Re: IO::Select & ssh problem

[cmv]

Folks-

After lots of twiddling, and some CB help (thanks ssandv++ clinton++), here is the version that seems to work best. Still have some strange things going on (like stdout seems to be in raw mode, and sometimes I control-c doesn't work), but overall it seems to be doing what I expect.

Use this when you need to run tail -f on a file that exists on a bunch of hosts, and want the output interleaved correctly.

Please make comments and/or give me alternative ways of doing this (under perl5.6 with no other modules but IO::Select).

Thanks

-Craig

use strict;
use warnings;

use IO::Select;

$|++;

my $pkey = "$ENV{HOME}/.ssh/PrivateKey";

my @logins = ( qw ( usr@host1 usr@host2 usr@host3) );

my $cmd = "'tail -f /tmp/growingfile'";

my @shell = ( '/usr/bin/ksh' => ( -c => "$cmd" ));

my @FDs;

# Create ssh tails as FDs on child processes...
foreach my $login (@logins) {
print STDERR "login=$login\n";
    my @sshcmd = ('/usr/bin/ssh' => (
        -t => (),
        #-v => (),
        -i => $pkey,
        -o => 'StrictHostKeyChecking no',
        $login,
        @shell,
    ));

    my $fd;
    if(my $child = open ($fd, '-|')) {
        print STDERR "I'm the parent\n";
        print STDERR "PARENT: \$!: $!...\n";
        print STDERR "Child pid=$child\n";
    }else{
        $|++;
        print STDERR "I am the child\n";
        exec @sshcmd;
    }
    push(@FDs, \*$fd);
}

my $sel = new IO::Select(@FDs);

while(my @ready = $sel->can_read) {
    foreach my $fh (@ready) {
        if(eof($fh)) {
            $sel->remove($fh);
            close($fh);
            next;
        }
        my $line = <$fh>;
        print "$fh: $line";
    }
}