Tuesday, November 13, 2012

How to Use xp_dirtree to List All Files in a Folder

UPDATED -- Dec 31, 2012 -- Be sure to read Part 2 of this post discussing xp_dirtree.

Last week I blogged about how to use an undocumented stored procedures to create folders.  This week we need to do the opposite.  We need to get a list of all files from a subfolder in order to process them.  In order to do that, we'll use another undocumented extended stored procedure; master.sys.xp_dirtree.  This stored procedure will display a list of every folder, every subfolder, and every file for path you give it.

Xp_dirtree has three parameters: 
  1. directory - This is the directory you pass when you call the stored procedure; for example 'D:\Backup'.
  2. depth  - This tells the stored procedure how many subfolder levels to display.  The default of 0 will display all subfolders.
  3. file - This will either display files as well as each folder.  The default of 0 will not display any files.
For today's example, we just want to display all of our backup files (*.BAK) in a particular folder. We need to all of the other parameters in order to show the files as well as any subfolders.

EXEC master.sys.xp_dirtree 'D:\Backup\TRON4\TEST2\MyDb1',0,1;

The output below will show us each subfolder and every file for the given directory.


We're only concerned about the BAK files.  So we'll need to create a temp table to hold the output of xp_dirtree.  Then we can select only the rows that are an actual file (isfile = 1) and that have a file extension of BAK.

IF OBJECT_ID('tempdb..#DirectoryTree') IS NOT NULL
      DROP TABLE #DirectoryTree;

CREATE TABLE #DirectoryTree (
       id int IDENTITY(1,1)
      ,subdirectory nvarchar(512)
      ,depth int
      ,isfile bit);

INSERT #DirectoryTree (subdirectory,depth,isfile)
EXEC master.sys.xp_dirtree 'D:\Backup\TRON4\TEST2\MyDb1',1,1;

SELECT * FROM #DirectoryTree
WHERE isfile =AND RIGHT(subdirectory,4) = '.BAK'
ORDER BY id;
GO

Below is the output.


This example only shows the files for a specific subfolder, which is used to get a list of files that are needed for purging before another database backup runs.  This stored procedure also can accept UNC paths (\\Server\Folder) to get a list of files and subfolders from a network drive.  In a future post, I will add on to this script to show all files in all subfolders for a given directory.  Until then, play around with xp_dirtree and its parameters to see the different outputs.  You may be able to incorporate this into your own code.