PHP stream_set_blocking() Function

The PHP stream_set_blocking() function sets blocking or non-blocking mode on a stream. This function works for any stream that supports non-blocking mode (currently, regular files and socket streams).

Syntax

stream_set_blocking(stream, enable)

Parameters

`stream`	`Required.` Specify the stream.
`enable`	`Required.` If enable is false, the given stream will be switched to non-blocking mode, and if true, it will be switched to blocking mode. This affects calls like fgets() and fread() that read from the stream. In non-blocking mode an fgets() call will always return right away while in blocking mode it will wait for data to become available on the stream.

Return Value

Returns true on success or false on failure.

Example:

The example below shows the usage of stream_set_blocking() function.

<?php
$fp = fsockopen("www.example.com", 80);
if (!$fp) {
  echo "Unable to open\n";
} else {
  fwrite($fp, "GET / HTTP/1.0\r\n\r\n");
  stream_set_blocking($fp, true);
  $res = fread($fp, 1000);

  $info = stream_get_meta_data($fp);
  fclose($fp);

  if ($info['timed_out']) {
    echo 'Connection timed out!';
  } else {
    echo $res;
  }
}
?>

The output of the above code will be similar to:

HTTP/1.0 404 Not Found
Content-Type: text/html
Date: Sun, 24 Oct 2021 04:58:59 GMT
Server: ECS (dna/63B4)
Content-Length: 345
Connection: close

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
    <head>
        <title>404 - Not Found</title>
    </head>
    <body>
        <h1>404 - Not Found</h1>
    </body>
</html>

❮ PHP Streams Reference