Sams Teach Yourself C in 21 Days

A better solution is to make sure there are no extra characters waiting in stdinbefore

prompting the user for input. You can do this by calling gets(), which reads any remain-

ing characters from stdin, up to and including the end of the line. Rather than calling

gets()directly from the program, you can put it in a separate function with the descrip-

tive name of clear_kb(). This function is shown in Listing 14.7.

LISTING14.7 clearing.c. Clearingstdinof extra characters to avoid errors

1: /* Clearing stdin of extra characters. */

2:

3: #include <stdio.h>

4:

5: void clear_kb(void);

6:

7: int main( void )

8: {

9: int age;

10: char name[20];

11:

12: /* Prompt for user’s age. */

13:

14: puts(“Enter your age.”);

15: scanf(“%d”, &age);

16:

17: /* Clear stdin of any extra characters. */

18:

19: clear_kb();

20:

21: /* Now prompt for user’s name: */

22:

23: puts(“Enter your first name:”);

24: scanf(“%s”, name);

25: /* Display the data. */

26:

27: printf(“Your age is %d.\n”, age);

28: printf(“Your name is %s.\n”, name);

29:

30: return 0;

31: }

32:

33: void clear_kb(void)

34:

35: /* Clears stdin of any waiting characters. */

36: {

37: char junk[80];

38: gets(junk);

39: }

354 Day 14

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