Function readwrite

examples/file/readwrite.c:22–147

file read write test */

/* file read write test */
void readwrite(const char* filename)
{
    int fd;
    int index, length;
    char* test_data;
    char* buffer;
    int block_size = TEST_DATA_LEN;

    /* open with write only & create */
    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0);
    if (fd < 0)
    {
        rt_kprintf("open file for write failed\n");
        return;
    }

    test_data = rt_malloc(block_size);
    if (test_data == RT_NULL)
    {
        rt_kprintf("no memory\n");
        close(fd);
        return;
    }

    buffer = rt_malloc(block_size);
    if (buffer == RT_NULL)
    {
        rt_kprintf("no memory\n");
        close(fd);
        rt_free(test_data);
        return;
    }

    /* prepare some data */
    for (index = 0; index < block_size; index ++)
    {
        test_data[index] = index + 27;
    }

    /* write to file */
    length = write(fd, test_data, block_size);
    if (length != block_size)
    {
        rt_kprintf("write data failed\n");
        close(fd);
        goto __exit;
    }

    /* close file */
    close(fd);

    /* reopen the file with append to the end */
    fd = open(filename, O_WRONLY | O_CREAT | O_APPEND, 0);
    if (fd < 0)
    {
        rt_kprintf("open file for append write failed\n");
        goto __exit;;
    }