/*
 *          File: strtest.cpp
 *        Author: Robert I. Pitts <rip@cs.bu.edu>
 * Last Modified: November 10, 1999
 *         Topic: Manipulating Strings
 * ----------------------------------------------------------------
 *
 * This program demonstrates some programmer-defined string functions.
 *
 */


#include <iostream.h>


/************************ Function Prototypes ************************/

/*
 * Function: StrLength
 * Usage: n = StrLength(str);
 *
 * Returns the length of a string, i.e., the number of characters in it,
 * not including the nul character (\0).
 */
int StrLength(char *str);

/*
 * Function: StrCompare
 * Usage: StrCompare(str1, str2);
 *
 * Compares two strings indicating their lexical order as follows:
 *
 *   If str1 < str2 returns a negative value.
 *   If str1 > str2 returns a positive value.
 *   If str1 == str2 returns zero.
 *
 * Upper- and lowercase letters are treated as being different.
 */
int StrCompare(char *str1, char *str2);

/*
 * Function: StrCopy
 * Usage: StrCopy(dest, source) or dest_ptr = StrCopy(dest, source);
 *
 * Copies the contents (i.e., the characters) of the 'source' string
 * into the 'dest' string.  The 'dest' string must contain enough space
 * to hold the source string otherwise the copy operation will try to
 * overwrite memory beyond the 'dest' string.  The 'dest' is returned.
 */
char *StrCopy(char *dest, char *source);

/*
 * Function: StrConcat
 * Usage: StrConcat(dest, source); or dest_ptr = StrConcat(dest, source);
 *
 * Appends the contents (i.e., the characters) of the 'source' string to
 * the end of the 'dest' string.  The 'dest' string must contain enough
 * space to hold these additional characters otherwise the concatenation
 * will try to overwrite memory beyond the 'dest' string.  The 'dest'
 * is returned.
 */
char *StrConcat(char *dest, char *source);


/*************************** Main Program **************************/

int main()
{
  char str1[80];         // An array to hold a string.
  char *str_ptr = str1;  // A pointer that refers to that array.
  char str2[80];         // Another array to hold a string.

  cout << "Enter 1st string (no spaces): ";
  cin >> str1;

  cout << "Enter 2nd string (no spaces): ";
  cin >> str2;

  cout << endl;

  cout << "\"" << str1 << "\" is of length " << StrLength(str1) << endl;
  cout << "\"" << str2 << "\" is of length " << StrLength(str2) << endl;

  cout << endl;

  int cmp = StrCompare(str_ptr, str2);  // Compare str1 and str2 (use pointer
                                        // str_ptr to refer to str1).

  if (cmp > 0)
    cout << "\"" << str1 << "\" is greater than \"" << str2 << "\"" << endl;
  else if (cmp < 0)
    cout << "\"" << str1 << "\" is less than \"" << str2 << "\"" << endl;
  else
    cout << "\"" << str1 << "\" is equal to \"" << str2 << "\"" << endl;

  StrCopy(str1, str2);

  cout << "\nAfter copying:\n1st string is \"" << str1
       << "\" and\n2nd string is \""
       << StrCopy(str2, "like") << "\"" << endl;

  StrConcat(str1, str2);

  cout << "\nAfter concatenating:\n1st string is \"" << str1
       << "\" and\n2nd string is \""
       << StrConcat(str2, "ness") << "\"" << endl;
  
  cout << endl;

  return 0;
}


/*********************** Function Definitions **********************/

int StrLength(char *str)
{
  //YOU FILL IN!
}

int StrCompare(char *str1, char *str2)
{
  //YOU FILL IN!
}

char *StrCopy(char *dest, char *source)
{
  //YOU FILL IN!
}

char *StrConcat(char *dest, char *source)
{
  //YOU FILL IN!
}