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Posted by PerlFAQ Server on March 16, 2008, 9:03 pm
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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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5.32: 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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are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.
If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
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| Similar Threads | Posted | | FAQ 5.30: How do I do a "tail -f" in perl? | October 25, 2004, 11:03 pm |
| FAQ 5.30 How do I do a "tail -f" in perl? | February 18, 2005, 6:03 pm |
| FAQ 5.31 How do I do a "tail -f" in perl? | May 3, 2005, 11:03 am |
| FAQ 5.31 How do I do a "tail -f" in perl? | July 19, 2005, 10:03 am |
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| FAQ 5.31 How do I do a "tail -f" in perl? | November 25, 2005, 5:03 pm |
| FAQ 5.31 How do I do a "tail -f" in perl? | January 8, 2006, 5:03 pm |
| FAQ 5.31 How do I do a "tail -f" in perl? | May 1, 2006, 3:03 am |
| FAQ 5.31 How do I do a "tail -f" in perl? | July 1, 2006, 3:03 am |
| FAQ 5.31 How do I do a "tail -f" in perl? | August 22, 2006, 9:03 pm |
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