Issue #197 Implement unpack_files operation

Author: mikehaertl

README.md

@@ -198,6 +198,17 @@ $pdf->multiStamp('/path/overlay_pages.pdf')
     ->saveAs('/path/stamped.pdf');
 ```
 
+#### Unpack Files
+
+Copy file attachments from a PDF to the given directory.
+
+```php
+use mikehaertl\pdftk\Pdf;
+
+$pdf = new Pdf('/path/my.pdf');
+$pdf->unpackFiles('/path/to/dir');
+```
+
 #### Generate FDF
 
 Create a FDF file from a given filled PDF form.

src/Pdf.php

@@ -215,7 +215,6 @@ public function shuffle($start, $end = null, $handle = null, $qualifier = null,
      *
      * @param string|null $filepattern the output name in sprintf format or
      * null for default 'pg_%04d.pdf'
-     * @return bool whether the burst command was successful
      * @return bool whether the burst operation was successful
      */
     public function burst($filepattern = null)
@@ -226,6 +225,20 @@ public function burst($filepattern = null)
         return $this->execute();
     }
 
+    /**
+     * Copy all attachments from the PDF to the given directory
+     *
+     * @param string|null $dir the output directory
+     * @return bool whether the operation was successful
+     */
+    public function unpackFiles($dir = null)
+    {
+        $this->constrainSingleFile();
+        $this->getCommand()->setOperation('unpack_files');
+        $this->_output = $dir;
+        return $this->execute();
+    }
+
     /**
      * Generate the FDF file for a single PDF file.
      *

tests/PdfTest.php

@@ -259,6 +259,19 @@ public function testCanBurstWithFilePattern()
         @unlink($dir . '/doc_data.txt');
     }
 
+    public function testUnpackFiles()
+    {
+        $document = $this->getDocument1();
+        $dir = __DIR__;
+
+        $pdf = new Pdf($document);
+        $this->assertTrue($pdf->unpackFiles($dir));
+        $this->assertEquals(
+            "pdftk 'A'='$document' unpack_files 'output' '$dir'",
+            (string) $pdf->getCommand()
+        );
+    }
+
     public function testCanCreateFdfFileFromPdf()
     {
         $form = $this->getFilledForm();