exist(x,'dir') slow for unavailable network drives

I use exist(x,'dir') to check existence of a directory x. My problem is that checking existence of an address on a network drive when computer is not connected to the network takes something about 50 seconds. Checking existence of the address when computer is connected to the network however takes something about 0.0005 seconds.

I tried using

[a,b]=dos('net use x')

and I get list of connected network drives but it does not return the connected network drives as separate variable.

How can I speed up this process? I really appreciate any help!

[Siddharth Sundar]

To check whether it is an issue with the operating system or specifically with the MATLAB function exist, try the following:

1) What happens when you try to access web pages when not connected to the internet?

2) Does the browser slowly resolve that it cannot find the file or does it give the 'not found' webpage quickly?

If it does take a long time to resolve that it cannot find the webpage, then I would think this might depend on operating system resolution attempting to connect to the web page and timing out.

[Mohammad Abouali]

I don't have access to windows (yes it happens). when you issue

[a,b]=dos('net use x')

what do you get in a and b. Copy/Paste the result so we can help you to parse that.

[Arsalan jamialahmadi]

Thanks Sddharth, I actually very fast get a response on my browser that I am not connected to internet. But in offline mode when I try to open one of network drives, it takes long time, it can be related to some time-out that I don't know about. This might be related to the low velocity of EXIST.

[Arsalan jamialahmadi]

Thanks Mohammad,

Result of running is attached to a text file attached to this comment.

Answer 1

[per isakson]

I use exist(x,'dir') to check existence of a directory x. What's the value of x ?

Did you mean to run

num = exist( 'x:\', 'dir' );

which is fast enough whether 'x:\' exists or not.

[Walter Roberson]

Including when the network is not connected?

[per isakson]

Good question. My guess is yes.

OP writes I get list of connected network drives and I guessed that x is her/his local drive letter.

[Arsalan jamialahmadi]

x normally is address of a directory on the network. So when Iam connected to the network, this checking is fast but as soon as my connection is lost, response from "Exist" is slow.