Merge pull request #386 from terrafrost/symlink

SFTP: add readlink and symlink functions

* terrafrost/symlink:
  SFTP: return $sftp object in unit tests
  SFTP: fix unit test
  SFTP: syntax error in unit test
  SFTP: add unit tests for symlinks
  SFTP: add readlink and symlink functions

phpseclib/Net/SFTP.php

@@ -312,6 +312,8 @@ class Net_SFTP extends Net_SSH2
                    SFTPv5+: http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.3
                pre-SFTPv5 : http://tools.ietf.org/html/draft-ietf-secsh-filexfer-04#section-6.5 */
             18 => 'NET_SFTP_RENAME',
+            19 => 'NET_SFTP_READLINK',
+            20 => 'NET_SFTP_SYMLINK',
 
             101=> 'NET_SFTP_STATUS',
             102=> 'NET_SFTP_HANDLE',
@@ -1557,6 +1559,86 @@ class Net_SFTP extends Net_SSH2
         return true;
     }
 
+    /**
+     * Return the target of a symbolic link
+     *
+     * @param String $link
+     * @return Mixed
+     * @access public
+     */
+    function readlink($link)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $link = $this->_realpath($link);
+
+        if (!$this->_send_sftp_packet(NET_SFTP_READLINK, pack('Na*', strlen($link), $link))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_NAME:
+                break;
+            case NET_SFTP_STATUS:
+                $this->_logError($response);
+                return false;
+            default:
+                user_error('Expected SSH_FXP_NAME or SSH_FXP_STATUS');
+                return false;
+        }
+
+        extract(unpack('Ncount', $this->_string_shift($response, 4)));
+        // the file isn't a symlink
+        if (!$count) {
+            return false;
+        }
+
+        extract(unpack('Nlength', $this->_string_shift($response, 4)));
+        return $this->_string_shift($response, $length);
+    }
+
+    /**
+     * Create a symlink
+     *
+     * symlink() creates a symbolic link to the existing target with the specified name link.
+     *
+     * @param String $target
+     * @param String $link
+     * @return Boolean
+     * @access public
+     */
+    function symlink($target, $link)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $target = $this->_realpath($target);
+        $link = $this->_realpath($link);
+
+        $packet = pack('Na*Na*', strlen($target), $target, strlen($link), $link);
+        if (!$this->_send_sftp_packet(NET_SFTP_SYMLINK, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS');
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            $this->_logError($response, $status);
+            return false;
+        }
+
+        return true;
+    }
+
     /**
      * Creates a directory.
      *

tests/Functional/Net/SFTPUserStoryTest.php

@@ -316,6 +316,31 @@ class Functional_Net_SFTPUserStoryTest extends PhpseclibFunctionalTestCase
         return $sftp;
     }
 
+    /**
+    * @depends testSortOrder
+    */
+    public function testSymlink($sftp)
+    {
+        $this->assertTrue(
+            $sftp->symlink('file3.txt', 'symlink'),
+            'Failed asserting that a symlink could be created'
+        );
+
+        return $sftp;
+    }
+
+    /**
+    * @depends testSymlink
+    */
+    public function testReadlink($sftp)
+    {
+        $this->assertInternalType('string', $sftp->readlink('symlink'),
+            'Failed asserting that a symlink\'s target could be read'
+        );
+
+        return $sftp;
+    }
+
     /**
     * @depends testSortOrder
     */