strspn

From cppreference.com
< c‎ | string‎ | byte
Defined in header <string.h>
size_t strspn( const char *dest, const char *src );

Returns the length of the maximum initial segment of the byte string pointed to by dest, that consists of only the characters found in byte string pointed to by src.

Contents

[edit] Parameters

dest - pointer to the null-terminated byte string to be analyzed
src - pointer to the null-terminated byte string that contains the characters to search for

[edit] Return value

The length of the maximum initial segment that contains only characters from byte string pointed to by src

[edit] Example

#include <string.h>
#include <stdio.h>
 
int main(void)
{
    char *string_find = "abcde312$#@";
    char *low_alpha = "qwertyuiopasdfghjklzxcvbnm";
    printf("%zu", strspn(string_find, low_alpha));
    return 0;
}

Output:

5

[edit] See also

returns the length of the maximum initial segment that consists
of only the characters not found in another byte string
(function)
finds the first location of any character in one string, in another string
(function)
C++ documentation for strspn