Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked
 
PerlMonks  

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

by tim (Initiate)
on Sep 05, 2000 at 23:08 UTC ( #31158=perlquestion: print w/replies, xml ) Need Help??

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?

Replies are listed 'Best First'.
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"; } } }
Re: How do I tail -f a file if it is NFS mounted?
by merlyn (Sage) on Sep 05, 2000 at 23:14 UTC
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); }
    I'm really not that much of an idiot. really.

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: perlquestion [id://31158]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others cooling their heels in the Monastery: (4)
As of 2021-04-21 04:51 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?