wcsspn

Compares the characters in a wide-character string against a set of wide characters. The function returns the length of the first substring comprised entirely of characters in the set of wide characters.

Format

#include  <wchar.h>

size_t wcsspn  (const wchar_t *wstr1, const wchar_t
               *wstr2);

Arguments

wstr1

A pointer to a null-terminated wide-character string. If this string is a null string, 0 is returned.

wstr2

A pointer to a null-terminated wide-character string that contains the set of wide characters for which the function will search.

Description

Return Values

x	The length of the segment.

Example

#include <stdlib.h>
#include <stdio.h>
#include <wchar.h>
#include <string.h>

/* This test sets up 2 strings, buffer and w_string. It then uses        */
/* wcsspn() to calculate the maximum segment of w_string that consists   */
/* entirely of characters from buffer.                                   */

#define BUFF_SIZE 20
#define STRING_SIZE 50

main()
{
    wchar_t  buffer[BUFF_SIZE];
    wchar_t w_string[STRING_SIZE];
    size_t result;

    /* Initialize the buffer */

    if (mbstowcs(buffer, "abcdefg", BUFF_SIZE) == -1) {
        perror("mbstowcs");
        exit(EXIT_FAILURE);
    }

    /* Initialize the string */

    if (mbstowcs(w_string, "abcedjklmabcjklabcdehjkl", STRING_SIZE)
        == -1) {
        perror("mbstowcs");
        exit(EXIT_FAILURE);
    }

    /* Using wcsspn - work out the largest string in w_string that   */
    /* consists entirely of characters from buffer                   */

    result = wcsspn(w_string, buffer);
    printf ("Longest segment found in w_string is: %d",result);

}

Running the example program produces the following result:

Longest segment found in w_string is: 5