How do I tail -f a file if it is NFS mounted?

tim has asked for the wisdom of the Perl Monks concerning the following question:

The standard answers to this question, found in the FAQ and in the perl cookbook, don't seem to be working. I'd like to avoid a tell-close-open-seek series of calls, as it seems that would add a lot of overhead.

Originally posted as a Categorized Question.

Comment on How do I tail -f a file if it is NFS mounted?

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Re: How do I tail -f a file if it is NFS mounted? by lhoward (Vicar) on Sep 05, 2000 at 23:12 UTC
I've used this technique before with quite a bit of success. Only problem is that it can't detect a "real" EOF (writer has stopped writing to the file) but that will be the case with just about any method: `#!/usr/bin/perl -w use IO::File; use strict; my $tail = new IO::File; $tail->open("<./log.dat"); while(1){ my @lines=$tail->getlines(); if(0==scalar(@lines)){ # wait 1 second before trying again... # to keep from hogging CPU cycles sleep 1; }else{ my $line; foreach $line(@lines){ chomp $line; print " \"$line\"\n"; } } }` [download]	[reply] [d/l]
Re: How do I tail -f a file if it is NFS mounted? by merlyn (Sage) on Sep 05, 2000 at 23:14 UTC
I would use File::Tail.	[reply]
Re: How do I tail -f a file if it is NFS mounted? by tim (Initiate) on Sep 06, 2000 at 00:23 UTC
Whoops :( My implementation of the example found in "perldoc -f seek" was incomplete. This one seems to work: `for (;;) { for ($curpos = tell(FILE); $_ = <FILE>; $curpos = tell(FILE)) { # search for some stuff and put it into files } sleep($for_a_while); seek(FILE, $curpos, 0); }` [download] I'm really not that much of an idiot. really.	[reply] [d/l]