# include <stdio.h>
# include <stdbool.h>
//
//  Program 10.4, Stephen Kochan, Programming in C.
//
int main ( void );
bool equalStrings ( const char s1[], const char s2[] );

int main ( void )
{
  const char stra[] = "string compare test";
  const char strb[] = "string";

  printf ( "\"%s\" and \"%s\"", stra, strb );
  if ( equalStrings ( stra, strb ) )
  {
  printf ( " are equal.\n" );
  }
  else
  {
    printf ( " are NOT equal.\n" );
  }

  printf ( "\"%s\" and \"%s\"", stra, stra );
  if ( equalStrings ( stra, stra ) )
  {
  printf ( " are equal.\n" );
  }
  else
  {
    printf ( " are NOT equal.\n" );
  }

  printf ( "\"%s\" and \"%s\"", strb, "string" );
  if ( equalStrings ( strb, "string" ) )
  {
  printf ( " are equal.\n" );
  }
  else
  {
    printf ( " are NOT equal.\n" );
  }

  printf ( "\"%s\" and \"%s\"", strb, "string " );
  if ( equalStrings ( strb, "string " ) )
  {
  printf ( " are equal.\n" );
  }
  else
  {
    printf ( " are NOT equal.\n" );
  }

  return 0;
}

bool equalStrings ( const char s1[], const char s2[] )
{
  int i;
  bool value;

  i = 0;

  while ( true )
  {
    if ( s1[i] != s2[i] )
    {
      value = false;
      return value;
    }
//
//  Characters are equal.  If they are "NULL", we are done.
//
    if ( s1[i] == '\0' )
    {
      value = true;
      return value;
    }
//
//  Get ready for next character.
//
    i = i + 1;
  }
}