From 90daef75c6e8e7c4c0571c99b63385f5806649e7 Mon Sep 17 00:00:00 2001
From: Juan Traverso <jtraverso@dext.es>
Date: Sun, 16 Jun 2013 11:12:20 +0200
Subject: [PATCH] [Process] Added support for stdout and stderr flush (Issue
 #7884)

---
 src/Symfony/Component/Process/Process.php     | 26 +++++++++++++++++++
 .../Process/Tests/AbstractProcessTest.php     | 18 +++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/src/Symfony/Component/Process/Process.php b/src/Symfony/Component/Process/Process.php
index 4822e8863ee8..6b042db5923a 100644
--- a/src/Symfony/Component/Process/Process.php
+++ b/src/Symfony/Component/Process/Process.php
@@ -532,6 +532,19 @@ public function getIncrementalOutput()
         return $latest;
     }
 
+    /**
+     * Clears the process output.
+     *
+     * @return Process
+     */
+    public function flushOutput()
+    {
+        $this->stdout = '';
+        $this->incrementalOutputOffset = 0;
+
+        return $this;
+    }
+
     /**
      * Returns the current error output of the process (STDERR).
      *
@@ -565,6 +578,19 @@ public function getIncrementalErrorOutput()
         return $latest;
     }
 
+    /**
+     * Clears the process output.
+     *
+     * @return Process
+     */
+    public function flushErrorOutput()
+    {
+        $this->stderr = '';
+        $this->incrementalErrorOutputOffset = 0;
+
+        return $this;
+    }
+
     /**
      * Returns the exit code returned by the process.
      *
diff --git a/src/Symfony/Component/Process/Tests/AbstractProcessTest.php b/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
index 5cd52efbd9bb..aaaf06447072 100644
--- a/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
+++ b/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
@@ -156,6 +156,15 @@ public function testGetIncrementalErrorOutput()
         }
     }
 
+    public function testFlushErrorOutput()
+    {
+        $p = new Process(sprintf('php -r %s', escapeshellarg('$n = 0; while ($n < 3) { file_put_contents(\'php://stderr\', \'ERROR\'); $n++; }')));
+
+        $p->run();
+        $p->flushErrorOutput();
+        $this->assertEmpty($p->getErrorOutput());
+    }
+
     public function testGetOutput()
     {
         $p = new Process(sprintf('php -r %s', escapeshellarg('$n=0;while ($n<3) {echo \' foo \';$n++;}')));
@@ -175,6 +184,15 @@ public function testGetIncrementalOutput()
         }
     }
 
+    public function testFlushOutput()
+    {
+        $p = new Process(sprintf('php -r %s', escapeshellarg('$n=0;while ($n<3) {echo \' foo \';$n++;}')));
+
+        $p->run();
+        $p->flushOutput();
+        $this->assertEmpty($p->getOutput());
+    }
+
     public function testExitCodeCommandFailed()
     {
         if (defined('PHP_WINDOWS_VERSION_BUILD')) {