Shawn H Corey <shawnhco...@gmail.com> writes:
>> open(FILE,"<./named-pipe") or die "Can't Open ./named-pipe: $!";
>> while(<FILE>){
>> print;
>> if(eof){
>> sleep 2;
>> seek (FILE,0,1);
>> }
>> }
>>
>> It seems at least to survive repeated restarts of system logger.
>>
>> If I write my script based on this code... what I'd be adding would be
>> code to get 1 or 2 rgx from the cmdline, then write the hits to
>> various files.
[...]
> In the general case, modules usually take care of special cases that you
> may not be aware of. That makes them the preferred method of solving a
> problem.
>
> In this case, the above code is a kludge. You can tell this because the
> program sleeps, rather than waiting on input. When a program does
> something to emulate what it really should be doing, it introduces code
> that may not work in all cases.
I'm having trouble with File::Tail... or more likely the way I'm
trying to use it is wrongly setup.
But first about that sleep comment. As I read a little of File::Tail
and its very likely I'm not really understanding what I'm reading but,
it appears to be saying that it `sleeps' at times... the times are
a little more sophisticated... but none the less sleep.
Now the problem.
I've taken the first examples in the perldoc File::Tail output:
http://search.cpan.org/~mgrabnar/File-Tail-0.99.3/Tail.pm
use File::Tail;
$file=File::Tail->new("/some/log/file");
while (defined($line=$file->read)) {
print "$line";
}
And tied to make it work for my case (/var/adm/slpipe in the script is a
named-pipe that the system logger reads into):
cat fltr_sl
#!/usr/local/bin/perl
use strict;
use warnings;
use File::Tail;
my ($file,$line);
my $fname_in = "/var/adm/slpipe";
$file=File::Tail->new("$fname_in");
while (defined($line=$file->read)) {
print "$line";
}
When I run it, it doesn't show any errors, and appears to be waiting
on the pipe.
But no data ever comes out. I used the same sequence as for the
earlier script the didn't use File::Tail (posted earlier in this
thread). That is.
1) start the script `fltr_sl' shown above
2) To make sure if data is flowing thru the pipe start
tail -f slpipe too.
2) kill -HUP the system logger.
3) Ensure some data is flowing thru the named-pipe by
running ssh r...@localhost from a user account
I see 7-8 lines output to the tail -f slpipe command, but nothing to
the perl script fltr_sl.
And as I write quite a few more lines are appearing at the
`tail -f slpipe' cmd, but still nothing at my perl filter.
Have I made some serious mistake in my attempted usage of File::Tail?
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