Sams Teach Yourself C in 21 Days

Thestrspn()Function ................................................................................

This function is related to the previous one,strcspn(), as the following paragraph

explains. Its prototype is

size_t strspn(const char *str1, const char *str2);

The function strspn()searchesstr1, comparing it character by character with the char-

acters contained in str2. It returns the position of the first character in str1that doesn’t

match a character in str2. In other words,strspn()returns the length of the initial seg-

ment of str1that consists entirely of characters found in str2. The return is 0 if no char-

acters match. Listing 17.11 demonstrates strspn().

LISTING17.11 strspn.c. Searching for the first nonmatching character with strspn()

1: /* Searching with strspn(). */

2:

3: #include <stdio.h>

4: #include <string.h>

5:

6: int main( void )

7: {

8: char buf1[80], buf2[80];

9: size_t loc;

10:

11: /* Input the strings. */

12:

13: printf(“Enter the string to be searched: “);

14: gets(buf1);

15: printf(“Enter the string containing target characters: “);

16: gets(buf2);

17:

18: /* Perform the search. */

19:

20: loc = strspn(buf1, buf2);

21:

22: if ( loc == 0 )

23: printf(“No match was found.\n”);

24: else

25: printf(“Characters match up to position %d.\n”, loc-1);

26: return 0;

27: }

Enter the string to be searched: How now Brown Cow?

Enter the string containing target characters:How now what?

Characters match up to position 7.

498 Day 17

OUTPUT

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