使用/不使用 ios::binary 模式打开流时使用读/写的区别

2022-01-04 00:00:00 binaryfiles io c++ filestream

在我使用以下代码片段的实验中，我没有发现任何特别的区别，无论是使用还是不使用 ios:binary 模式创建流:

In my experiments with the following code snippet, I did not find any particular difference whether i created the streams with/without the ios:binary mode:

int main()
{
    ifstream ostr("Main.cpp", ios::in | ios::binary | ios::ate);
    if (ostr.is_open())
    {
        int size = ostr.tellg();
        char * memBlock = new char[size + 1];
        ostr.seekg(0, ios::beg);
        ostr.read(memBlock, size);
        memBlock[size] = '';
        ofstream file("trip.cpp", ios::out | ios::binary);
        file.write(memBlock, size);
        ostr.close();
    }
}

在这里，我试图将原始源文件复制到另一个具有不同名称的文件中.

Here I am trying to copy the original source file into another file with a different name.

我的问题是在使用/不使用 ios::binary 模式打开 fstream 对象时，读/写调用(与二进制文件 IO 相关联)有什么区别?使用二进制模式有什么好处吗?文件IO什么时候用什么时候不用?

My question is what is the difference between the read/write calls(which are associated with binary file IO) when an fstream object is opened with/without ios::binary mode ? Is there any advantage of using the binary mode ? when to and when not to use it when doing file IO ?

推荐答案

binary 和 text 模式之间的唯一区别是如何处理 ' ' 字符.

The only difference between binary and text mode is how the ' ' character is treated.

在binary 模式下，没有 翻译.

在text模式下 在写入时被翻译成行尾.
在 text 模式下，end of line sequence 在读取时被翻译成 .

In text mode is translated on write into a the end of line sequence.
In text mode end of line sequence is translated on read into .

行尾是平台相关的.

示例:

LF    ('x0A'):      Multics, Mac OS X, BeOS, Amiga, RISC OS
CRLF  ('x0Dx0A'): Microsoft Windows, DEC TOPS-10, RT-11
CR:   ('x0D'):      TRS-80, Mac OS Pre X
RS:   ('x1E'):      QNX pre-POSIX implementation.

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