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Re: Need help with algorythm [message #40456 is a reply to message #40455]

Sun, 04 August 2013 19:57

dolik.rce
Messages: 1789
Registered: August 2008
Location: Czech Republic

Ultimate Contributor

lectus wrote on Sun, 04 August 2013 19:02

I need to watch when files are modified.
Do you have ideas how can I implement this in U++?

Depends a lot on your exact case. Is it GUI or CLI app? What platform(s)? How soon do you need to know about file being modified?

Assuming multiplatform GUI app, then for most purposes you can probably be just fine with using something like SetTimeCallback(-1000, callback(MyFunc)), where MyFunc would look like

void MyFunc() {
    static FileTime last = GetFileTime("somefile");
    FileTime current = GetFileTime("somefile");
    if (last == current) 
        return;
    last = current;
    // do actual work here
}

Of course, polling is not really efficient thing to do... On Linux you can use inotify to get a callback whenever file changes, on Windows you could use FileSystemWatcher or something. Both should cut down both the overhead from polling and the time till you notice the change and can react. The price is writing more code if you need it multiplatform... If you do this thouhg, it would be nice to create generalized class or function for this that could be added to U++ Wink

Best regards,
Honza

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