path: root/src/string/strn/strndup.c

/**
 * slibc — Yet another C library
 * Copyright © 2015, 2016  Mattias Andrée (maandree@member.fsf.org)
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <string.h>
#include <stdlib.h>



/**
 * Duplicate a string.
 * 
 * This is a GNU extension.
 * 
 * @param   string  The string to duplicate.
 * @param   maxlen  Truncate the string to this length, if it is longer.
 *                  A NUL byte is guaranteed to always be written
 *                  upon successful completion.
 * @return          The new string. `NULL` is returned on error
 *                  and `errno` is set to indicate the error.
 * 
 * @throws  ENOMEM  The process could not allocate sufficient amount of memory.
 * 
 * @since  Always.
 */
char* strndup(const char* string, size_t maxlen)
{
  size_t n = strnlen(string, maxlen) + 1;
  char* r = malloc(n * sizeof(char));
  return r == NULL ? NULL : memcpy(r, string, n * sizeof(char));
}