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Diffstat (limited to 'nuttx/lib/string/lib_strndup.c')
-rw-r--r-- | nuttx/lib/string/lib_strndup.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/nuttx/lib/string/lib_strndup.c b/nuttx/lib/string/lib_strndup.c new file mode 100644 index 000000000..68b7c74c3 --- /dev/null +++ b/nuttx/lib/string/lib_strndup.c @@ -0,0 +1,93 @@ +/************************************************************************ + * lib/string//lib_strndup.c + * + * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 <nuttx/config.h> + +#include <string.h> + +#include "lib_internal.h" + +/************************************************************************ + * Global Functions + ************************************************************************/ +/************************************************************************ + * Name: strndup + * + * Description: + * The strndup() function is equivalent to the strdup() function, + * duplicating the provided 's' in a new block of memory allocated as + * if by using malloc(), with the exception being that strndup() copies + * at most 'size' plus one bytes into the newly allocated memory, + * terminating the new string with a NUL character. If the length of 's' + * is larger than 'size', only 'size' bytes will be duplicated. If + * 'size' is larger than the length of 's', all bytes in s will be + * copied into the new memory buffer, including the terminating NUL + * character. The newly created string will always be properly + * terminated. + * + ************************************************************************/ + +FAR char *strndup(FAR const char *s, size_t size) +{ + FAR char *news = NULL; + if (s) + { + /* Get the size of the new string = MIN(strlen(s), size) */ + + size_t allocsize = strlen(s); + if (allocsize > size) + { + allocsize = size; + } + + /* Allocate the new string, adding 1 for the NUL terminator */ + + news = (FAR char*)lib_malloc(allocsize + 1); + if (news) + { + /* Copy the string into the allocated memory and add a NUL + * terminator in any case. + */ + + memcpy(news, s, allocsize); + news[allocsize] = '\0'; + } + } + return news; +} |