Passing data from C++ to PHP

Question

I need to pass a value from PHP to C++. I think I can do with PHP's passthru() function. Then I want C++ to do something to that value and return the result to PHP. This is the bit I can't work out, does anyone know how to pass data from C++ to PHP? I'd rather not use an intermediate file as I am thinking this will slow things down.

score 6 · Accepted Answer · edited Nov 13 '11 at 12:20

6

You could have your c++ app send its output to stdout, then call it from PHP with backticks, e.g.

$output=`myapp $myinputparams`;

edited Nov 13 '11 at 12:20

genesis

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answered Jun 09 '09 at 15:27

Paul Dixon

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Thank you very much to all answer-ers, I expect I will need to graduate to the more flexible solutions in time but for now this has worked. Thanks. – Columbo Jun 09 '09 at 16:15

score 1 · Answer 2 · answered Jan 19 '11 at 18:39

wow thanks a lot to Columbo & Paul Dixon.

Now I can run php to call c++ thn pass back value to php~ =)

Here I provide a sample cpp & php for it:

A simple program for adding up inputs:

a.cpp (a.exe):

#include<iostream>
#include<cstdlib>
using namespace std;

int main(int argc, char* argv[]) {
  int val[2];
  for(int i = 1; i < argc; i++) { // retrieve the value from php
      val[i-1] = atoi(argv[i]);
  }
  int total = val[0] + val[1]; // sum up
  cout << total;  // std::cout will output to php
  return 0;
}

sample.php:

<?php
    $a = 2;
    $b = 3;
    $c_output=`a.exe $a $b`; // pass in the two value to the c++ prog
    echo "<pre>$c_output</pre>"; //received the sum
    echo "Output: " . ($output + 1); //modify the value in php and output
?>

output:

5
Output: 6

Jacob B · Answer 3 · 2009-06-09T15:40:08.967

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This article about wrapping C++ classes in a PHP extension may help.

EDIT: all the solutions in other answers are far simpler, but less flexible. It all depends on what you need.

edited Jun 09 '09 at 15:40

answered Jun 09 '09 at 15:26

Jacob B

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I would say if anything a socket connection is more flexible, you can send binary data anywhere to do anything :) Your solution may be better in another sense in that it integrates php and c++ code which may or may not be more what the OP is asking. – Doug T. Jun 09 '09 at 15:43
On the other hand, you still need to serialize/deserialize any data you want to send, which IMO qualifies as less flexible. The advantage of using a language's extension interface is that you get to handle the language's data structures directly--for sockets you "only" get strings of bytes. – Jacob B Jun 09 '09 at 16:20
Out of these three methods which in your opinios would be the quickest. To me it appears that the backticks method has to start and execute the C++ script whereas the sockets and (I think) wrapper methods rely on C++ programs that are memory resident and so can respond quicker. Does that seem reasonable or have I got it wrong? – Columbo Jun 09 '09 at 16:33
Yes, that's correct. Wrapper script is faster than sockets by a little tiny bit--there's some extra overhead due to serialization and memory allocation. Backticks have to not only start the C++ script but also, I believe, invoke the shell. – Jacob B Jun 09 '09 at 17:03

score 0 · Answer 4 · answered Jun 09 '09 at 15:29

If you need to communicate to a running C++ program, a socket connection over the localhost might be the simplest, most platform-independent and most widely supported solution for communicating between the two processes. Sockets were traditionally built to communicate over network interfaces, but I have seen them used in many cases as a method of doing a pipe. They are fairly ubiquitous and supported in most modern languages.

Here's a C guide for socket programming. for your C++ program.

Passing data from C++ to PHP

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