Please note that the callback function never gets called when the stream is (at least) of type socket. It is probably the same for the file:// proto although I've not done further tests.
I'm using php 5.3.3.
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
stream_notification_callback — A callback function for the notification context parameter
$notification_code,$severity,$message,$message_code,$bytes_transferred,$bytes_maxA callable function, used by the notification context parameter, called during an event.
注意:
This is not a real function, only a prototype of how the function should be.
notification_code
One of the STREAM_NOTIFY_* notification constants.
severity
One of the STREAM_NOTIFY_SEVERITY_* notification constants.
messagePassed if a descriptive message is available for the event.
message_codePassed if a descriptive message code is available for the event.
The meaning of this value is dependent on the specific wrapper in use.
bytes_transferred
If applicable, the bytes_transferred will be
populated.
bytes_max
If applicable, the bytes_max will be
populated.
没有返回值。
示例 #1 stream_notification_callback() example
<?php
function stream_notification_callback($notification_code, $severity, $message, $message_code, $bytes_transferred, $bytes_max) {
switch($notification_code) {
case STREAM_NOTIFY_RESOLVE:
case STREAM_NOTIFY_AUTH_REQUIRED:
case STREAM_NOTIFY_COMPLETED:
case STREAM_NOTIFY_FAILURE:
case STREAM_NOTIFY_AUTH_RESULT:
var_dump($notification_code, $severity, $message, $message_code, $bytes_transferred, $bytes_max);
/* Ignore */
break;
case STREAM_NOTIFY_REDIRECTED:
echo "Being redirected to: ", $message;
break;
case STREAM_NOTIFY_CONNECT:
echo "Connected...";
break;
case STREAM_NOTIFY_FILE_SIZE_IS:
echo "Got the filesize: ", $bytes_max;
break;
case STREAM_NOTIFY_MIME_TYPE_IS:
echo "Found the mime-type: ", $message;
break;
case STREAM_NOTIFY_PROGRESS:
echo "Made some progress, downloaded ", $bytes_transferred, " so far";
break;
}
echo "\n";
}
$ctx = stream_context_create();
stream_context_set_params($ctx, array("notification" => "stream_notification_callback"));
file_get_contents("http://php.net/contact", false, $ctx);
?>以上示例的输出类似于：
Connected... Found the mime-type: text/html; charset=utf-8 Being redirected to: http://no.php.net/contact Connected... Got the filesize: 0 Found the mime-type: text/html; charset=utf-8 Being redirected to: http://no.php.net/contact.php Connected... Got the filesize: 4589 Found the mime-type: text/html;charset=utf-8 Made some progress, downloaded 0 so far Made some progress, downloaded 0 so far Made some progress, downloaded 0 so far Made some progress, downloaded 1440 so far Made some progress, downloaded 2880 so far Made some progress, downloaded 4320 so far Made some progress, downloaded 5760 so far Made some progress, downloaded 6381 so far Made some progress, downloaded 7002 so far
示例 #2 Simple progressbar for commandline download client
<?php
function usage($argv) {
echo "Usage:\n";
printf("\tphp %s <http://example.com/file> <localfile>\n", $argv[0]);
exit(1);
}
function stream_notification_callback($notification_code, $severity, $message, $message_code, $bytes_transferred, $bytes_max) {
static $filesize = null;
switch($notification_code) {
case STREAM_NOTIFY_RESOLVE:
case STREAM_NOTIFY_AUTH_REQUIRED:
case STREAM_NOTIFY_COMPLETED:
case STREAM_NOTIFY_FAILURE:
case STREAM_NOTIFY_AUTH_RESULT:
/* Ignore */
break;
case STREAM_NOTIFY_REDIRECTED:
echo "Being redirected to: ", $message, "\n";
break;
case STREAM_NOTIFY_CONNECT:
echo "Connected...\n";
break;
case STREAM_NOTIFY_FILE_SIZE_IS:
$filesize = $bytes_max;
echo "Filesize: ", $filesize, "\n";
break;
case STREAM_NOTIFY_MIME_TYPE_IS:
echo "Mime-type: ", $message, "\n";
break;
case STREAM_NOTIFY_PROGRESS:
if ($bytes_transferred > 0) {
if (!isset($filesize)) {
printf("\rUnknown filesize.. %2d kb done..", $bytes_transferred/1024);
} else {
$length = (int)(($bytes_transferred/$filesize)*100);
printf("\r[%-100s] %d%% (%2d/%2d kb)", str_repeat("=", $length). ">", $length, ($bytes_transferred/1024), $filesize/1024);
}
}
break;
}
}
isset($argv[1], $argv[2]) or usage($argv);
$ctx = stream_context_create();
stream_context_set_params($ctx, array("notification" => "stream_notification_callback"));
$fp = fopen($argv[1], "r", false, $ctx);
if (is_resource($fp) && file_put_contents($argv[2], $fp)) {
echo "\nDone!\n";
exit(0);
}
$err = error_get_last();
echo "\nErrrrrorr..\n", $err["message"], "\n";
exit(1);
?>
Executing the example above with:
php -n fetch.php
http://no2.php.net/get/php-5-LATEST.tar.bz2/from/this/mirror
php-latest.tar.bz2 will output something similar too:
Connected... Mime-type: text/html; charset=utf-8 Being redirected to: http://no2.php.net/distributions/php-5.2.5.tar.bz2 Connected... Filesize: 7773024 Mime-type: application/octet-stream [========================================> ] 40% (3076/7590 kb)
Please note that the callback function never gets called when the stream is (at least) of type socket. It is probably the same for the file:// proto although I've not done further tests.
I'm using php 5.3.3.A couple of notes regarding the examples here (I'm using PHP 7.0.18):
1) fopen() did not provide STREAM_NOTIFY_PROGRESS for me but `file_get_contents()` worked fine.
2) The bytes transferred when transferring a zip file seems to always be shy by 8192 (8k). This varies depending on filetype and also breaks STREAM_NOTIFY_PROGRESS when the filesize is below 8k. I modified the function and it's now displaying the correct amount transferred and percentage downloaded on zip files above 8k. I'm not sure why the callback is so inconsistent but hopefully this is helpful to someone. This was also modified to only display progress:
<?php
$ctx = stream_context_create();
stream_context_set_params($ctx, array("notification" => "stream_notification_callback"));
$fileData = @file_get_contents('http://example.com/test.zip',false,$ctx);
function stream_notification_callback($notification_code, $severity, $message, $message_code, $bytes_transferred, $bytes_max) {
static $filesize = null;
switch($notification_code) {
case STREAM_NOTIFY_FILE_SIZE_IS:
$filesize = $bytes_max;
break;
case STREAM_NOTIFY_CONNECT:
echo "Connected...\n";
break;
case STREAM_NOTIFY_PROGRESS:
if ($bytes_transferred > 0 && $filesize >= 8192) {
$bytes_transferred += 8192;
if (!isset($filesize)) {
printf("\rUnknown filesize.. %2d kb done..", $bytes_transferred/1024);
} else {
$length = (int)(($bytes_transferred/$filesize)*100);
printf("\r[%-100s] %d%% (%2d/%2d kb)", str_repeat("=", $length). ">", $length, ($bytes_transferred/1024), $filesize/1024);
}
}
break;
}
}
?>A couple of unreported behaviors:
- case 1) if this callback calls die/exit($msg), it will print $msg, then the execution will go on until the request/wrapper is consumed, emitting a "PHP Warning: Failed to call user notifier" on each invocation of the callback. After the last callback invocation, the script is immediately terminated.
- case 2) if this callback throws an exception, it will behave the same way as exit/die, except for the fact that after the last callback invocation it does not terminate the script. The exception is instead raised in the scope of the request/wrapper, and can be caught with a try catch (right there or at a higher level).
Example code for case 1). The final "TEST ECHO" string will NOT be printed.
<?php
$context = stream_context_create(['http' => ['ignore_errors' => true,]]);
stream_context_set_params($context, ['notification' => function () {
die('error');
}]);
file_get_contents('https://www.google.com', false, $context);
echo "TEST ECHO";
?>
Example code for case 2). The exception is raised at the level of the file_get_contents call, it's catched, and the final "TEST ECHO" gets printed.
<?php
$context = stream_context_create(['http' => ['ignore_errors' => true,]]);
stream_context_set_params($context, ['notification' => function () {
throw new Exception('...');
}]);
try{
file_get_contents('https://www.google.com', false, $context);
}catch(exception $e) { }
echo "TEST ECHO";
?>