rt-thread-official/examples/file/readwrite.c

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-02-10     Bernard      first version
 * 2020-04-12     Jianjia Ma   add msh cmd
 */

#include <rtthread.h>
#include <dfs_posix.h>

#define TEST_DATA_LEN     120

/* 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;;
    }

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

    /* open the file for data validation. */
    fd = open(filename, O_RDONLY, 0);
    if (fd < 0)
    {
        rt_kprintf("check: open file for read failed\n");
        goto __exit;
    }

    /* read the data (should be the data written by the first time ) */
    length = read(fd, buffer, block_size);
    if (length != block_size)
    {
        rt_kprintf("check: read file failed\n");
        close(fd);
        goto __exit;
    }

    /* validate */
    for (index = 0; index < block_size; index ++)
    {
        if (test_data[index] != buffer[index])
        {
            rt_kprintf("check: check data failed at %d\n", index);
            close(fd);
            goto __exit;
        }
    }

    /* read the data (should be the second time data) */
    length = read(fd, buffer, block_size);
    if (length != block_size)
    {
        rt_kprintf("check: read file failed\n");
        close(fd);
        goto __exit;
    }

    /* validate */
    for (index = 0; index < block_size; index ++)
    {
        if (test_data[index] != buffer[index])
        {
            rt_kprintf("check: check data failed at %d\n", index);
            close(fd);
            goto __exit;
        }
    }

    /* close the file */
    close(fd);
    /* print result */
    rt_kprintf("read/write test successful!\n");

__exit:
    rt_free(test_data);
    rt_free(buffer);
}

#ifdef RT_USING_FINSH
#include <finsh.h>
/* export to finsh */
FINSH_FUNCTION_EXPORT(readwrite, perform file read and write test);

static void cmd_readwrite(int argc, char *argv[])
{
    char* filename;

    if(argc == 2)
    {
        filename = argv[1];
    }
    else
    {
        rt_kprintf("Usage: readwrite [file_path]\n");
        return;
    }
    readwrite(filename);
}
FINSH_FUNCTION_EXPORT_ALIAS(cmd_readwrite, __cmd_readwrite, perform file read and write test);
#endif /* RT_USING_FINSH */