PHP Manual»Stream Functions»stream_copy_to_stream

stream_copy_to_stream

(PHP 5, PHP 7, PHP 8)

stream_copy_to_stream — Copies data from one stream to another

Description

function stream_copy_to_stream(
    resource $from,
    resource $to,
    ?int $length = null,
    int $offset = 0
): int|false

Makes a copy of up to length bytes of data from from to to, starting at the current position in from, or at offset if it is greater than 0. If length is null, all remaining content in from will be copied.

Parameters

from: The source stream
to: The destination stream
length: Maximum bytes to copy. By default all bytes left are copied.
offset: If greater than 0, the position in from, counted from the start of the stream, at which to start copying: from is first moved to that position, as with fseek() and SEEK_SET. If 0 (the default) or negative, no seek is performed and copying starts at the current position in from.

Return Values

Returns the total count of bytes copied, or false on failure.

Changelog

Version	Description
8.0.0	`length` is now nullable.

Examples

Example #1 A stream_copy_to_stream() example

<?php
$src = fopen('http://www.example.com', 'r');
$dest1 = fopen('first1k.txt', 'w');
$dest2 = fopen('remainder.txt', 'w');

echo stream_copy_to_stream($src, $dest1, 1024) . " bytes copied to first1k.txt\n";
echo stream_copy_to_stream($src, $dest2) . " bytes copied to remainder.txt\n";

?>

Notes

Note:
When from is a socket stream in blocking mode, copying stops as soon as no data is received within the stream timeout, even if the end of the stream has not been reached. false may then be returned, even though the data read until then has already been written to to. This timeout defaults to default_socket_timeout and can be changed with stream_set_timeout().