gistfile1.txt

$paths = explode(PATH_SEPARATOR, getenv('PATH'));
foreach ($paths as $path) {
	$phpExecutable = $path . DIRECTORY_SEPARATOR . 'php' . (isset($_SERVER['WINDIR']) ? '.exe' : '');
	if (file_exists($phpExecutable) && is_file($phpExecutable)) {
		exec(escapeshellarg($phpExecutable) . ' -v', $phpVersion);
		if (substr(array_shift($phpVersion), 0, strlen('PHP ' . PHP_VERSION)) === 'PHP ' . PHP_VERSION) {
			echo $phpExecutable;
		}
	}
}

foreach ($paths as $path) {
$phpExecutable = $path . DIRECTORY_SEPARATOR . 'php' . (isset($_SERVER['WINDIR']) ? '.exe' : '');
if (file_exists($phpExecutable) && is_file($phpExecutable)) {
$phpVersion = trim(exec(escapeshellcmd($phpExecutable) . ' -r "echo PHP_VERSION;"'));
if ($phpVersion === PHP_VERSION) {
return $phpExecutable;
}
}
}

The last version as nicely formatted code block:

<?php
$paths = explode(PATH_SEPARATOR, getenv('PATH'));
foreach ($paths as $path) {
    $phpExecutable = $path . DIRECTORY_SEPARATOR . 'php' . (isset($_SERVER['WINDIR']) ? '.exe' : '');
    if (file_exists($phpExecutable) && is_file($phpExecutable)) {
        $phpVersion = trim(exec(escapeshellcmd($phpExecutable) . ' -r "echo PHP_VERSION;"'));
        if ($phpVersion === PHP_VERSION) {
            return $phpExecutable;
        }
    }
}

BTW: This code is rather a reminder, "php -v" returns completely different strings that needs some parsing. but it would be great if we could get that to work sometime..