Hello all,

I wrote a little script to watch growing logfiles. It works nicely, just the output cannot be browsed if piped to less. Example usage:

terminal1 $ touch /tmp/my.log
terminal2 $ perl script.pl -p . /tmp/my.log | less +F
terminal1 $ echo "lala" >> /tmp/my.log
terminal1 $ echo "lala" >> /tmp/my.log
terminal1 $ ...
[download]

There is no visible output in terminal2, only if you interrupt less with ctrl-C.

#!/usr/bin/perl -w
use strict;

$| = 1;

use Getopt::Std;

my %opts;
getopts( 'p:f:s:h', \%opts );
my $pattern = $opts{p} || "pdf";
my $sleep = $opts{'s'} || 5;
my $logfile = shift || "/tmp/a.log";

my $fh = select( STDOUT ); $|=1; select( $fh );

print "watching file '$logfile' for pattern '$pattern'\n";

open(LOGFILE, "<" . $logfile) or die "not readable: '$logfile'$!\n";

seek(LOGFILE, 0, 2);
while (1) {
    while (<LOGFILE>) {
        print if /$pattern/o;
    }
    sleep $sleep;
    seek(LOGFILE, 0, 1);
}
[download]

Thanks for your time! Axel.

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