strpbrk

Defined in header `<string.h>`
char strpbrk( const char dest, const char *breakset );	(1)
/QChar/ strpbrk( /QChar/ dest, const char *breakset );	(2)	(since C23)

1 ) Scans the null-terminated byte string pointed to by dest for any character from the null-terminated byte string pointed to by breakset, and returns a pointer to that character.

2) Type-generic function equivalent to (1). Let T be an unqualified character object type.

If dest is of type const T*, the return type is const char*.
Otherwise, if dest is of type T*, the return type is char*.
Otherwise, the behavior is undefined.

If a macro definition of each of these generic functions is suppressed to access an actual function (e.g. if (strpbrk) or a function pointer is used), the actual function declaration (1) becomes visible.

The behavior is undefined if either dest or breakset is not a pointer to a null-terminated byte string.

Parameters

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

Return value

Pointer to the first character in dest, that is also in breakset, or null pointer if no such character exists.

Notes

The name stands for "string pointer break", because it returns a pointer to the first of the separator ("break") characters.

Example

#include <stdio.h>
#include <string.h>
 
int main(void)
{
    const char* str = "hello world, friend of mine!";
    const char* sep = " ,!";
 
    unsigned int cnt = 0;
    do {
       str = strpbrk(str, sep); // find separator
       if(str) str += strspn(str, sep); // skip separator
       ++cnt; // increment word count
    } while(str && *str);
 
    printf("There are %u words\n", cnt);
}

Output:

There are 5 words

References

C11 standard (ISO/IEC 9899:2011):

7.24.5.4 The strpbrk function (p: 368)

C99 standard (ISO/IEC 9899:1999):

7.21.5.4 The strpbrk function (p: 331)

C89/C90 standard (ISO/IEC 9899:1990):

4.11.5.4 The strpbrk function