fflush()
fflush() — Flushes the output to a file.
Built-in function of PHP 8.5. The manual lists it as available in PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.
What it does
This function forces a write of all buffered output to the resource pointed to by the file stream.
Signature
fflush(resource $stream): bool
Parameters
| Parameter | Type | What it takes |
|---|---|---|
| $stream | resource | The file pointer must be valid, and must point to a file successfully opened by fopen() or fsockopen() (and not yet closed by fclose()). |
Return value
Returns true on success or false on failure.
Example
A runnable snippet:
$filename = 'bar.txt'; $file = fopen($filename, 'r+'); rewind($file); fwrite($file, 'Foo'); fflush($file); ftruncate($file, ftell($file)); fclose($file);
See also
All PHP 8.5 built-in functions
Reference card built from the PHP manual page fflush() (PHP documentation, CC BY 3.0). The page is generated from the manual, so the wording of the parameter and return value text follows php.net.