Running a python program during idle time only

Discussion in 'Python' started by los, May 21, 2005.

  1. los

    los Guest

    Hi,

    I'm trying to create a program similar to that of Google's desktop that
    will crawl through the hard drive and index files. I have written the
    program and as of now I just put the thread to sleep for 1 second after
    indexing a couple of files.

    I'm wondering if anyone knows of a way that I could make so that the
    program will run at full speed only runs after the computer has been
    idle for a while. I've looked at the "nice" command but that's not
    exactly what I want.

    Let me know if it isn't clear what I explained above.

    Thanks
     
    los, May 21, 2005
    #1
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  2. los

    Mike Meyer Guest

    "los" <> writes:
    > I'm trying to create a program similar to that of Google's desktop that
    > will crawl through the hard drive and index files. I have written the
    > program and as of now I just put the thread to sleep for 1 second after
    > indexing a couple of files.
    >
    > I'm wondering if anyone knows of a way that I could make so that the
    > program will run at full speed only runs after the computer has been
    > idle for a while. I've looked at the "nice" command but that's not
    > exactly what I want.


    On Unix, nice is exactly the answer. It's a lot more fine-grained than
    what you're talking about, though. But it's the way things like
    setiathome manage to run continuously without interfering with normal
    usage.

    If that's to fine grained for you, you could try waking up every few
    minutes and checking the load average (via os.getloadavg), and only
    doing work if the load average is low - say less than .5. While
    running, you check the load average every couple of minutes and stop
    if it rises noticably above 1 (you). The problem with this approach is
    that it doesn't deal well with multiple tools doing this. I.e. - if
    you run setiathome, your load average will always be above 1, so you
    have to adjust your check value to take into account anything else
    that might be in the background. Nice handles this automatically.

    <mike
    --
    Mike Meyer <> http://www.mired.org/home/mwm/
    Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.
     
    Mike Meyer, May 21, 2005
    #2
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  3. los

    Donn Cave Guest

    Quoth Mike Meyer <>:
    | "los" <> writes:
    | > I'm trying to create a program similar to that of Google's desktop that
    | > will crawl through the hard drive and index files. I have written the
    | > program and as of now I just put the thread to sleep for 1 second after
    | > indexing a couple of files.
    | >
    | > I'm wondering if anyone knows of a way that I could make so that the
    | > program will run at full speed only runs after the computer has been
    | > idle for a while. I've looked at the "nice" command but that's not
    | > exactly what I want.
    |
    | On Unix, nice is exactly the answer. It's a lot more fine-grained than
    | what you're talking about, though. But it's the way things like
    | setiathome manage to run continuously without interfering with normal
    | usage.

    Well, he could certainly try it if he hasn't already, but I wouldn't
    be too surprised if it really isn't exactly what he wants. Maybe it
    depends on the scheduler, and maybe things have gotten a lot better
    in that department, but from my experience a process can be niced pretty
    hard and still tie up a lot of resources. A disk crawler sounds like
    a good example.

    I don't have any brilliant ideas, though. Your suggestion to use
    os.getloadavg sounds good to me. It might be kind of neat if there
    were some kind of APM ioctl that would register the calling process
    for notification of pending disk spin down, low power mode etc.

    Donn
     
    Donn Cave, May 21, 2005
    #3
  4. There's probably a way to tell how long the user has been idle, but here's
    how you can check the CPU load to see if it's elevated... (of course
    your program might elevate it too.)

    On linux, you can read from /proc/loadavg

    Here's a fun thing to try on windows...

    make sure you have the win32all package installed...

    import win32com.client
    computer="."
    query="select LoadPercentage from Win32_Processor where DeviceID = 'CPU0'"
    objWMIService = win32com.client.Dispatch("WbemScripting.SWbemLocator")
    objSWbemServices = objWMIService.ConnectServer(computer,"root\cimv2")
    rows = objSWbemServices.ExecQuery(query)
    print rows[0].LoadPercentage

    import time

    for count in xrange(4):
    print objSWbemServices.ExecQuery(query)[0].LoadPercentage
    time.sleep(1)

    The microsoft docs on the info you can get on the processor is here:
    http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/win32_processor.asp

    If you run this from a shell like PyCrust, you won't see anything for
    four seconds, and then it will all show up.

    What are you using for the text indexing? PyLucene???

    -Jim

    On 5/21/05, Donn Cave <> wrote:
    > Quoth Mike Meyer <>:
    > | "los" <> writes:
    > | > I'm trying to create a program similar to that of Google's desktop that
    > | > will crawl through the hard drive and index files. I have written the
    > | > program and as of now I just put the thread to sleep for 1 second after
    > | > indexing a couple of files.
    > | >
    > | > I'm wondering if anyone knows of a way that I could make so that the
    > | > program will run at full speed only runs after the computer has been
    > | > idle for a while. I've looked at the "nice" command but that's not
    > | > exactly what I want.
    > |
    > | On Unix, nice is exactly the answer. It's a lot more fine-grained than
    > | what you're talking about, though. But it's the way things like
    > | setiathome manage to run continuously without interfering with normal
    > | usage.
    >
    > Well, he could certainly try it if he hasn't already, but I wouldn't
    > be too surprised if it really isn't exactly what he wants. Maybe it
    > depends on the scheduler, and maybe things have gotten a lot better
    > in that department, but from my experience a process can be niced pretty
    > hard and still tie up a lot of resources. A disk crawler sounds like
    > a good example.
    >
    > I don't have any brilliant ideas, though. Your suggestion to use
    > os.getloadavg sounds good to me. It might be kind of neat if there
    > were some kind of APM ioctl that would register the calling process
    > for notification of pending disk spin down, low power mode etc.
    >
    > Donn
    > --
    > http://mail.python.org/mailman/listinfo/python-list
    >
    >
     
    James Carroll, May 21, 2005
    #4
  5. | ....
    | I'm wondering if anyone knows of a way that I could make so that
    | the program will run at full speed only runs after the computer
    | has been idle for a while.

    Perhaps looking at some ScreenSaver code could be useful ....

    I've never considered how this is done myself,
    but ScreeSavers seem to know that a user hasn't
    done anything for a while ....


    --
    Stanley C. Kitching
    Human Being
    Phoenix, Arizona

    ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
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    Cousin Stanley, May 22, 2005
    #5
  6. On Friday 20 May 2005 08:06 pm, los wrote:
    > I'm wondering if anyone knows of a way that I could make so that the
    > program will run at full speed only runs after the computer has been
    > idle for a while. I've looked at the "nice" command but that's not
    > exactly what I want.


    You need to define what "idle" means: Screensavers do this in more
    than one way, but typically, "idle" means "no user input has occured",
    in which case you are looking for the time since the last input signal
    from keyboard or mouse (not sure how to do this off the top of my
    head, but that's the "screensaver" approach).

    This is much less meaningful on a multiuser / multiple terminal
    machine, of course. And it's really nonsense on a machine that is
    also acting as a server. That's why "nice" seems like a more logical
    solution for these types of machines.

    Someone's already mentioned checking the load average, which
    sounds like a good idea for your application.


    --
    Terry Hancock ( hancock at anansispaceworks.com )
    Anansi Spaceworks http://www.anansispaceworks.com
     
    Terry Hancock, May 23, 2005
    #6
  7. los

    los Guest

    Thanks for all the replies.

    I did try using nice under windows. I created a java program that
    would just loop and print numbers on the screen. Even when I ran that
    simple program with nice, (lets call it program A) as soon as I started
    the program the cpu went all the way to 100% usage. Then when I ran
    another program that did the same thing (lets call it program B),
    program A halted to let B finish, then it started again. Nevertheless
    it still hogged all the cpu while I was using the computer.

    For my indexing program I just wrote a simple python program and called
    on the python os.walk() method to iterate through the drive and then it
    connects to a database to store some information. Then I wrote a
    simple interface to connect to the database to search for files using
    visual basic. Once everything is indexed it works fine, but it would
    be nice to have the program looping through and indexing the files all
    the time to account to file updates, deletes, and relocation, but
    without hurting the performance when I'm using the computer.

    So really what I am looking for is some way to have the program only
    start indexing and crawling through the hd after 5 minutes of no user
    interaction with the computer.

    I'm going to take a look at this CPU load possibility. But I'm afraid
    that this will work similarly to "nice" in which case it will let the
    program kick in when the CPU isn't being used heavily, but I might
    still be using the computer.

    thanks once again!

    -los
     
    los, May 23, 2005
    #7
  8. I think you can keep your sleep commands in your program to keep it
    from hogging the cpu even when you are running it as nice.

    You know, even more important than cpu load (since your indexer is
    accessing the hard drive, is hard drive access..) You can monitor the
    bytes / second going to the hard drives using a WMI query similar to
    the one that gives you LoadPercentage for a cpu.

    If something Is trying to read and write to the hard drive, and your
    indexer is going at the same time, hard drive head contention can slow
    down both processess to a crawl. (Say your program is in C:/apps and
    another program is simutaneously trying to read from C:/data... the
    heads have to seek back and forth between the two spots on the hard
    drive, and it's much faster to do all the C:/apps accesses and then
    later do all the C:/data accesses.)

    So I think my approach would be to have the indexer take about 10% of
    cpu load while it is active, and as soon as another process is doing
    enough reading / writing to the hard drive, stop and wait for about
    five minutes... then continuing.

    The screen saver idea is another good one. I found this the other day...
    http://homepage.hispeed.ch/py430/python/win32screensaver-0.3.2.zip

    The problem is that any potential user that really likes their pretty
    screen saver (Helios under Ubuntu... droool............ slurp.) then
    they can't have both your indexer and their pretty screensaver active
    during idle time.

    -Jim


    On 23 May 2005 10:32:18 -0700, los <> wrote:
    > Thanks for all the replies.
    >
    > I did try using nice under windows. I created a java program that
    > would just loop and print numbers on the screen. Even when I ran that
    > simple program with nice, (lets call it program A) as soon as I started
    > the program the cpu went all the way to 100% usage. Then when I ran


    <snip>
     
    James Carroll, May 23, 2005
    #8
  9. Fwd: Running a python program during idle time only

    I think you can keep your sleep commands in your program to keep it
    from hogging the cpu even when you are running it as nice.

    You know, even more important than cpu load (since your indexer is
    accessing the hard drive, is hard drive access..) You can monitor the
    bytes / second going to the hard drives using a WMI query similar to
    the one that gives you LoadPercentage for a cpu.

    If something Is trying to read and write to the hard drive, and your
    indexer is going at the same time, hard drive head contention can slow
    down both processess to a crawl. (Say your program is in C:/apps and
    another program is simutaneously trying to read from C:/data... the
    heads have to seek back and forth between the two spots on the hard
    drive, and it's much faster to do all the C:/apps accesses and then
    later do all the C:/data accesses.)

    So I think my approach would be to have the indexer take about 10% of
    cpu load while it is active, and as soon as another process is doing
    enough reading / writing to the hard drive, stop and wait for about
    five minutes... then continuing.

    The screen saver idea is another good one. I found this the other day...
    http://homepage.hispeed.ch/py430/python/win32screensaver-0.3.2.zip

    The problem is that any potential user that really likes their pretty
    screen saver (Helios under Ubuntu... droool............ slurp.) then
    they can't have both your indexer and their pretty screensaver active
    during idle time.

    -Jim







    On 23 May 2005 10:32:18 -0700, los <> wrote:
    > Thanks for all the replies.
    >
    > I did try using nice under windows. I created a java program that
    > would just loop and print numbers on the screen. Even when I ran that
    > simple program with nice, (lets call it program A) as soon as I started
    > the program the cpu went all the way to 100% usage. Then when I ran
    > another program that did the same thing (lets call it program B),
    > program A halted to let B finish, then it started again. Nevertheless
    > it still hogged all the cpu while I was using the computer.
    >
    > For my indexing program I just wrote a simple python program and called
    > on the python os.walk() method to iterate through the drive and then it
    > connects to a database to store some information. Then I wrote a
    > simple interface to connect to the database to search for files using
    > visual basic. Once everything is indexed it works fine, but it would
    > be nice to have the program looping through and indexing the files all
    > the time to account to file updates, deletes, and relocation, but
    > without hurting the performance when I'm using the computer.
    >
    > So really what I am looking for is some way to have the program only
    > start indexing and crawling through the hd after 5 minutes of no user
    > interaction with the computer.
    >
    > I'm going to take a look at this CPU load possibility. But I'm afraid
    > that this will work similarly to "nice" in which case it will let the
    > program kick in when the CPU isn't being used heavily, but I might
    > still be using the computer.
    >
    > thanks once again!
    >
    > -los
    >
    > --
    > http://mail.python.org/mailman/listinfo/python-list
    >
    >
     
    James Carroll, May 23, 2005
    #9
  10. los

    Mike Meyer Guest

    "los" <> writes:

    > Thanks for all the replies.
    >
    > I did try using nice under windows. I created a java program that
    > would just loop and print numbers on the screen. Even when I ran that
    > simple program with nice, (lets call it program A) as soon as I started
    > the program the cpu went all the way to 100% usage. Then when I ran
    > another program that did the same thing (lets call it program B),
    > program A halted to let B finish, then it started again. Nevertheless
    > it still hogged all the cpu while I was using the computer.


    Actually, CPU usage going to 100% when you run a cpu-intensive program
    under nice is what you expect - even want. The idea is that the nice'd
    prog soaks up all the "unused" cpu on the system. You don't say whether
    program B was niced or not, but from the description, it wasn't. And you
    got the behavior I thought you wanted: the nice'd program quit using
    any CPU at all while the normal program was running.

    At least, that's the behavior I want from my backgrounded tasks.

    > For my indexing program I just wrote a simple python program and called
    > on the python os.walk() method to iterate through the drive and then it
    > connects to a database to store some information. Then I wrote a
    > simple interface to connect to the database to search for files using
    > visual basic. Once everything is indexed it works fine, but it would
    > be nice to have the program looping through and indexing the files all
    > the time to account to file updates, deletes, and relocation, but
    > without hurting the performance when I'm using the computer.


    As has been pointed out, your daemon is doing disk i/o, which nice won't
    mediate properly.

    > So really what I am looking for is some way to have the program only
    > start indexing and crawling through the hd after 5 minutes of no user
    > interaction with the computer.


    Why 5 minutes? What if you've gone to get a cup of coffee while something
    that takes more than five minutes is completing?

    I'm sure there are tools for doing this kind of thing on windows. That's
    pretty much how screen savers work. I haven't written a screen saver
    for windows, though - so I have no idea what you're looking for.

    Note that the screen savers I have written still lowered their priority
    to avoid interfering with any long-running tasks you may be waiting on.
    At least for CPU usage.

    > I'm going to take a look at this CPU load possibility. But I'm afraid
    > that this will work similarly to "nice" in which case it will let the
    > program kick in when the CPU isn't being used heavily, but I might
    > still be using the computer.


    I think you're right.

    On a completely different topic, this looks like the wrong way to solve
    the problem. You want to update a search engine based on changes to the
    underlying file system. The right way to do this isn't to just keep
    rescanning the file system, it's to arrange things so that your scanner
    gets notified of any changes made to the file system. I did something like
    this for my web site search engine, but that's hooked into the SCM that's
    used for propogating changes to the web site. I know someone is working
    on patches to the FreeBSD kernel to make this kind of thing work. It would
    seem that some of the "backup" facilities that worked by keeping a mirror
    of the disk on separate media would have to have used such hooks, but maybe
    not.

    I'm not sure this is possible. If it is, it's almost certainly deep magic.

    <mike
    --
    Mike Meyer <> http://www.mired.org/home/mwm/
    Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.
     
    Mike Meyer, May 24, 2005
    #10
  11. los

    David Rushby Guest

    los wrote:
    > I'm trying to create a program similar to that of Google's desktop

    that
    > will crawl through the hard drive and index files. I have written

    the
    > program and as of now I just put the thread to sleep for 1 second

    after
    > indexing a couple of files.
    >
    > I'm wondering if anyone knows of a way that I could make so that the
    > program will run at full speed only runs after the computer has been
    > idle for a while. I've looked at the "nice" command but that's not
    > exactly what I want.


    On Windows:

    1) You can use API calls in the win32file.ReadDirectoryChangesW()
    family to register to receive notification (event-based, not
    polling-based) of changes to one or more directory structures.

    2) You can register to be informed X amount of time after the computer
    "becomes idle", as explained at
    http://msdn.microsoft.com/library/default.asp?url=/library/en-us/taskschd/taskschd/idle_triggers.asp
    :
    """
    An idle trigger is an event-based trigger that is fired a specific
    amount of time after the computer becomes idle. The computer is
    considered to be in an idle state when no keyboard or mouse input
    occurs.
    """
    I haven't actually written any code to do this, but it appears to be
    accessible from Python via the win32com.taskscheduler.taskscheduler
    module; interface
    PyIScheduledWorkItem.[CreateTrigger(TASK_EVENT_TRIGGER_ON_IDLE) +
    SetIdleWait(...)].

    There are related example programs in
    site-packages\win32comext\taskscheduler\test\test_addtask*.py

    3) You can programmatically lower the priority of your process with
    win32process.SetPriorityClass().

    ---

    So if you combine the three, you can create an indexing program that:

    a) Only operates when changes are actually made to the file system (no
    busy-wait).

    b) Defers all processing until the computer is "idle"; or also runs
    when the computer is not idle, yet yields priority to other processes;
    or runs under both conditions, but with a more aggressive priority when
    the computer is idle.
     
    David Rushby, May 24, 2005
    #11
  12. "los" <> writes:

    > Thanks for all the replies.
    >
    > I did try using nice under windows. I created a java program that
    > would just loop and print numbers on the screen. Even when I ran that
    > simple program with nice, (lets call it program A) as soon as I started
    > the program the cpu went all the way to 100% usage. Then when I ran
    > another program that did the same thing (lets call it program B),
    > program A halted to let B finish, then it started again. Nevertheless
    > it still hogged all the cpu while I was using the computer.


    Well, shouldn't it? You don't want to waste CPU cycles. If your
    program is niced to a low priority, it will run _only when more
    important tasks doesn't run_. I.e.: It stays out of the way when
    higher priority processes claim the computer, while still utilizing
    the rest of the computational power.

    My experience is that properly niced processes can use almost 100
    percent CPU, and still not have any noticeable effect on my other use
    of the computer.

    Asbj.S.
    --
    Asbjørn Sæbø, post.doc.
    Centre for Quantifiable Quality of Service in Communication Systems
    Norwegian University of Science and Technology
    <URL: http://www.q2s.ntnu.no/ >
     
    =?iso-8859-1?q?Asbj=F8rn_S=E6b=F8?=, May 24, 2005
    #12
  13. los

    los Guest

    Yes it should. The problem is that I notice a loss in performance when
    the program is running at 100% CPU. Even though it is nice, if you try
    to open up new applications, or switch between them, you notice your
    computer lagging a little bit. That's why even though I'm not using
    the cpu that much as I'm just reading my email, or browsing the web, I
    wouldn't necessarily want the indexing program to be running at full
    pace. If you use google's desktop program, you'll notice that once the
    computer has been idle for a few minutes your CPU will go to 100%, but
    as soon as you move your mouse, or hit a keystroke the cpu will drop to
    5-10% usage. That's the behavior I'm trying to achieve.

    Thanks David for your suggestions. That seems to be what I was looking
    for. I'm going to try to incorporate those changes in my code and see
    what I can come up with. Thanks for everyone who responded as well. I
    really appreciate it.

    -los
     
    los, May 24, 2005
    #13
  14. Mike Meyer wrote:
    > On a completely different topic, this looks like the wrong way to solve
    > the problem. You want to update a search engine based on changes to the
    > underlying file system. The right way to do this isn't to just keep
    > rescanning the file system, it's to arrange things so that your scanner
    > gets notified of any changes made to the file system. I did something like
    > this for my web site search engine, but that's hooked into the SCM that's
    > used for propogating changes to the web site. I know someone is working
    > on patches to the FreeBSD kernel to make this kind of thing work. It would
    > seem that some of the "backup" facilities that worked by keeping a mirror
    > of the disk on separate media would have to have used such hooks, but maybe
    > not.


    I think you're right that filesystem change notification is what Carlos
    needs.

    If you're interested in using Linux, Carlos, "inotify" is a new kernel
    module that can notify your program of filesystem changes. It's not
    folded into the mainline kernel yet, but it's a clean patch.

    http://www.edoceo.com/creo/inotify/

    I don't know if Windows has anything like it. I'd be interested to hear
    if it does.

    Shane
     
    Shane Hathaway, May 27, 2005
    #14
  15. los

    John Abel Guest

    Shane Hathaway wrote:

    >Mike Meyer wrote:
    >
    >
    >>On a completely different topic, this looks like the wrong way to solve
    >>the problem. You want to update a search engine based on changes to the
    >>underlying file system. The right way to do this isn't to just keep
    >>rescanning the file system, it's to arrange things so that your scanner
    >>gets notified of any changes made to the file system. I did something like
    >>this for my web site search engine, but that's hooked into the SCM that's
    >>used for propogating changes to the web site. I know someone is working
    >>on patches to the FreeBSD kernel to make this kind of thing work. It would
    >>seem that some of the "backup" facilities that worked by keeping a mirror
    >>of the disk on separate media would have to have used such hooks, but maybe
    >>not.
    >>
    >>

    >
    >I think you're right that filesystem change notification is what Carlos
    >needs.
    >
    >If you're interested in using Linux, Carlos, "inotify" is a new kernel
    >module that can notify your program of filesystem changes. It's not
    >folded into the mainline kernel yet, but it's a clean patch.
    >
    >http://www.edoceo.com/creo/inotify/
    >
    >I don't know if Windows has anything like it. I'd be interested to hear
    >if it does.
    >
    >Shane
    >
    >

    Using the PyWin32 extensions, you can register an event with the kernel,
    and then have the script sleep. If I can remember how, I'll post some
    code. It's been a while since I coded specific Win32 stuff.

    J
     
    John Abel, May 27, 2005
    #15
  16. los

    John Abel Guest

    John Abel wrote:

    >Shane Hathaway wrote:
    >
    >
    >
    >>Mike Meyer wrote:
    >>
    >>
    >>
    >>
    >>>On a completely different topic, this looks like the wrong way to solve
    >>>the problem. You want to update a search engine based on changes to the
    >>>underlying file system. The right way to do this isn't to just keep
    >>>rescanning the file system, it's to arrange things so that your scanner
    >>>gets notified of any changes made to the file system. I did something like
    >>>this for my web site search engine, but that's hooked into the SCM that's
    >>>used for propogating changes to the web site. I know someone is working
    >>>on patches to the FreeBSD kernel to make this kind of thing work. It would
    >>>seem that some of the "backup" facilities that worked by keeping a mirror
    >>>of the disk on separate media would have to have used such hooks, but maybe
    >>>not.
    >>>
    >>>
    >>>
    >>>

    >>I think you're right that filesystem change notification is what Carlos
    >>needs.
    >>
    >>If you're interested in using Linux, Carlos, "inotify" is a new kernel
    >>module that can notify your program of filesystem changes. It's not
    >>folded into the mainline kernel yet, but it's a clean patch.
    >>
    >>http://www.edoceo.com/creo/inotify/
    >>
    >>I don't know if Windows has anything like it. I'd be interested to hear
    >>if it does.
    >>
    >>Shane
    >>
    >>
    >>
    >>

    >Using the PyWin32 extensions, you can register an event with the kernel,
    >and then have the script sleep. If I can remember how, I'll post some
    >code. It's been a while since I coded specific Win32 stuff.
    >
    >J
    >
    >

    Couldn't find my code, but this page has various ways of doing it on Win32.

    http://tgolden.sc.sabren.com/python/win32_how_do_i/watch_directory_for_changes.html

    HTH

    J
     
    John Abel, May 27, 2005
    #16
  17. los

    John Abel Guest

    Shane Hathaway wrote:

    >Mike Meyer wrote:
    >
    >
    >>On a completely different topic, this looks like the wrong way to solve
    >>the problem. You want to update a search engine based on changes to the
    >>underlying file system. The right way to do this isn't to just keep
    >>rescanning the file system, it's to arrange things so that your scanner
    >>gets notified of any changes made to the file system. I did something like
    >>this for my web site search engine, but that's hooked into the SCM that's
    >>used for propogating changes to the web site. I know someone is working
    >>on patches to the FreeBSD kernel to make this kind of thing work. It would
    >>seem that some of the "backup" facilities that worked by keeping a mirror
    >>of the disk on separate media would have to have used such hooks, but maybe
    >>not.
    >>
    >>

    >
    >I think you're right that filesystem change notification is what Carlos
    >needs.
    >
    >If you're interested in using Linux, Carlos, "inotify" is a new kernel
    >module that can notify your program of filesystem changes. It's not
    >folded into the mainline kernel yet, but it's a clean patch.
    >
    >http://www.edoceo.com/creo/inotify/
    >
    >I don't know if Windows has anything like it. I'd be interested to hear
    >if it does.
    >
    >Shane
    >
    >

    As an alternative to inotify there's this
    http://oss.sgi.com/projects/fam/, with various libraries ( Perl, Python,
    etc ).

    J
     
    John Abel, May 27, 2005
    #17
  18. los

    los Guest

    I'm writting the code with the win32 module I found. The way I'm
    planning on attacking the problem after reading all the remarks is as
    follows:

    1.) have the program run a full system index, and once it completes it
    turn the flag on a configuration file to true
    2.) after this initial index, every time the program is started it will
    check this flag in the configuration file, and if it has had the full
    system index then the system will be kept up to date using the win32
    modules, listening for events and changes made to the file system. I
    am basing my code pretty closely to what I found in the last example of
    this page
    http://tgolden.sc.sabren.com/python/win32_how_do_i/watch_directory_for_changes.html

    I'm aware that in case the program isn't running, all the changes made
    to the file system during that time won't be picked up next time the
    program starts. I haven't thought of a good way to solve this problem
    other than just do a full system index every once in a while to
    actually go through each directory updating and deleting records as
    necessary.

    Thanks once again for the posts!

    -los
     
    los, Jun 1, 2005
    #18
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