FAQ 5.32 How do I do a "tail -f" in perl?
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From: PerlFAQ Server on 21 Mar 2010 18:00 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 . -------------------------------------------------------------------- 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. -------------------------------------------------------------------- The perlfaq-workers, a group of volunteers, maintain the perlfaq. They 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. |