/*-----------------------------

     enum.c -- 使用枚举类型的值

 -----------------------------*/

 #include <stdio.h>

 #include <string.h>

 //#include <stdbool.h>    //C99特性

 #define LEN 30

 char* s_gets(char *st, int n);

 enum spectrum {red, orange, yellow, green, blue, violet};

 const char *colors[] = {"red", "orange", "yellow", "green", "blue", "violet"};

 int main()

 {

     char choice[LEN];

     int color;

     bool color_is_found = false;

     puts("Enter a color (empty line to quit):");

     while (s_gets(choice, LEN) != NULL && choice[] != '\0')

     {

         for (color = red; color != violet; ++color)

         {

             if (strcmp(choice, colors[color]) == )

             {

                 color_is_found = true;

                 break;

             }

         }

         if (color_is_found)

             switch (color)

             {

             case red:

                 puts("Roses are red.");

                 break;

             case orange:

                 puts("Poppies are orange.");

                 break;

             case yellow:

                 puts("Sunflowers are yellow.");

                 break;

             case green:

                 puts("Grass is green");

                 break;

             case blue:

                 puts("Bluebells are blue");

                 break;

             case violet:

                 puts("Violets are violet");

                 break;

             }

         else

             printf("I don't know about the color %s.\n", choice);

         color_is_found = false;

         puts("Next color, please (empty line to quit):");

     }

     puts("Goodbye");

     return ;

 }

 char* s_gets(char *st, int n)

 {

     char *ret_val, *find;

     if (ret_val = fgets(st, n, stdin))

     {

         if (find = strchr(st, '\n'))

             *find = '\0';

         else

             while (fgetc(stdin) != '\n') continue;

     }

     return ret_val;

 }