(PHP 5)
vfprintf — Write a formatted string to a stream
Write a string produced according to format to the stream resource specified by handle .
Operates as fprintf() but accepts an array of arguments, rather than a variable number of arguments.
Returns the length of the outputted string.
Example#1 vfprintf(): zero-padded integers
<?php
if (!($fp = fopen('date.txt', 'w')))
return;
vfprintf($fp, "%04d-%02d-%02d", array($year, $month, $day));
// will write the formatted ISO date to date.txt
?>