From a89b3380603625a59b94a7659b7a6b7c12efc94c Mon Sep 17 00:00:00 2001
From: Pierre Rudloff <contact@rudloff.pro>
Date: Sun, 14 May 2017 00:52:59 +0200
Subject: [PATCH] Improve the way we test if a command can be ran (see #109)

---
 classes/VideoDownload.php | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/classes/VideoDownload.php b/classes/VideoDownload.php
index 04db621..0be13d4 100644
--- a/classes/VideoDownload.php
+++ b/classes/VideoDownload.php
@@ -220,7 +220,7 @@ class VideoDownload
      */
     private function getRtmpProcess(\stdClass $video)
     {
-        if (!shell_exec('which '.$this->config->rtmpdump)) {
+        if (!$this->checkCommand([$this->config->rtmpdump, '--help'])) {
             throw(new \Exception('Can\'t find rtmpdump'));
         }
         $builder = new ProcessBuilder(
@@ -240,6 +240,22 @@ class VideoDownload
         return $builder->getProcess();
     }
 
+    /**
+     * Check if a command runs successfully
+     *
+     * @param array $command Command and arguments
+     *
+     * @return bool False if the command returns an error, true otherwise
+     */
+    private function checkCommand(array $command)
+    {
+        $builder = ProcessBuilder::create($command);
+        $process = $builder->getProcess();
+        $process->run();
+
+        return $process->isSuccessful();
+    }
+
     /**
      * Get a process that runs avconv in order to convert a video to MP3.
      *
@@ -249,7 +265,7 @@ class VideoDownload
      */
     private function getAvconvMp3Process($url)
     {
-        if (!shell_exec('which '.$this->config->avconv)) {
+        if (!$this->checkCommand([$this->config->avconv, '-version'])) {
             throw(new \Exception('Can\'t find avconv or ffmpeg'));
         }
 
@@ -307,7 +323,7 @@ class VideoDownload
      */
     public function getM3uStream(\stdClass $video)
     {
-        if (!shell_exec('which '.$this->config->avconv)) {
+        if (!$this->checkCommand([$this->config->avconv, '-version'])) {
             throw(new \Exception('Can\'t find avconv or ffmpeg'));
         }