数据业务开发部案例10-字符数组赋值字符串导致文件内容错误.doc

7 试题
#define MAX_BUFFER_LEN 256
int main()
{
    char strBuffer[MAX_BUFFER_LEN + 1];
    FILE* fileRead = NULL;
    if ((fileRead = fopen("./read ", "rb")) == NULL)
    {
        return -1;
    }
    FILE* fileWrite = NULL;
    if ((fileWrite = fopen("./write ", "wb")) == NULL)
    {
  fclose(fileRead);
        return -1;
    }
    while (!feof(fileRead))
    {
        memset(strBuffer, 0, sizeof(strBuffer));
        ULONG iBufferLen = fread(strBuffer, sizeof(char), MAX_BUFFER_LEN, fileRead);
        string m_strBuffer = strBuffer;
        ULONG m_iBufferLen = strlen(m_strBuffer.c_str());
        if (m_iBufferLen > 0)
        {
            ULONG nWrite = fwrite(strBuffer, sizeof(char), m_iBufferLen, fileWrite);
            if (nWrite == m_iBufferLen)
            {
                continue;
            }
        }
        else if (m_iBufferLen == 0)
        {
            break;
        }
        fclose(fileRead);
        fclose(fileWrite);
        return -1;
    }
    fclose(fileRead);
    fclose(fileWrite);   
    return 0;
}

下列说法一定正确的是 BD
A 文件拷贝（排除异常情况），read与write的文件内容相同
B 文件拷贝（排除异常情况），read与write的文件内容有可能不相同
C 程序中变量iBufferLen与m_iBufferLen的值相等
D 程序中变量iBufferLen与m_iBufferLen的值有可能不相等