Question

I have a PHP script that takes a few minutes to finish processing. While the page is still loading, I want to show part of the PHP output as it becomes available, which can be done using ob_start() and ob_flush().

After the entire script has finish executing, I want to save all the PHP output right from the start into a HTML file. This can be done using ob_start() and file_put_contents("log.html", ob_get_contents());

Problem: However, because we are calling ob_flush() along the way, the final file that gets saved with file_put_contents() appears to be separated into different files. I suspect this has to do with the buffer being cleared by the ob_start() calls before file_put_contents() is called, but why did it not just save the output between the final ob_flush() and file_put_contents() to the file, but instead saves several different files? (I may be wrong, the seperate partial files may be due to partial execution of the script)

In other words, how do I show PHP output as a long script executes, and still save all the PHP output to a single HTML file?

PHP Code

// Start the buffering
ob_start();

......

ob_flush();

......

ob_flush();

......

file_put_contents("log.html", ob_get_contents());

Answer 1

Couple of ways I can think of:

1. Keep a variable (called something like $content), and append the current buffer every time you call ob_flush():

   $content = '';
   ...
   $content .= ob_get_contents();
   ob_flush();
   ...
   $content .= ob_get_contents();
   ob_flush();
   ...
   file_put_contents('log.html', $content . ob_get_contents());
   ob_flush();
   

2. Use fopen():

   $fp = fopen('log.html', 'w+');
   ...
   fwrite($fp, ob_get_contents());
   ob_flush();
   ...
   fwrite($fp, ob_get_contents());
   ob_flush();
   ...
   fwrite($fp, ob_get_contents());
   fclose($fp);
   ob_flush();