/**************************************************************************** * libs/libc/string/lib_memchr.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: memchr * * Description: * The memchr() function locates the first occurrence of 'c' (converted to * an unsigned char) in the initial 'n' bytes (each interpreted as * unsigned char) of the object pointed to by s. * * Returned Value: * The memchr() function returns a pointer to the located byte, or a null * pointer if the byte does not occur in the object. * ****************************************************************************/ #undef memchr /* See mm/README.txt */ FAR void *memchr(FAR const void *s, int c, size_t n) { FAR const unsigned char *p = (FAR const unsigned char *)s; while (n--) { if (*p == (unsigned char)c) { return (FAR void *)p; } p++; } return NULL; }