From 9605ec0dbd511f36ff96c39596e295ccc48f8870 Mon Sep 17 00:00:00 2001
From: Florian Eckerstorfer <florian@eckerstorfer.co>
Date: Sat, 11 Feb 2017 13:34:03 +0100
Subject: [PATCH] Add createFromPID static method

---
 README.md                       | 13 ++++++++++++-
 src/BackgroundProcess.php       | 23 +++++++++++++++++++----
 tests/BackgroundProcessTest.php | 21 +++++++++++++++++++++
 3 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index fd0fb43..c84d375 100644
--- a/README.md
+++ b/README.md
@@ -50,7 +50,7 @@ echo "\nDone.\n";
 
 If the process runs you can stop it:
 
-```
+```php
 // ...
 if ($process->isRunning()) {
     $process->stop();
@@ -72,6 +72,17 @@ In practice, the following methods will throw an exception if called on a Window
 - `Cocur\BackgroundProcess\BackgroundProcess::isRunning()`
 - `Cocur\BackgroundProcess\BackgroundProcess::stop()`
 
+### Create with existing PID
+
+If you have a long running process and store its PID in the database you might want to check at a later point (when you don't have the BackgroundProcess object anymore) whether the process is still running and stop the process.
+
+```php
+use Cocur\BackgroundProcess\BackgroundProcess;
+
+$process = BackgroundProcess::createFromPID($pid);
+$process->isRunning(); // -> true
+$process->stop();      // -> true
+```
 
 Change Log
 ----------
diff --git a/src/BackgroundProcess.php b/src/BackgroundProcess.php
index 413d975..599265c 100755
--- a/src/BackgroundProcess.php
+++ b/src/BackgroundProcess.php
@@ -62,7 +62,10 @@ public function __construct($command = null)
      */
     public function run($outputFile = '/dev/null', $append = false)
     {
-        if(is_null($this->command)) return;
+        if($this->command === null) {
+            return;
+        }
+
         switch ($this->getOS()) {
             case self::OS_WINDOWS:
                 shell_exec(sprintf('%s &', $this->command, $outputFile));
@@ -134,13 +137,13 @@ public function getPid()
 
         return $this->pid;
     }
-    
+
     /**
      * Set the process id.
-     * 
+     *
      * @param $pid
      */
-    public function setPid($pid)
+    protected function setPid($pid)
     {
         $this->pid = $pid;
     }
@@ -174,4 +177,16 @@ protected function checkSupportingOS($message)
             throw new RuntimeException(sprintf($message, PHP_OS));
         }
     }
+
+    /**
+     * @param int $pid PID of process to resume
+     *
+     * @return Cocur\BackgroundProcess\BackgroundProcess
+     */
+    static public function createFromPID($pid) {
+        $process = new self();
+        $process->setPid($pid);
+
+        return $process;
+    }
 }
diff --git a/tests/BackgroundProcessTest.php b/tests/BackgroundProcessTest.php
index 5793ff4..3f5707c 100644
--- a/tests/BackgroundProcessTest.php
+++ b/tests/BackgroundProcessTest.php
@@ -182,4 +182,25 @@ public function stopShouldThrowExceptionIfWindows()
         $process = new BackgroundProcess('sleep 1');
         $process->stop();
     }
+
+    /**
+     * @test
+     * @covers Cocur\BackgroundProcess\BackgroundProcess::createFromPID()
+     */
+    public function createFromPIDShouldCreateObjectFromPID()
+    {
+        if (preg_match('/^WIN/', PHP_OS)) {
+            $this->markTestSkipped('Cocur\BackgroundProcess\BackgroundProcess::createFromPID() is not supported on Windows.');
+
+            return;
+        }
+        $process = new BackgroundProcess('sleep 1');
+        $process->run();
+        $pid = $process->getPid();
+
+        $newProcess = BackgroundProcess::createFromPID($pid);
+
+        $this->assertEquals($pid, $newProcess->getPid());
+        $this->assertTrue($newProcess->stop());
+    }
 }