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From: PerlFAQ Server on 5 Aug 2010 12:00
This is an excerpt from the latest version perlfaq5.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .

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5.33: How do I do a "tail -f" in perl?

First try

seek(GWFILE, 0, 1);

The statement "seek(GWFILE, 0, 1)" doesn't change the current position,
but it does clear the end-of-file condition on the handle, so that the
next "<GWFILE>" makes Perl try again to read something.

If that doesn't work (it relies on features of your stdio
implementation), then you need something more like this:

for (;;) {
for ($curpos = tell(GWFILE); <GWFILE>; $curpos = tell(GWFILE)) {
# search for some stuff and put it into files
}
# sleep for a while
seek(GWFILE, $curpos, 0); # seek to where we had been
}

If this still doesn't work, look into the "clearerr" method from
"IO::Handle", which resets the error and end-of-file states on the
handle.

There's also a "File::Tail" module from CPAN.



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corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.

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