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Re: web page update notifier

by b10m (Vicar)
on Jun 17, 2004 at 21:04 UTC ( [id://367763]=note: print w/replies, xml ) Need Help??


in reply to web page update notifier

In this snippet, you actually download the whole file each time you (cron) run(s) the script. Wouldn't it be nicer if you'd just ask for a HEAD and check the "Last-Modified" header and do some local testing on that?

$ HEAD http://www.server.tld/page.htm | grep "Last-Modified"
--
b10m

All code is usually tested, but rarely trusted.

Replies are listed 'Best First'.
Re^2: web page update notifier
by Juerd (Abbot) on Jun 17, 2004 at 21:16 UTC

    In this snippet, you actually download the whole file each time you (cron) run(s) the script.

    Not true.

    From LWP::UserAgent, that LWP::Simple uses under the hood:

    $ua->mirror( $url, $filename ) This method will get the document identified by $url and store it in file called $filename. If the file already exists, then the request will contain an "If-Modified-Since" header matching the modification time of the file. If the document on the server has not changed since this time, then nothing happens. If the document has been updated, it will be downloaded again. The modification time of the file will be forced to match that of the server.

    Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }

      Aren't you defeating the mirror check by renaming $file to "$file.old" before giving $file to the mirror call by which time it won't exists?


      Examine what is said, not who speaks.
      "Efficiency is intelligent laziness." -David Dunham
      "Think for yourself!" - Abigail
      "Memory, processor, disk in that order on the hardware side. Algorithm, algoritm, algorithm on the code side." - tachyon

        Aren't you defeating the mirror check by renaming $file to "$file.old" before giving $file to the mirror call by which time it won't exists?

        Oops; yes. Updated.

        Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }

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