Q65994: Testing If a Drive or Directory Exists from a Batch File
Article: Q65994
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:3.x,4.x,5.x,6.0,6.2,6.21,6.22; WINDOWS:3.11
Operating System(s):
Keyword(s):
Last Modified: 17-DEC-2000
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft MS-DOS operating system versions 3.1, 3.2, 3.21, 3.3, 3.3a, 4.0, 4.01, 5.0, 5.0a, 6.0, 6.2, 6.21, 6.22
- Microsoft Windows for Workgroups version 3.11
-------------------------------------------------------------------------------
SUMMARY
=======
You can use the IF EXIST statement to check for the presence of a directory. For
example, to test for C:\WIN and then change to C:\WIN if it exists, use the
following batch file:
C:
IF NOT EXIST C:\WIN\NUL GOTO NOWINDIR
CD \WIN
:NOWINDIR
MORE INFORMATION
================
NUL always exists on a local MS-DOS FAT drive; therefore, if C:\WIN exists,
C:\WIN\NUL exists. This technique can also be used to verify that a drive
exists. For example:
IF EXIST E:\NUL GOTO USE_E
If an unformatted disk is tested, or if the floppy disk drive is empty, an INT 24
error (Abort, Retry, Fail?) occurs.
Neither of these tests works correctly with network devices or any other device
that does not have a block device-driver-controlled FAT file system (for
example, when you are using Windows for Workgroups 3.11 with 32-Bit File Access
enabled).
Prior to using this technique, you should know what network software the client
is using, what type of server they're connecting to, and the file system the
server is using.
The following table shows when IF EXIST returns NUL:
With 32-Bit File
No 32-Bit With 32-Bit Access and NetWare
Drive Type File Access File Access 3.x connectivity
Local FAT correctly always never
Windows for Workgroups FAT correctly always never
Microsoft LAN Manager HPFS never always never
Windows NT FAT/NTFS never always never
NetWare correctly never never
Additional query words: 3.20 3.21 3.30 3.30a 4.00 4.01 5.00 5.00a 6.00 6.20 6.21 6.22 vfat lanman true false positive negative
======================================================================
Keywords :
Technology : kbAudDeveloper kbWFWSearch kbWFW311 kbMSDOSSearch kbMSDOS321 kbMSDOS400 kbMSDOS320 kbMSDOS330a kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS310 kbMSDOS500 kbMSDOS330 kbMSDOS401 kbMSDOS500a
Version : MS-DOS:3.x,4.x,5.x,6.0,6.2,6.21,6.22; WINDOWS:3.11
=============================================================================
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.