encryptstring.cpp

C++高级编程这本书所附的源代码

#include <iostream>
#include <string>
#include <cstring>

using namespace std;

string encrypt(const char* input);

int main(int argc, char** argv)
{
  if (argc < 2) {
    cerr << "Usage: " << argv[0] << " string-to-be-encrypted" << endl;
    return -1;
  }

  cout << encrypt(argv[1]);

  return 0;
} 

/**
 * Performs a very weak form of "encryption" by 
 * adding 13 to each character of the string.
 */
string encrypt(const char* input)
{
  char* encrypted = new char[strlen(input) + 1];

  for (unsigned int i = 0; i < strlen(input); i++) {
    encrypted[i] = input[i] + 13;
  }
  encrypted[strlen(input)] = '\0';

  string result(encrypted);

  delete[] encrypted;

  return result;
}