LabVIEW
finding most recent file in a directory
Is there a simple and easy way in labview to write a program that goes into a directory and looks for the most recent file. I can think of one way where I use the list directory vi to obtain an array of the file names in the directory and then use the file/directory info vi to obtain a time stamp for each file in the directory and afterwards sort all the time stamps. I'm not sure if this is the simplest way to do this, and wanted to ask if anyone on the discussion forums knows of any.
Thank you
@unclebump wrote:
Try here. http://zone.ni.com/devzone/cda/epd/p/id/3175
This example is not that great and a few tweaks can greatly improve it!
- Building the path with string operations inside the loop automatically breaks this VI on anything but windows. There is a reason we have the "build path" function! It should always be used. The "string to path" and "path to string" should only be used for OS specific tasks.
- You probably want to skip files that are actually links. Newer versions of "File/Directory info" tell you if the path points to a link instead of a file with a boolean output.
- WIy do we need to keep an array of all files and maintain the corret index in a shift register. It seems more intuitive and less wasteful to just keep the newest file path in the shift register and not worry about the index.
- ...
The image below shows a quick attempt at improving the example. Modify as needed.
Message Edited by altenbach on 04-12-2007 02:45 AM
@abenigma wrote:
i know this is an old thread but it does just what it's supposed to and it would seem it works fine just as it is.
i was wondering if i had done the right modifications according to what you suggested altenbach?
also, i was thinking that i would set the default folder as an input from the main VI (maybe with additional subdir), your thoughts?
and one last thing, if i want to get the entire file path (including name and extension) as output instead of just folder, how would i go about it?
attached is the modified VI.
I think your code is pretty good. The only suggestion I would have is to wire a constant to the uninitialized shift register index.
I attached my attempt to do the same using OpenG. It is going to be less efficient without a doubt, but I wasn't sure what would be more useful, having the newest file or the oldest, so my code finds both, as well as sorts the files by their date/time. Saved in 2012.
abenigma wrote:i was wondering if i had done the right modifications according to what you suggested altenbach?
No, you are building an potentially huge array of paths, only to later keep only one element. This is wasteful and inefficient. All you need to keep is the currently newest path as in my code. Right?
abenigma wrote:also, i was thinking that i would set the default folder as an input from the main VI (maybe with additional subdir), your thoughts?
Sorry, I don't understand what you are trying to say here. If you set the folder via an input terminal, the default value is irrelevant. Please explain.
@abenigma wrote:
iand one last thing, if i want to get the entire file path (including name and extension) as output instead of just folder, how would i go about it?
I don't understand your point. My VI already outputs the entire path, including name and extension (note the "build path" primitive!). Make sure your indicator is wide enough to display it.
