how to check a file for every 15 mins thr' program

This is a discussion on how to check a file for every 15 mins thr' program within the Linux Programming forums, part of the Platform Specific Boards category; hi, I am writing a program which is going to be run as deamon process.I want this deamon process to ...

  1. #1
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    Smile how to check a file for every 15 mins thr' program

    hi,
    I am writing a program which is going to be run as deamon process.I want this deamon process to check for a presence of a file placed in one directory for every 15 mins.
    I know how to make a process to run as deamon but not getting idea for checking file for every 15 mins.If it is possible by using alarm() function,how to use it.Can anybody tell me with example to use alarm().
    Also if there is any other way to do,I welcome those ideas.

    Thank You,
    Nitin

  2. #2
    and the hat of int overfl Salem's Avatar
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    Why not just have sleep(60*15) inside an infinite loop?
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
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    Quote Originally Posted by Salem
    Why not just have sleep(60*15) inside an infinite loop?
    sleep takes milliseconds as the argument, thus it should be sleep(60 * 15 * 1000)

    But if he's using linux, he should be using the function usleep, which takes the number of microseconds to wait, thus: usleep(60 * 15 * 1000 * 1000);
    Last edited by hardi; 12-30-2006 at 02:44 PM.

  4. #4
    and the hat of int overfl Salem's Avatar
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    > sleep takes milliseconds as the argument, thus it should be sleep(60 * 15 * 1000)
    This is the Linux board, and POSIX sleep takes seconds.

    Win32 Sleep (note the S), takes milliseconds.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
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    Frequently Quite Prolix dwks's Avatar
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    You could have a simple script launched by cron every 15 minutes.
    Code:
    #!/bin/sh
    [ -e thefile ] && the_file_exists_deal_with_it
    That would probably be somewhat inefficient though.
    dwk

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    Recent Linux versions support change notification. Check out inotify, for example.

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    Thank You guys for solutions.
    Salem is correct sleep() takes seconds not miliseconds as argument in linux programming.

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    checking presence of file in directory

    I am downloadig file form server to client for every 15 mins trough C my program.So I want to check the file is downloaded or not in specific directory.
    How do I check the presence of the file in specified dirctory in C? So if the file got downloaded then I can proceed to download next file from server.

    Thank You,
    Nitin

  9. #9
    CSharpener vart's Avatar
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    fopen(file, "r") ?
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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    Vart , I am the files I am downloading are media files,so I dont want to open these files.I just wanted to check the presence of the file in directory.Your soulution is also correct ,so that i will get fd of file if it is present.Is there any other way to check presence of file?

  11. #11
    pwns nooblars
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    fopen is nice and easy though, if it fails you don't have the file, if it doesn't the file is present so just close it and call it good.

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