Detect New File in a Directory
29 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
lynniz
il 13 Ott 2011
Risposto: Walter Roberson
il 27 Ago 2022
Hi All,
Last time when I google this question, I actually found a function that does what I need, but I couldn't find it this time.
Basically what I need is to monitor a directory for any new files. If there are new files, I will read the files in and continue to monitor for new files.
Any help will be greatly appreciated!
Thank you,
Lynniz
2 Commenti
Walter Roberson
il 13 Ott 2011
The mechanisms for doing this are operating-system specific. Please indicate which OS you are using.
Risposta accettata
Honglei Chen
il 13 Ott 2011
Hi lynniz,
You can use dir to list all the files under a certain directory, cache it and constantly query the folder and use setdiff to see whether a new file showed up. The following example shows a brief example. Note that I'm assuming everything underneath the directory is a regular file. If you have subdirectories, you can filter them out using the isdir field in the result of dir.
dir_content = dir;
filenames = {dir_content.name};
current_files = filenames;
while true
dir_content = dir;
filenames = {dir_content.name};
new_files = setdiff(filenames,current_files);
if ~isempty(new_files)
% deal with the new files
current_files = filenames;
else
fprintf('no new files\n')
end
end
Of course you may want to define an exit flag to get you out of the loop easily.
HTH
3 Commenti
Fangjun Jiang
il 13 Ott 2011
What if file name keeps the same but it is newly updated? You might need to check the time stamp of the file, compare it to the last time that the checking is done, to see if it is "new".
Più risposte (2)
Dimitrios Patikas
il 27 Ago 2022
Modificato: Dimitrios Patikas
il 27 Ago 2022
To avoid looping over and over again, you may use a timer function and keep it working on the background unless younstom the timer. An example to get always the newest file:
t = timer;
t.TimerFcn = @timerFunc;
t.Period = 0.6; % how often you want to check
t.ExecutionMode = 'fixedRate';
t.start % use t.stop to stop the timer
function timerFunc(~,~)
persistent CurrentNewest
Path = 'A/path/you/want/to/keep/track';
CurrentNewest = 'NewestFilename.new'
ListFiles = dir(Path);
ListFiles = ListFiles(~[ListFiles.isdir]);
[~, idx] = sort([ListFiles.datenum]);
newest = ListFiles(idx(end));
if ~strcmp(newest.name, CurrentNewest)
disp(['The newest file is now: ', newest.name])
CurrentNewest = newest.name;
end
end
0 Commenti
Vedere anche
Categorie
Scopri di più su File Operations in Help Center e File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!