filehandle.write(buffer[, offset[, length[, position]]])

buffer 写入文件。

offset 确定要写入的缓冲区部分,length 是整数,指定要写入的字节数。

position 指从文件开头数据应被写入的偏移量。 如果 typeof position !== 'number',则数据将写入当前位置。 参见 pwrite(2)

对于这种情况,请使用 fs.createWriteStream()

在 Linux 上,以追加模式打开文件时,位置写入不起作用。 内核会忽略位置参数,并始终将数据追加到文件末尾。

Write buffer to the file.

The Promise is resolved with an object containing a bytesWritten property identifying the number of bytes written, and a buffer property containing a reference to the buffer written.

offset determines the part of the buffer to be written, and length is an integer specifying the number of bytes to write.

position refers to the offset from the beginning of the file where this data should be written. If typeof position !== 'number', the data will be written at the current position. See pwrite(2).

It is unsafe to use filehandle.write() multiple times on the same file without waiting for the Promise to be resolved (or rejected). For this scenario, use fs.createWriteStream().

On Linux, positional writes do not work when the file is opened in append mode. The kernel ignores the position argument and always appends the data to the end of the file.