Deno.copy

copy

• copy(dst: Writer, src: Reader): Promise<number>

• • 定义在 lib.deno.ns.d.ts:675

  从 src 拷贝文件至 dst，拷贝至 src 的 EOF 或有异常出现时结束。 copy() 函数返回一个 Promise, 成功时 resolve 并返回拷贝的字节数，失败时 reject 并返回拷贝过程中的首个异常。

  Copies from src to dst until either EOF is reached on src or an error occurs. It resolves to the number of bytes copied or rejects with the first error encountered while copying.

    const source = await Deno.open("my_file.txt");
    const buffer = new Deno.Buffer()
    const bytesCopied1 = await Deno.copy(Deno.stdout, source);
    const bytesCopied2 = await Deno.copy(buffer, source);
  

  因为 copy() 函数在读到 EOF 时停止，所以不会将 EOF 视为异常（区别于 read() 函数）。

  Because copy() is defined to read from src until EOF, it does not treat an EOF from read() as an error to be reported.

参数

-   ##### dst: [Writer](interfaces/deno.writer.html)

    需要拷贝至的目标位置

    The destination to copy to

-   ##### src: [Reader](interfaces/deno.reader.html)

    拷贝的源位置

    The source to copy from

返回 Promise<number>