/**************************************************************************** * libs/libc/string/lib_stpncpy.c * * Copyright (C) 2018 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: stpncpy * * Description: * Copies the string pointed to by 'src' (including the terminating NUL * character) into the array pointed to by 'dest'. strncpy() will not * copy more than 'n' bytes from 'src' to 'dest' array (including the * NUL terminator). * * If the array pointed to by 'src' is a string that is shorter than 'n' * bytes, NUL characters will be appended to the copy in the array * pointed to by 'dest', until 'n' bytes in all are written. * * If copying takes place between objects that overlap, the behavior is * undefined. * * Returned Value: * If a NUL character is written to the destination, the stpncpy() * function will return the address of the first such NUL character. * Otherwise, it will return &dest[n] * ****************************************************************************/ #ifndef CONFIG_LIBC_ARCH_STPNCPY FAR char *stpncpy(FAR char *dest, FAR const char *src, size_t n) { FAR char *end = dest + n; /* End of dest buffer + 1 byte */ FAR char *ret; /* Value to be returned */ /* Copy up n bytes, breaking out of the loop early if a NUL terminator is * encountered. */ while ((dest != end) && (*dest = *src++) != '\0') { /* Increment the 'dest' pointer only if it does not refer to the * NUL terminator. */ dest++; } /* Return the pointer to the NUL terminator (or to the end of the buffer * + 1). */ ret = dest; /* Pad the remainder of the array pointer to 'dest' with NULs. This * overwrites any previously copied NUL terminator. */ while (dest != end) { *dest++ = '\0'; } return ret; } #endif