Above that line place the ob_start Docs function which will start output buffering. This means that the output buffer is initiated and stopped with ob_end_clean(). Check network response to css request in browser's developer tools ( F12 usually). This function will turn output buffering. ob_start()とセットで使用する関数. PHP CLI no longer had the CGI environment variables to. ob_end_flush () turns off output buffering and sends the buffered data to the output, while flush () forces PHP to flush the output buffer immediately, sending. Which however is less reliable for multiple reasons: Even if <?php ob_start(); ?> starts the first script, whitespace or a BOM might get shuffled before, rendering it ineffective. If the optional parameter erase is set to FALSE, the buffer will not be deleted until the script finishes (as of PHP 4. Basically you just wrap your html in ob_start(); this will return the html as a string so you can echo it. html cache file. gzgetss — Get line from gz-file pointer and strip HTML tags. ob_start() triggers output buffering which stores all output in a buffer for later use. Definition and Usage. Any PHP function playing with output headers (header (), setcookie (), session_start ()) will in fact use the internal sapi_header_op () function which just fills in the headers buffer. If output buffering is in effect it returns an associative array containing the status of buffering. can please elaborate… how to kill. If it's > 0 without you calling ob_start, you know that PHP is doing the gzipping. 3 and 5. ob_start is a PHP function which turns output buffering on. 1. Advantages of output buffering for Web developers. ฟังก์ชัน ob_start () เปิดบัฟเฟอร์การส่งออก (output) เป็น function ของ PHP ที่ไว้ประการใช้ output buffering จะใช้คู่กับ function ob_end_flush () บัฟเฟอร์เอาต์พุตสามารถ. Use of ob_start() and ob_get_clean() 4. – webnoob Oct 29, 2012 at 10:29The CLI for PHP does not use output buffering (or more specifically the buffing is not related to the ob_ functions). If you want to further process the buffer's contents you have to call ob_get_contents () before ob_end_clean () as the buffer contents are discarded when ob_end_clean () is called. 自前バッファ. 1. At the start yes, but i cant get it to work. 輸出緩衝區是可堆疊的，這即意謂著，當有一個 ob_start() 是活躍的時， 你可以調用另一個 ob_start() 。 只要確保又正確調用了 ob_end_flush() 恰當的次數即可。 如果有多重輸出回調函數是活躍的，輸出內容會一直按嵌套的順序依次通過它們而被過濾。As soon as ob_flush() and flush() are executed, the browser will start indicating that some content is coming. output_compression to 0 or Off; 3) setting Apache variables such as "no-gzip" either through apache_setenv () or through entries in . If you call them. The ob_get_clean () function is an in-built PHP function that is used to clean or delete the current output buffer. Output buffers are stackable, that is, you may call ob_start () while another ob_start () is active. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an internal buffer. 3. With output buffering enabled, your program can still "output" HTML but it will not be send immediately. The trade off between one extra line of code but easier code to understand is well worth it. See Also. ob_start — Ausgabepufferung aktivieren. The above code. When a file is included, parsing drops out of PHP mode and into HTML mode at the beginning of the target file, and resumes again at the end. 이는 사실상 모든 출력을 사용자 브라우저에 보냅니다. 3. How to pass a callback function with parameters for ob_start in PHP? Hot Network Questions Creating buffer for MultiPolygon that covers all its surroundings in QGIS Should I send a PDF or Google Drive link to professors? Build a culture of Accountability Novel: Hidden (floating?) island with aptitude tests and sterilization after multiple. // Works send_test_email( 122, '[email protected]' ); /* When you have executed send_test_email() above the method generate_html() is executed and ob_start and ob_end_clean() is executed. limit. I try with DOMPDF, but I have a problem with defining the string. Session variables are set with the PHP global variable: $_SESSION. If it has a value of 4096, then output buffering is on. Tambahkan fungsi ob_start() sebelum output pertama, dan panggil fungsi ob_end. Next thing is to begin with ob_start(); Then you need ob_flush(); flush(); before any echo or print. Featured on MetaYou can use PHP's output buffers and functions like ob_start(); and ob_get_contents(); to read the contents of your PHP output into a string. ";php; ob-start; or ask your own question. Steps: Send new value to phpScript1 with clientScript1. 1 requires an absolute URI as argument to » Location: including the scheme, hostname and absolute path, but some clients accept relative URIs. ob_get_clean () essentially executes both ob_get_contents () and ob_end_clean () . I try to convert dynamic php database file to pdf. Kohana. 2. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an internal buffer. The output buffer must be started by ob_start () with PHP_OUTPUT_HANDLER_CLEANABLE flag. php file you should fetch result & create table with results. ob_start and php. First my syntax is parsed and reformatted. . Output buffering is a feature in PHP that allows you to capture and manipulate output before it is sent to the browser or client. We have built a prototype application in PHP and JS using Server-Sent Events (single AJAX requests, multiple streamed events sent by event handlers in PHP). Let us look at. Return Values: The ob_get_length () function returns the length of the current output buffer in bytes as an integer. ob_start (); session_start (); if. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. 1. Yes it is, you really don't need the else ob_start() part, nor the gzip check. When the rest of the code executes, the echo statement is outputted to the page. Now, I have a Controller that uses ob_start since it's a fairly long running-time of a certain method and I want feedback to the user what's going on and what the script does. That makes PHP to send no output to the browser. When a PHP script ends, the buffer is automatically flushed to the user. La plupart des navigateurs web supporte la compression gzip (IE, Mozilla, Firefox, Opera,. However, after implementing this ob_start('error_logging'); the ob_flush's don't seem to work. implicit_flush bool. Actually, we can use type regulation - intval (ob_get_contents ()), for cheking On/Off output buffering, but it lays the possible problems in the future. It doesn't affect db connection. But that's a silly way to do it when it's on your own server. In PHP 8. When session_start() is called or when a session auto starts, PHP will call the open and read session save handlers. This function discards the contents of the output buffer. – Buffer HTML Data Using the ob_start Method and Get Data Using the ob_get_contents Method in PHP Buffer String Data and Replace Chars in the String Using the ob_start Method With a Callback Function We will initialize a buffer with the ob_start method and then output a simple string which will be automatically buffered; we will then get the data. Redirect. Next we send the header without any problem as we've not yet spit out any output. PHP PHP Array. 6 daevid at daevid dot com. ob_start is a PHP function which turns output buffering on. A callback function can be passed in to do processing on the contents of the buffer before it gets flushed from the buffer. PHP Regular Expression Functions. ob_start — Turn on output buffering. The W3Schools online code editor allows you to edit code and view the result in your browser Bitmask of PHP_OUTPUT_HANDLER_* constants. ob_end_flush(); # CODE THAT NEEDS IMMEDIATE FLUSHING ob_start(); If this does not work then what may even be happening is that the client does not receive the packet. Tôi nhắc đến cơ chế cache vì các hàm ob_start (), ob_get_contents (), ob_clean (), ob_end_flush () sẽ hỗ trợ chúng ta trong quá trình thực hiện cơ chế. A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor(). My searches on SO brought me solutions likeTo get the output of the page into a variable, you'd need to use file_get_contents with a URL. Definition and Usage. Just call flush whenever you want to force the content to the browser. PHP Collective Join the discussion. ob_get_clean (): string|false. > ob_flush() until. 3) Other page requests from the user will return the cookie name and valueWhen I call ob_start() but not any of the end methods, the output is still being sent as if I would call ob_end_flush(). This is equivalent to calling the PHP function flush() after each and every call to print or echo and each and every HTML block. This function should be used in place of exec() or system() when the output from the Unix command is binary data which needs to be passed directly back to the browser. This function's behaviour is controlled by the url_rewriter. I would try ob_end_flush(), ob_flush(), and flush(). Note: HTTP/1. This includes information about PHP compilation options and extensions, the PHP version, server information and environment (if compiled as a module), the PHP environment, OS version information, paths, master and local values of configuration options, HTTP headers, and the PHP License. For example, if you are in a foreach loop and at the end of each loop you want to. And you can't redirect using the header function after you output to the page. e. Also look at answers to this question. This parameter can be used to limit the number of stack frames printed. Then, you can use ob_flush and flush to keep flushing the output. I also shell_exec() shell scripts which use PHP CLI. The ob_end_flush () function deletes the topmost output buffer and outputs all of its contents. My only problem is that with some large pages PHP runs out of memory. Given an expression and a callback, returns a string where all matches of the expression are replaced with the substring returned by the callback. This parameter is a bitmask for the following options: debug_print_backtrace () options. About;. display members' bar or what) because they will be cached as well. APC is an opcode cache: The Alternative PHP Cache (APC) is a free and open opcode cache for PHP. You may execute ob_end_clean() to discard (clean) buffer. See the below code snippet. One of PHP_OUTPUT_HANDLER_START (0), PHP_OUTPUT_HANDLER_CONT (1) or PHP_OUTPUT_HANDLER_END (2) name: Name of active output handler or ' default output handler' if none is set: del: Erase-flag as set by ob_start() If called with full_status = true an array with one element for each active output buffer level is returned. The optional separator parameter sets the field delimiter (one single-byte character only). PHP Docs. Its goal is to provide a free, open, and robust framework for caching and optimizing PHP intermediate code. This can be done with the ob_start () function, which causes the output to be stored in an internal buffer. This function will send the contents of the output buffer (if any). gzencode — Create a gzip compressed string. The ob_end_flush () function is a useful tool for flushing the output buffer and turning off output buffering in your PHP web application. A better way to do this is to use the first two parameters accepted by ob_start: output_callback and chunk_size. I also shell_exec() shell scripts which use PHP CLI. ). Example Get your own PHP Server. It can likewise be engaged with a call to ob_start(); atop the invocation script. If you call them from callback. 0. ob_end_clean(), ob_end_flush(), ob_clean(), ob_flush() and ob_start() may not be called from a callback function. Apr 18, 2018 at 21:07. 1. If you call them from callback function, the. goes to the buffer and at the end whatever is accumulated within the buffer, passes goes through the ob_start's callback. So, until browsers begin to show buffered content. Using output buffering. up. PHP has an exception model similar to that of other programming languages. Is this always the case or does it depend on a PHP version or configuration parameter? PHP 5. 3. Understanding ob_start() function in php. This function will send the contents of the topmost output buffer (if any) and turn this output buffer off. The name and value will be added to URLs (as GET parameter) and forms (as hidden input fields) the same way as the session ID when transparent URL rewriting is enabled with session. ob_start();. output_reset_rewrite_vars — Reset URL rewriter values. PHP가 사용하는 백엔드 (CGI, 웹 서버 등)에 관계 없이 PHP의 출력 버퍼를 비웁니다. 0. ob_start(null, 4096); // Once the buffer size exceeds 4096 bytes, PHP automatically executes flush, ie. ob_clean — Clean (erase) the output buffer. Essentially the PHP at some point is using. 0. This function does not destroy the output buffer like ob_end_clean () does. ob_start(); callback function. php file instead of in a function that outputs to an admin page. The php script inherits your environment when you run it from shell, but not when you run it from the web. Definition and Usage. php; ob-start; or ask your own question. Sehingga output tidak langsung ditampilkan ke dalam browser melainkan akan ditampilkan terakhir-terakhir menjelang program PHP selesai dieksekusi. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Definition and Usage. Delete an output buffer without sending its contents to the browser: <?php. Hope this will help you. The code for the page that turns the receipt page ('Receipt_Template_2. You will need to store the new value somewhere because multiple instances of a script do not share variables just like that. Description ¶. <? session_start (); isset ($_SESSION ['email'])` && `isset ($_SESSION ['passwrd'])`. You can find more details at php. 2. 2. In other words ob_end_clean () just means discard all things in buffer. Class object not working inside ob_start callback. A solution is to force a clean environment. 5 the headers are sent. Take a look at very simple example for PHP 5. Output streaming with PHP ob_start & ob_get_clean. This new value can be stored in a file, database or as a session variable, etc. Buffer Simple String Using the ob_start Method Then Get Data Using the ob_get_contents Method in PHP. from functools import partial output_buffer = None print_orig = print def ob_start (fname="print. Output Buffer shows "1" 1. テンプレートエンジンがどうたらこうたらと前置きしましたが、要するにechoとob_startと自前バッファの速度比較でした。. – Don't Panic. When you write your scripts, output buffering can be turned on by calling the ob_start function, and this is where it gets confusing, because you can actually start multiple "levels" of buffering — each call to ob_start will begin a new level of buffering. Here's my problem. 10. HEREDOC (<<<) is just another way to write a string data into a variable. 標準出力のバッファリングを有効化するPHP関数ob_start. Now, let's create a new page called "demo_session1. – shudder. 4 ob_* functions. 0 How to replace die() statement? 2 ob_start not working in PHP 5. php (the code is above)The PHP ob_start() function turns on the output buffering. 0. Everything works normally but the returned HTML structure is broken. The output may be caught by another output buffer or, if there are no other output buffers, sent directly to the browser. gzeof — Test for EOF on a gz-file pointer. ob_start ()를 여러번 호출해도 오류는 발생하지 않는다. If you use cPanel (most hosts do), there is an option in there to change the php. I try to convert dynamic php database file to pdf. Usually, if you just need to format a string with HTML, just use. Description ¶. Next we send the header without any problem as we've not yet spit out any output. PHP7. Solution for this is to store your form in a variable then return it,To create a new output buffer and start writing to it, call ob_start(). FYI, you might want to stop using the MySQL extension since it's deprecated. The ob_start () function creates an output buffer. Some guides say you have to set output_buffering = Off in your php. Like in the given example, <p>Hello world</p> is written outside the PHP code block, which is supposed to be output to the client immediately. The difference between var_dump and var_export is that var_export returns a "parsable string representation of a variable" while var_dump simply dumps information about a variable. If output buffering is not in effect, it returns an empty array. Tambahkan fungsi ob_start() sebelum output pertama,. ob_clean (): bool. Hence, if you have any redirection calls on your page, those will. つまり、別の ob_start () がアクティブなときに ob_start () を呼び出すことができます。. ob_end_clean modifies variables as well. PHPは、WEBブラウザという手近な実行環境を持つプログラミング言語です。. is not included when determining the maximum time that the script. Some PHP programmers put ob_start () on the first line of all of their code*, and I'm pretty certain that's what going on here. This function does not destroy the output buffer like ob_end_flush () does. Load 7 more related questions Show fewer related. ob_clean — Clean (erase) the output buffer. Using the ob_get_clean() function is straightforward. I just got done creating the composer library for this very purpose. e. If it takes 10 seconds for that page to load, rather than seeing a new line every 2 seconds, then it means that it is being cached by your webserver. With output buffering enabled, your program can still "output" HTML but it will not be send immediately. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an internal buffer. g. For cPanel setting => Sofware/Services => Optimize Website < here choose option what you want >. ob_start を理解するためにはまず PHP (PHP: Hypertext Preprocessor) の特徴を知っておく必要があります。 PHP は今では汎用言語として利用されていますが、元々はただの HTML 用のテンプレートツールであり、今でも HTML に埋め込むような構文を特徴としています。 I'm generating a ton of XML that is to be passed to an API as a post variable when a user click on a form button. The below code is not printing anything in the browser. I think that function will be prone to further bugs, therefor using ob_start/ob_end_clean is easier to comprehend and better for future code maintenance. ob_start() - Turn on output buffering; var_dump() - Dumps information about a variable;PHP ob_start () "output buffering start → 출력 버퍼링 시작 ". 그러므로 출력 버퍼를 비우려면 ob_flush. ini involving setting output_buffer and/or zlib. You can call ob_start () more than once in your script. This is not the same as a template cache (what you are demonstrating), and it has little impact on output buffering. [2007-08-29 17:15 UTC] ce at netage dot bg Description: ----- it is actually a duplicate problem with 40429, but since you have closed the bug I cannot reopen it, but it is still present with all versions including the new 5. This callback is called internally by PHP when the session starts or when session_start() is called. PHP가 사용하는 백엔드 (CGI, 웹 서버 등)에 관계 없이 PHP의 출력 버퍼를 비웁니다. How to Use the ob_get_clean() Function. The redirect upon successful completion in your post method form processing code should be to the exact same URL of the current page, to cause a get request for that page. この記事では「 PHPのob_startでまとめて結果出力!シンプル解説で最短理解 」といった内容について、誰でも理解できるように解説します。この記事を読めば、あなたの悩みが解決するだけじゃなく、新たな気付きも発見できることでしょう。お悩みの方はぜひご一読ください。1. ini or server configuration files. Tôi nhắc đến cơ chế cache vì các hàm ob_start(), ob_get_contents(), ob_clean(), ob_end_flush() sẽ hỗ trợ chúng ta trong quá trình thực hiện cơ chế này. Going by the comments of OP, I'm going to assume OP wants a timer on the command line and presume the <br> was meant to convey a newline. If there is no cached file, it calls ob_start () and creates a . With output buffering, your HTML is stored in a variable and sent to the browser as one piece at the end of your script. However, like I mentioned, if the webserver is. We hope this article has been informative and useful in understanding. Flags can be used to. net:The ob_start function may change the working directory of the PHP process when it invokes the user-defined callback. 출력 버퍼링을 켜는 PHP 명령어. Something like this: <?php include 'MPDF57/mpdf. ob end will send the ouput from the script and buffer will be cleaned. PHP: Using ob_start or another method to separate variables and propogate data. The function ob_start turns output buffering on. The ob_get_contents() function is a built-in function in PHP that allows you to get the contents of the output buffer. If you're using mod_php, you can write incrementally out to the. From the manual: "Output buffers are stackable, that is, you may call ob_start () while another ob_start () is active. You can use the ob_start() function with a callback to remove whitespaces before and after the tags, comments, and whitespace sequences. 0, so it cannot be used inside an ob_start() callback function. It means if they get halfway through outputting the page and decide there's an error, they can clear the buffer and output an error page instead. Some PHP programmers put ob_start () on the first line of all of their code*, and I'm pretty certain that's what going on here. In the above example, the `ob_start ()` function begins output buffering, and `ob_flush ()` sends the partial result to the browser. PHP script works on localhost, but doesn't works on hosting. output_callback. ob_start doesn't work with some functions. ini output_buffering. Basically, the correct cause of action is to move all of the processing code above any output to the browser. ob_gzhandler() is an in-built PHP function, used as an callback. function print_gzipped_output() {. Program 1: The following program demonstrates the ob_get_contents () Function. PHP supports single line and multi line comments. gzgetc — Get character from gz-file pointer. aus. Parameters. Warning: Cannot modify header information - headers already sent by (output started at /some/file. Learn how to use the ob_start () function in PHP to start output buffering and modify your output before sending it to the client. it will work as you would use ob_start with no. It will work. 自前. ob_end_clean — Clean (erase) the output buffer and turn off output buffering. ini file? If output_buffering is turned on, then PHP will buffer almost the entire page, so what's the point in creating yet another buffer using ob_start? @true PHP is already buffering that entire page, so wouldn't ob_start be. Find centralized, trusted content and collaborate around the technologies you use most. php redirect using ob_start() and ob_end_flush() php functions. The problem is the client gets verified in verify. ob_start ( callable $callback = null, int $chunk_size = 0, int $flags = PHP_OUTPUT_HANDLER_STDFLAGS ): bool. With the help of this. This question is in a collective: a subcommunity defined by tags with relevant content and experts. PHP Collective Join the discussion. If output buffering is still active when. buffer. The above code improve server performance as PHP will send bigger chunks of data, for example, 4KB (wihout ob_start call, php will send each echo to the browser). net ob-start function description. So every time you do an echo, the output of that is added to the buffer. 2. PHP CLI no longer had the CGI environment variables to. It deals with text (mostly) produced by php. ob_end_clean modifies variables as well. 1) ob_flush (), flush () in any combination with other output buffering functions; 2) changes to php. 5. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an internal buffer. Try using output buffer like this : ob_start (); // your includes echo ob_get_clean (); Use this in all of your includes, and you will not get any errors. Just make sure that you call ob_end_flush() the appropriate number of times. I've choosed to use ob_start('callback') and ob_end_flush() at the end of the page. The former specifies a callback to handle output as it's buffered, and the latter specifies the size of the chunks of output to handle. Below is my code:PHP ob_start skeleton only working first time. Take a look at very simple example for PHP 5. Cách dùng ob start , ob flush (), flush () Trong PHP vốn đã chạy nhanh nay còn có thêm cơ chế cache làm cho ngôn ngữ PHP ngày càng hoàn hảo. Description ¶. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an. I get. This doesn't work. When output buffer is ended it is sent to the client (browser). The ob_flush () function outputs the contents of the topmost output buffer and then clears the buffer of the contents. If a page uses ob_start ('ob_gzhandler. I would start by turning off all plugins, and see if there blank lines are still there. Actually, we can use type regulation - intval (ob_get_contents ()), for cheking On/Off output buffering, but it lays the possible problems in the future. Điều này giúp tránh việc gửi header hoặc thiết lập cookie trước khi nội dung được xuất ra. For user defined functions, use ob_start(). Php code isn't rendered to the browser so although you have a line break to make the file look tidy, it won't be displayed on the page. Cách đơn giản để hiểu về ob_start là: Hãy ghi nhớ mọi thứ mà bình thường sẽ được xuất ra, nhưng chưa làm gì với nó cả. 5. The output buffer must be started by ob_start () with PHP_OUTPUT_HANDLER_CLEANABLE flag. I try with DOMPDF, but I have a problem with defining the string. flush — Flush system output buffer. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. Share. I have the feeling I can use an ob_start() to buffer the rest of the page and only show a spinner. As a PHP developer, you may need to get the contents of the output buffer. The output_callback parameter may be bypassed by passing a NULL value. If output_callback returns FALSE original input is sent to the browser. This stores all generated content into an output buffer, and displays it in one go. php; ob-start; or ask your own question. ob_get_clean — Get current. x and PHP 5. What is the ob_get_clean() Function? The ob_get_clean() function is a PHP built-in function that allows you to get the contents of the output buffer and turn off output buffering. output_add_rewrite_var — Setzt URL-Rewrite-Variablen. The ob_get_flush () function outputs the contents of the topmost output buffer, returns the contents and the deletes the buffer. ob_flush — Flush (send) the output buffer. Output buffers are stackable, that is, you may call ob_start () while another ob_start () is active. Each try must have at least one corresponding catch or finally block. I want to build a cache system for a e-commerce platform. php it checks if a session has been created in-order to block hackers to enter member area and sends them back to the login page. Once you call ob_start(), then only buffering starts, and all your echo etc. The ob_start () function creates an output buffer. <?php ob_start (); // Start the. output_add_rewrite_var — Add URL rewriter values. The ob_get_contents () function has different return behaivor in PHP 5. The problem has been reproduced on two unique servers both. any program written in. However, the problem is, it parses the PHP include() and stores only the HTML content. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an internal buffer. Program 1: The following program demonstrates the ob_get_length () function. See the syntax, usage, and examples of the. 2 Answers. 1. Just make sure that you call ob_end_flush () the appropriate number of times. For what you are trying to do, there is no need to use ob_start and ob_flush. It’s also used to get the output buffering again after cleaning the buffer. Problem with ob_start function in php. A session is started with the session_start () function. So this post provides a quick copy/paste example that I can grab the next time I need to output buffer something. Collectives™ on Stack Overflow. separator. จะเห็นว่าโค้ดด้านบนนี่ PHP แยกอยู่ของ PHP HTML แยกอยู่ของ HTML ทำให้ดูโค้ดได้ง่ายเวลามันอยู่ใน editor. 2. Stack Overflow Public questions & answers; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Talent Build your employer brand Definition and Usage. ob_start says: Output buffers are stackable, that is, you may call ob_start() while another ob_start() is active. phase. This can be used for many purposes, one of them is being able to send headers even after producing output, since the output wasn't sent yet thanks to buffering. If you use XAMPP for instance, you can go to this link and check if output buffering is on or off. This function will turn output buffering on and begin capturing all output sent by the script. The ob_start () function don’t accepts any parameter specifically but it works by accepting some optional parameters. 逐次echo. ob_gzhandler() Used as a callback function for ob_start() to compress the contents of the buffer when sending it to the browser: ob_implicit_flush() Turns implicit flushing on or off: ob_list_handlers() Returns an array of callback function names that are being used by the topmost output buffer: ob_start() When the return parameter is used, this function uses internal output buffering prior to PHP 7. Description ¶. First, since PHP is generally *nix-based, it makes sense that the line endings are always instead of \r . ob_start( 'ob_gzhandler', 16000, // to send data continuously PHP_OUTPUT_HANDLER_FLUSHABLE // but not removable and cleanable ); Output compression can be also activate by directive zlib. Then, `flush ()` flushes the output buffer and forces the server to send the data to the browser immediately. Share.