PHP Server Side Printing Ubuntu Server

Question

I have been all over stack looking at what is required to do this and have wound up being slightly confused.

Lets get one thing straight this is a local based intra-net and I do understand that PHP is server side.

I am running a company management solution on a web based PHP,JAVA,Jquery Idea. and we would like to print reports directly from the "LINUX" server and receipts etc.

I have installed cups on the server and the server is printing fine and I am now just stuck on whether or not it is actually possible to get the server to print our pdf files we are generating directly from the PHP code.

I would be happy even if we had a bash script to run and check a directory print the pdf and then delete it, even though I would see this as a work around for the time being.

Like I said I do understand that if this was done on the WWW then there would be certain exploits that could be used. If I were to run this system on the www I would have a totally different site that did not allow printing and this function would not be necessary.

Thank You in advance

Alex

Answer 1

If CUPS is configured properly, printing a PDF from the shell is literally as easy as

lpr myfile.pdf

So, once you have written your PDF to a temporary file, you can use any of the available PHP functions to execute that shell command: exec(), shell_exec(), system()

You could even do it without writing a temporary file and feed the data directly to lpr via STDIN (try cat myfile.pdf | lpr as an example on the shell).

You can feed data to a program's STDIN in PHP if you run it using proc_open(). The first example from the PHP Manual can be adapted to something like this:

<?php
$descriptorspec = array(
   0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
);

$process = proc_open('lpr', $descriptorspec, $pipes);

if (is_resource($process)) {
    // $pipes now looks like this:
    // 0 => writeable handle connected to child stdin
    // 1 => readable handle connected to child stdout
    // Any error output will be appended to /tmp/error-output.txt

    fwrite($pipes[0], $pdf_data);
    fclose($pipes[0]);
}
?>

Answer 2

Use PHP::PRINT::IPP

It is the most secure and easiest way for printing from Web using PHP. Here you don't have to enable exploitable php functions like exec(), shell_exec() etc.

Basic Usage

 <?php
  require_once(PrintIPP.php);

  $ipp = new PrintIPP();                        
  $ipp->setHost("localhost");
  $ipp->setPrinterURI("/printers/epson");
  $ipp->setData("./testfiles/test-utf8.txt"); // Path to file.
  $ipp->printJob();                                                          
?>

Reference

Answer 3

Judicious use of php's shell_exec() should allow you to print PDFs synchronously, immediately after their creation, thus avoiding the need for bash.

I've not used shell_exec() for printing so can't help with the detail but essentially, if you can successfully compose a UNIX print command, then you can write the shell_exec() instruction.