PHP reference

tempnam

Creates a temporary file with a unique name.

Syntax

tempnam(string $directory, string $prefix): string|false

Parameter	Type	Description
$directory	string	The folder for the file.
$prefix	string	The start of the file name.

string|falseThe path to the created file, or `false`.

A temporary file for an export:

<?php
 
$file = tempnam(sys_get_temp_dir(), 'export_');
file_put_contents($file, 'id,name');
 
echo file_get_contents($file);
 
unlink($file);

Output:

id,name

The file is created at once, so the name is guaranteed to be free. Delete it with unlink() when you are done.

Reading and writing files — Working with files in PHP — writing, reading, appending, reading line by line, checking existence and deleting.