Php – Get the number of pages in a PDF document

pdfPHP

This question is for referencing and comparing. The solution is the accepted answer below.

Many hours have I searched for a fast and easy, but mostly accurate, way to get the number of pages in a PDF document. Since I work for a graphic printing and reproduction company that works a lot with PDFs, the number of pages in a document must be precisely known before they are processed. PDF documents come from many different clients, so they aren't generated with the same application and/or don't use the same compression method.

Here are some of the answers I found insufficient or simply NOT working:

Using Imagick (a PHP extension)

Imagick requires a lot of installation, apache needs to restart, and when I finally had it working, it took amazingly long to process (2-3 minutes per document) and it always returned 1 page in every document (haven't seen a working copy of Imagick so far), so I threw it away. That was with both the getNumberImages() and identifyImage() methods.

Using FPDI (a PHP library)

FPDI is easy to use and install (just extract files and call a PHP script), BUT many of the compression techniques are not supported by FPDI. It then returns an error:

FPDF error: This document (test_1.pdf) probably uses a compression technique which is not supported by the free parser shipped with FPDI.

Opening a stream and search with a regular expression:

This opens the PDF file in a stream and searches for some kind of string, containing the pagecount or something similar.

$f = "test1.pdf";
$stream = fopen($f, "r");
$content = fread ($stream, filesize($f));

if(!$stream || !$content)
    return 0;

$count = 0;
// Regular Expressions found by Googling (all linked to SO answers):
$regex  = "/\/Count\s+(\d+)/";
$regex2 = "/\/Page\W*(\d+)/";
$regex3 = "/\/N\s+(\d+)/";

if(preg_match_all($regex, $content, $matches))
    $count = max($matches);

return $count;
  • /\/Count\s+(\d+)/ (looks for /Count <number>) doesn't work because only a few documents have the parameter /Count inside, so most of the time it doesn't return anything. Source.
  • /\/Page\W*(\d+)/ (looks for /Page<number>) doesn't get the number of pages, mostly contains some other data. Source.
  • /\/N\s+(\d+)/ (looks for /N <number>) doesn't work either, as the documents can contain multiple values of /N ; most, if not all, not containing the pagecount. Source.

So, what does work reliable and accurate?

See the answer below

Best Answer

A simple command line executable called: pdfinfo.

It is downloadable for Linux and Windows. You download a compressed file containing several little PDF-related programs. Extract it somewhere.

One of those files is pdfinfo (or pdfinfo.exe for Windows). An example of data returned by running it on a PDF document:

Title:          test1.pdf
Author:         John Smith
Creator:        PScript5.dll Version 5.2.2
Producer:       Acrobat Distiller 9.2.0 (Windows)
CreationDate:   01/09/13 19:46:57
ModDate:        01/09/13 19:46:57
Tagged:         yes
Form:           none
Pages:          13    <-- This is what we need
Encrypted:      no
Page size:      2384 x 3370 pts (A0)
File size:      17569259 bytes
Optimized:      yes
PDF version:    1.6

I haven't seen a PDF document where it returned a false pagecount (yet). It is also really fast, even with big documents of 200+ MB the response time is a just a few seconds or less.

There is an easy way of extracting the pagecount from the output, here in PHP:

// Make a function for convenience 
function getPDFPages($document)
{
    $cmd = "/path/to/pdfinfo";           // Linux
    $cmd = "C:\\path\\to\\pdfinfo.exe";  // Windows
    
    // Parse entire output
    // Surround with double quotes if file name has spaces
    exec("$cmd \"$document\"", $output);

    // Iterate through lines
    $pagecount = 0;
    foreach($output as $op)
    {
        // Extract the number
        if(preg_match("/Pages:\s*(\d+)/i", $op, $matches) === 1)
        {
            $pagecount = intval($matches[1]);
            break;
        }
    }
    
    return $pagecount;
}

// Use the function
echo getPDFPages("test 1.pdf");  // Output: 13

Of course this command line tool can be used in other languages that can parse output from an external program, but I use it in PHP.

I know its not pure PHP, but external programs are way better in PDF handling (as seen in the question).

I hope this can help people, because I have spent a whole lot of time trying to find the solution to this and I have seen a lot of questions about PDF pagecount in which I didn't find the answer I was looking for. That's why I made this question and answered it myself.

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