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-

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:

 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]);
}
?>