the problem?

EDIT: Accidentally wrote "crashes" rather than "closes", my program doesn't crash or segfault or anything, it just closes without outputting to the outputfile.