From: "Peña, Botp" <botp@...>
Date: 2007-11-16T17:05:28+09:00
Subject: Re: ruby/pcap with threads

From: kenny roytman [mailto:kenny.roytman@gmail.com] 
# Hi Everyone,
# Can someone please explain why I don't see any output from the
# following code?  I'm stumped.  By the way, "en1" is the name of my
# network device.  Thanks.
# 
# code:
#       1 require 'pcaplet'
#       2
#       3 include Pcap
#       4
#       5
#       6 x = Thread.new {
#       7   pcaplet = Pcaplet.new("-i en1")
#       8
#       9   pcaplet.each_packet { |pkt|
#      10     puts "#{pkt.src.to_num_s}:#{pkt.sport}
# #{pkt.dst.to_num_s}:#{pkt.dport}" if pkt.ip?
#      11   }
#      12
#      13 }
#      14
#      15 x.join
#      16


i simplified your code, but it works..
pcaplet is quite old, you might try modifying some to remove deprecation warnings...

botp@pc4all:~/pcap$ cat test.rb
require 'pcaplet'
include Pcap
x = Thread.new {
  pcaplet = Pcaplet.new("-i eth0")
  pcaplet.each_packet { |pkt|
    puts pkt
  }
}
x.join

botp@pc4all:~/pcap$ sudo ruby test.rb
/usr/local/lib/ruby/site_ruby/1.8/i686-linux/pcap.so: warning: do not use Fixnums as Symbols
/usr/local/lib/ruby/site_ruby/1.8/i686-linux/pcap.so: warning: do not use Fixnums as Symbols
/usr/local/lib/ruby/site_ruby/1.8/i686-linux/pcap.so: warning: do not use Fixnums as Symbols
10.2.87.95:6771 > 239.192.152.143:6771 len 127 sum 35035
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
10.2.10.123:2048 > pc4all.bugo.dmpi:22 .A....
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
10.2.10.123:2048 > pc4all.bugo.dmpi:22 .A....
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
10.2.10.123:2048 > pc4all.bugo.dmpi:22 .A....
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
10.2.10.123:2048 > pc4all.bugo.dmpi:22 .A....
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
10.2.10.123:2048 > pc4all.bugo.dmpi:22 .A....
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
10.2.10.123:2048 > pc4all.bugo.dmpi:22 .A....
pc4all.bugo.dmpi:22 > 10.2.10.123:2048 .AP...
<ctl-c interrupt>

kind regards -botp