Instructions for using the buffer.copy method in node.js_node.js

Method description:

Perform copy and replacement operations between different buffers.

Copy data from the source buffer and replace it at the specified location in the target buffer.

Grammar:

Copy code The code is as follows:

buffer.copy(targetBuffer, [targetStart], [sourceStart], [sourceEnd])

Receive parameters:

targetBuffer Target buffer, buffer to perform copy replacement

targetStart The starting position of target buffer data replacement

sourceStart The starting position of source buffer data copy

sourceEnd The end position of source buffer data copy

Example:

In this example, the data between 16 and 20 of buf1 is extracted, the data is copied to buf2, and replacement starts from position 8 of buf2.

Copy code The code is as follows:

buf1 = new Buffer(26);
buf2 = new Buffer(26);
for (var i = 0 ; i < 26 ; i ) {
buf1[i] = i 97; // 97 is ASCII a
buf2[i] = 33; // ASCII !
}
buf1.copy(buf2, 8, 16, 20);
console.log(buf2.toString('ascii', 0, 25));