Sorting strings by length

1. Read the manpage of qsort().
2. Consider the following program, which will read N words and sort them in alphabetical order.

   
   #include <iostream>
   using std::cin;
   using std::cout;
   
   int cmpFunc( const void *p1, const void * p2)
   {
       const char* str1 = *(const char **)(p1);
       const char* str2 = *(const char **)(p2);
       return strcmp(str1, str2);
   }
   
   void show_array(char* a[], int n)
   {
       int i;
       for (i=0; i<n; i++)
           cout << a[i] << '\n';
   }
   
   int main()
   {
       const int N = 10;
       char word[N][20];
       char* a[N];
   
       for (int i=0; i<N; i++)
       {
           cin >> word[i];
           a[i] = &word[i][0];
       }
   
       qsort(a, N, sizeof(a[0]), cmpFunc);
       show_array(a, N);
       return 0;
   }
   
   

3. Modify the cmpFunc() so that the words will be sorted by string length first, and then by case-sensitive alphabetical order. That is, "was" will be in front of "about", while "IBM" will be in front of "ear".