How to save unique filename to directory with FPDF? - php

Question

I would like to save each newly generated PDF file with a unique filename to the "receipts" directory after generating the PDF using the FPDF library... As it is now, the PDF is overwritten each time. Can I append a time-stamp to the PDF filename? Example --->( /receipt_month-day-year-hour-seconds.pdf )
Absolute uniqueness desired, but not super critical.
$pdf->Output('receipts/receipt.pdf', 'F');

Answer 1

An easy (but not foolproof) way of ensuring a filename is unique would be to add a microtime timestamp to the filename. Microtime includes thousanths of a second, so would probably work unless your site has a lot of traffic:
$pdf->Output('receipts/receipt-' . microtime(true) . '.pdf', 'F');
If you want your timestamp to be like receipt_12-26-2017.pdf, then:
$pdf->Output('receipts/receipt_' . date("m-d-Y") . '.pdf', 'F');
If you really want to ensure your filenames are unique per directory, you could do something like this:
<?php
function get_filenames($source_dir, $include_path = FALSE, $_recursion = FALSE)
{
static $_filedata = array();
if ($fp = #opendir($source_dir))
{
// reset the array and make sure $source_dir has a trailing slash on the initial call
if ($_recursion === FALSE)
{
$_filedata = array();
$source_dir = rtrim(realpath($source_dir), DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR;
}
while (FALSE !== ($file = readdir($fp)))
{
if (#is_dir($source_dir.$file) && strncmp($file, '.', 1) !== 0)
{
get_filenames($source_dir.$file.DIRECTORY_SEPARATOR, $include_path, TRUE);
}
elseif (strncmp($file, '.', 1) !== 0)
{
$_filedata[] = ($include_path == TRUE) ? $source_dir.$file : $file;
}
}
return $_filedata;
}
else
{
return FALSE;
}
}
function force_unique_filename( $dir_list, $file_name, $x = 2 )
{
/**
* Dir list may be an array of file names, or in the case of
* cURL, the list may be supplied as a string. If an array, we
* just convert the array to a string so it is checked as a string.
*/
if( is_array( $dir_list ) )
{
$dir_list = implode( ' ', $dir_list );
}
while( strpos( $dir_list, $file_name ) !== FALSE )
{
// Use pathinfo to break apart the filename
$info = pathinfo( $file_name );
// Get the file extension of the file
$ext = '.' . $info['extension'];
// Get the name of the file without extension
$file_name = basename( $file_name, $ext );
// Remove the filename suffix before adding a new one
$pattern = '/\(\d+\)/';
$replacement = '';
$file_name = preg_replace( $pattern, $replacement, $file_name );
// Add new filename suffix
$file_name .= '(' . (string) $x . ')' . $ext;
// Increment the number we are using in a filename suffix "($x)"
$x++;
}
return $file_name;
}
// -----------------------------------------------------------------------
// This directory should be an absolute path...
$source_dir = './receipts';
// The desired filename
$filename = 'receipt_' . date("m-d-Y") . '.pdf';
// Get all of the filenames in this directory
$filenames = get_filenames( $source_dir, FALSE, FALSE );
// Get the unique filename
$unique_filename = force_unique_filename( $filenames, $filename );
$pdf->Output('receipts/' . $unique_filename, 'F');