zircon/kernel/lib/libc/string/strspn.c

// Copyright 2016 The Fuchsia Authors
// Copyright (c) 2008 Travis Geiselbrecht
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#include <string.h>

size_t strspn(char const *s, char const *accept) {
  const char *p;
  const char *a;
  size_t count = 0;

  for (p = s; *p != '\0'; ++p) {
    for (a = accept; *a != '\0'; ++a) {
      if (*p == *a)
        break;
    }
    if (*a == '\0')
      return count;
    ++count;
  }

  return count;
}