Sams Teach Yourself C in 21 Days

Manipulating Strings 495

17

• strspn()


• strpbrk()


• strstr()

Thestrchr()Function ................................................................................

Thestrchr()function finds the first occurrence of a specified character in a string. The

prototype is

char *strchr(constchar *str, int ch);

The function strchr()searchesstrfrom left to right until the character chis found or

the terminating null character is found. If chis found, a pointer to it is returned. If not,

NULLis returned.

Whenstrchr()finds the character, it returns a pointer to that character. Knowing that

stris a pointer to the first character in the string, you can obtain the position of the

found character by subtracting strfrom the pointer value returned by strchr(). Listing

17.9 illustrates this. Remember that the first character in a string is at position 0. Like

many of C’s string functions,strchr()is case-sensitive and will, therefore, report that

the character “F”isn’t found in the string “raffle”.

LISTING17.9 strchr.c. Using strchr()to search a string for a single character

1: /* Searching for a single character with strchr(). */

2:

3: #include <stdio.h>

4: #include <string.h>

5:

6: int main( void )

7: {

8: char *loc, buf[80];

9: int ch;

10:

11: /* Input the string and the character. */

12:

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

14: gets(buf);

15: printf(“Enter the character to search for: “);

16: ch = getchar();

17:

18: /* Perform the search. */

19:

20: loc = strchr(buf, ch);

21:

22: if ( loc == NULL )

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