rockOS/libc/string/memmove.c

/**
 *  memmove implementation of rockOS
 *  Copyright (C) 2022 Furkan Mudanyali
 *
 *  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 <https://www.gnu.org/licenses/>.
 */

#include <string.h>

void* memmove (void* dstptr, const void* srcptr, size_t size) {
    unsigned char* dst = (unsigned char*) dstptr;
    const unsigned char* src = (const unsigned char*) srcptr;

    if (dst < src) {
        for (size_t i = 0; i < size; i++) {
            dst[i] = src[i];
        }
    } else {
        for (size_t i = size; i != 0; i--) {
            dst[i-1] = src[i-1];
        }
    }
    return dstptr;
}