From e762b0dc29c46a2e3a4c355b5b8667afe34eab35 Mon Sep 17 00:00:00 2001
From: terrafrost <terrafrost@php.net>
Date: Thu, 5 May 2016 10:54:29 -0500
Subject: [PATCH] SFTP: add is_writable, is_writeable and is_readable

---
 phpseclib/Net/SFTP.php                     | 70 ++++++++++++++++++++++
 tests/Functional/Net/SFTPUserStoryTest.php | 22 +++++++
 2 files changed, 92 insertions(+)

diff --git a/phpseclib/Net/SFTP.php b/phpseclib/Net/SFTP.php
index 4d10dbe1..4840f269 100644
--- a/phpseclib/Net/SFTP.php
+++ b/phpseclib/Net/SFTP.php
@@ -2350,6 +2350,76 @@ class Net_SFTP extends Net_SSH2
         return $result === NET_SFTP_TYPE_SYMLINK;
     }
 
+    /**
+     * Tells whether a file exists and is readable
+     *
+     * @param string $path
+     * @return bool
+     * @access public
+     */
+    function is_readable($path)
+    {
+        $path = $this->_realpath($path);
+
+        $packet = pack('Na*N2', strlen($path), $path, NET_SFTP_OPEN_READ, 0);
+        if (!$this->_send_sftp_packet(NET_SFTP_OPEN, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_HANDLE:
+                return true;
+            case NET_SFTP_STATUS: // presumably SSH_FX_NO_SUCH_FILE or SSH_FX_PERMISSION_DENIED
+                return false;
+            default:
+                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS');
+                return false;
+        }
+    }
+
+    /**
+     * Tells whether the filename is writable
+     *
+     * @param string $path
+     * @return bool
+     * @access public
+     */
+    function is_writable($path)
+    {
+        $path = $this->_realpath($path);
+
+        $packet = pack('Na*N2', strlen($path), $path, NET_SFTP_OPEN_WRITE, 0);
+        if (!$this->_send_sftp_packet(NET_SFTP_OPEN, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_HANDLE:
+                return true;
+            case NET_SFTP_STATUS: // presumably SSH_FX_NO_SUCH_FILE or SSH_FX_PERMISSION_DENIED
+                return false;
+            default:
+                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS');
+                return false;
+        }
+    }
+
+    /**
+     * Tells whether the filename is writeable
+     *
+     * Alias of is_writable
+     *
+     * @param string $path
+     * @return bool
+     * @access public
+     */
+    function is_writeable($path)
+    {
+        return $this->is_writable($path);
+    }
+
     /**
      * Gets last access time of file
      *
diff --git a/tests/Functional/Net/SFTPUserStoryTest.php b/tests/Functional/Net/SFTPUserStoryTest.php
index c01948f4..9f0977e6 100644
--- a/tests/Functional/Net/SFTPUserStoryTest.php
+++ b/tests/Functional/Net/SFTPUserStoryTest.php
@@ -686,5 +686,27 @@ class Functional_Net_SFTPUserStoryTest extends PhpseclibFunctionalTestCase
             $sftp->get('offset.txt'),
             'Failed asserting that you could upload into the middle of a file.'
         );
+
+        return $sftp;
+    }
+
+    /**
+     * @depends testUploadOffsets
+     */
+    public function testReadableWritable($sftp)
+    {
+        $sftp->chmod(0000, 'offset.txt');
+        $this->assertFalse($sftp->is_writable('offset.txt'));
+        $this->assertFalse($sftp->is_writeable('offset.txt'));
+        $this->assertFalse($sftp->is_readable('offset.txt'));
+
+        $sftp->chmod(0777, 'offset.txt');
+        $this->assertTrue($sftp->is_writable('offset.txt'));
+        $this->assertTrue($sftp->is_writeable('offset.txt'));
+        $this->assertTrue($sftp->is_readable('offset.txt'));
+
+        $this->assertFalse($sftp->is_writable('nonexistantfile.ext'));
+        $this->assertFalse($sftp->is_writeable('nonexistantfile.ext'));
+        $this->assertFalse($sftp->is_readable('nonexistantfile.ext'));
     }
 }