does "if exist" exist? 3

[realtree]

i'm trying to write a batch file to install some programs.
i want to use

if not exist "C:\Program Files" goto changedir

it works fine, but it needs to be compatible with all windows machines. (I already tried using %ProgramFiles%, but I found that win98 doesn't have this as a default) I tried

if exist "C:\Program Files" echo yea

and

if exist C:\Progra~1 echo yea

but it still don't echo back! (and I DO know that it IS a valid directory). I do know a little bit of pascal, but I don't have it at work, and I truly only know a little bit right now.

also: True or False? For the most part,(as far as batch scripting goes) if it works on win98 and NT4, it'll work on them all.

 

[puppet]

Have you tried

if exist C:\Progr* echo yea

 

[realm174]

Correct me if I'm wrong, but "exist" works for files, not for folders in 98. In XP, it does behave differently.

I created the following batch file:

echo off
if exist c:\progra~1 echo folder ~1 is there
if exist c:\progra~1\desktop.ini echo file exists in ~1
if exist "c:\program files" echo long name works for folder
if exist "c:\program files\desktop.ini" echo long name works for files
if exist "c:\progra~1\." echo dot is there
if exist "c:\progra~1\.." echo dot dot is there

Here's the result in 98SE:
file exists in ~1
long name works for files

Here's the result in XP Home
folder ~1 is there
long name works for folder
dot is there
dot dot is there

Bottom line is, the operating system you're using does not allow "exist" to operate on folders, it only works with filename.

Hope this helps..



Cheers,

Realm174

 

[jrbarnett]

Hi,

You can use the following trick to check for the existence of a folder in DOS/9x:

if exist "c:\foldername\nul" goto continue
md c:\foldername
:continue
rem copy files here

The nul device is an old trick basically checking for the equivalent of a bottomless pit under the folder.

John

 

[realm174]

Hey John! I forgot about that old trick... but you're right, it works!! Ahhh the good ol' DOS days : )

Cheers,



Cheers,

Realm174

 

[tviman]

Don't forget that your batch file is running is a DOS environment and will only recognize file/folder names of 8 characters or less.

There's always a better way. The fun is trying to find it!

 

[realtree]

I see... very nice! * can be used (duh) instead of nul. except if it's empty, it won't return. good way to test the emptyness of a folder tho.

So then "C:\Program Files\nul" should work in all windows versions.... wait I just tried it on an XP Pro box, doesn't work. Why does M$ have to mess around so much!?! I could use progra~1, but it's not fool proof. would be nice to use full names.

the final line as of now reads:

if not exist C:\Progra~1\nul goto changedir

I don't have access to all of the OS though. will this work in 95(sadly, some ppl still use it), 98, NT, ME, 2K, and XP?

btw, I was looking at pascal and trying to relate my DOS routines to the dos and standard units there. Too bad I don't get it. Oh well, 9 days til my C++ and VB courses start!