How can I get the path of the PHP binary from PHP?

Linux Only

Use the "which" command to find php.

$phpPath = exec("which php");

Note this does not guarantee the same php executable that your web server may be using, but rather the first instance that was found while looking through the paths.

A method using environment variables, assuming the php executable is in the system path.

function getPHPExecutableFromPath() {
  $paths = explode(PATH_SEPARATOR, getenv('PATH'));
  foreach ($paths as $path) {
    // We need this for XAMPP (Windows)
    if (strstr($path, 'php.exe') && isset($_SERVER["WINDIR"]) && file_exists($path) && is_file($path)) {
        return $path;
    }
    else {
        $php_executable = $path . DIRECTORY_SEPARATOR . "php" . (isset($_SERVER["WINDIR"]) ? ".exe" : "");
        if (file_exists($php_executable) && is_file($php_executable)) {
           return $php_executable;
        }
    }
  }
  return FALSE; // Not found
}

Maybe the best solution is in the Symfony process component:

PhpExecutableFinder.php and ExecutableFinder.php. In use:

<?php
    use Symfony\Component\Process\PhpExecutableFinder;

    $phpFinder = new PhpExecutableFinder;
    if (!$phpPath = $phpFinder->find()) {
        throw new \Exception('The php executable could not be found, add it to your PATH environment variable and try again');
    }

    return $phpPath;

Normally, in a simple default PHP installation under Windows, the php.ini file is located and loaded from the same directory of the PHP binary.

To simplify, Windows users:

echo dirname(php_ini_loaded_file()).DIRECTORY_SEPARATOR.'php.exe';

Voilà!

Of course, if you are using multiple .ini files, it may not work if the files are not into the same PHP binary directory. BTW, this may solve to most of cases. Windows developers running PHP from local development environment.

In Windows, using WAMP, you can use the ini variable - extension_dir - as it is placed in the PHP folder.

Like this:

echo str_replace('ext/', 'php.exe', ini_get('extension_dir'));

As of PHP 5.4 you can simply use the PHP_BINARY reserved constant.

It's very easy!

var_dump(getenv('PHPBIN'));

But it works only on Windows, so we should use this answer.

How did I get this? I just typed echo echo phpinfo(); and searched the php path there. Just see here:

Then I just getting it here: php getenv and ... you see the result.

For Windows and XAMPP:

$php = getenv('PHPRC') . '/php.exe';

if(is_file($expected)){
   return $php;
}